COMPARATIVE STUDY OF HATCHLING SUPPLEMENTS

COMPARATIVE STUDY OF HATCHLING SUPPLEMENTS 

Today, poultry farming is one of the profit-making agro based sector that provides continuous flow of income round the year by the sale of egg and meat. The magnificent expansion of poultry industry is also due to the fact that it provides the main source of animal protein through meat and eggs at cheaper rate as compared to other sources of animal protein.

Despite of this progress, the poultry industry is also witnessing series of problems such as various disease outbreaks, harsh climatic conditions, high cost of feeding and day by day decreasing profit margin. The success of broiler production depends on maximum weight gain within minimum period and which can be fulfilled by proper nutritional and managemental practices. Under high density rearing of birds, additional important role of nutrition is that birds are not only fed for efficient production or reproductive performances but must also be fed to minimize infectious disease and occurrence of their stress.

In context of Indian poultry industry, the problem of immunosuppression has been felt to be prominent due to various factors like managemental conditions, intensive production system, and infectious diseases. Therefore, it is highly essential to find ways and means for enhancement of immune response by management practices right from hatching tray, immediate post hatch supply of nutrient and water.

Hence, the present research work was aimed to observe comparative study of hatchling supplements (fruits) on growth performance of commercial broiler chicken during summer season, while reviewing the literature emphasis was given on influence of early post hatch nutrition on gastrointestinal tract development and subsequent performance of broiler.

Auckland et al. (1969, 1971^a&b) studied compensatory growth after under nutrition in market turkeys. They reported that effect of low protein feeding and realimentation on body composition. They stated that the poults receiving only 20 per cent protein were 17 per cent lighter at 6 weeks than the fully fed group. They recorded that the percentage protein required for maximum growth in the 6 to 10 week stage was similar in both group when turkeys were fully fed or undernourished from 0 to 6 weeks. They further added that percentage of protein required in the 6 to 10 week stage, subsequently allowed maximum body weight at 20 weeks of age. Turkeys fed 29 and 17 per cent protein or 20 and 22 per cent protein in starter and grower diets respectively reached the same live weight at 20 weeks as fully fed turkeys which received 29 per cent protein from o to 6 weeks and 24 per cent protein from 6 to 10 weeks. They showed that reduced body weight of turkeys up to 6 weeks of age, from the feeding of low protein diets, resulted in weight gain equal to the controls at market age, but with a significant improvement in feed:gain ratio and an overall reduction in protein intake.

Bayer et al. (1975) studied duodenal villus area and epithelial cellular migration in conventional and germ-free chicks.They recoded the morphological and epithelial cellular kinetic differences noted in the small intestine of older germ-free animals. The results of this study demonstrated that by day seven, the villus area was significantly (p < 0.01) larger and the crypt depth was significantly (p < 0.05) deeper in the conventional chicks than in the germ-free chicks. The active proliferative cellular pool in the crypts of the conventional chicks were more than twice the size of the analogous proliferative compartments in the germ-free chicks. In addition, the rate of epithelial cellular migration from the crypt villus junction to the villus tip was approximately 1.7 times faster in the conventional chicks.  They stated that after hatching the birds had to make the transition from using the energy supplied by the endogenous nutrients of the yolk to the utilization of exogenous feed through the intestine. They also stated that immediately after hatching, dramatic changes occured in size, morphology and function of gastrointestinal tract.

 Thaxton and Parkhurst (1976) studied growth, efficiency, and livability of newly hatched broilers as influenced by hydration and intake of sucrose. They observed that at the end of eight weeks, both groups of birds exhibited significantly heavier body weights and numerically lower feed conversion ratios than their respective hatch-mates that received water and feed or a 10 percent sucrose solution and feed simultaneously. They also stated that, the birds that received sucrose prior to the placement of feed exhibited numerically greater body weights and lower feed conversion ratios than the chicks that received only water prior to feed. Their data suggested that hydration and hydration accompanied by a readily available energy substrate favor metabolism that results in growth.

Lesson and summers (1978) studied dietary self-selection in turkeys. They found that birds given the choice to select a high energy low protein diet, or a high protein low energy diet, had similar body weights to that of control birds at market age. it was considered that under commercial conditions eggs hatch out over a period of 48 h, and that chicks might be held for an additional 24 h prior to being given access to food and water, during which time body weight decreases. They had showed that early access to food results in more rapid intestinal development in the immediate post-hatch period, which initiates growth some 24 h post ingestion. They also stated that all birds with early access to nutrients were 8–10% heavier than chicks held for 36 h post-hatch without food. Although feed efficiency was not changed by early nutrition, the percentage of breast meat was increased by 7–9% in all birds receiving early access to food. They also stated that in providing the newly hatched chicks with food even in the hatching trays, which would have the effect of stimulating development of the intestinal tract at least 24 h sooner. They also found the birds which were given the choice to select a high energy low protein diet, or a high protein low energy diet, had similar weights to that of control birds at market age but with an improved feed gain ratio and carcass protein.

Moran (1985) studied digestion and absorption of carbohydrates in fowl and events through perinatal development. Starch is the main carbohydrate in the food of poultry. Starch granules are digested by pancreatic amylase in the small intestine. Intestinal villi have enterocytes that project microvilli with a fibrous glycocalyx from the surface. These fine structures are envisaged to entrap water that is mixed with mucin from nearby goblet cells to form the "unstirred water layer." Maltose, maltotriose and alimit dextrins must diffuse across this first barrier to absorption to be hydrolyzed by maltase and sucrase-isomaltase immobilized at the membrane; however, the resultant glucose, once formed, accrues at the surface to provide a concentration advantage. Fowl adjust to changes in dietary starch by altering the amount of amylase released, intestinal surface area and enterocyte carbohydrase concentration. Enterocytes arising during embryonic development have no carbohydrases and are not involved with glucose absorption, but they appear to be specialized for maternal immunoglobin transfer in ovo. Embryonic villi are stimulated by transfer activity, and their growth depends on enterocytes arising from the crypt. Mature crypt cells are capable of digestion-absorptive activities and dominate the villus shortly after the chick hatches when yolk sac reserves are depleted.

Plavnik and Hurwitz (1985, 1988) investigated the possibility of utilizing a compensatory growth program to improve the feed utilization of market weight broilers by restricting feed during the 3 to 14 day period for 7 days, at a level of 1.5 kcal/g body weight. They considered to the present level of feed intake just meet maintenance requirements, and anticipated, little or no gain in body weight they noted that the program did achieve enhanced feed utilization, and in some cases, body weight of the compensatory birds did not equal that of the control group at market age. Their was an increase in the carcass fat content of the test birds by restricting feed of turkeys, starting at 7 days of age for a 10 day period. Similarly, they noted better body weight, feed utilization and meat yield in the early feed restricted birds as compared to the controls at 20 week of age.

Katanbaf et al. (1988) studied relationships allomorphic from hatching at 56 days of age in parental lines and F1 crosses of chickens selected for high or low body weight. Organ growth of male chickens selected for high and low 56-day body weight and their reciprocal F₁crosses was compared at a common age (56 days) or at a common body weight. Organs that differed at a common body weight included weights of proventriculus, small intestine, lungs, feathers and abdominal fat and length of esophagus. Organ weights that differed at a common age included esophagus, gizzard, heart, liver, lungs, breast, legs, feathers and abdominal fat, and lengths of shank, esophagus and small intestine. Heterosis for most organs was less than 15%. Those exhibiting heterosis greater than 30% included weights of fat depots and feathers, plus lengths of the esophagus, small intestine and shank. Heterosis for these traits, however, varied depending on whether comparisons were made at common body weight or age. They observed that biological functions of organs at specific ages might not reflect the situations at common body weights and suggested differences in resource allocations among populations. Selection for high and for low body weight at 56 days of age resulted in compromises in resource allocations. Specifically, selection for high juvenile body weight favored relatively heavier breasts, legs, abdominal fat depots and small intestines while selection for low juvenile body weight favored relatively heavier feathers and gizzard. The pancreas, liver and small intestines developed rapidly after hatching, emphasizing the importance of these organs to the newly hatched chick.

Plavnik and Hurwitz (1991) reported that the response of broiler chickens and turkey poults to food restriction of varied severity during early life. They restricted food for 7, 5, 10 and 7 d, respectively after hatch. They observed that early food restriction Body weights reduced, abdominal fat content was reduced, Food conversion efficiency and meat yield were improved by early-age food restriction but carcass fat was not affected in chickens and turkey poults. 

Donaldson et al. (1992) studied dietary carbohydrate level and glucose metabolism in turkey poults. They fed diets with varying carbohydrate levels for 24 hr post-hatch to two different strains of turkey poults resulted in lower hepatic glucose-6-phosphatase activity and higher plasma glucose levels as dietary carbohydrate level were increased.  There were no differences between the strains in liver weight or glucose-6-phosphatase activity, Blood glucose values were consistently higher in both strains when sampled 1 hr after initial sampling of fasted poults. In some instances the increase in total enzyme activity might be too small to keep up with increase in feed intake, lipase secretion in relation to feed intake may contribute to the relatively poor utilization of some dietary lipids during the first 10 days or so after hatch. They suggested the importance of the type of nutrients to be fed during early period. Chicks fed low protein (18.6 or 28 %) or high carbohydrate diets for the first 48 h produced higher glycogen reserves in the liver.

Murakami et al., (1992) studied growth and utilization of nutrients in newly hatched chick with or without removal of residual yolk. They conducted experiments to characterize the growth and utilization of nutrients in newly-hatched chicks, and to determine nutritional roles of residual yolk by comparing chicks with or without deutectomy (removal of residual yolk sac). Rapid growth during 14 days after hatch was observed in the fed chicks. Daily feed intake was found increased linearly for 15 days post-hatch, resulted in a high efficiency (80%) of feed utilization. Residual yolk in the abdomen averaged 6.4 g at hatch but rapidly disappeared during the first 3 days. Post-hatch starvation resulted in a decrease in carcass lipid content but did not modify the disappearance rate of yolk in the abdomen. Weight of the digestive tract per unit body weight increased markedly up to 3-7 days of age which was followed by a gradual decrease in the fed chicks. Metabolizability of dietary energy and absorption of dietary lipid were the highest at hatch, which declined to the lowest at day 5 or 6, and thereafter gradually increased. They further claimed that the deutectomy did not influence the metabolizability of dietary energy and lipid, and the carcass composition, but delayed the growth by 2 days behind the control chicks. They stated that the metabolism and nutrition of newly-hatched chicks markedly fluctuate and that the residual yolk had crucial role in complementing the nutrients absorbed to assure their rapid growth post-hatch. The rapid growth of intestine reached the maximum between 3 and 7 days and declined thereafter. The length of small intestine increased during the first week after hatching even when the birds are fasted but for villus development initiation of feed intake was found essential.

Tarvid (1992) studied effect of early postnatal long-term fasting on the development of peptide hydrolysis in chicks. The early development of peptide hydrolysis in the digestive tract of chick was investigated by fasting and fed ad lib, during the first decade of postnatal period pancreatic carboxypeptidase A (CPA) activity was found maximum at the moment of hatch. On the second day CPA activity was considerably diminished in starved and fed l groups of chicks. He further stated that starvation (3-4 days) led to the significant increase of CPA total and specific activity, whereas the amount of enzyme in pancreas of fed chicks was low.  Aminopeptidase (AP) activity of the small intestinal surface was less sensitive to starvation. The increase of activity in all intestinal parts was observed only on the 4th day of fasting. The most sensitive to starvation were dipeptidases. Changes in their activity (2-fold increase) were detected after 24 hr of starvation.  They also stated that formation of specific physiological proximo-distal gradient of intestinal exopeptidase activities began only after the moment of the first feeding,  this gives evidence that the development of peptide hydrolysis depends not only on the age of the chickens but also on the normal physiological beginning of the process of exogenous nutrition.

Pinchasov and Noy (1993) reported that Comparison of post-hatch holding time and subsequent early performance of broiler chicks and turkey 'poults.  They studied the effect of a holding period, lasting up to 48 h post-hatch, on early growth and mortality rate in broiler chicks and turkey poults.  After 48 hrs of deprivation from food and water birds of both species lost about a tenth of their initial post-hatch weight. Weight loss were more marked in poults subjected to heat stress. The duration of the holding period adversely affected early growth. During the 48 h holding period, the relative weight of residual yolk was found decreased in both species by approximately half of its weight in the just hatched chicks and poults. Relative yolk size was much higher in poults than in broilers.  On day 1 weight loss was attributed to degradation of the yolk sac, whereas on day 2 only about two thirds of the loss could be attributed to residual yolk. Body composition of newly hatched broiler chicks did not differ from those held for 24 h despite shortage of energy. It was noted that, after 48 h body fat content was markedly reduced compared to newly hatched or 24 h old birds. Irrespective of access to food, the relative size of the gastrointestinal tract was found increased with holding time in both species. It was concluded that post-hatch birds deprived of food and water for 48 h face a severe shortage of energy, causing alterations in body composition. This in turn adversely affects early growth and increases mortality rate under heat stress.

Zubair and Leeson (1994) studied effect of varying period of early nutrient restriction on growth compensation and carcass characteristics of male broilers. They were conducted experiment to determine growth and carcass characteristics of male broilers subjected to varying periods of early nutrient restriction. They restricted Nutrient by feeding a starter diet in which the major ingredients were replaced with 50% oat hulls. Complete growth compensation by all birds were attained by 35 d, Varying the period of nutrient restriction did not affect growth compensation. There were no statistical difference in other carcass characteristics measured at both 42 and 49 d of age. The improvement in feed efficiency noted with compensatory growth were due to the smaller body mass of the bird up to the point of growth compensation.

Pinchasov (1995) explained early transition of the digestive system to exogenous nutrition in domestic post-hatch birds.The early transition of the digestive system to exogenous nutrition in domestic post-hatch birds. The effect of early transition of  the digestive system  t o  exogenous nutrition was examined  in three experiments with growing birds.  The relative weights of the gastrointestinal tract (GIT) and its ingesta content, and the amylolytic capability of the pancreas were examined during the immediate post-hatch period (to 30 h). Oral administration of nutrients immediately after hatching only slightly influenced the growth of the pancreas and its amylolytic activity, but significantly increased GIT weight in both species, in a dose-dependent manner. It is suggested that early post-hatching exposure of the digestive system by the forced administration of nutrient mixture induces anatomical and metabolic changes in the digestive system slightly earlier than in birds with late access to feed. This increases GIT content and plasma glucose levels, resulting in enhanced feed consumption and growth promotion.  

Uni et al. (1995) studied post-hatch changes in morphology and function of the small intestine in heavy and light strain chicks The morphology of the small intestines of heavy (Arbor Acres) and light (Lohman) chicks was determined post-hatch in parallel with digestion, enzyme secretion, and passage time. Villus height and volume increased from 4 to 10 d, particularly in the jejunum and ileum. The number of enterocytes per villus increased with age, but enterocyte density was greater in jejunum than ileum. Villus volume and enterocyte density was greater in Arbor Acres than Lohman chicks from hatching and the rate of change with age was similar in both strains. Enzyme secretion to the duodenum was higher per gram of feed intake in heavy-strain birds on Day 4 after hatching but thereafter no differences were apparent. No differences in fatty acid digestion were observed with age or between strains. Nitrogen digestion increased in both strains from approximately 70% on Day 4 to close to 90% on Day 14. Starch digestion was 90 to 95% from 4 to 14 d in Arbor Acres birds, but increased from approximately 80% on Day 4 in Lohman chicks to 93% on Day 14. Feed intake may determine the amount of uptake in post-hatch chicks.

Dibner et al. (1998) studied early feeding and development of the immune system in neonatal poultry.  They stated that time from hatching to the onset of feeding is obviously a critical period in the development of hatchling poultry. It was clear that just keeping birds alive the first several days after hatching may squander an important opportunity for future health and production. It was also important to provide both water and nutrients, particularly carbohydrates. The impact of providing feed early was more than simply giving birds a head start over those where feeding is delayed a day or two. What was consumed in the first days following hatching can play a definitive role in achieving the genetic potential of the bird for body weight, muscle yield and immune competence.

Jin et al. (1998) studied digestive system development in post-hatch poultry. They observed that gastrointestinal tract of the newly hatched chick was in a process of development and maturation. In the chicks of domestic fowl and turkeys, the rate of development of the gastrointestinal tract exceeds the rate of body weight gain both physically (relative weight) and morphologically (villus height and perimeter, and villus volume). Rapid development was especially evident in the duodenum, jejunum and pancreas. They observed variation in activities of digestive enzymes in the pancreas and intestinal brush border specific activities of these enzymes were found decreased with age. Total digestive enzyme activity was found increased during the early post-hatch period due to  rapid increase in the weight of the pancreas and intestines. This increase in total enzyme activity might up with increases in feed intake. For example, a lag in lipase secretion in relation to feed intake may contribute to the relatively poor utilization of some dietary lipids during the first 10 days or so after hatch. Although research findings on digestion and nutrient utilization have varied, there were numerous indications that, in addition to certain lipids, the utilization of some carbohydrates and protein were less efficient during the first week or two after hatch than in older chickens and turkeys. Overall, these observations suggested that additional research were warranted to obtain more definitive information on the development of gastrointestinal function in young poultry.

Noy and Sklan (1998) studied metabolic responses to early nutrition. They reported that early access to nutrients causes short- and long-term increases in body weight and a higher proportion of breast meat at marketing in both chicks and poults. They further reported that utilization of yolk close to hatch was by transport to the circulation and to the gastrointestinal tract. The presence of feed probably increased the latter route. Dramatic increases in size and length of the small intestines occur close to hatch. Growth of the villi and the crypt depth were depressed when feed was withheld. Pancreatic and biliary secretions to the intestine begin before hatch; the amount of secretion per gram exogenous feed intake changes little after hatch. Brush border enzyme activities increase with intestinal mass and exogenous feed intake. Digestion of lipids was high at 4 days whereas starch and N digestion was lower and increased with age. The enhanced growth caused by early feeding may be due to several effects: improved nutritional maturity of the bird, stimulation of the utilization of yolk, increased intestinal development, and long-term metabolic effects.

Noy and Sklan (1999) studied the effect of different types of early feeding on performance in chicks and poults. The changes in body weight and composition were examined in broilers that either had immediate access to feed and water or had not been fed for 48 h post-hatch. Chicks without access to feed decreased in BW by 7.8% in the 48 h post-hatch, which was equivalent to 5.3 kcal/45 g chick/d. It was noted that, during this period the small intestines increased in weight and protein content by 80% or more and decrease in yolk fat and protein could account for most of the changes in body composition in the feed-deprived chick. In contrast, fed chicks grew by 5 g and used 4.5 kcal/d for maintenance, during this period, small intestines increased in weight by 110%. Intestinal absorption of exogenous nutrients was determined from hatch through 4 d post-hatch by administration of a bolus of labeled glucose, methionine, or oleic acid, together with a non-absorbed substances.

Vieira and Moran (1999a) recorded the effects of delayed placement and used litter on broiler yields. They reported broiler chicks held 24 hr after hatching and transport before placement have reduced early body weight gain which is not recovered by marketing at 7 wk and chicks with delayed access showed 50% reduction in yolk sac with contents, reduced weight gain at 3week which was never recovered, and may caused additional mortality. They also reported that placement of broiler chicks on used litter also leads to an early reduction in weight gain, but full growth compensation subsequently occurs and body weight at slaughter is similar to chicks on new litter. Birds grown on used litter showed and increase in the weight of breast fillets in relation to other parts, particularly when chick placement was delayed.

            Vieria and Moran (1999b) studied effects of egg origin and chick post-hatch nutrition on broiler live performance and meat yields. They reported that weight of hatching eggs can influence broiler live performance regardless of hen age. The chick hatches with a yolk sac which provides nutrients for the transition to independent feeding. They further added that alterations in egg weight and composition do not affect the proportion of yolk sac to body weight as much as its composition, particularly with eggs from very young hens. The contents of the yolk sac were high in fat and protein but very low in carbohydrate, which could lead to ketosis with prolonged fasting. Enhancing the first feed with either carbohydrate or gluconeogenics. The digestive system of the chick was physically complete at hatching but was not fully competent at nutrient retrieval as many enterocytes are orientated to immunoglobulin uptake. Villi length and enzymatic activity increases with feeding, reaching maturity within a few weeks. Access to food and water after hatching varies, and long delays until placement were common. These delays cause losses in live performance. Loss in body weight due to late placement or under nutrition may also affect early muscle development. These adverse effects extend to marketing age and reduced meat yield

Sklan et al. (2000) worked on hydrolysis and absorption in the small intestines of post-hatch chicks. They stated that in the immediate post-hatch period, chicks must transfer from metabolic dependence on yolk to utilization of exogenous feed. They described changes in intestinal luminal pancreatic enzyme activity and mucosal uptake post-hatch as influenced by feed and Na intake. Chicks with access to feed increased in BW and small intestinal weight in the 48-h post-hatch, whereas chicks without access to feed decreased in BW; however, small intestinal weight increased during this period. Chicks ingesting feed showed increases in total intestinal trypsin, amylase and lipase activities that were correlated with intestinal weights and BW. Chicks without access to feed showed little change in trypsin and amylase activities, and these increased only after feed consumption. Feeding a low-Na diet did not significantly change the regression coefficient between pancreatic enzyme activity and BW. Mucosal uptake was estimated by measuring Na⁺, K⁺-adenosine triphosphatase (ATPase) activity in small intestinal segments. In fed birds this activity increased in relationship to growth, whereas in non-fed birds uptake increased only after access to feed. Low-Na diets allowed only minimal mucosal uptake in all intestinal segments. This worked indicates that secretion of trypsin and amylase into the intestine was triggered by feed intake. In addition, Na plays a critical role in intestinal uptake in the immediate post-hatch period.

Mozdziak et al (2002) studied Early post-hatch starvation induces myonuclear apoptosis in chickens. Myofiber growth is dependent upon the contribution of new nuclei from the mitotically active satellite cell population. They examined satellite cell mitotic activity in conjunction with different nutritional paradigms during the early post-hatch period.  Mitotically active satellite cells were identified in the pectoralis thoracicus and quantitated using Bird with immunohistochemistry in combination with computer-based image analysis. Satellite cell mitotic activity was significantly higher in the birds fed a standard starter diet compared to all other treatments at 3 d post-hatch. However, there were no differences in satellite cell mitotic activity among treatments at 9 d post-hatch. They further suggested that any improvements in meat yield through early nutritional supplementation do not appear to occur through a satellite cell pathway and that there were no compensatory response in the satellite cell population following re-feeding after early post-hatch starvation.

Praharaj et al. (2002) studied genotype by dietary lysine interaction for growth and response to sheep red blood cells and Escherichia coli inoculation in commercial broiler Chicks. The interaction between nutrition and immunity were also studied utilizing various genotypes of broiler chickens  They observed that the  requirement of protein and critical amino acids was conducted to assess the interaction between genotypes and dietary lysine content in commercial broiler chicks by measuring growth, and response to sheep red blood cells (SRBC) and Escherichia coli (E. coli) inoculation. Genotype by dietary lysine interaction was significant for body weights at 14 and 28 d of age, but not at 42 d of age. Genotype by dietary lysine interaction was not significant for feed efficiency, for antibody titers against SRBC, and for air sac lesion score, relative bodyweight change, and relative weights of bursa and spleen in response to E. coli inoculation. However, a significant interaction was observed between the levels of lysine and dosage of SRBC for antibody titers. There was significant genotype by dietary lysine interaction for cutaneous basophilic hypersensitivity (CBH) response to PHA-P at 12 and 24 h of PI. It may be concluded that to obtain optimum body weight and immunity in commercial broilers the dietary lysine requirement may be recommended specific to the genotype.

Boersma et al. (2003) studied administering oasis hatching supplement prior to chick placement increases initial growth with no effect on body weight uniformity of female broiler breeders after three weeks of age .They stated that extended transportation times for broiler breeder chicks can cause chicks to become weak and dehydrated prior to placement. They observed that Oasis post-hatch weights were lower than control weights; however, BW were greater for the Oasis vs. control pullets at 1, 2, 3 and 4 wk as were the BW gains for 0 to 1, 1 to 2, 2 to 3 and 16 to 18 wk. The Oasis treatment showed more variation in BW uniformity at 1 and 3 wk (±10%) and 1 and 2 wk (± 15%; percentage within the flock mean). They claimed that the Oasis nutritional supplement could be effective for increasing BW during the first few weeks of life with no negative effect on uniformity after this time. This might be especially beneficial when breeder chicks are subjected to extended transportation times or when hatching weights of chicks are low.

Halevy et al. (2003) the effect of early post-hatch feeding on skeletal muscle growth and satellite cell myogenesis was studied in turkey poults. Poults were either fed immediately post-hatch or food deprived for the first 48 h and then re-fed for the rest of the experiment. Body and breast muscle weights were lower in the starved poults than in fed controls throughout the experiment (P<0.05). Cultures of breast muscle satellite cells revealed significantly higher DNA synthesis in the fed group than in the starved group as early as d 1 (P<0.05). These levels continued to rise, reaching approximately 500-fold those of feed-deprived poults on d 4. In the latter group, thymidine incorporation peaked only on d 6, and then declined. Thereafter, it decreased to the same levels as those in the fed group. Satellite cell number per gram muscle increased until d 4, and was higher in the fed group than in the starved group (P < 0.05). Pax7 levels in cell cultures derived from the fed group were markedly higher than in the starved group on d 2 (P<0.05). Myogenin levels in both culture and muscle were higher in the fed than in the starved groups until d 4 (P<0.05). Phosphorylation of the survival factor Akt and cyclin-dependent kinase inhibitor p21 levels were higher in cells derived from the fed group relative to those from the starved group 48 h post-hatch (P<0.05). Similarly, Akt phosphorylation and insulin-like growth factor I (IGF-I) levels were significantly higher in the muscles of the fed group (P<0.05). Together, these results suggest that immediate post-hatch feeding of poults is critical for satellite cell survival and myogenesis probably via IGF-I.

Uni et al. (2003) studied morphological, molecular and functional changes in the chicken small intestine of the late-term embryo. They has been described rapid development of the gastrointestinal tract post-hatch however, little information exists concerning the development of the small intestine in the pre-hatch period. The present study examined the morphological, cellular, and molecular changes occurring in the small intestine toward the end of the incubation period by examining the expression of intestinal genes that code for brush border digestive enzymes and transporters, their biochemical activities, and the morphological changes in the mucosal layer. They confirmed that during the last 3 d of incubation the weight of the intestine, as a proportion of embryo weight, increased from approximately 1% on d 17 of embryonic age to 3.5% at hatch. At this time the villi could be divided into two main developmental stages, differing in their length and shape, with the larger villi often being pear-shaped and the smaller villi being narrower and having a rocket-like shape.

Juul-Madsen et al. (2004) studied the changes in body weight (BW) gain, immune phenotype and viability of commercial broilers, either given feed and water immediately after hatch or food-deprived for 24 or 48 h, were analysed in order to study the effect of early or late start of first feeding. They claimed that  chickens fed immediately had a 6.1% higher BW at slaughter age than those food-deprived for 48 h, while those chickens food-deprived for 24 h only had a 1.4% higher weight than those deprived for 48 h.  Those fed immediately and those food-deprived for 24 h did not differ significantly in BW. Humoral immune status were measured as specific IgG antibody production and concentration of IgM and IgG in serum. Cellular immunological variables were the proportion of circulating leukocyte subpopulations and the relative expression of leukocyte surface markers, including the relative expression of Major Histocompatibility Complex (MHC) antigens.  Differences were found between the three feeding treatments in the relative expression of MHC class II molecules, the relative expression of BU-1 molecules, and the ratio of CD4:CD8 single positive cells.  For the MHC class II molecules, a lower expression was found on the surface of mainly B-cells in chickens fed immediately compared with the two other feeding regimes. These results suggest that food deprivation for 24- 48 h may be unfavourable to the growth, viability, and the immune performance of broilers.

Simone Pophal (2004) studied post-hatch myofiber growth is dependent upon the addition of new nuclei from the mitotically active satellite cell population. They said that objective of this study was to examine the relationship between different levels of dietary lysine and satellite cell mitotic activity during the early post-hatch period. They informed that mitotically active satellite cells were identified in the Pectoralis thoracicus and quantified using BrdU immunohistochemistry in combination with computer-based image analysis. Satellite cell mitotic activity were significantly (P<0.05) lower in the starved compared to any of the fed groups. However, satellite cell mitotic activity was highest (P<0.05) in the birds that were provided a lysine deficient diet (0.82%). They claimed that it was possible to nutritionally stimulate the satellite cell population in the early post-hatch chick, and that it was an important endeavour to re-examine the nutritional requirements of the early post-hatch chick to optimize meat yield.

Uni and Ferket (2004) studied methods for early nutrition and their potential. Several factors may limit the development and viability of late-term embryos and hatchlings. They informed that nutrient content of the egg needed for the development of tissues and nutrient reserves (glycogen, muscle, yolk) of the embryo through to hatch;  They  stated that ability of the gastrointestinal tract to digest utilize nutrients from an external carbohydrate and protein-rich diet; and  The ability of chicks and poults to rely on the residual nutrients in the yolk sac during the first few days post-hatch. These limitations are manifested by in the “chick or poult quality” phenomena. Approximately 2% to 5% of hatchlings do not survive the critical post-hatch “adjustment” period and many survivors exhibit stunted growth, inefficient feed utilization, reduced disease resistance, or poor meat yield. These limitations can be alleviated by the administration of food in the hatchery immediately post-hatch, a technology termed “Early Feeding”, or by administration of food into the amnion of late term embryo, what we define as “In Ovo Feeding”. A great potential exists in “combining” the early feeding and the in ovo feeding methods. Since the modern broiler increases its body weight by 50-fold from hatch until market age at 42 days, the first few critical days of “adjustment” represent a much greater proportion of the bird's life span than in the past. Consequently, early feeding methods will have a great impact on overall growth and well-being of the bird, particularly as genetic selection for increased growth performance continues in the future.

Kemp et al. (2005) studied genotype–nutrition interactions in broilers; response to balanced protein in two commercial strains. They had undertaken a trial using different levels of balanced protein showed significant and economically important differences in the response of commercial broiler strains. At deficient levels one strain maintained feed intake and therefore grew better. Only one of the two strains showed continuing important responses to protein levels higher than those normally recommended. They further stated that that importance of determining optimum amino acid and protein levels by economic analysis of response data was emphasised by these findings.

Moore et al. (2005) studied muscle development in the late embryonic and early post-hatch poult.  Satellite cells are mitotically active cells in skeletal muscle that contribute new nuclei to growing myofibers. They stated that objective of this experiment was to determine satellite cell mitotic activity in turkey embryos, early post-hatch poults, and 1 week-old poults. And they observed that Satellite cell mitotic activity was lower (P < 0.05) at 25E compared to day of hatch. Furthermore, there was an age-related decrease (P < 0.05) in satellite cell mitotic activity between 1 day post-hatch to one week-of-age. And the low satellite cell mitotic activity at 25E suggested that late embryonic development may be a developmental period to target increasing satellite cell mitotic activity. Furthermore, the normally high satellite cell mitotic activity immediately post-hatch suggests that the early post-hatch period was also an important target for nutritional manipulations aimed at improving skeletal muscle growth and meat yield.

It is apparent that satellite cell mitotic activity decrease with age through the first week post-hatch, indicating the importance of the immediate post-hatch period to manipulate mature muscle size. Delayed placement of poults results in a decrease in satellite cell mitotic activity and a preservation of the proliferative reserve satellite cell population that could result in decreased breast meat yield at market age. They claimed that the importance of the immediate post-hatch period in muscle development, increasing satellite cell mitotic activity.

            Saki (2005) studied Broiler performance in the end of rearing period may be influenced by post-hatch feeding. They observed that organelles (legs, wings, back, breast meat, abdominal fat, full intestinal, gizzard and neck) had shown similar reaction. Body weight increased significantly (P<0.05) by starter feeding compared with other treatments in seven and forty two days. They claimed that result of this study has shown that starter feeding (in first 24 hours) had the desirable performance in comparison with other treatments.

Uni et al. (2006) studies the ovo feeding: impact on gut development, energetic status, gene expression and growth performance. Dietary factors and feeding behavior during the first few days after hatch can have marked effects on how residual yolk is used to support growth and development. Without access to feed and water, however, the development of the neonatal chick is dependent on residual nutrients found in the yolk sac that have been depleted during the hatching process. Delayed access to feed and water will result in a mortality rate of about 5%, poor growth, decreased disease resistance, and impaired levels of muscle development .It is often thought that the residual yolk found in the chick is sufficient to maintain the bird until feed is offered. However, the initiation of growth may be more dependent on feed consumption than the nutrients found in the yolk post-hatch .When feed consumption starts soon after hatch, the nutrients provided by the feed are complementary to the yolk nutrients.  Initiation of feed consumption as close to hatch as possible is necessary to support early muscle development, which may ultimately affect meat yield.  In contrast, early muscle development is seriously compromised when feed is withheld during the first few days after hatch.  They observed that fasted chicks exhibit lower protein synthesis in the Pectoralis thoracicus, whereas observed increased levels of apoptosis.  Satellite cell mitotic activity, the major source of myofiber growth via myonuclear accretion, is highest early post-hatch and decreases with age as birds mature .Chicks that experience delayed access to feed immediately post-hatch exhibit lower satellite cell mitotic activity when compared to their fed counterparts.

Moran (2007) studied nutrient needs central to satisfactory egg incubation well-being undergo several major changes from fertilization until the reliance of the chick on feed. Glucose is central, with the initiation of incubation until the chorioallantois accesses O₂ to use for fatty acid oxidation. Nutrient recovery from albumen and yolk is largely commensurate with body assembly through to completion of the embryo by 14 d. Remaining albumen mixes with the amniotic fluid and is orally consumed until initiation of emergence. A portion of the albumen is absorbed by the small intestine to expand body glycogen reserves. The residual not absorbed contains digestive enzyme contributions and enters the yolk sac through its stalk at the jejunum and ileum. Interaction of the albumen-amnion digestive enzyme mixture with yolk sac contents leads to diverse alterations that influence subsequent use of lipids. Rapid removal of very low-density lipoprotein ensues, until pipping with triglycerides, expanding body fat depots while cholesterol deposits in the liver. A concurrent translocation of Ca from shell mineralizes the skeletal system while also crossing yolk sac villi for deposition on phosvitin-based granules accruing in its lumen. Loss of chorioallantois with pipping and the start of pulmonary respiration predispose a dependence on glycolysis to support emergence. Small intestinal villi progressively reorient their enterocytes from macromolecule transfer to competence at digestion and absorption after hatching. Mobilization of body fat complements contributions from the yolk sac to provide fatty acids for generating energy, heat, and water while also combining with hepatic cholesterol for membrane expansion and continued development. Calcified granules evacuate the yolk sac to further skeletal mineralization in the absence of shell contributions. Egg mass, its interior quality, and turning during early incubation directly influence the ability of the embryo to access nutrients and provide resources to support emergence and the transition of the chick to self-sufficiency.

Gonzales et al. (2008) studied the study was designed to evaluate the productive consequences of fasting neonatal chicks obtained from strains genetically divergent for growing. They reported that immediately after hatching, all chicks had similar relative yolk sac weights (14.13%, 14.50%, and 15.49% for Hy-Line, Cobb, and JA57, respectively). The yolk sac retractions were proportionally higher for Cobb and JA57 chicks up to 144 h (6 days) after placement, but were not influenced by 36h of feed fasting. At 7 and 14 days of age only Cobb chicks had their body weight and weight gain significantly (P<0.05) depressed by 36h feed fasting after hatching. Results indicate that broiler chicks with intense initial growth rates (Cobb 500) need an outstanding nutritional supply, either from exogenous (feed) or endogenous (residual yolk) sources, to achieve a final weight compatible with their genetic constitution. For slow-growing chicks (Hy-Line), nutritional supplementation via yolk sac seems to be more important than exogenous supply (feed) of nutrients during the neonatal period.

Henderson et al. (2008) studied effect of an early nutritional supplement on broiler performance.  Seven experiments were conducted to compare the use of Early Bird, no supplementation (NS) in chick boxes when chicks were held for a 24 h simulated shipping period. They reported that in all experiments, chicks that received EB during simulated shipping experienced significantly less body weight loss during the 24hrs holding period (p<0.05) and were significantly heavier at 7 d. At slaughter, EB treated broilers were 58 g heavier than the controls. They further stated that early feeding could not only impact the general well being of the chick but also had significant effects on early growth, leading to increased weight gains that persisted through out broiler production.  

Husseiny et al. (2008) studied Influence of fasting or early feeding on Broiler performance. They explained the effect of early feeding on yolk sac absorption and enhance the gastrointestinal tract development in neonatal broiler chicks. They also worked on  the extent of yolk sac absorption and survivability in newly hatched chicks with held feed (for 1, 2, 3, 4, 5 or 6 days then switch to control diet), and also worked on the feed utilization, yolk sac absorption and gastrointestinal tract maturation in newly hatched chicks when fed different treatments. And also worked on supplementation of some nutrients in water (glucose, amino acid (Meth and Lys), amino vit, vitamins soluble in water, electrolyte and tap water) and effects on yolk sac absorption and gastrointestinal tract maturation in newly hatched chicks. Results obtained were as follows: Yolk was rapidly utilized in fed than in fasting chicks at 1^st and 2^nd days of age. However, the lowest CP% of yolk sac were recorded at 4^th day of fasting and better absorption of nutrients from yolk sac after 72h of life were observed in group fasting compared with the group which was fed. Moreover, Starvation over the first 2-d post-hatch period retards growth, reduced ultimate meat yield and weight loss after 5 day starvation resulted in completely death of all chicks. Starvation in the early period (0-7d) significantly (P<0.01) decreased BWG and poor feed conversion (FC) compared to the control group at 3 and 6 weeks of age. Chicks fed control diet (23%CP) for 48hrs, 7 days, 3 or 6 weeks of age recorded significantly (P<0.01) the highest body weight and body weight gain .Furthermore, starvation of chickens significantly (P<0.01) reduced weight of liver, heart, proventriculus with gizzard and length of intestine and two cecum at first week of chick’s life compared to those with early access to feed. Chicks fed yolk sac or fresh egg yolk for 48hrs recorded the lowest liver weight and length of intestine and two cecum compared with the other experimental treatments. Chicks fed control diet (23% CP) for 48hrs or 7 days recorded significantly (P<0.01) the highest internals organs compared with the other treatments .However, no significant differences in abdominal fat and immune response between different treatments In conclusion, starvation over the first 2-ds post-hatch period retard growth performance and yolk utilization were rapid in fed than in fasting chicks at 1^st and 2^nd day of age. They observed that study early feeding complete diet results in considerable performance.

Molenaar et al. (2009) studied effect of protein and energy level in feed on post-hatch chick Performance. They explained that broiler chicks increase their body weight approximately 50-fold within 40 days of age and because of their short life cycle, growth during the first week important. This was also reflected in the positive relation between body weights in the first week and body weights at marketing. To start development of the bird post-hatch, early feed was important, as was emphasized in different studies. The post-hatch bird is anatomically complete, but digestive, immune and thermo-regulatory systems still need to develop .Besides utilization of exogenous feed, the residual yolk of chicks is also utilized during the first days post-hatch Diet composition may interact with this utilization of yolk. The physiological condition of post-hatch chicks was in comparison to older chicks different and this might contribute to a difference in nutritional requirements. Optimal feed formulations for specifically the first days post-hatch of broiler chickens are less known. Feed formulations are often based on average requirements for a longer period and therefore not necessarily optimal for the first days post-hatch. This study was performed to gain more insight in the nutritional requirements of birds in the first days after hatch. This study evaluates the effect of protein and energy level on body weight and feed intake of chicks till 4 days post-hatch.

Yang et al.  (2009) studied the effects of starter feeding time on growth of Yangzhou geese. They were conducted an experiment to investigate the effects of starter feeding time on yolk sac absorption of newly hatched Yangzhou gosling. They demonstrated that the maximum fasting period with no significantly negative effect on final performance of the bird were at 36 h post-hatch. Therefore, to ensure good performance, Yangzhou geese should be fed from 12 to 36 h post-hatch. The study showed a beneficial effect of feeding before 36 h on body weight of goslings. They claimed that the body weight of birds fasted for 24 h were significantly higher than that of those fasted for 48 h. It has been demonstrated that early feeding could affect early growth of birds significantly, leading to increased weight gains that persist throughout the broiler production period.

Tabedian et al. (2010) studied “Effect of fasting or post-hatch diet’s type on performance of broiler chicks” They confirmed that chicks who were fed with 48EG (egg powder+glucosesyrup) diet, had higher (P<0.05) weight gain than both the control and the other experimental groups. In entire experimental period
(1-42days), feeding E48 or EG48 resulted in higher weight gain than control group. At 21 to 42 days of age, feeding E24 did result to higher feed intake than control. Over the entire experimental period, the chicks fed both egg powder and glucose syrup had significantly higher (P<0.05) feed intake than control. No significant differences in feed conversion ratios occurred among the treatment diet groups. The percentage of dressing weight was significantly (P<0.01) increased by feeding GE diet for 48 h or E diet for 24h at day 21 and by feeding E diet for 48h at day 42. Chicks not having access to feed for 24h and 48h had significantly lower blood sugar and for 24h a higher percentage of heterophil, HDL concentration increased markedly for 48h and LDL concentration increased for 24 h and 48 h. They confirmed that, the diet composition affects chick development post-hatch and feeding a semi moist diet with high protein and suitable energy levels containing egg powder and glucose syrup for 48 hours post-hatch was beneficial for post-hatch growth.

Van den Brand et al. (2010) Studied early feeding affects resistance against cold exposure in young broiler chickens. They observed that in field conditions, a fasting period of 24 to 72 hrs after hatch was common, which was associated with delayed gastrointestinal development and yolk utilization and retarded subsequent performance. Their aim of this study was to investigate effects of diet composition in early fed broiler chickens on their (thermoregulatory) development. They concluded that early fed diet composition in broiler chickens was (besides general development) important for development of both body temperature and resistance against cold exposure, probably as a reflection of a changed metabolic rate. In the period between hatch and d 10, when chickens were not full-blown homeotherm, body temperature was strongly related to ambient temperature. This experiment showed that the transition from a poikilotherm to a full-blown homeotherm animal might be stimulated by early feeding after hatch and feed composition is important. It could be speculated whether this was only a matter of energy intake. They noted comparable effects regarding body development and body temperature with the same diets. On the other hand, it was clearly shown that early feeding post-hatch increases subsequent BW gain. An increased BW also results in higher heat production and consequently an improved resistance against cold exposure could be expected. However, to their knowledge, relationships between level of feed intake early post-hatch and heat production or body temperature were not available in literature. Therefore, it could not be excluded that the improved resistance against cold exposure in the pre-starter-fed chickens was a matter of energy intake and consequently increased metabolic rate and higher heat production.

Velleman et al. (2010) studied effect of post-hatch Feed Restriction on Broiler Breast Muscle Development and Muscle. They found that feed restriction resulted in a significant decrease in body weight in birds from I day part hatch through 28days age there was reduction in body weight through 42 days of study. They found that pectoralis major muscle weight was significantly reduced by feed restriction. They further mentioned that the weight on pectoralies major muscle reduced significantly from 14- 28 days They recorded that their was no interaction between age and treatment for both body weight and pectoralis major muscle weight.      effect of an immediate post-hatch growth restriction mediated through a 20% growth restriction the first 2 wk post-hatch was studied for its effect on pectoralis major muscle morphological structure and the expression of the myogenic transcriptional regulatory factors The growth restricted birds had increased fiber necrosis and larger and more extensive fat cell depots beginning at 28 d post-hatch. The BW of the growth restricted birds was significantly reduced compared to control birds through 28 d. Pectoralis major weight was significantly reduced through 28 d. Together these results suggest that the immediate post-hatch feeding regimen to chicks is critical for the appropriate morphological development of the pectoralis major muscle.

Willemsen et al.  (2010) studied delay in feed access and spread of hatch: importance of early nutrition. In a commercial hatchery, chicks (or poults) hatch over a 24-48 hour period. All chicks remain in the incubator until the majority of the chicks have emerged from the shell. Once removed from the incubator, the newly hatched chick has to undergo several hatchery treatments and is then transported before being placed on the broiler farm. This means that, under practical conditions, chicks are deprived of feed and water for up to 72 hours. In addition, the time of hatch within the hatching window and the spread of hatch cause variability in the amount of time that chicks are feed deprived. Literature on feed deprivation after hatch clearly demonstrates the detrimental effects of any delay in feed access on performance of the chicks with respect to growth, immune system activation, digestive enzyme stimulation and organ development. Improved management strategies, such as shortening the hatching window or the time to first feeding by specific management measures, provide an alternative in dealing with the negative effects caused by a delay in feed access. The development of pre-starter diets that better meet the needs of the newly hatched chicks or in ovo feeding to bridge the gap between hatch and first feeding provide other alternatives in overcoming these problems. However, speculation remains regarding the importance of in ovo or early feeding, or whether the in ovo or early feeding itself is responsible for the beneficial effects reported. They stated that effects of any delay in feed access on performance of the chicks with respect to growth, immune system activation, digestive enzyme stimulation and organ development decreases.

Abed et al. (2011) studied the broiler chicks possess enough growth potential to compensate long-term feed and water depravation during the neonatal period. They stated that Broiler performance to the end of the rearing period may be negatively influenced by delayed access to feed and water immediately after hatch. The results showed that extending post-hatch deprivation of feed and water had a significant negative impact on bird performance. Broilers deprived for 48 h had lower body weights, average daily gains and feed intakes compared to the control and to a lesser extent to the other treatments. Average daily gain, daily feed intake and feed conversion ratio were mostly significantly affected by feed and water deprivation regimens during the first week of the rearing period. At marketing age, the negative impact of severe feed and water deprivation on the birds’ performance was substantially decreased, though birds with a 48 h delayed access to feed and water had lower average daily gains and feed intakes compared to the control. Birds mortality rate (%) was not affected by feed and water deprivation during the neonatal period. The results also indicated that the relative weights of the jejunum, ileum and liver of birds getting access to feed and water only at 48 h after arrival were significantly lower when compared to the other groups. The broiler carcass characteristics, abdominal fat percentage at 42 days of age, and gastrointestinal measurements at 21 and 42 days of age were not influenced by the different treatments. In conclusion, the results of this experiment confirmed that immediate access to feed and water after placement will ensure the optimal performance of broiler chicks at market age, and that broiler chicks do not have enough potential to fully compensate for growth retardation caused by long-term deprivation of feed and water during the neonatal period.

Danisman and Gous (2011) studied this paper reports the allometric relationships between some of the physical parts and body protein weight of three commercial broiler strains reared, sexes separate, on four dietary protein levels to six weeks of age. Birds were sampled at day old and then weekly from each of the treatments to determine the weights of the physical parts and the chemical composition of each of 582 birds. Allometric regressions were compared between strains, sexes and dietary protein levels using linear regression with groups. Whereas these regressions were similar over strains and sexes, some interactions were evident between factors, and differences occurred when broilers were fed differing dietary protein levels. These differences may be explained on the basis that lipid is deposited to different extents in each of the parts in response to dietary protein, although this was not tested. The allometric regressions presented are an attempt to provide information that would enable the prediction of the weights of breast meat, thigh, drum and wing at different stages of growth of broilers whose genotype and feed composition are adequately described.

Shafey et al. (2011) studied effects of glucose supplementation of drinking water on the performance of fasting newly hatched chicks. They stated that the effects of delaying access to feed and water after hatch and glucose supplementation of drinking water on the performance of broiler chickens were investigated delaying access to feed for up to 48 h immediately after hatch depressed performance, weight of bursa of fabricius and heart and small intestine length and thickness. However, the Delaying access to Feed period did not influence mortality percentage, feed efficiency, composition of eviscerated carcass and body weight percentage of small intestine, heart and lymphoid organs of chickens when compared with birds fed immediately after hatch. Access to feed and water after hatch increased body weight gain feed intake and eviscerated carcass weight The addition of glucose for up to 10% to drinking water of Delaying access to Feed birds in the 1st 72 h did not influence the performance and eviscerated carcass of Delaying access to Feed birds.

They explained that the period from hatching of chicks to the initiation of feeding could have critical impacts on its subsequent short and long term performance. Access to feed immediately after hatch is beneficial to initiate the growth of chickens. The delay in feeding of hatchling reduced body weight gain, weight of crop, proventriculus, small and large intestines, liver and pancreas, satellite cell activity and DNA synthesis in muscular tissue and breast yield of broilers and altered immune system. They further stated that newly hatched chicks were lacking of glycogen during the post-hatching period and the only way to increase glycogen concentrations was feeding. During this period, the hatching chicks make the transition from egg nutrients to exogenous feed.  They suggested that providing some form of oral carbohydrate may have a significant glycogenic effect. Chicks and poults subjected to early post-hatch feed deprivation for 34 and 48 h, respectively after arrival had a significant reduction in body weight and breast yield compared to birds given either immediate access to feed and water or Oasis.

Rashed Abdullah (2011) studied effects of early feed restriction during delayed placement on the performance and gut health of broilers. He said that newly hatched chicks may experience long periods of fasting prior to placement in commercial hatcheries. He conducted trials to investigate the effects of early feed restriction and various supplements on the performance and gut health of broiler chicks. He observed that early feeding led to increased feed intake and body weight of chicks, brooding chicks in cages resulted in an improved body weight, increased feed intake, and increased feed:gain ratio. Chicks placed immediately had markedly improved body weight, and feeding the hatching supplement numerically improved body weight at the end of the trial compared to early fasting. It had showed that holding chicks or poults for more than 24 h without feed and water resulted in impaired growth performance.

  Ali Asgar et al. (2012) studied broiler chickens performance in response to early feeding. Now a days, shortening of the rearing period could make a more priority than last decades for broiler producers. Early post-hatch feeding is the most critical stage during chicken life. Body weights at first day of age were similar for all treatments. Body weight and carcass yield were significantly lower by fasting treatment than the other treatments at 21, 35 and 42 days. However, lower abdominal fat was found in fasting treatment in comparison to other treatments. Lower significant in feed intake was found by fasting treatment than others treatment at 35 and 42 days age. Highest feed conversion ratio was shown by fasting treatment than other treatments at 21 days of age. Non-significant differences were observed in weight of total digestive system, small intestine, gizzard, liver and pancreas in all treatments. The results of this study have showed desirable performance by early past-hatch feeding in comparison to other treatments at the end of rearing period.