No abstract

The present study was carried out in Rabbit Research Unit at Sakha Research Station located in Kafr El-Shiekh governorate, Egypt to assess the impact of N-acetylecysteine (NAC) administration on the physiological, reproductive and productive performance of rabbit does. A total number of 21 pregnant, healthy, primiparous New Zealand White (NZW) rabbit does aged between 5-6 months with an average initial body weight (BW) of 3052 g were used. They were divided into three equal groups. The first group (G1) was served as control group without any administration. The second and third groups (G2 and G3) were injected subcutaneously with 50 and 100 mg NAC / kg BW, respectively. The injection with NAC doses started on day 14 of pregnancy and continued for seven consecutive days. The experiment lasted continuously for three months. The obtained results showed that, NAC treatment reduced the oxidative stress in pregnant rabbit does, G2 and G3 had the highest values of GST and the lowest values of both MDA and H 2 O 2 in comparison with those of G1.Total protein, albumin, globulin and A/G ratio did not significantly affected by NAC injection and tended to increase with pregnancy progress. In contrast, level of triglycerides decreased (P<0.05) in G2 and G3 than that of G1 and declined with progress of gestation till kindling. Treated groups decreased their blood urea nitrogen (BUN) values and increased their creatinine (CR) levels than those of G1. With progress of pregnancy, levels of BUN tended to decrease and CR levels tented to increase. Both transaminase enzymes (AST and ALT) activities decreased by NAC treatment and by pregnancy progress, particularly in G3. The changes in live BW of does in the three groups across the experimental period were insignificant. NAC injection achieved weaning day, G2 and G3 had heavier kits' weight than those in G1 by 26 and 20 %, respectively. Litter size increased obviously due to NAC treatment by 19 to 35 % in G2 and by 5.5 to 23.1 % in G3 than that in G1 during the all experimental days. Mortality rate reduced by NAC injection being the lowest in G2 (4.7 %) followed by G3 (11.2%) and the highest in G1 (23.6 %). Total milk yield was increased significantly in G3 and insignificantly in G2 compared to that of G1 by 17.5 and 4.5 %,respectively. The high dose was more effective in promoting milk production. The effect of NAC treatment on all milk components was insignificant, except milk lactose. From the first wk to the last wk, milk composition (%) of milk protein, milk lactose, milk total solids and milk solids not fats increased (P<0.05) whereas milk fat decreased. In conclusion, this study proved not only the effectiveness, but also the safety of NAC application and its capability to improve rabbit's performance particularly with high dose (100 mg/kg BW). Further studies are urgently needed to confirm our findings.

Seventy two rabbits, 35 days old and weighing 622g average body weight, were used for the present study. The rabbits were randomly assigned into 4 equal treatments (n=18). Animals in treatment 1 served as a control group and were given basal diet without supplementation, while rabbits in treatments 2, 3 and 4 were given nano-copper in the diet at levels 25, 50 and 75 mg/kg diet, respectively. The experiment lasted for 8 weeks. The results revealed that, rabbits fed diets supplemented with 50 or 75 mg Cu/ kg diet as Nano-Cu recorded significantly higher (P<0.01) final body weight and performance index also, recorded better feed conversion ratio during all growth periods than the control group. The group of rabbits fed diet supplemented with 50 mg Nano-Cu/kg diet significantly achieved the best relative growth rate percentage. Dietary supplementation with 50 mg Nano-Cu /kg diet significantly recorded higher carcass, fore part, trunk and hind part percentages comparing with the control group, it also significantly reduced abdominal fat by 28.4%. The Nano-Cu supplementation significantly (P<0.05) increased activity of superoxide dismutase enzyme compared with the control group. Copper content in rabbits liver significantly increased by increasing dietary Nano-Cu. Dietary Nano-Cu supplementation significantly (P<0.05) increased the population of total bacterial count and lactolacillus counts and decreased the population of ureolytic bacteria, Escherichia coli and clostridium spp. Supplementation of Nano-Cu to rabbit diets significantly increased plasma hemoglobin, red blood cells count and lymphocytes percentage. Economical efficiency

This study evaluates low protein diets with amino acid supplement on growth, biochemical markers and muscle amino acids profile in broilers under high ambient temperature. A total of 480 one-day-old chicks were allocated into three treatments with four replicates (n = 40). Control fed optimal protein and optimal amino acids which contains 23% and 21% crude protein (CP) with 65% methionine + cysteine/ lysine (Met + Cys/Lys) and 55% threonine/lysine (Thr/Lys), LPOA (low protein and optimal amino acids) which contains 21% and 19% CP with 65% Met + Cys/Lys and 55% Thr/Lys and 3. LPHA (low protein and high amino acids) which contains 21 and 19% CP with 74% Met + Cys/Lys and 67% Thr/Lys, respectively during the summer months (The temperatures 32 ± 3 °C, and the relative humidity 72.5% ± 4). Birds fed LPOA diets significantly highest body weight, while those fed LPHA recorded significantly the lowest body weight (BW). Dressing percentages not revealed significantly affected by reducing dietary protein levels, while the blood plasma total protein, albumin, and globulin were not significant differences due to dietary low protein. Chicks fed LPHA diets recorded the highest liver content of malonaldehyde. It could be concluded that feeding the Cobb 500 broilers on low protein diets with the same amino acid levels had no adverse effect on growth, carcass markers, and liver function, however increased amino acids levels to low protein diets may led negative impacts for the broiler performance under high ambient temperature.