In this research, Data of milk yield, fat and protein percentage of Khuzestani buffalo were used. The daily records of milk yield were collected in the south-west of Iran where buffalo experienced a hot climate. The data set was constructed with 8,123 records of 1,430 first lactation buffalo. A univariate random regression model (RR/CF) was applied to data. Regression of additive genetic effect based on Legendre polynomials from the day of lactation was considered in the model. The results showed that maximum residual variance for the milk and fat production was estimated at the beginning of the lactation period. The minimum amount of additive genetic variation of milk and fat traits was seen in the early lactation period and the maximum amount of the component was estimated at the end of the lactation period. The lowest heritability of the mentioned traits was at the beginning of the lactation period. The level of this parameter increased to mid-lactation and was at its maximum during the late months of lactation, then decreased to the end of lactation. The estimated additive genetic correlations between close test-days were higher than faraway test-day records for each milk yield and milk fat content. Based on the results of this study, a random regression model with fitting orders 3 and 4, seems to be suitable for additive covariance functions in order to analyze the milk test-day records of buffaloes.

Murrah is a predominant milch breed of buffalo in India with superior genetic potential for milk production. Estimation of genetic parameters for production and reproduction traits is prerequisite for making breeding plan and efficient management decisions. This work was undertaken to understand the influence on performance traits by various factors (genetic and non-genetic) along with assessment of genetic parameters in Murrah buffaloes. The genetic parameters were figured using mixed model least-squares analysis. The results revealed that season and period in which animals calved, affects the performance of Murrah breed and may be considered during its evaluation. The heritability estimates for first lactation 305 days/less milk yield (305FLMY), first lactation total milk yield (FLTMY), first Lactation Length (FLL1), Wet average (WA), Herd average (HA), Age at first calving (AFC1) and Age at first service (AFS1) were 0.39+-0.10, 0.29+-0.09, 0.14+-0.09, 0.29+-0.09, 0.3+-0.11, 0.27+-0.09 and 0.22+-0.09, respectively. The phenotypic and genetic correlation amid 305FLMY and majority of another production trait were positive and significant. Thus, it may be concluded that appropriate estimation of genetic parameters leads to robust selection for performance traits for genetic improvement in Murrah buffalo.

Data on 4971 test-day milk yield traits [milk (TDMY), fat (TDFY) and protein (TDPY)] for 691 Egyptian buffalo cows, daughters of 120 sires and 532 dams were used for fitting the lactation curve parameters of milk, fat and protein yields using multiple-trait animal model. The random effects included in the model were direct additive genetic, permanent environment and error, while the fixed effects were herd test-day, year and season of calving and parity as well as days in milk as a covariable. The means for TDMY, TDFY, TDPY and lactation curve parameters [initial (a), ascending slope (b), descending slope (c), persistency (P), and maximum milk production during lactation (Ymax) and the peak test-day (PY)] were estimated. Heritabilities of TDMY, a, b, c, P, PY and Ymax were 0.22, 0.37, 0.38, 0.39, 0.37, 0.37 and 0.38, respectively. The corresponding heritabilities for TDFY and fat curve parameters were 0.21, 0.41, 0.40, 0.39, 0.38, 0.36 and 0.42, while the estimates for TDPY and protein curve parameters were 0.22, 0.38, 0.40, 0.40, 0.38, 0.40 and 0.43, respectively. Genetic correlations among TDMY and curve parameters of a, b, c, P, PY and Ymax were 0.31, -0.23, -0.34, 0.52, 0.48 and 0.87, respectively. Genetic and phenotypic correlations between milk yield traits were high (mostly of 0.83 and 0.99), like the correlations between curve parameter in milk, fat and protein (from 0.71 to 0.96). In practice, genetic selection for lactation curve parameters (a, P and Ymax) in the Egyptian buffalo would improve total milk yield traits.

Udder length, width and height are very important parameters to identify good dairy animals. Udder measurements including length, width and height on 437 Nili Ravi buffaloes were recorded before and after miking with 1180 records at 6 Experimental Stations in Punjab, Pakistan. Heritabilities were estimated using Best Linear Unbiased Prediction techniques. Environmental factors viz age of the buffalo at scoring, stage of lactation, parity, herd and season were included in the model. Least square means for udder length, width and height before milking were found as 52.65+-6.87, 53.52+-6.19 and 54.34+-4.99 cm and after milking as 47.08+-6.57, 48.15+-5.79 and 55.39+-5.15 cm, respectively. Heritability estimates for udder length, width and height before milking were found as 0.08+-0.07, 0.22+-0.08 and 0.22+-0.09, while after milking as 0.14+-0.07, 0.20+-0.08 and 0.09+-0.08, respectively. All the factors significantly affected before milking udder length. A significant effect of herd, parity, season of scoring and age on udder width before milking was observed. Herd, stage of lactation, parity and age of the buffalo at scoring significantly affected udder height before milking. Significant effect of herd, parity, stage of lactation and age of the buffaloes at classification on most of the traits suggest that managemental factors are important. Moderate heritability estimates for these udder traits provide a fair scope for improvement through selection and breeding which will help to increase milk yield in Nili Ravi buffaloes.