Early nutritional strategies

Effects of time of initiation of feeding after hatching and diet composition on performance, carcass characteristics, digestive tract development and immune responses of broilers

This study was conducted to evaluate the effects of time of initiation of feeding after hatching and influence of diet composition on growth performance, carcass characteristics, digestive tract development and immune responses of broilers. A total of straight-run 420 Ross 308 broiler chicks were randomly allotted to six treatments with five replicates of 14 chicks each. The dietary treatments consisted of feeding a maize-soybean meal diet immediately posthatching until 14 days of age (Control), fasting for 24 or 48 h posthatching, feeding maize for 24–48 h posthatching, and feeding a maize gluten-dextrose pre-starter diet for 5 days posthatching. The study lasted from 0 to 42 days of age. For the entire 42-day period, chicks fasted or fed maize for 48 h posthatching or those fed the maize gluten-dextrose diet for 5 days posthatching had lower (P < 0.05) feed intake and lower (P < 0.05) weight gain compared with the Control. However, birds fasted or those fed maize for 24 or 48 h posthatching had similar (P > 0.05) feed intake and weight gain as the Control. The duodenal villus height and villus height:crypt depth ratio were lower (P < 0.05) and the duodenal crypt depth was higher (P < 0.05) in birds fasted for 48 h posthatching compared with the Control. Conversely, birds fasted for 48 h posthatching had higher (P < 0.05) jejunal villus height and villus height:crypt depth ratio and lower (P < 0.05) jejunal crypt depth compared with the Control. The antibody titres against Newcastle disease was lower (P < 0.05) for the groups other than the Control, whereas the antibody titres against Avian Influenza virus was lower (P < 0.05) in birds fasted for 48 h posthatching and in those fed maize for 48 h posthatching compared with the Control. Also, birds fed maize for 24 h posthatching had lower (P < 0.05) antibody titres against sheep red blood cells compared with the other treatments. These results indicated that feeding a maize-soybean meal starter diet immediately after hatch has a beneficial effect on growth performance and immune response of broilers and improves morphological development of the intestine.

Effect of in ovo supplementation of nano forms of zinc, copper, and selenium on post-hatch performance of broiler chicken

Background and Aim:

Nanoparticles can bypass conventional physiological ways of nutrient distribution and transport across tissue and cell membranes, as well as protect compounds against destruction prior to reaching their targets. In ovo administration of nanoparticles, may be seen as a new method of nano-nutrition, providing embryos with an additional quantity of nutrients. The aim of the study is to examine the effect of in ovo supplementation of nano forms of zinc, copper and selenium on the hatchability and post hatch performance of broiler chicken.

Materials and Methods:

Nano form of zinc at 20, 40, 60 and 80 µg/egg, nano form of copper at 4, 8, 12 and 16 µg/egg and nano form of selenium at 0.075, 0.15, 0.225 and 0.3 µg/egg were in ovo supplemented (18^th day incubation, amniotic route) in fertile broiler eggs. Control group in ovo fed with normal saline alone was also maintained. Each treatment had thirty replicates. Parameters such as hatchability, hatch weight and post hatch performance were studied.

Results:

In ovo feeding of nano minerals were not harmful to the developing embryo and did not influence the hatchability. Significantly (p<0.05) best feed efficiency for nano forms of zinc (2.16), copper (2.46) and selenium (2.51) were observed, when 40, 4 and 0.225 µg/egg respectively were in ovo supplemented. Except in nano form of copper at 12 µg per egg which had significantly (p<0.05) highest breast muscle percentage there was no distinct trend to indicate that dressing percentage or breast muscle yield was influenced in other treatments.

Conclusion:

Nano forms of zinc, copper and selenium can be prepared at laboratory conditions. In ovo feeding of nano forms of zinc, copper and selenium at 18^th day of incubation through amniotic route does not harm the developing embryo, does not affect hatchability.

Effect of egg weight on composition, embryonic growth, and expression of amino acid transporter genes in yolk sac membranes and small intestines of the domestic pigeon (Columba livia)

The objective of this study was to investigate the effect of egg weight on the composition of the egg, the growth of the embryo, and the expression of amino acid transporter genes in the yolk sac membranes and small intestines of the domestic pigeon (Columba livia). A total of 240 fertilized eggs were collected and divided into two groups based on the weight of the eggs, light (LE) and heavy (HE). The composition of 20 eggs from each group was measured, and the remaining eggs were weighed and placed in an incubator. On embryonic days (E) 9, 11, 13, and 15 and day of hatch (DOH), 15 embryos/hatchlings from each group were measured for embryonic growth, and samples were collected. The HE had heavier yolk and albumen weights than the LE (P < 0.01). Compared with the LE, the HE had heavier yolk-free embryonic body and yolk sac weights from E13 to DOH (P < 0.05). Additionally, the HE had larger yolk sac membrane weights from E13 to E15 (P < 0.05) and had more residual yolk sac content on DOH than those of the LE (P < 0.01). The yolk absorption was greater for the HE than for the LE from E11 to E13 (P < 0.05). Furthermore, the abundance of CAT2 and PepT1 mRNA in the yolk sac membranes was greater in the HE than in the LE on E13 (P < 0.05). Compared with the LE, the gene expression of EAAT2 in the intestine on E13 was greater in the HE, whereas the expression of EAAT3 was lower in the HE (P < 0.05). Taken together, our results suggest that egg weight influenced the composition of the eggs, embryonic development, and expression of amino acid transporter genes in the yolk sac membranes and small intestines of pigeon embryos.

Composition of more specialised pre-starter and starter diets for young broiler chickens: a review

The broiler industry has experienced remarkable improvements in productivity owing to high priority placed on genetic programming, nutrition and management practices. Nutrition of the meat chicken is driven by the need to satisfy the constantly increasing genetic potential, resulting in the shortening of the rearing time required to get the bird to market weight. The concept of feeding broilers a more specialised pre-starter diet for the first 10–14 days of age is gaining interest, as this now accounts for more than 20% of the time for grow-out. Specialised diets may be formulated to be highly digestible or aim to provide specific nutrients at a higher level to meet nutritional requirements of the bird. The effectiveness of specifically formulated pre-starter or starter diets depends on potential carryover effect to increase the bird performance up to the market age. There is evidence that some nutrient requirements of birds, digestible amino acids in particular, in the first 10 days of life may be higher than the current industry recommendation. Among cereals, rice with its lower non-starch polysaccharide content may be a better cereal for pre-starter diets than are corn or wheat. Inclusion of fibrous ingredients in low-fibre diets of young broilers may also stimulate gut development and enhance nutrient utilisation, leading to improved bird performance. There are inconsistencies in responses to various feed additives tested specifically for pre-starter diets of broilers. Finally, with an increasing demand for removal of antibiotic growth promoters from all broiler feeds, focus on formulations to ensure sustainable growth at start will gain importance.

Prospects of in ovo feeding and nutrient supplementation for poultry: the science and commercial applications--a review

In ovo supplementation of poultry embryos was first reported several decades ago, but it is only recently that concerted research has been directed at developing the technology for this process to be routinely used by the poultry industry. Although the technology of in ovo feeding was patented more than 10 years ago, it has not been widely adopted by the poultry industry. This review examines the early development of the enteric system of the poultry embryo; defines and distinguishes between in ovo feeding and in ovo nutrient administration; highlights the importance of early feeding of the chick; and discusses the development of in ovo feeding technology and its effects on hatchability, growth, gut health and immune response of chicks. The range of possible nutrients that can be administered is also explored. The limitations associated with embryo development and nutrient metabolism are highlighted, leading to the prediction of the future role of in ovo feeding in the poultry industry.

Evaluation of effects of EarlyBird associated with FloraMax-B11 on Salmonella Enteritidis, intestinal morphology, and performance of broiler chickens

A posthatch fasting period of 24 to 72 h is a common and inevitable practice in commercial poultry production. This delay in start of feed intake has been reported to negatively affect yolk utilization, gastrointestinal development, slaughter weight, breast meat yield, performance, and to also depress immunological development, making the birds more susceptible to infection from pathogens such as Salmonella. Furthermore, public concerns regarding the considerable human rates of illness reported and the emergence of antibiotic-resistant strains of Salmonella have doubled the challenge on the poultry industry to find alternative means of Salmonella control. In the present study, we evaluated the effects of a combination of early feeding with probiotic supplementation on morphological development of mucosa, control of Salmonella, and overall performance in broiler chickens. We used a blend of a commercially available perinatal supplement, EarlyBird (EB; Pacific Vet Group USA Inc., Fayetteville, AR), and a successful probiotic supplement, FloraMax-B11 (FM; Pacific Vet Group USA Inc.), to evaluate the effects on gut morphology, Salmonella intestinal colonization, and horizontal transmission, along with its effects on BW and related performance in broiler chickens under simulated commercial hatching management and shipping conditions. Morphometric analysis showed increased villus height, villus width, villus to crypt ratio, and villus surface area index in chickens treated with EB + FM groups. Significant reductions in Salmonella recovery, incidence, and horizontal transmission were also observed among the same groups, suggesting beneficial effects of early feeding and competitive exclusion by probiotic bacteria. Improved gut morphology and Salmonella exclusion was very well supported by BW data with significantly lower early BW loss and overall BW gains in birds treated with EB + FM mixture. The results of this study demonstrated that the combination of EB and FM improved gut morphology, reduced the amount of Salmonella that could be recovered, as well as improved BW when compared with controls and each product individually. These data address both animal welfare and food safety concerns faced by the poultry industry.

Nano-nutrition of chicken embryos. The effect of silver nanoparticles and ATP on expression of chosen genes involved in myogenesis

It has been suggested that the quantity and quality of nutrients stored in the egg might not be optimal for the fast rate of chicken embryo development in modern broilers, and embryos could be supplemented with nutrients by in ovo injection. Recent experiments showed that in ovo feeding reduces post-hatch mortality and skeletal disorders and increases muscle growth and breast meat yield. Adenosine triphosphate (ATP) is a "ready for use" energetic molecule, while nanoparticles of silver (Nano-Ag) may penetrate tissues as well as cells and localise inside cells. In this investigation, we hypothesised that silver nanoparticles could be used as a protective carrier for ATP as well as an active agent. ATP and/or an ATP complex with Nano-Ag would be delivered to the muscle cells as a gene expression regulator and promoter of growth and development of embryo breast muscle. A collection of 160 broiler eggs was randomly divided into a Control group without injection and injected groups with hydrocolloids of Nano-Ag, ATP or a complex of Nano-Ag and ATP (Nano-Ag/ATP). The embryos were evaluated on day 20 of incubation. The results indicate that the application of ATP to chicken embryos increases expression of fibroblast growth factor 2 (FGF2), vascular endothelial growth factor (VEGF) and Na(+)/K(+) transporting ATPase (ATP1A1), which may indicate that an extra energy source can enhance molecular mechanisms of muscle cell proliferation. Nano-Ag also up-regulated expression of FGF2, VEGF, ATP1A1 and, also up-regulated expression of myogenic differentiation 1(MyoD1), affecting cell differentiation. The results indicate that ATP and Nano-Ag may accelerate growth and maturation of muscle cells.

Silver nanoparticles administered to chicken affect VEGFA and FGF2 gene expression in breast muscle and heart

Nanoparticles of colloidal silver (AgNano) can influence gene expression. Concerning trials of AgNano application in poultry nutrition, it is useful to reveal whether they affect the expression of genes crucial for bird development. AgNano were administered to broiler chickens as a water solution in two concentrations (10 and 20 ppm). After dissection of the birds, breast muscles and hearts were collected. Gene expression of FGF2 and VEGFA on the mRNA and protein levels were evaluated using quantitative polymerase chain reaction and enzyme-linked immunosorbent assay methods. The results for gene expression in the breast muscle revealed changes on the mRNA level (FGF2 was up-regulated, P < 0.05) but not on the protein level. In the heart, 20 ppm of silver nanoparticles in drinking water increased the expression of VEGFA (P < 0.05), at the same time decreasing FGF2 expression both on the transcriptional and translational levels. Changes in the expression of these genes may lead to histological changes, but this needs to be proven using histological and immunohistochemical examination of tissues. In general, we showed that AgNano application in poultry feeding influences the expression of FGF2 and VEGFA genes on the mRNA and protein levels in growing chicken.

Minimising weight loss in new broiler hatchlings through early feeding of simple sugars

Two experiments were conducted to assess the effect of delayed access to feed after hatch and the potential of two carbohydrate oligomers, trehalose and palatinose, as supplements for early feeding of broiler chickens. A total of 360 and 252 straight run broiler chicks were used in Experiments 1 and 2, respectively, with each involving six treatments and six replicates. The diets were commercial in nature and supplemented with palatinose or trehalose (at 10 or 20 g/kg). Chicks were allowed to access feed within 8 h of hatch or 36 h. In Experiment 2, the supplements were fed at 10 or 20 g/kg diet; the commercial diets was also fed immediately or delayed. One of the diets contains zinc-bacitracin at 50 ppm and fed within 8 h of hatch. Delayed access to feed and water was found to reduce starting weight at placement whereas early access to feed generally improved it. Supplementation with trehalose, in particular led to higher (P < 0.001) 21-day weights than in the other groups although feed conversion ratio was not improved. The benefits of early feeding was demonstrated and trehalose may have some potential as an early feed supplement but further studies are required into how it can be applied at economic levels to minimise production costs down.