No abstract

The aim of the present study was to investigate the effects of hot summer climatic conditions (compared to winter) on the libido, semen quality traits, level of serum testosterone hormone and some physiological and body measurements of Egyptian Suffolk rams. A parameter for the tolerance of the rams to adverse hot climatic conditions, designated as the tunica dartos index (TDI), was estimated as the multiplication of the percentage change in scrotal length and that of the percentage difference between rectal temperature and scrotal skin temperature. The relationships between the TDI and semen characteristics were also estimated. The results showed that in summer, the reaction time, pH, percentage dead and abnormal spermatozoa, acrosomal damage and temperatures of rectum, body skin and scrotal skin and scrotal length were significantly higher, while sperm motility, sperm concentration, scrotal circumference and testis length were significantly lower than in winter. The correlation coefficient (r) values estimated between the TDI and each of the semen pH, ejaculate volume, sperm motility and sperm cell concentration were positive, and those estimated between the TDI and each of the reaction time, dead and abnormal spermatozoa and acrosomal damage were negative. The best values of libido (low reaction time), semen pH, semen motility percentage, sperm cell concentration and testosterone level were recorded with a high TDI level (7.5 and more), while those of percentage of dead spermatozoa, sperm abnormalities and acrosomal damage were recorded with a low TDI level (less than 4.5). It can be concluded that the TDI correlates well with the reproductive ability of the ram and can be a reliable parameter to indicate the tolerance of rams to hot subtropical conditions in Egypt.

No abstract

The present study was carried out on the pure Bauscat (Bau), pure New Zealand (NZW) and pure Californian (Cal) strains of rabbit. Overall reproductive performance for overdue does of the three breeds was determined and compared with that of does delivering at the normal time. Overdue does of the Bau and NZW breeds had a significantly (P < 0·05) higher annual mean number of pups weaned than overdue Cal does. There was a high incidence of pup mortality in post-mature litters, and the causes of this high mortality were crushing of the skull followed by subsequent stillborn-birth difficulties and intra-uterine death in all three breeds. Obliteration of the anterior fontanelle of pups from post-mature litters occurred in 71%, 75% and 69 % of the deaths diagnosed at birth in the Bau, NZW and Cal breeds, respectively. Induction of parturition with either PGF2α or oxytocin reduced pup mortality in overdue does. The birth-to-remating interval was significantly (P < 0·01) lower in overdue does in which parturition was induced with PGF2∞ but significantly longer when parturition was induced with oxytocin.

The present work was conducted to study the effect of selenium (Se) plus vitamin E (Vitam E) and AD 3 E vitamins (Vitam AD 3 E) mixture as two alleviation techniques on heat stressed rabbits during hot summer season of Egypt. In total 45 New Zealand white (NZW) male rabbits were used in this research. The animals were divided into three equal groups. The 1 st group was kept without any treatment and served as control group. The 2 nd and 3 rd groups were supplemented daily 1m/l in drinking water with Se plus E and AD 3 E vitamins mixture, respectively. The experiment lasted 7 weeks during hot summer season (from third week of July to the end of August, 2017). Results showed that adding both of Se plus vitamin E and AD 3 E vitamins mixture in drinking water decreased (P≤0.001) rectal, skin, ear temperature and respiration rate compared with the control group. Adding both of Se plus vitamin E and AD 3 E vitamins mixture in drinking water improved (P≤0.05) final live body weight and feed intake and decreased (P≤0.001) daily water intake in comparative with control group. Adding both of Se plus vitamin E and AD 3 E vitamins mixture in drinking water increased (P≤0.01) serum total protein, albumin and globulin concentrations and decreased (P≤0.05) urea-N and creatinine concentrations in male rabbits. Serum cortisol level was (P≤0.001) lower while Triiodothyronine (T 3 ), Thyroxin (T 4 ) hormonal levels were (P≤0.001) higher in both two treatment groups compared with control. Normal sperm, volume, count, motility and live sperm increased (P≤0.001) while dead sperm was decreased (P≤0.001) in the two treatment groups compared with control group. It can be concluded that the two techniques can alleviate the negative effects of heat stress on rabbits under hot summer season in Egypt.