Development Of Broiler Chickens Research Articles

Novel Candidate Genes Involved in an Initial Stage of White Striping Development in Broiler Chickens.

White striping (WS) is a myopathy characterized by the appearance of white stripes parallel to the muscle fibers in the breast of broiler chickens, composed of adipose and connective tissues. This condition causes economic losses and, although common, its etiology remains poorly understood. Hence, the objective was to identify genes and biological mechanisms involved in the early stages of WS using a paternal broiler line that grows slightly slower than commercial ones, at 35 days of age, through the RNA sequencing of the pectoralis major muscle. Thirty genes were differentially expressed between normal and WS-affected chickens, with 23 upregulated and 7 downregulated in the affected broilers. Of these, 14 genes are novel candidates for WS and are implicated in biological processes related to muscle development (CEPBD, DUSP8, METTL21EP, NELL2, and UBE3D), lipid metabolism (PDK4, DDIT4, FKBP5, DGAT2, LIPG, TDH, and RGCC), and collagen (COL4A5 and COL4A6). Genes related to changes in muscle fiber type and the processes of apoptosis, autophagy, proliferation, and differentiation are possibly involved with the initial stage of WS development. In contrast, the genes linked to lipid metabolism and collagen may have their expression altered due to the progression of the myopathy.

Dynamic changes in insulin-like growth factor binding protein expression occur between embryonic and early post-hatch development in broiler chickens

Somatotropic gene expression has been altered by genetic selection, and developmental changes in insulin-like growth factor (IGF) and IGF binding protein (IGFBP) expression may contribute to rapid growth and muscle accretion in commercial broilers. The objective of this study was to evaluate changes in somatotropic axis activity between embryonic day (e) 12 and post-hatch day (d) 21. Liver and breast muscle (pectoralis major) were collected to measure gene expression, and blood was collected post-hatch to measure circulating IGFs. Liver IGF1 rose rapidly post-hatch and, in muscle, IGF1 exhibited a dynamic expression pattern. Levels decreased from e14 to e20, returned to e14 levels at d3, decreased again at d10, and stayed low thereafter. In both tissues, mRNA levels of several IGFBPs changed between embryogenesis and post-hatch. Liver IGFBP2 increased between e12 and e20, returned to e12 levels on d1, and remained low. Conversely, liver IGFBP4 expression was greater post-hatch than during embryogenesis. Expression of select IGFBPs was depressed in liver during the peri-hatch period. Liver IGFBP1, IGFBP3, IGFBP5, and IGFBP7 mRNA levels all decreased around this time and returned to embryonic levels by d3. In breast muscle, expression of both IGFBP2 and IGFBP4 was reduced after hatch. Circulating insulin-like growth factor IGF1 and IGF2 levels did not change between hatch and d21. These data suggest that post-hatch IGF effects are likely modulated by target tissue IGFR1 and IGFBP expression rather than changes in circulating hormone levels, with promotion or restriction of IGF-receptor binding regulating growth. Downregulation of several IGFBPs synthesized in the liver may facilitate the metabolic transition from utilizing yolk lipids to dietary carbohydrates. Several IGFBPs produced in breast muscle appear to have growth-promotive effects during embryogenesis but restrict growth of this tissue after hatch, as their post-hatch downregulation could facilitate local IGF signaling. These developmental gene expression patterns suggest that somatotropic hormonal signaling regulating growth and muscle accretion might be controlled through differential actions of IGFBPs and provide a basis for future functional studies.

Effects of Lactobacillus plantarum on Broiler Health: Integrated Microbial and Metabolomics Analysis.

Given China's prohibition on the utilization of antibiotics as feed additives in 2020, we aim to investigate nutrition additives that are both efficient and safe. Lactobacillus, a well-recognized beneficial probiotic, has explicitly been investigated for its effects on health status of the host and overall impact on food industry. To evaluate effects of Lactobacillus plantarum (LW) supplementation on broiler chicken, we conducted comprehensive multi-omics analysis, growth performance evaluation, RT-qPCR analysis, and immunofluorescence. The findings revealed that LW supplementation resulted in a substantial progress in growth performance (approximately 205g increase in final body weight in comparison to the control group (p < 0.01)). Additionally, LW exhibited promising potential for enhancing antioxidant properties of serum and promoting gut integrity and growth as evidenced by improved antioxidant indices (p < 0.01), intestinal villus morphology (p < 0.01), and enhanced gut barrier function (p < 0.01). Meanwhile, the multi-omics analysis, including 16S rRNA sequencing and liquid chromatography-tandem mass spectrometry, revealed an enrichment of beneficial microbes in the gut of broilers that were supplemented with LW, while simultaneously depleting harmful microorganisms. Moreover, a noteworthy modification was observed in gut metabolic profiling subsequent to the execution of the probiotic strategy. Specifically, variations were noticed in the levels of metabolites and metabolic pathways such as parathyroid hormone synthesis, inflammatory mediator regulation of TRP channels, oxidative phosphorylation, and mineral absorption. Taken together, our findings validate that LW administration produces valuable effects on the health and growth performance of broilers owing to its capability to boost the gut microbiota homeostasis and intestinalmetabolism. Present findings signify the potential of LW as a dietary additive to promote growth and development in broiler chickens.

Transcriptomic and epigenomic landscapes of muscle growth during the postnatal period of broilers

BackgroundBroilers stand out as one of the fastest-growing livestock globally, making a substantial contribution to animal meat production. However, the molecular and epigenetic mechanisms underlying the rapid growth and development of broiler chickens are still unclear. This study aims to explore muscle development patterns and regulatory networks during the postnatal rapid growth phase of fast-growing broilers. We measured the growth performance of Cornish (CC) and White Plymouth Rock (RR) over a 42-d period. Pectoral muscle samples from both CC and RR were randomly collected at day 21 after hatching (D21) and D42 for RNA-seq and ATAC-seq library construction.ResultsThe consistent increase in body weight and pectoral muscle weight across both breeds was observed as they matured, with CC outpacing RR in terms of weight at each stage of development. Differential expression analysis identified 398 and 1,129 genes in the two dimensions of breeds and ages, respectively. A total of 75,149 ATAC-seq peaks were annotated in promoter, exon, intron and intergenic regions, with a higher number of peaks in the promoter and intronic regions. The age-biased genes and breed-biased genes of RNA-seq were combined with the ATAC-seq data for subsequent analysis. The results spotlighted the upregulation of ACTC1 and FDPS at D21, which were primarily associated with muscle structure development by gene cluster enrichment. Additionally, a noteworthy upregulation of MUSTN1, FOS and TGFB3 was spotted in broiler chickens at D42, which were involved in cell differentiation and muscle regeneration after injury, suggesting a regulatory role of muscle growth and repair.ConclusionsThis work provided a regulatory network of postnatal broiler chickens and revealed ACTC1 and MUSTN1 as the key responsible for muscle development and regeneration. Our findings highlight that rapid growth in broiler chickens triggers ongoing muscle damage and subsequent regeneration. These findings provide a foundation for future research to investigate the functional aspects of muscle development.

Effect of Ginger Root Extract on Intestinal Oxidative Status and Mucosal Morphometrics in Broiler Chickens.

This study was designed to assess the effect of ginger root extract (GRE) supplementation on the oxidative status and intestinal mucosal development in broiler chickens for 6 weeks. Day-old chicks (Ross 708 strain, n = 432) were distributed into six treatments with six replicate of twelve birds each: Negative CON (basal), MX (basal diet + bacitracin methylene disalicylate (BMD) 0.055 g/kg diet), GRE-1 (basal diet + 0.375% GRE), GRE-2 (basal diet + 0.75% GRE), GRE-3 (basal diet + 1.5% GRE), GRE-4 (basal diet + 3% GRE). Growth indices, goblets cell count, mucin (MUC2) in ileum tissue, antioxidant (SOD, CAT, and GPX) in ileum and liver, biological antioxidant potential (BAP), and reactive oxygen metabolite level in blood and intestinal villi measurement were determined. Body weight (BW) was highest (p < 0.05) in all groups except GRE-4, body weight gain (BWG) was best in GRE-1, while FCR was least in all groups except GRE-4. Optimum MUC2 gene expression, SOD, CAT, blood antioxidants, and intestinal morphometric values were observed in GRE-3. The inclusion of ginger root extract up to 1.5% improved growth and reduced oxidative stress while enhancing mucosal development in broiler chicks.

Productive qualities of broiler chickens at different levels of soluble fraction of fish waste hydrolyzate in feed

The growth and development of broiler chickens at different levels of the soluble fraction of fish waste hydrolyzate in mixed fodder was studied. The processing of commercial fish is accompanied by the formation of secondary resources, the scope of practical application of which is quite wide (fish proteins are a unique natural material used in various industries, but not fully utilized. Wastes resulting from fish processing are a source of valuable nutritional and biologically active substances, and thus serve as raw materials for various products, including dietary supplements. In order to determine the optimal rate of introduction of the soluble fraction of fish waste hydrolyzate into broiler chicken feed, a scientific and economic experiment was conducted that lasted 42 days. The research was conducted on broiler chickens of the Cobb-500 cross. The difference in the feeding of the experimental groups was that broiler chickens of the first (control) group received complete feed, which corresponded to the nutritional standards in all periods, and the additional introduction of a soluble fraction of fish waste hydrolyzate was: The 2nd experimental group received 0.2 % of the feed additive; poultry of the 3rd and 4th experimental groups consumed feed containing 0.4 and 0.6 % of the experimental additive. It was found that an increase in the content of the soluble fraction of fish waste hydrolyzate in the diet by 0.6 % contributes to an increase in live weight of chickens by 266 g, or 10.25 %, and a decrease in feed costs per 1 kg of live weight gain by 3.8 % compared to the control. It was found that during the growing period, broiler chickens of the 4th group had the highest absolute live weight gain of 2823.8 g, which is 2.63 %, 8.32 % and 10.36 % higher than in the 3rd, 2nd experimental and control groups. The use of feed with a soluble fraction of fish waste hydrolyzate in the feed with a content of 0.6 % increased the average daily weight gain for the entire period of the experiment by 7 g, or 11.63 %, and absolute weight gain by 265.2 g, or 10.36 %, respectively.

Effectiveness of probiotics in growing broiler chicken

Antibacterial preparations are used to prevent bacterial diseases in poultry when raising broilers but given the negative factor of their residual accumulation in meat and the acquisition of resistance by pathogens, it became necessary to find alternative means. The purpose of this study was to determine the effectiveness of various concentrations of Bacillus coagulans on the growth and development of broiler chickens. Methods employed: microbiological; physiological to determine the state of health and safety of chickens; zootechnical; pathological; statistical. The chickens in the experiment had a higher live weight at Day 35: in Group 1 – by 11%, in Group 2 – by 15.4%, and in Group 3 – by 18.4%, as opposed to the control. The average daily body weight gain of chickens in groups with B. coagulans was higher, in Group 1–by 10.8%, in Group 2–by 15%, and in Group 3–by 18.3%. The preservation rate in all experimental groups, regardless of the probiotic concentration, was 100%, while in the control group – 80%. There was an increase in live weight in the following groups: Group 1–by 11%, Group 2 – by 15.5%, Group 3 – by 19%. Feed conversion was lower in Group 1 by 5.3%, in Group 2 – by 3.4%, and in Group 3 – by 2%, compared to the control. At the end of the study, the level of Lactobacillus sp. in the intestines of chickens in Group 1 was 33.78% higher, in Group 2 – by 50%, in Group 3 – by 78.37%; a decrease in the content of Enterobacteriaceae sp. in Group 1–by 51.48%, in Group 2 – by 65.11%, in Group 3–by 90.67%; Staphylococcus sp. in Group 1–by 15.04%, in Group 2–by 35.44%, in Group 3–by 51.47% (p≤0.05), in contrast to the control. The average bursal weight in Group 1 was 4.82% higher, in Group 2–30% higher, in Group 3–37.53% higher, and the bursal index was 15%, 25%, and 30% higher, respectively, compared to the control

Evaluation of the Application Value of Cottonseed Protein Concentrate as a Feed Protein Source in Broiler Chickens

Cottonseed protein concentrate (CPC) has the function of replacing soybean meal to maintain normal animal growth and development. This study involved 180 Arbor Acres (AA) broilers, which were randomly assigned to three different treatments. Each treatment had six replicates, with each replicate consisting of 10 chicks. The control group was fed a basal diet, while the CPC-1 and CPC-2 groups used CPC to replace 25% and 50% of the soybean meal in the basal diet, respectively. The study showed that replacing soybean meal with 25% CPC in broilers’ diets can maintain normal growth, while substituting 50% of soybean meal with CPC negatively affects the growth and development of broiler chickens. Furthermore, the CPC-1 group showed a significant increase in serum total antioxidant capacity, superoxide dismutase enzyme activity, and immunoglobulin content, along with a decrease in malondialdehyde content. Based on the research results mentioned above, it was speculated that CPC has the potential to replace around 25% of soybean meal in broiler feed without causing any negative impact on growth performance. This suggests that CPC could be a viable alternative to soybean meal in broiler diet.

Chitosan Hydroxyapatite: Physic-chemical Properties and its Effect on the Growth and Development of Broiler Chickens

The current study aimed to obtain a calcium-containing, biocompatible drug based on chitosan Bombyx mori. Composites of Chitosan (CS) Bombyx mori with hydroxyapatite (HA) in the ratio of CS/HA = 50:50 mass percentage were synthesized in situ conditions at Ca/P = 1.67 mol% with intensive stirring for one hour at a speed of 1400 rpm and a temperature of 40 ± 2ºС. It was revealed that the components form an intermediate complex through –N-Ca, O-Ca, O (glycosidic bond)–Ca, H–O-bonds interacted by electrostatic forces. Atomic force microscopy studies indicated particles in the 100-50 nm size range on the polymer matrix surface. The polymer matrix prevented the growth of HA crystals and particle agglomeration. It was also determined that the CS/HA composite was non-toxic, and the LD50 was more than 5000 mg/kg. The composites were introduced into the chickens’ diet in groups for 30 days at 25 to 40 mg/kg doses. The findings indicated an increased survival rate of chickens by 100%, improved the morphological parameters of the blood, and enhanced the contents of calcium, phosphorus, and hemoglobin. The addition of CS/HA=50:50 mass percentage contributed to an increase in the number of erythrocytes in the blood of broilers and hemoglobin by 11-12%. It should be noted that CS/HA did not adversely affect other morphological parameters of chicken blood. Therefore, CS/HA is recommended for the prevention of osteoporosis and osteomalacia in broiler chickens.

Growth performance, nutrient digestibility, intestinal morphology, cecal mucosal cytokines and serum antioxidant responses of broiler chickens to dietary enzymatically treated yeast and coccidia challenge

BackgroundThere is a growing search for natural feed additives to alleviate the deleterious effects of coccidia infection in poultry production. This study aimed to investigate the effect of enzymatically treated yeast (ETY) on the growth performance, nutrient digestibility, intestinal morphology, antioxidative status, and cecal mucosa cytokines of coccidia-challenged broiler chickens.MethodsFrom d 1 to 14 post hatching, 480 broiler chickens were allocated to 3 corn-soybean meal-based experimental diets with increasing concentrations of ETY (0, 1, or 2 g/kg). The experiment was designed as a randomized complete block design with body weight (BW) used as a blocking factor. On d 14 post hatching, the birds were re-randomized within each of the 3 experimental diets. Each of the 3 diet groups was split into a challenge or no-challenge group. This resulted in a 3 × 2 factorial arrangement of treatments. The coccidia challenge was administered on d 15 by an oral gavage.ResultsDietary ETY improved (P < 0.05) the G:F of birds on d 21 regardless of the challenge state and linearly increased (P < 0.01) the apparent ileal digestibility of dry matter (DM), nitrogen, and gross energy (GE). The coccidia challenge decreased (P < 0.05) BW gain and feed intake of broiler chickens and reduced (P < 0.01) the total tract retention of DM, GE, and nitrogen. The coccidia challenge increased (P < 0.01) the mRNA gene expression of TNFα, IL-1β, IL-10, and IL-6 in the cecal mucosa. There was a tendency (P = 0.08) for ETY to linearly reduce IL-1β expression. Additionally, ETY supplementation increased (P < 0.05) the gene expression of OCLN. Serum catalase increased (P < 0.05) with dietary ETY in broiler chickens on d 21. Dietary ETY linearly increased (P < 0.05) the ileal villus height to crypt depth ratio, and ileal goblet cell density in broiler chickens. The ileal and excreta oocyst counts decreased (P < 0.01) with increasing supplementation of dietary ETY in coccidia-challenged broiler chickens on d 21.ConclusionsDietary ETY enhanced nutrient utilization and augmented intestinal development in broiler chickens. However, dietary ETY did not completely attenuate the adverse effects of a coccidia challenge in broiler chickens.

Effects of access to feed, water, and a competitive exclusion product in the hatcher on some immune traits and gut development in broiler chickens

ABSTRACT 1. This study evaluated the effect of access to feed, water, and the competitive exclusion (CE) product Broilact®, administered in the hatcher, on broiler performance, caecal microbiota development, organ development, intestinal morphology, serum levels of IgY and vaccine-induced antibody responses. 2. In total, 250 chicks were hatched in a HatchCareTM hatcher and divided into four groups, given access to feed, water and the CE product sprayed on the chicks (CEs); access to feed, water, and the CE product in water (CEw); access to feed and water (Cpos); or no access to feed and water (Cneg) in the hatcher. 3. At the research facility, 10 chicks per hatching treatment were euthanised for organ measurements. The remaining 200 chicks were randomly distributed to 20 pens. On d 11, all birds were vaccinated against avian pneumovirus (APV). Three focal birds per pen were blood-sampled weekly for quantification of IgY and serum antibodies to APV. On d 11 and 32, two birds per replicate pen were euthanised for organ measurements and sample collection. Feed intake and body weight were recorded weekly. 4. Delayed access to feed and water reduced weight gain and feed intake early in life. At the end of the study, no differences in body weight remained. 5. There were some early effects on organs, with depressed intestinal development and higher relative gizzard weight for the Cneg group at placement. No treatment effects on the immune traits measured were detected. 6. The relative abundance of seven bacterial genera differed between treatment groups at d 11 of age. The results suggested that chickens are capable of compensating for 40 h feed and water deprival post-hatch. Provision of Broilact® did not have any persistent performance-enhancing properties, although different outcomes under rearing conditions closer to commercial production cannot be ruled out.

Goloba kusi (Hornstedtia scottiana [F. Muell.] K. Schum.) fruit as a feed additive to improve the histological structures and growth performance of broiler.

The broiler farming industry in Indonesia has enormous potential, with chicken meat that can be optimized by providing adequate and high-quality feed. However, the main raw material for the feed still relies on imported products, which makes it necessary to produce alternative materials from native plants. Therefore, this study aimed to investigate the effect of giving Goloba kusi fruit (GF) (Hornstedtia scottiana [F. Muell.] K. Schum.) on the growth of the small intestine, pectoralis major, and gastrocnemius muscle, as well as the development of broiler chickens. This study used a completely randomized design, in which 300 day-old Chicks were divided into five groups, consisting of 12 chickens in each group with five replications. The GF treatments, namely, 0% (control [CON]), 0.625% (GF1), 1.25% (GF2), 2.5% (GF3), and 5% (GF4) were administered through per kg basal feed. Subsequently, three chickens from each replication were taken, decapitated on the neck, subjected to surgery for histological preparations, and stained with Hematoxylin-Eosin and Periodic acid-Schiff-alcian blue. The variables observed included small intestine morphology, muscle morphology, and chicken growth performance. The results showed that the small intestine morphology, muscle morphology, and chicken growth performance of the GF4 (5%) group increased significantly compared to the CON group. The administration of GF with an optimum concentration of 5% through basal feed improves small intestine morphology, muscle morphology, and chicken growth performance.

Effects of feeding a thermomechanical, enzyme-facilitated, coprocessed yeast and soybean meal on growth performance, organ weights, leg health, and gut development of broiler chickens

The development of a healthy gut during prestarter and starter phases is crucial to drive chicken's productivity. This study aimed to evaluate the effects of a thermomechanical, enzyme-facilitated, coprocessed yeast and soybean meal (pYSM) on growth performance, organ weights, leg health, and gut development in broiler chickens. A total of 576 as-hatched broiler chicks were randomly allotted to 3 dietary treatments (8 replicates/treatment, 24 chickens/replicate): a control group (C) without the pYSM, a treatment group 1 (T1), in which the pSYM was included at 20, 10, 5, 0, and 0% levels in the prestarter, starter, grower, finisher I, and finisher II feeding phases, respectively, and a treatment group 2 (T2), in which the pSYM was included at 5, 5, 5, 0, and 0% levels in each feeding phase. On d 3 and 10, 16 broilers/treatment were euthanized. The T1 broilers tended to show higher live weight (d 3 and 7) and average daily gain (prestarter and starter phases) than the other groups (P ≤ 0.10). Differently, pYSM-based diets did not influence the growth performance of the other feeding phases and the whole experimental period (P > 0.05). Relative weights of pancreas and liver were also unaffected by pYSM utilization (P > 0.05). Litter quality tended to have higher average scores in C group (P=0.079), but no differences were observed for leg health (P > 0.05). Histomorphometry of gut, liver, and bursa of Fabricius was not affected by diet (P > 0.05). Gut immunity was driven to an anti-inflammatory pattern, with the reduction of IL-2, INF-γ, and TNF-α in the duodenum of treated birds (d 3, P < 0.05). Also, MUC-2 was greater in the duodenum of C and T2 group when compared to T1 (d 3, P=0.016). Finally, T1-fed chickens displayed greater aminopeptidase activity in the duodenum (d 3 and 10, P < 0.05) and jejunum (d 3, P < 0.05). Feeding high levels of pYSM (10-20%) to broilers in the first 10 d tended to improve growth performance in the prestarter and starter phases. It also positively downregulated proinflammatory cytokines during the first 3 d, as well as stimulated the aminopeptidase activity in the prestarter and starter periods.

Growth performance, carcass characteristics, serum biochemistry and digestive tract development in broiler chickens fed with chitosan oligosaccharide

Growth performance, carcass characteristics, serum biochemistry and digestive tract development in broiler chickens fed with chitosan oligosaccharide

The Effects of Lactobacillus farciminis and Lactobacillus rhamnosus on Growth, Blood Biochemical, and Meat Quality Indicators of Specific Pathogen-Free Broiler Chickens.

The aim of our study was to evaluate the effects of Lactobacillus farciminis and Lactobacillus rhamnosus on live weight gain, feed consumption indicators, and some metabolic blood biochemical and meat quality indicators of specific pathogen-free Ross 308 broiler chickens. We carried out the study in three trials and included a total of 780 unsexed Ross 308 chickens, which we randomly divided into two groups: the control group (Con, n = 390, basal diet) and the probiotic group (ProL, n = 390, basal diet + a powder consisting of L. farciminis and L. rhamnosus 4 g/10 kg of feed). We raised broilers until day 35. We determined the amount of feed consumed, the average daily weight gain, the feed conversion ratio, the average daily feed intake, and the cumulative feed intake once a week. We collected blood samples from 45 broilers from each group at the end of the study. In addition, we slaughtered 30 broilers from each group by cervical dislocation to obtain a breast muscle sample (without skin) to determine meat quality in these chickens (cholesterol and unsaturated, omega-3, omega-6, omega-9, and saturated fatty acids). Feeding a probiotic mixture containing L. farciminis and L. rhamnosus did not significantly affect the growth and feed intake indicators. Feeding these probiotics significantly lowered the blood serum cholesterol levels but did not provide the expected reduction in meat cholesterol levels. However, feeding a probiotic mixture increased the levels of polyunsaturated fatty acids (omega-3 and omega-6 fatty acids) in the breast meat and decreased saturated fatty acids. To better explain the effect of the combination of lactic acid bacteria (L. farciminis and L. rhamnosus) on the growth and development of broiler chickens in our study, histological and immunohistochemical examinations should be performed.

Early Post-Hatch Nutrition Influences Performance and Muscle Growth in Broiler Chickens.

The poultry industry is under pressure to produce safe and good quality meat in the welfare conditions. Many areas such as genetics, biosecurity, and immunoprophylaxis were improved, and hatchery is one of the areas in which welfare could be improved for better production output. The aim of the study was to investigate the effect of early post-hatch nutrition providing body weight and muscle development in broiler chickens. The experiment involving two groups (chicken hatched with access to water and feed in the hatcher, and chicken without feed and water in hatcher) was replicated three times, and the body weights and breast-muscle index of the randomly chosen 30 chickens per group in each term were measured on the 1st, 7th, 21st, and 35th day of life. The breast-muscle sample was taken for genetic examination (the expression of the myoD, myoG, and MRF4 genes) and histological examination. The results showed that the positive effect of early nutrition was observed on the seventh day of bird life with higher expression of myoG and MRF4 and higher body weight of the birds. The positive effect of early nutrition on the diameter of the breast-muscle fibers was visible on days 21 and 35 of chicken life. The average final body weight in groups with early access to food and water was 5% higher than in groups hatched under classic conditions. Conclusions: early feeding in the hatcher improves performance and muscle growth in broiler chickens.

EXPERIENCE OF EFFECTIVE APPLICATION OF NATURAL GROWTH STIMULATOR "IMUNOCHASNYK"

A study of the effectiveness of using the natural growth stimulator "Imunochasnyk" on the growth and development of broiler chickens was conducted. For conducting research, 4 groups of broiler chickens of 100 1-day-old heads were formed according to the principle of analogues. The control group was fed standard full-rational compound feed. Throughout the experiment, all groups received a standard basic diet according (to the recipe "Cremix" by LLC). The first, control group, of chickens received a standard basic diet without the addition of any additives. The second experimental group of chickens received the natural growth stimulator "Imunochasnyk" in the amount of 500 g/t of compound feed. The third experimental group received the natural growth stimulator "Imunochasnyk" in the amount of 1000 g/t of feed, the fourth experimental group received a commercial phytogenic analogue in the amount of 150 g/t of compound feed (according to the manufacturer's instructions for use). Supplements were fed to birds from one day to 42 days of age. In the process of the experiment, the general condition, preservation of the bird and zootechnical indicators were monitored. It was established that the researched natural growth stimulator "Imunochasnyk" has a positive effect on the productivity of broiler chickens and improvesfeed assimilation. As a result of the use of the "Imunochasnyk" feed additive, the live weight of broiler chickens in the experimental groups was 5.1-6.5% higher compared to control birds. The use of the natural growth stimulator "Imunochasnyk" in the amount of 500 g/ton as part of complete feed guaranteed an increase in average daily gains by 6.8%, the addition of "Imunochasnyk" in the amount of 1000 g/ton of compound feed – 5.3% compared to the control, without adding feed additive. The use of a feed additive contributed to the improvement of feed conversion, and the level of protein in poultry meat increased.

ВЛИЯНИЕ КОРМОВОЙ ДОБАВКИ «ПИК-АНТИСТРЕСС» НА СОДЕРЖАНИЕ МАКРОЭЛЕМЕНТОВ В КРОВИ И ТКАНЯХ ЦЫПЛЯТ-БРОЙЛЕРОВ ПРОМЫШЛЕННОГО ВЫРАЩИВАНИЯ

Growth and development of broiler chickens with intensive fattening, especially in the finishing period, reaches a peak in intensity. Under conditions of technological stress, mineral metabolism takes an active part in the development of the adaptation syndrome. Feeding the bird with a stress protector at a dose of 1269 g / t of feed led to a statistically significant increase in the ash content of the pectoralis minor, serum calcium, magnesium in the bone tissue and a decrease in phosphorus in the pectoralis minor; at a dose of 1693 g / t of feed, it significantly increased the ash content of the skin, the content of calcium in the blood, magnesium in the bone tissue, and reduced the level of phosphorus in the femoral muscles.

Prenatal effects of red and blue light on physiological and behavioural parameters of broiler chickens

Light during incubation can influence embryonic and postembryonic development of chickens, but the underlying mechanisms are poorly understood. Previous studies have demonstrated that red and blue lights during incubation had opposite effects on the development of embryonic melatonin biosynthesis; red light results in the highest and blue light in the lowest amplitude of the daily rhythm. Therefore, in this study, we investigated if exposure to monochromatic red (632 nm) and blue (463 nm) light during incubation can differently influence growth, selected biochemical (glucose, cholesterol, triacylglycerols) and endocrine (corticosterone and thyroid hormones) traits and behavioural parameters during postembryonic development in broiler chickens. For analysis, we used 10 and 11 hatchlings incubated in red and blue light, respectively and 10 birds per each group (six males and four females) in 3-weeks-old broilers. During the rapid growth phase (days 18, 20 and 21 of age), higher body weight was recorded in broilers incubated under red compared to blue light, whereas endocrine and metabolic traits did not differ between the treatments. The improved growth rate was related to behavioural traits, mainly because chickens incubated in red light exhibited more passive (resting, standing, preening, dust bathing) and less active behaviours (walking, foraging, fighting, wing-flapping) than the blue-light incubated birds. The time spent for eating and drinking and the results of the tonic immobility test did not differ between both groups. Our results suggest that red and blue monochromatic light during incubation can differently program the postembryonic development of broilers, with possible consequences for their growth and welfare.

Influence of Feeding Omega-3 Polyunsaturated Fatty Acids to Broiler Breeders on Indices of Immunocompetence, Gastrointestinal, and Skeletal Development in Broiler Chickens.

Modern broiler chickens are associated with rapid growth rates and superior feed efficiency. However, they are also susceptible to physiological and metabolic disorders (e.g., skin lesions, lameness, sudden death, enteric diseases, myopathies) that exert substantial economic losses to producers. This is further exacerbated by consumer pressure and mandated cessation of production practices such as indiscriminate use of antimicrobial growth promoters. Manipulation of broiler breeder (BB) nutrition and management can influence chick quality, robustness, and resilience to stressors in the production environment. The present review examines the role of feeding BB functional polyunsaturated omega-3 fatty acids (n-3 PUFA) and subsequent impact on the indices of immunocompetence, skeletal, and gastrointestinal (GIT) development in broiler chickens. Research in mammalian and avian models led evidence that perinatal feeding of long chain n-3 PUFA such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) engender transgenerational effects through regulation of a variety of biological processes including development of vital organs such as skeleton, brain and GIT. It is shown that feeding poultry breeders n-3 PUFA decreases inflammatory states and enriches hatching eggs with n-3 PUFA and immunoglobulins. Further evidence also shows that after 15 days of incubation, chicken embryos preferentially utilize long chain n-3 PUFA-critical for optimal cell, tissues, and organ development. Enrichment of n-3 PUFA in newly hatchling tissues reduce proinflammatory eicosanoids with consequences of enhanced bone mineralization. Dietary n-3 PUFA also modulates breeder GIT microbiota with consequences of microbial colonization and succession in chicks. As well, research shows that feeding poultry breeders n-3 PUFA bolsters progeny immunocompetence through enhanced passive immunity and antibody titres against routine vaccination. In conclusion, it appears that chicks may benefit from the incorporation of n-3 PUFA in the breeder diets; however, little attention is paid to fatty acids composition in breeder nutrition. We also highlight gaps in knowledge and future research perspectives.