Factors affecting production traits of dairy cattle under prince of Songkla University dairy farm condition

Factors affecting production traits of crossbred Holstein Friesian (H) and Red Sindhi (R) in southern Thailand were investigated. One hundred and thirty records of the crossbred cattle born between 1978-1994 were collected from the Prince of Songkla University (PSU) Hat Yai, Songkhla dairy farm. The economically important production traits analysed under this study were milk yield, fat yield, fat percentage and lactation length. Univariate, multivariate analysis of covariance and least-square (LS) means were performed using the GLM procedure. Under the grazing management system on the PSU dairy farm conditions, the results of this study showed that the coefficient of correlations between milk yield and fat yield, milk yield and lactation length, fat yield and fat percentage and fat yield and lactation length were 0.90, 0.84, 0.46 and 0.82, respectively (P0.01). There were highly significant (P0.01) associations of breed group year of calving and number of lactations and significant (P0.05) associations of season of calving and age at first calving with production traits. LS means +- SE of milk yield and lactation length of the crossbred cow between H100 percent sire x H75 percent R25 percent dam (4,461.7+-446.5 kg, 334.1+-31.3 days) were higher (P0.05) than those between H100 percent sire x R100 percent dam (3,153.4+-215.5 kg, 260.4+-15.1 days) and H75 percent RS25 percent sire x H75 percent dam (3,226.8+-456.3 kg, 280.1+-32.0 days) but no significant difference (P0.05) from the crossbreed between H100 percent sire x H50 percent R50 percent dam (3,925.7+-316.5 kg, 311.2+-22.2 days). Milk yield and fat yield of the cow calving in the first season (Jan-Apr) were higher (P0.05) than those in the second (May-Aug) and third season (Sep-Dec). It is suggested that in southern Thailand the crossbred cattle between H100 percent sire x H75 percent R25 percent dam or H100 percent sire x H50 percent R50 percent dam can be raised with a good milk-producing potential.