The data were taken from the "Enhancing of Mutton Production through goat breeding" a Project run at Livestock Production Research Institute Bahadurnagar (Okara); the growth performance of Beetal goats were compared by statistical non-linear models, like Exponential, Gompertz and Logistic models. These models were based to obtain the best fitted model by following the criteria of mean absolute error (MAE), root mean squared error (RMSE), and mean absolute percentage error (MAPE). Run test were used to check the independence and normality of the models and residuals were checked by Shapiro-Wilk test. Errors were found to be normal and independently distributed. Body weights of Beetal goats and Bucks were examined by shape of the curves and it revealed that the values of α, β and γ of Gompertz model were higher than that of exponential and logistics in both the district of Okara and Sahiwal. Also, values of MAE, RMSE and MAPE of Gompertz model were lower than the logistic and exponential.

Data on some production performance traits of 1000 milch Sahiwal cows from 3451 cows maintained at the Livestock Experiment Station, Bahadurnagar, Okara, Pakistan during the period from 2000 to 2009 were selected to study the relationship between 12 linear type traits and reproductive performance of the Sahiwal cows. The reproductive efficiency (RE) was measured in terms of calving interval from the first five lactations. The type scores were standardized for stage of lactation, age at first calving and scoring. The mean scores of linear type traits (rump width, stature, chest and body, suspensory ligament) varied from 72.6±0.78 to 81.1±0.83 points. The estimates of heritability (h 2) for most of these type traits were medium 0.31±0.22 to high 0.82±0.31 and indicated the existence of large additive genetic variability for these traits in this breed. The phenotypic correlations of linear type traits with RE ranged between-0.1.6 ± 0.08 and 0.10 ± 0.09. All the 12 linear type traits accounted for 92.96% of the variability in RE of Sahiwal cows. Step-wise regression analysis revealed that 75% of the variation accounted by all linear type traits in RE could be predicted by a subset of four type traits (TT) which included stature, chest and body, pelvic angle and udder depth. It was concluded that in the case of absence of records, the reproductive performance of Sahiwal cows can be predicted at an early age using some linear type traits.

The aims of the study were to investigate the fixed effects which are considered to influence ewe productivity and to estimate the genetic parameters for ewe productivity traits of Lohi sheep. Genetic parameters were estimated by restricted maximum likelihood (REML) procedure using the GENSTAT program. The effects of year and age of ewe were significant for fertility, litter size at birth (LSB), litter size at weaning (LSW), litter weight at birth (LWB) and litter weight at weaning (LWW). The least squares means of fertility, LSB, LSW, LWB and LWW were 0.904, 1.422, 1.358, 6.689 kg and 41.577 kg, respectively. The means of total number of lambs born (TLB), total number of lambs weaned (TLW), total birth weight of lambs (TWB) and total weight of lambs weaned (TWW) per ewe over four lambing opportunities were 5.48, 5.25, 25.61 kg and 162.47 kg, respectively. Estimates of heritability for fertility, LSB, LSW, LWB and LWW were 0.0250, 0.0533, 0.0430, 0.0462 and 0.0255, respectively; and estimates of repeatability for these traits were 0.1242, 0.0787, 0.0772, 0.0882 and 0.0715, respectively. The low estimates of heritability and repeatability obtained in the current study for ewe productivity traits indicate that selection based on the ewe's own performance may result in slow genetic improvement.