Milk yield, fat yield, and fat percentage during the first three lactations were studied using New York Holsteins that were milked twice daily over a 305-d, mature equivalent lactation. Those data were used to estimate variances from direct and maternal genetic effects, cytoplasmic effects, sire by herd interaction, and cow permanent environmental effects. Cytoplasmic line was traced to the las...

calving records from april 1998 to september 2006 comprising 104,572 calving events from 16 dairy herds of iran were used to analyze the potential effect of dystocia on calf stillbirth and productive traits in iranian holsteins. statistical analyses of production traits were performed using a linear mixed model procedure. also, a logistic regression model was constructed to analyze the effect o...

The objective of the study was to evaluate genotype by environment interaction (GxEI) for yield traits in Holstein, Simmental and Brown breed cattle in Slovenia using multiple trait analysis. Data from Slovenian milk-recording scheme was used. The lactation records on cows having first to third calving in the period 1990-2004 and milk, protein and fat yield in 305 days were studied. The variabl...

With the objective of evaluating measures of milk yield persistency, 27,000 test-day milk yield records from 3362 first lactations of Brazilian Gyr cows that calved between 1990 and 2007 were analyzed with a random regression model. Random, additive genetic and permanent environmental effects were modeled using Legendre polynomials of order 4 and 5, respectively. Residual variance was mod...

The effects of fat supplementation and weaning system on commercial milk yield and milk composition were determined on 129 East Friesian crossbred ewes. Prior to lambing, ewes were randomly assigned to one of two weaning systems. The DY1 system involved weaning of ewes from their lambs within 24 to 36 hr post-partum and then twice-daily machine milking. In the MIX system, ewes had access to the...

Received: 7 March, 2014 Accepted: 21 May, 2014 Published: 20 July, 2014 The data consisted of 37118 TD milk record of 5851 primiparous Holstein cows of Tunisia. Herd-years of calving means for milk production traits were clustered in three levels using the CLUSTER procedure in SAS software. Production levels included low, medium and high levels. Genotype by environment interaction were investig...

The aim of this study was to evaluate the effect of fat supplementation for enhancing milk conjugated linoleic acid (CLA) in early lactation without affecting ruminal fermentation. 24 Holstein dairy cows were assigned to a completely randomized design employing a 2 × 4 factorial arrangement. Factors were particle size (15 and 25 mm) and two different sources of alfalfa supplemented with and wit...

The objective of the present study was to determine the effects of rumen-protected choline (RPC) supplementation on body condition, milk production and milk choline content during the periparturient period. Thirty-two Holstein cows were allocated into two groups (RPC group - with RPC supplementation, and control group - without RPC supplementation) 28 days before the expected calving. Cows were...

Due to the great demand for buffalo milk by-products the interest in technical-scientific information about this species is increasing. Our objective was to propose selection criteria for milk yield in buffaloes based on total milk yield, 305-day milk yield (M305), and test-day milk yield. A total of 3,888 lactations from 1,630 Murrah (Bubalus bubalis) cows recorded between 1987 and 2001, from ...