Bovine leukemia virus (BLV) is distributed worldwide and affects dairy cattle causing severe economic losses. The BLV has been serologically reported in Egypt, but few studies have evaluated its associated risk factors and genetic classification. Therefore, this study assessed risk factors associated with BLV infection and identified the genetic diversity of the Egyptian strain. The study was conducted on 500 dairy cattle distributed in four Governorates located in Northern Egypt. Overall, the seroprevalence of BLV infection among Egyptian dairy cattle was 18.2%. The grazing cattle in the losing house system had higher odds for BLV seropositivity, and bad practice such as the use of a single needle or one plastic glove for more than one animal was considered a significant risk factor for BLV infection. Besides, the sequencing and phylogenetic analysis for one Egyptian BLV strain was performed, and the obtained results confirmed the clustering of Egyptian BLV strain into genotype-1. The assessment of associated risk factors for BLV infection and determination of its genetic classification are essential to implement an effective control program.

The aim was to evaluate the performance, blood lipid profile, and the relative expression of growth-related genes in purebred white and brown quail lines and their crossbred lines. A total of 240 one-day-old Japanese quail chicks of white and brown line, their crossbred line (WBQ: male white × female brown), and reciprocal crossbred line (BWQ: male brown × female white) were divided into four equal groups (60 birds each). The white quail line showed significantly higher final body weight, daily gain, and feed intake compared with the other quail lines (p < 0.001). Meanwhile, both crossbred quail lines (WBQ and BWQ) showed significantly lower FCR compared with both purebred quail lines (p = 0.001). Both crossbred quail lines showed greater dressing percentages compared with both purebred quail lines (p = 0.038). The brown quail line showed significantly (p = 0.05) higher levels of serum triglycerides and VLDL compared with the white and BWQ lines. The WBQ crossbred line exhibited significantly higher mRNA expression of GHR and IGF-1 genes compared with other quail lines (p < 0.001). Both crossbred lines (WBQ and BWQ) exhibited negative heterosis percentages for body weight (−4.39 and −3.90%, respectively) and feed intake (−10.87 and −14.59%, respectively). Meanwhile, heterosis percentages for FCR (−6.46 and −9.25%, respectively) and dressing percentage (7.54 and 6.38%, respectively) were improved in both crossbred lines. The WBQ line showed high heterosis percentages for the expression of GHR and IGF-1 genes (52.28 and 88.81%, respectively). In conclusion, the WBQ line exhibited significantly greater dressing percentage and better FCR, as well as higher mRNA expression of GHR and IGF-1 genes. These results may be helpful to improve breeding programs and to develop commercial lines of meat-type Japanese quail.

| The aim of this study was to investigate the effect of temperament on maintenance activities, productive performance and biochemical parameters (cortisol and prolactin) in Friesian dairy cows. These investigations were carried out on one hundred Friesian dairy cows (3 to 6 years old), which were milked with machine with a rate of three times a day and eight hours interval. The cows were classified according to their temperament during milking into calm, nervous (restless) and aggressive . Observation was carried out 3 hours per week (6 minute interval for each cow through one hour observation for each group), by using a focal sample technique. The obtained results revealed that there were a non significant differences between different types of temperament of dairy cow on ingestive behavior although the eating, ruminating times were increased with calm temperament. Resting and sleeping were increased with calm temperament and the differences were highly significant . Interestingly, grooming increased in calm animals. The daily milk, day in milk and total milk production was increased with calm temperament and decreased with nervous and aggressive temperament and the differences were highly significant. The level of cortisol was significantly increased in aggressive cows than calm and nervous cows. The prolactin level was significantly increased with nervous temperament. Conclusion: Temperament of animals especially during milking process is considered vital managemental factor must be kept in order to maintain the productive efficiency, alternatively the whole income.