Utilization of live body weight, measurements, and eye muscle components to predict carcass performance of fattened Egyptian male buffalo calves.

Carcass performance of 12 fattened male buffalo calves equally grouped by slaughter weights of 300, 350, 400, and 450 kg was evaluated. Six parameters of body measurements such as chest girth, height at withers, body length, body depth, width at pin bones, and diagonal body length were recorded for each calf immediately before slaughter to test their relationships with live body weight, carcass weight (hot and cold) and its components (head, legs, liver, heart, etc.), and eye muscle area at the 10th-13th ribs. Boneless meat and bones formed 36.6 to 39.0% and 9.3 to 11.0% of live weight, respectively. Chest girth had strong correlation with all carcass traits except bone weight and was the best predictor of boneless meat and carcass fat weights (R2 = 0.90, 0.78). The slaughter weight and height at withers and the 10th-13th rib fat weight were the best predictors of hot and cold carcass (R2 ≥ 97.0), carcass bones (R2 = 76%), and hot and cold carcass (R2 = 85.0, 86.5%) weights, respectively.

Manipulation of reproductive seasonality using melatonin implantation in Anglo-Nubian does treated with controlled internal drug release and equine chorionic gonadotropin during the nonbreeding season.

The objective of this study was to compare the efficiency of hormonal treatments on ovarian activity and reproductive performance in anestrous Anglo-Nubian does during the nonbreeding season (February to May). A total of 48 multiparous does were divided into 2 groups (24 lactating does and 24 dry does). In each group, animals were allocated randomly into 2 equal subgroups (12 does each). In the first subgroup, does received a single 18-mg melatonin implant for 42 d followed by a controlled internal drug release (CIDR) device for 19 d in conjunction with 500 IU of equine chorionic gonadotropin (eCG) i.m. on the day of CIDR device removal. The second subgroup received CIDR combined with eCG in parallel with the first subgroup. Melatonin implantation induced a luteotrophic effect, expressed as an increasing number of corpora lutea, increased serum progesterone concentration, and reduced estradiol concentration. Regardless of treatment, dry does showed greater value of progesterone concentration. With the advancement of day of treatment, number of total follicles, small follicles, and medium follicles tended to increase to the greatest values at the day of CIDR device insertion. Furthermore, at day of mating, the numbers of large follicles reached the greatest value, which was associated with the lowest value of the number of corpora lutea. At day of mating, serum progesterone concentration achieved the lowest value, which increased until d 56 of pregnancy. The estradiol:progesterone ratio showed the opposite trend. The detrimental effect of reproductive seasonality, expressed as cessation of estrus behavior and fertile mating during the nonbreeding season, was successfully alleviated by the CIDR-eCG protocol. Furthermore, melatonin implantation in conjunction with the CIDR-eCG protocol enhanced conception rate and fecundity at d 28 of pregnancy and prolificacy at d 56 of pregnancy compared with does that were not implanted. Interestingly, does that failed to conceive did not come to heat again. In conclusion, the beneficial effect of melatonin implantation in conjunction with the CIDR-eCG protocol on the luteotrophic effect was reflected in the increasing number of corpora lutea, increasing progesterone concentration, and decreasing estradiol concentration. Furthermore, conception rate, prolificacy, and fecundity were improved compared with does that were not implanted during the nonbreeding season.