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A trial was conducted to explore the effect of feeding graded concentrations of green tea extract (GTE; 125, 250, 500, 1000 and 2000 mg/kg) on the growth performance, serum lipid profile, liver glutathione-reduced, thigh muscle malondialdehyde and humoral immune response against Newcastle disease virus vaccines of broiler chickens from hatching to 42 d of age. The results of broilers fed on GTE were contrasted to those fed on butylated hydroxytoluene (BHT; 125 mg/kg) or unsupplemented controls. The obtained results revealed no significant difference among treatments in the measured growth performance parameters (body weight, average daily gain, average daily feed intake and feed conversion ratio), per cent liveability and serum lipid profile (total lipid, total cholesterol, high-density, low-density and very low-density lipoprotein cholesterols). Dietary intake of GTE resulted in a significant increase in the liver glutathione-reduced level compared to the control. The glutathione-reduced level of broilers fed on the BHT diet was not significantly different from that of broilers fed on GTE or control diets. Feeding GTE or BHT resulted in a significant decrease in the malondialdehyde level of meat tissue. The specific antibody titre against Newcastle disease virus vaccines was significantly increased at 28 and 35 d of age in broilers fed on diets supplemented with GTE but not with BHT. In conclusion, GTE was found to possess antioxidant and immunostimulant characteristics for broilers when supplemented to their diets, and its optimum inclusion level ranged from 125 to 500 mg/kg.

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For its role in the mediation of growth hormone (GH) galactopoietic effect, growth hormone receptor (GHR) was considered a functional candidate gene for milk performance in cattle. However, its genetic variation and potential effect have not been investigated in Egyptian buffaloes. This study aimed to screen GHR for polymorphisms and study their associations with milk traits in Egyptian buffaloes. Polymerase chain reaction, single-strand conformation polymorphism, and sequencing were used to identify mutations in 4 exons (E4–E6 and E8) of the GHR gene in 400 Egyptian buffaloes. No polymorphisms were found in E4, while 2 SNPs (c.380G>A/p.Arg127Lys and c.387C>T/p.Gly129) in E5, one silent mutation (c.435A>G/p.Pro145) in E6, and another missense mutation (c.836T>A/p.Phe279Tyr) in E8 were detected. The c.380G>A SNP in the extracellular domain was associated with milk yield, fat %, protein %, and 305-day milk, fat and protein yield, with higher levels in animals carrying the mutant A allele. The c.836T>A SNP in the transmembrane domain was associated with milk yield, fat %, protein %, and 305-day milk, fat and protein yield, with higher milk yield and lower fat %, protein %, fat and protein yield in the mutant A allele-animals. Interestingly, animals with the two mutant AA alleles produced higher milk yield, fat %, protein %, fat and protein yield, accompanied with upregulated expressions of GHR, GH, insulin-like growth factor 1 (IGF1), prolactin (PRL), prolactin receptor (PRLR), β-casein (encoded by CSN2 gene), and diacylglycerol acyltransferase-1 (DGAT1) genes and proteins in milk somatic cells. Therefore, selection of Egyptian buffaloes with mutant AA haplotypes for the novel c.380G>A SNP and the well-known c.836T>A SNP could improve milk yield and quality in buffaloes.

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The aim of this investigation was to evaluate the semen quality traits of purebred male rabbits and their crosses under subtropical Egyptian conditions. A full 3 x 3 diallel crossing was performed for producing the first generation progeny of New Zealand White (N), Flander (F) and Rex (R) breeds. The highest ejaculate volume (p< 0.05) and percentage of live sperms (p<0.01) with the lowest percentage of sperm cell morphological abnormalities (p<0.05) had been recorded in the NF bucks. Moreover, they possessed positive estimates of direct heterosis for ejaculate volume, mass motility (Mm), individual motility (Im) and sperm cell concentration (SCC). On the contrary, pH had negative estimates of direct heterosis in all crosses and their reciprocal. Semen pH was negatively correlated with SCC (r = -0.18), Mm (r = -0.13) and Im (r = -0.23). In conclusion, the superiority of crossbreeding was particularly obvious in the New Zealand White x Flander males, which cumulated heterosis and favorable maternal effects of the Flander dams.

This study examined the effect of dietary treatments containing mannan-oligosaccharides (MOS) on some blood biochemical, haematological parameters and carcass traits of 60 weaned purebred New Zealand White (NZW) and New Zealand White × Rex (NZW × RX) crossbred rabbits. They were assigned to a 2 × 3 factorial arrangement (two genetic groups; and three dietary treatments of zero, 0.5 or 1.0 g MOS/kg of diet). Blood samples have been collected at slaughter at 10 weeks of age. Significant differences were observed among dietary treatments for all biochemical and haematological parameters with the exception of triglycerides. There was a genetic group and dietary treatment interaction for albumen (P < 0.001), cholesterol (P = 0.002), red blood cell count (RBC) (P = 0.007), haemoglobin (Hb) concentration (P = 0.009) and haematocrit % (P < 0.001) observed. Rabbits from the NZW × RX genetic group fed a diet with 1.0 g/kg MOS had the highest plasma cholesterol level (0.97 ± 0.012 mmol/L), whereas the lowest level (0.89 ± 0.012 mmol/L) was detected in rabbits from the NZW × RX genetic group fed the Control diet. Rabbits from the NZW genetic group fed the diet with 1.0 g/kg MOS had the highest RBC (4.27 ± 0.083 × 106/mm3) whereas rabbits from the same genetic group fed the diet with 0.5 g/kg MOS had the highest Hb concentration (11.43 ± 0.097 g/dL) and haematocrit (30.29 ± 0.163%). Some carcass traits such as liveweight, hot and reference carcass weight (P < 0.001), percentage of periscapular, and perirenal fat relative to reference carcass weight (P < 0.05) were significantly affected by the dietary MOS supplementation. In conclusion, MOS supplementation in the diet, especially 1.0 g/kg, improved immunity, health indicators in the blood, liveweights and carcass weights of rabbits without any harmful effects on the other carcass traits. Furthermore, purebred NZW and NZW × RX crossbred rabbits showed relatively similar performance for all traits of interest. A significant interaction between genetic group and dietary supplementation of MOS was shown for albumen, cholesterol, RBC and haematocrit %.

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