RESUMEN
OBJECTIVE: This work aimed at studying dietary energy supplementation effects during late pregnancy upon the metabolic status of does, as well as on the birth weight (BW), body temperature, and metabolic profile for their kids and the net economic profit. MATERIALS AND METHODS: Eighty pregnant does (Egyptian Nubian) were equally split into four dietary treatments; the control (CON) receiving basal diet, the basal diet with 200 gm corn starch and 100 gm of molasses /h/d added (MS), the basal diet with 300 gm/h/d of corn grains added (CG), and the basal diet with 300 gm/h/d of barley grains added (BG). RESULTS: Body weight and temperature of kids were significantly higher in MS and BG groups, respectively. The serum concentration of albumin (Alb), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels are significantly decreased. At the same time, urea and vitamin A increased dramatically in the BG group before giving birth. After birth, conversely, the serum concentration of albumin, AST, ALT, cholesterol, and vitamin A significantly increased with energy supplementation. Kids in the BG group show the most high level of albumin. Furthermore, all supplemented groups increased dramatically in vitamin A. The economic efficiency of the MS group, followed by the BG group, was significantly higher compared to the other treatments. CONCLUSION: It is beneficial for Egyptian farmers to feed extra concentrate (especially barley) to the does during late gestation stages to produce healthy kids with optimal BW and body temperature, as well as to avoid metabolic disorders that may affect the does at this critical stage. Finally, it can be said that this dietary supplementation may also increases the profit margins of the farmers.
RESUMEN
AIM: This study aimed to investigate the effects of protein reduction with supplementation of limiting amino acids (AA, tryptophan, threonine, and valine) on growth performance, blood biochemical, immunity parameters, and carcass traits in broiler chickens. MATERIALS AND METHODS: Three hundred one-day-old broiler chicks were randomly allotted into three treatment groups, with five replicates per treatment and 20 broiler chickens per replicate. The three experimental diets were formulated with different dietary crude protein (CP) %, (control [CON] and CON with 1% [CP-1%] or 2% [CP-2%] less CP units) during the starter, grower, and finisher phases. The CP of the experimental diets were 22, 21, and 20% for the starting period (day 1-14); 20, 19, and 18% CP for the growing period (day 15-28); and 18, 17, and 16% CP for the finishing period (day 29-35) in CON, CP-1%, and CP-2%, respectively. The low-CP diets (CP-1% and CP-2%) were supplemented with combined AA, threonine+tryptophan+valine, to meet the respective levels of the CON diet. RESULTS: The CP-2% group had greater (p<0.05; linear, p<0.05) final body weight and gain and better feed conversion ratio. The combined AA inclusion in the low-CP diet (CP-1% and CP-2%) increased (p<0.001; linear, p<0.001) carcass and breast meat yield as well as CP% of breast meat. The reduction of CP% with AA supplementation (CP-2%) decreased (p<0.05; linear, p<0.05) serum triglycerides, glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, and alkaline phosphatase, while increased (p<0.01; linear, p<0.01) phagocytic activity and phagocytic index. The mRNA expression of splenic and cecal tonsil interleukin 4 and interferon gamma was upregulated (p<0.001; linear, p<0.001) in the low-CP diets supplemented with AA (CP-1% and CP-2%). Dietary supplementation with AA to low-protein diets improved (p<0.01; linear, p<0.01) the economic returns of broiler chickens. CONCLUSION: A reduction of dietary CP and increased synthetic AA such as threonine, valine, and tryptophan should be considered to improve performance, health, and immunity in broiler chickens.