this research was conducted to assess the effect of substituting corn for barley grain in diet on performance and reproductive characteristics of early lactating, holstein dairy cattle. a number of fifteen cows in their second lactation (26±11 dim) with 36.7±5.6 kg milk/d were investigated for 75 day (15 day for adaptation and 60 day for sampling) in a completely randomized design. the iso-ener...

Rubber flooring in dairy cows has been discussed controversially, because different studies found as well advantages as disadvantages regarding claw health. Until today little is known regarding the effect of rubber flooring on the reproductive performance of dairy cows. Therefore, the study aimed at comparing fertility and the milk yield of dairy cows on concrete or rubber flooring. Days to fi...

In the past decade, a global demand for products from organic agriculture has increased rapidly. Milk quality is of major interest to all parties. Therefore, the objective of this study was to compare cow performance and product quality on conventional and organic diets. 72 Holstein dairy cows were allotted to one of four diets: a conventional diet (CON40), an organic diet with a low amount of ...

the effect of barley grain processing and source of supplemental fat on performance of lactating dairy cows were studied in a replicated 4 × 4 latin square design with 21-d periods and a 2 × 2 factorial arrangement. eight holstein cows with mean body weight (bw) of 572 ± 71 kg and 45 ± 10 days in milk were allocated to 4 dietary treatments including 1) ground barley with cottonseed 2) pelleted ...

Horn fly infestations negatively impact economic traits of beef cattle. Our objective was to determine the impact of horn flies on beef cattle milk yield and quality. Cows (n = 53) were derived from Brangus dams and sired by Bonsmara (n = 7), Brangus (n = 13), Charolais (n = 8), Gelbvieh (n = 5), Hereford (n = 12), and Romosinuano (n = 8) bulls. Horn fly counts and estimates of milk yield and q...

Milk performance (protein and fat content) and milk fatty acids (FA) profile of dairy cows under supplementation with two sources of concentrate, oilseeds (C, cottonseed) at two levels, low (5kg DM/cow/day) and high (7 kg DM/cow/day), and cereal grains (B, barley) at high rate (7 kg DM/cow/day), were studied in three herds (n=36) of spring calving Holstein-Friesian dairy cows (200 days in milk)...

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...

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 objective was to review the effects of production stressors on reproductive performance of dairy cows. It has been well documented that genetic selection for milk yield over the last 50 yr has been associated with reduced fertility. In addition to negative associations between yield and conception rate, there is also an association between milk production and expression of behavioral estrus...