an experiment was conducted in early lactating buffaloes for the period of 3 months in jadakheria and polisimal village of limkhedataluka in dahod district of gujarat to assess the effect of supplementation of bypass fat on milk production, composition, body weight change and economic efficiency. forty buffaloes in their 2nd and 3rd lactation were equally divided in completely randomized design...

Ten lactating multiparous Holstein cows were used in a cross-over design with two dietary treatments and 28-d periods (with 14 d as an adaptation) to study the effect of restaurant fat on milk production and composition. Each cow was offered 14.7 kg DM /d of the basal concentrate diet based on barley and corn (crude protein = 17.7%, neutral detergent fiber = 23.5%, and acid detergent fiber = 5....

milk and fat yields in 3x and 4x milking schedule in holstein cows of iran were investigatedusing 374170 milk and fat yield test day records measured on the 1st and 2nd lactions of 54580 dairycattle coming from 205 herds. the records had been collected from 2007 to 2009 by the iraniananimal breeding center (iabc). the results indicated that an increases in the milking frequency from3x to 4x inc...

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...

genetic parameters and trends for milk and fat yields as well as for fat percentage were estimated from 35,438 milk production records (305d, 2x) of 17,971 holstein dairy cattle in 133 herds during the period of 1990-2003 in khorasan province. variance components were estimated using restricted maximum likelihood statistical method applying univariate and repeatability animal models. for the un...

To determine whether insulin exerts an effect on milk fat yield through the direct regulation of milk fat synthesis in the mammary gland, the hyperinsulinemic-euglycemic clamp procedure was performed in lactating goats in the present study. The effects of the hyperinsulinemic-euglycemic clamp on milk yield, milk composition, milk fatty acid yield and the expression levels of mRNAs of milk fat s...

the aim of this study was to estimate genetic parameters of age at first calving and its relationship with productive traits of holstein dairy cows. a total of 24491 first lactation records (2x 305d) which were collected from 1995 to 2009 were used. the general linear model (glm) procedure was applied to determine effective factors on studied traits. herd-year-season (hys) and age at first calv...

The experiment was carried out on lactating Holstein Friesian cows with the objectives of evaluating the effect of stage of age, pregnancy, lactation, parity and on yield, and components (fat, protein, solid not fat and lactose) and pH of milk. Milk samples were directly collected from the teat and immediately analysed using milk. The result showed that lactation stage and pregnancy significant...

Dairy cattle breeding programs have been based in the selection for traits related to milk production. In this research a data set of 63 herds of East Azerbaijan province Holstein cattle, collected during 2002-2013 by the Iranian Animal Breeding Center was used to estimate the repeatability and heritability of three traits of economic importance. Genetic parameters for first three lactations of...

Heritability estimates, by year of freshening of daughter, were obtained from daughter-dam and granddaughter-granddam regressions using 61,482 triply matched first lactations of artificially sired Holstein cows obtained from the Northeast Dairy Records Processing Laboratory. After adjusting for herd-year-season effects, residual effects may include additive and other genetic effects of the anim...