A comparison of several methodologies of selection index for productive and reproductive characteristics in Egyptian buffaloes.

Data on Egyptian buffalo first lactation records (n = 1167) available at Mehalet Mousa Farm (between 2002 and 2015) of the Animal Production Research Institute (APRI), Cairo, Egypt, were used to analyse the genetic parameters of total milk yield (TMY), lactation time (LP), and age at first calving (AFC). Additionally, four selection indices were created by using a single phenotypic standard derivation as relevant economic values. The data were evaluated using multiple-trait derivative-free restricted maximum likelihood (MTDFREML). The estimated heritabilities for TMY, LP, and AFC were 0.22, 0.17, and 0.08 respectively and the phenotypic and genetic correlations between TMY and LP were 0.76 and 0.56, respectively, and between AFC with TMY and LP were nеgаtivеs. Using a selection index that incorporates TMY, LP, and AFC (RIH = 0.68) looks to be optimum for increased genetic gain and a shorter generation interval; as a result, selection should thus be exercised near the end of the first lactation.

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.