Since the initial report in 1978 of galactopoietic effects of a photoperiod of 16 h of light:8 h of darkness, numerous studies have confirmed long-day stimulation of milk yield. The endocrine factor(s) responsible for increased milk yield, however, has eluded identification. Recent studies suggest that insulin-like growth factor-I (IGF-I) may mediate the galactopoietic response to long day phot...

the aim of the present study was to investigate the relation between different indices of milk yield andbody condition score (bcs) with the commencement of the luteal activity (c-la) during the postpartumperiod in high producing dairy cows. seventy-one multiparous healthy (free of detectable reproductivedisorders) holstein dairy cows (mean peak milk yield = 56.7 ± 7.4 kg) were used in the prese...

Recent research has demonstrated the unsurpassed value of breast-feeding in promoting the optimal nutrition of the human neonate. Breast milk has been shown to have a uniquely appropriate composition for the neonate at a time when growth and development are occurring at a near-maximal rate, yet when many of the body's systems (digestive, hepatic and renal) are relatively immature. The N require...

Results from 4 switchback field trials involving 608 cows were combined to assess the effects of a protected B vitamin blend (BVB) vs 10 mg of unprotected biotin upon milk yield (kg), fat %, protein %, fat yield (kg) and protein yield (kg) in primiparous and multiparous cows. Trials consisted of 3 DHIA periods executed in the order control-test-control. Cows from 45 to 300 days in milk (DIM) at...

The aim of this present study is to describe changes occurring during the milking of cows in various periods following the introduction of an AMS (automatic milking system). The following cow milking parameters were analysed: milkings per cow per day, milking yield, milking speed and milking duration. An increase in milk yield in AMS barns has been found to be possible, but it is affected by a ...

The study was conducted to find the association of -Lactoglobulin locus with the milk performance traits in 157 lactating Sahiwal cows maintained at Cattle yard, NDRI, Karnal. Two different variants of -Lactoglobulin were detected from DNA by PCR-RFLP. It was found that the frequency of B allele was predominantly high (0.84± 0.03) than that of A allele (0.16± 0.03) in the population studied. ...

Variance and covariance components for milk yield, survival to second freshening, calving interval in first lactation were estimated by REML with the expectation and maximization algorithm for an animal model which included herd-year-season effects. Cows without calving interval but with milk yield were included. Each of the four data sets of 15 herds included about 3000 Holstein cows. Relation...

Angus bulls (n = 24) were selected for either high or low milk EPD, but with similar growth EPD and mated within location (n = 6) at random to Angus cows. Daughters from these matings were bred to calve first at 2 yr of age to common reference sires across locations. Lactation records for 192 daughters were used to evaluate 12-h milk yield, percentage of milk fat and protein, and weaning weight...

AKDAG, F., O. CADIRCI and B. SIRIKEN, 2010. Effect of estrus on milk yield and composition in Jersey cows. Bulg. J. Agric. Sci., 16: 783-787 This study was performed to demonstrate the effect of estrus on milk yield and composition in Jersey. In this study, 15 jersey cows which were at the same estrus period, in the third lactation period and breeding under uniform housing and feeding condition...

The objective of the present study was to determine the effects of feeding pelletized broccoli byproducts (PBB) on milk yield and milk composition in dairy cows. In Trial 1, an in vitro gas test determined the optimal replacement level of PBB in a concentrate mixture in a mixed substrate with Chinese wild ryegrass hay (50:50, w/w) at levels of 0, 10%, 20%, 30%, or 40% (dry matter basis). When t...