Interactive effects of dietary protein and nano-chitosan on growth performance, immune response, and histological aspects of lymphoid organs in broiler chickens.

A feeding trial was conducted to assess the effect of partial replacement of dietary soybean meal by three plant protein sources: coconut, rocket seed, and black cumin meals with their combination in the presence or absence of nano-chitosan (NCH) on growth performance and immune response in broiler chickens. Five starter and grower diets were formulated and used from 1 to 42 days of age. The NCH was added to starter and grower diets at 1.0 g/kg. Five-hundred-fifty-day-old Arbor Acres Plus broiler chicks were randomly divided into ten treatments with five equal replications. Final body weight (FBW), body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR), and blood plasma parameters were investigated. Histological aspects of lymphoid organs (thymus: T, bursa of Fabricius: B, and spleen: S) were characterized. Apart from added NCH, the FBW, BWG, and FCR of broilers fed the diets containing the tested plant proteins were significantly superior to the control ones. However, FI of birds fed the diets containing CM alone or combined with RSM plus BCM was significantly reduced. All experimental broilers displayed high plasma levels of IgG compared with the control group. There were significant increases in plasma concentrations of IgM, IgA, and T4 for groups that fed the diets containing RSM, BCM, and mixture of CM, RSM, and BCM compared with their controls. The T3 levels of broilers fed the tested plant proteins were significantly increased compared with the controls. Aside from plant protein source, broilers fed the NCH-enriched diets achieved significant increases in levels of IgM, TAC, and FSH and activities of CAT and SOD but reduced the MDA level compared with control. The interactions between plant protein source and added nano-chitosan were not interrelated. Furthermore, CM, RSM, and BCM can be used as complementary dietary proteins singly or combined with NCH with no adverse effects on growth performance. Addition of NCH molecules has a positive effect on live body weight and increases feed intake compared with control chicks.

Effects of L-carnitine supplementation of diets differing in energy levels on performance, abdominal fat content, and yield and composition of edible meat of broilers.

Responses to supplemental dietary L-carnitine of broilers fed on diets with different levels of metabolizable energy (ME) were investigated using growth performance and some carcass measurements. Three isonitrogenous diets containing 13.5, 12.8 or 12.2 MJ ME/kg were formulated, with or without supplemental L-carnitine (50 mg/kg) and fed ad libitum from 18 to 53 d of age. Supplemental L-carnitine increased body-weight gain (BWG) and improved feed conversion (FC) during the first 2 weeks of study. FC was also improved during the fourth week of the experiment. Weights of breast yield and thigh meat yield were significantly increased, whereas quantity and percentage of abdominal fat were reduced by supplemental L-carnitine. A significant interaction between supplemental dietary L-carnitine and dietary energy level was noted for BWG and FC during the second week of study.

Effects of dietary L-carnitine on the performance and egg quality of laying hens from 65-73 weeks of age.

The effects of L-carnitine supplementation (50-500 mg/kg diet) of a practical layer diet, based on maize, soyabean and wheat, on the performance of laying hens and some indices of egg quality were studied for 8 weeks, using 65-week-old hens kept in cages. Albumen quality (albumen height and Haugh (1937) unit score) was improved, while yolk index and yolk colour score were not affected by dietary L-carnitine. The percentage of egg-white increased and that of egg yolk decreased in response to dietary supplementation of L-carnitine. Dietary L-carnitine did not influence laying performance (egg production rate, mean egg weight, daily feed intake, daily egg mas and feed conversion) or external egg quality measured by egg weight, egg-shape index or by eggshell quality, either measured directly as shell breaking strength or indirectly as shell weight, shell thickness or shell weight per unit surface area. Based on the results of the present study, L-carnitine had a beneficial effect on albumen quality and could modify the components of the edible part of the egg, during the late laying period.

Effects of dietary L-carnitine supplementation and protein level on performance and degree of meatness and fatness of broilers.

Feeding high-protein diets to broilers is a known means for improving performance and carcass composition and quality, however, the combined effects of dietary protein (CP) level concurrent with L-carnitine (CN) supplementation are not known. Performance and carcass traits of broilers fed CN-supplemented diets of different CP-levels were studied from 18 to 53 days of age. Three isocaloric diets containing 18, 20 or 22% CP were formulated, with or without added CN (50 mg/kg), and used. Apart from CP level, supplemental CN attained significantly higher body weight gain (BWG) and feed conversion (FC), means of BWG were 351 vs. 332 and 371 vs. 353 g, and those of FC were 1.25 vs. 1.33 and 1.73 vs. 1.84 for the first and second week of the experimental period, respectively. Amount and percentage of abdominal fat and ether extract (EE) contents of breast meat of 53-day-old broilers were significantly reduced (means of AF were 43.5 vs. 51.5 g, equivalent to 1.98 vs. 2.39%, those of EE were 1.82 vs. 2.24%) in response to CN supplementation. A significant interaction between added CN and CP level was noted on BWG and FC of broilers from 18 to 32 days of age.

Influence of dietary L-carnitine on performance and carcass quality of broiler chickens.

Effects of dietary L-carnitine supplementation on the performance, carcass yield and components, abdominal fat and composition of meat of broiler chickens were investigated. Ross broiler chicks, 18-day-old were used in this experiment. Four experimental diets were formulated, by adding three levels of supplemental L-carnitine (50, 100 or 150 mg/kg) to a basal diet and used from 18 to 46 days of age. Apart from the level of supplementation, L-carnitine (CN) addition resulted in significant increases (P < 0.05) in body weight gains (BWG) of broilers (means were 397 vs. 365 and 410 vs. 377 g, for the first and second weeks of the experimental period, respectively). Abdominal fat (AF) contents of 46-day-old broilers were significantly decreased, both as absolute weights (P < 0.05) and as percentages of body weight (P < 0.01), by added CN (means of AF were 36.8 vs. 44.8 g, equivalent to 1.87 vs. 2.32%). Level of added CN had no effect on BWG or AF of broilers. It was concluded that the effectiveness of supplemental L-carnitine for improving BWG and/or decreasing AF of broilers may depend on the age at which L-carnitine is added. Under the conditions of this study, a supplementation of 50 mg L-carnitine per kg diet proved to be effective.