An incomplete 8 x 8 Latin square trial (4-wk periods; 12 wk total) using 32 multiparous and 16 primiparous Holstein cows was conducted to assess the production response to crude protein (CP), digestible rumen-undegraded protein (RUP), and rumen-protected Met (RPM; fed as Mepron; Degussa Corp., Kennesaw, GA). Diets contained [dry matter (DM) basis] 21% alfalfa silage, 34% corn silage, 22 to 26% ...

some factors affecting crude protein balance (cpb), as a measure of efficiency, were studied using 2824 records of 501 lactating holstein cows. the cpb (kg d-1) was calculated as crude protein (cp) intake (kg) minus cp yield (kg). two different statistical methods including principal components (pcs) and general linear model analyses were used to study the effects of different factors. crude pr...

performance, digestibility of nutrients, microbial nitrogen flow (mnf) and nitrogen efficiency (ne) inearly lactating holstein cows were investigated by diet supplementation with sodium caseinate (cn).multiparous lactating holstein cows (n = 15) with an average body weight of 638 kg and 21 days in milkwere assigned to a completely randomized design (five cows per treatment) and fed a basal diet...

Deoiled soy lecithin is a feed additive enriched in phospholipids. Our study evaluated the effects of dietary deoiled supplementation on (1) milk production and composition, (2) plasma fatty acid (FA) content yield, (3) apparent FA digestibility absorption lactating dairy cows fed fractionated palm fat. In split-plot Latin square design, 16 Holstein (160 ± 7 days milk; 3.6 1.2 parity) were rand...

To determine the effect of alkaline hydrogen peroxide treatment of whole canola seed on milk fatty acid composition, 12 multiparous lactating Holstein cows (618 kg, 47 d in milk) were fed total mixed rations in a replicated (3) 4 x 4 Latin square designed experiment. The control diet contained no supplemental fat source. Canola seed (11.2%), either crushed or treated with alkaline hydrogen pero...

The Trivers-Willard hypothesis predicts the unequal parental investment between daughters and sons, depending on maternal condition and offspring reproductive potential. Specifically, in polygynous populations where males have higher reproductive variance than females, it predicts that mothers in good condition will invest more in sons, whereas mothers in poor condition will invest more in daug...

This work presented economic weights (EWs) calculated for Holstein cattle raised in Slovak dairy productions using a bio-economic approach. EWs are calculated for alternatives with (A) and without (B) market quota. Both alternatives included three market payment systems of milk (base price per milk value was corrected according to content of fat, protein and somatic cells). Marginal EWs for mil...

this study was performed to evaluate the effects of crud protein (cp) level on dry matter intake in prepartum period, productive performance and health of fresh cows. twenty multiparous holstein cows were assigned randomly to one of two dietary treatments. dietary treatments were treatment 1, 13% cp of dm (control), and treatment 2, 16% cp of dm. diets were similar in lactation net energy and r...

Several processes have been suggested to protect lipids from bioactivity of the rumen microorganisms. The majority of experiments with conjugated linoleic acid (CLA) were conducted using calcium salts of CLA. The objectives of this study were to determine the effects of encapsulated CLA (E-CLA) that was supplemented during days 21 to 100 post partum (PP), on milk fat depression, recovery rate a...

This study compared the effects of two levels of crude protein (CP) fed during late gestation on the performance, blood metabolites, and ovarian activity of Holstein cows. One-hundred and six cows (42 primigravid and 64 multiparous) 32 d before calving were divided into two groups and fed diets containing moderate (12.7% CP, 36% rumen undegradable protein, (RUP) or high (14.7% CP, 40% RUP) prot...