Milk production is largely dependent on the shape of the lactation curve. Relevant elements of the lactation pattern are the peak yield, which represents the maximum milk yield during the lactation, and the lactation persistency, which expresses the ability of animals to maintain a reasonably constant milk yield after the lactation peak (Figure 1). Thus, persistent animals are those that show f...

Major objectives were to evaluate effects of three schemes of bST-supplementation of Holstein cows (142.8 mg/14 d, POSILAC) during the prepartum and/or postpartum periods through 63 d (±3 d) of lactation. Measures evaluated the potential of treatments to improve body weight (BW) and body condition score (BCS), provoke changes in plasma concentrations of somatotropin (ST) and IGF-I, and improve ...

a data file containing 607662 (317608) milk (open days) records belonging 294417 (177838) holstein cows that were calved from 1983 to 2008 was used. the bivariate repeatability model was used for data analyzing so that herd, calving year, calving month, days in milk (only for milk trait) and calving age for each parity, were assumed as fixed effects and additive genetics and permanent environme...

Milk yield from 160 Brangus cows sired by 65 Brangus bulls was measured over a 3-yr period with a single-cow milking machine to estimate the relationship of actual milk yield of daughters and their calves' BW with cow sire EPD for milk during the preweaning period. Milk yield was measured six times per year at an average 49, 78, 109, 138, 168, and 198 d postpartum. The regression of daughters' ...

The objectives of this study were to analyze the genetic properties of three measures of lactation persistency in Polish Holstein-Friesian cows, and possibly to choose one measure which could be used for estimation of breeding value for lactation persistency in the Polish dairy cattle population. Data included 117,327 first three lactations of 110,141 cows calved in 1995-2009. The lactation cur...

This study was conducted to 1) determine milk yield of sows that were machine milked up to four times daily; 2) determine the effect of pig substitution on milk yield; 3) assess litter weight changes for sows that are milked; and 4) determine milk composition. Eight sows were milked four times daily to d 51 postpartum. Sows either maintained their own litter or had a week-old replacement litter...

The purpose of this study was to determine the lactation performance of dairy cows fed dried or wet distillers grains (DG) with solubles (DDGS or WDGS) at 2 dietary concentrations. A trial using 15 cows was designed as a replicated 5 x 5 Latin square with periods of 4 wk each and data collected during wk 3 and 4 of each period. Diets, on a dry matter basis, were: control, 10% DDGS, 20% DDGS, 10...

stats are a family of latent transcription factors that reside in the cytoplasm of resting cells. the stat1 transcription factor gene located on the chromosome 2 at interval 60 to 63 cm. this factor upon stimulation with inf gamma, dimerizes and translocate to the nucleus where mediates transcriptional regulation. in this study, we estimated the allele and genotype frequencies of stat1/pag1 gen...

The influence of milk yield and milk composition on the diagnosis of Mycobacterium avium ssp. paratuberculosis (MAP) by milk ELISA in the context of the total IgG secretion patterns in milk throughout lactation and serum concentrations were investigated. A 2-yr trial was performed in which 1,410 dairy cows were sampled monthly and MAP milk ELISA status and milk yield and composition were determ...

six red sokoto (rs) and west african dwarf (wad) does, raised intensively in livestock farm of michael okpara university were evaluated for milk yield and composition in a ten-week study. the animals in their first parity were fed cut-and-carry forages in a cafeteria arrangement between 07:00-08:00 h daily and also were allowed access to concentrate supplementation by 14:00 h. the forage consis...