Evaluation of various feeding programmes on growth performance, carcass and meat qualities of Thai indigenous crossbred chickens

This study was conducted to evaluate the effects of various feeding programmes on growth performance, carcass characteristics, and the meat qualities of Thai indigenous crossbred (50%) Korat chickens to obtain suitable feeding programmes. A total of 480 one-day-old mixed-sex Korat chickens were randomly allotted to four treatments, namely FP1, FP2, FP3 and FP4, with four replicates for each treatment (30 birds per replicate) in a completely randomized design. Chickens in FP1 were fed diets with 21, 19, 17 and 15% crude protein (CP) in periods of 0–3, 3–6, 6–9 and 9–13 weeks old, respectively. Chickens in FP2 were fed diets with 21, 19, 17 and 15% CP in periods of 0–3, 3–5, 5–7 and 7–13 weeks old, respectively. Chickens in FP3 were fed diets with 21, 19, 17, 15 and 14% CP in periods of 0–2, 2–5, 5–8, 8–10 and 10–13 weeks old, respectively. Chickens in FP4 were fed diets with 21, 19, 17, 15 and 14% CP in periods of 0–2, 2–4, 4–6, 6–8 and 8–13 weeks old, respectively. At 13 weeks old, the results showed that Korat chickens fed with FP4 had a higher feed intake, but poorer feed conversion rate (FCR), protein efficiency ratio (PER), and energy efficiency ratio (EER) values than the FP1, FP2 and FP3 treatments. However, the values for bodyweight gain and blood urea nitrogen (BUN) did not differ among treatments. None of the parameters for carcass traits, meat characteristics, and meat qualities revealed differences among treatments, except for the protein content in the thigh meat of chickens fed with FP4, which had a lower value than that of the other treatments. In conclusion, FP3 represented the most beneficial results for reducing feed costs without affecting growth performance, carcass traits, nutrient composition of meat, and meat characteristics of chickens.Keywords: carcass trait, growth, indegenous crossbred chicken, meat yield, protein leve

Modified dietary fiber from cassava pulp affects the cecal microbial population, short-chain fatty acid, and ammonia production in broiler chickens

International audienc

Growth performance and accretion of selected amino acids in response to three levels of dietary lysine fed to fast- and slow-growing broilers

Literature data indicate that feed intake is sensitive to the dietary Lys content particularly in fast-growing birds. From a conceptual and a practical viewpoint, an interaction between genotype (i.e., fast-growing vs. slow-growing birds) and dietary Lys content is of interest, but it needs confirmation owing to a dearth of studies addressing this issue. A study was conducted with 266 Cobb 500 birds and 266 Thai native crossbreed birds serving as models for fast-growing broilers (FGB) and slow-growing broilers (SGB), respectively. Within genotype, chicks were randomly allocated to diets containing either a high (H-LYS = 1.36%), medium (1.17%), or low Lys (1.01%) content. Growth performance and the accretion of protein and selected amino acids were determined in birds from 1 to 21 d of age. Treatments were arranged in a factorial design with 6 replications/treatment. Low Lys vs. H-LYS caused a 42.1% lower feed intake in FGB (P < 0.001), but not in SGB (P = 0.596). The feed conversion ratio (FCR (g feed/g BW gain)) was lowest in FGB (P < 0.001) and increased with decreasing dietary Lys contents (P < 0.001). The Lys induced increase in FCR, however, was more pronounced in SGB (P = 0.025). The absolute protein gain (g/bird) was influenced by the Lys content of feed and decreased by ∼54% and ∼23% in FGB and SGB, respectively (P < 0.001). The efficiency (% of intake) of protein accretion was found to be greater in FGB (P ≤ 0.001) and decreased with decreasing dietary Lys (P ≤ 0.001). The efficiency of Lys accretion was found to be negatively affected by the dietary Lys content in FGB (P < 0.001) but not SGB (Pgenotype × dietary Lys = 0.008). It can be concluded that a dietary Lys content of 1.01% does not safeguard both growth performance and body protein accretion efficiency in both FGB and SGB. The suboptimal growth performance in FGB, but not SGB, is partially counteracted by a Lys-induced reduction in feed intake

Reproductive performance and fertility response of laying hens as affected by dietary energy and antioxidant substance supplementation

Reproductive performance and fertility response of laying hens as affected by dietary energy and antioxidant substance supplementation. 1. International Conference on Tropical Animal Science and Production (TASP 2016

Transcriptome analysis identifies genes affected by heat stress in hen uterovaginal junction

Session 55, Poster 16International audienceFemale birds have the potential to modulate the motility of resident sperms. Heat stress decreases the reproductiveability of broiler breeder hens. However, its effects on the sperm storage tubules (SSTs) in the uterovaginal junction(UVJ), the primary site of sperm residence, remain unclear. In this study, we used RNA-sequencing to identify thedifferentially expressed genes (DEGs) in UVJ tissues containing SSTs of breeder hens affected by heat stress (36 °Cfor 6 h). A total of 561 genes, including 181 upregulated and 380 downregulated DEGs, were found to be differentiallyexpressed compared to those in chickens raised under thermoneutral conditions (23 °C). Gene Ontology analysisrevealed 209 significantly enriched terms involving heat shock proteins (HSPs). Kyoto Encyclopaedia of Genes andGenomes analysis identified nine significant pathways, including the protein processing in endoplasmic reticulum,neuroactive ligand-receptor interaction, biosynthesis of amino acids, ferroptosis, and nitrogen metabolism pathways.Protein-protein interaction network analysis of DEGs revealed two large networks. Our findings indicate that heatstress inhibits innate immunity in UVJ tissues of broiler chickens and that heat-stressed chickens protect their cells byincreasing the expression levels of HSPs. Our results suggest that DEGs, including HSP25, HSPA5, HSPA8, GKN2,IL4I1, PDK4, TAT, CA, LHCGR, GPX, and interferon-stimulating genes may be used to further investigate SSTs inUVJ tissues of heat-stressed hens

Growth performance and accretion of selected amino acids in response to three levels of dietary lysine fed to fast- and slow-growing broilers

Literature data indicate that feed intake is sensitive to the dietary Lys content particularly in fast-growing birds. From a conceptual and a practical viewpoint, an interaction between genotype (i.e., fast-growing vs. slow-growing birds) and dietary Lys content is of interest, but it needs confirmation owing to a dearth of studies addressing this issue. A study was conducted with 266 Cobb 500 birds and 266 Thai native crossbreed birds serving as models for fast-growing broilers (FGB) and slow-growing broilers (SGB), respectively. Within genotype, chicks were randomly allocated to diets containing either a high (H-LYS = 1.36%), medium (1.17%), or low Lys (1.01%) content. Growth performance and the accretion of protein and selected amino acids were determined in birds from 1 to 21 d of age. Treatments were arranged in a factorial design with 6 replications/treatment. Low Lys vs. H-LYS caused a 42.1% lower feed intake in FGB (P < 0.001), but not in SGB (P = 0.596). The feed conversion ratio (FCR (g feed/g BW gain)) was lowest in FGB (P < 0.001) and increased with decreasing dietary Lys contents (P < 0.001). The Lys induced increase in FCR, however, was more pronounced in SGB (P = 0.025). The absolute protein gain (g/bird) was influenced by the Lys content of feed and decreased by ∼54% and ∼23% in FGB and SGB, respectively (P < 0.001). The efficiency (% of intake) of protein accretion was found to be greater in FGB (P ≤ 0.001) and decreased with decreasing dietary Lys (P ≤ 0.001). The efficiency of Lys accretion was found to be negatively affected by the dietary Lys content in FGB (P < 0.001) but not SGB (Pgenotype × dietary Lys = 0.008). It can be concluded that a dietary Lys content of 1.01% does not safeguard both growth performance and body protein accretion efficiency in both FGB and SGB. The suboptimal growth performance in FGB, but not SGB, is partially counteracted by a Lys-induced reduction in feed intake