ABSTRACT:
The main objective of this study was to investigate the effect of adding betaine with different levels of guandino acetic acid (GAA) on the productive and reproductive performances of the Mamourah chickens strain, under Egyptian summer conditions. A total number of 192 laying hens and 24 cocks of Mamourah chickens at 48 weeks of age (At 63.24 % egg production) was used in a completely randomized design and randomly assigned into 8 experimental similar groups in body weight and egg production (24 hens + 3 cocks in each treatment group), each group with three replications (8hens +1 cock in each replicate) and was kept in a single cage within an open system house until 60 weeks of age. The experimental 8 groups were arranged as control, and that fed a basal diet supplemented with 1600 mg betaine/kg diet, while the third up fifth groups were fed a basal diet supplemented with 600, 800 and 1000 mg guandino acetic acid/kg diet, respectively, and from the sixth to the eighth groups were fed a basal diet supplemented with 1600 mg betaine/kg diet and 600, 800 and 1000 mg guandino acetic acid/kg diet.
The obtained results showed that, dietary betaine and GAA had no significant (P<0.05) effect on body weight changes (BWC),feed intake (FI), egg weight (EW), hatchability/fertility eggs (%), chick hatch weight (gm), total antioxidant capacity (TAOC) of Mamourah layers during the whole experimental period. Feed conversion ratio (FCR), egg production (EP) and egg mass (EM) significantly (P<0.01) improved in hens fed the diet containing 1600 mg betaine + 600 mg/Kg GAA as compared to the control group. Fertility eggs (%) and hatchability/total eggs (%) were significantly (P<0.05 and 0.01) higher for layers fed diets contained betaine, GAA and their mixtures., Increasing the amount of GAA significantly (P≤0.05) increased the superoxide dismutase (SOD) and glutathione peroxidase (GPX). However, Malonidialdehyde (MDA) caused decreased significantly (P≤0.05) with supplementing either dietary betaine, GAA and their mixtures as compared with the control group. Dietary supplementation of either betaine, GAA and their mixtures improved significantly (P<0.05) sperm motility (%), dead spermatozoa (%), sperm abnormalities (%), sperm-cell concentration (X 109/ml) and acrosomal damage (%) as compared with the control group. Feeding Mamourah layers a diet supplemented with1600 mg betaine + 600 mg GAA recorded the highest net revenue and the best economical efficiency.
In conclusion, dietary supplementation of betaine with various levels of GAA might be potentially used to improve each of EP, fertility eggs (%) and hatchability per total eggs (%) of Mamourah laying hens and most characters of semen quality for cocks under summer season conditions in Egypt.