BACKGROUND Dairy cows are often fed a high-concentrate diet to meet lactating demands, yet long-term concentrate feeding induces subacute ruminal acidosis (SARA) and leads to a decrease in milk fat. Stearoyl-CoA desaturase1 (SCD1) participates in fatty acid biosynthesis in the liver of lactating ruminants. Here, we conducted this study to investigate the impact of lipopolysaccharide derived fro...

We compared diurnal patterns of vaginal temperature in lactating cows under grazing conditions to evaluate genotype effects on body temperature regulation. Genotypes evaluated were Holstein, Jersey, Jersey x Holstein and Swedish Red x Holstein. The comparison of Holstein and Jersey versus Jersey x Holstein provided a test of whether heterosis effects body temperature regulation. Cows were fitte...

background: metabolic profiles have been used in efforts to predict pre parturient problems and fertility, to diagnose metabolic diseases, and to assess nutritional status in dairy cows. these profiles may help to confirm the diagnosis of sub clinical diseases, to be aware of possible causes of infertility in the herds, or to monitor improvement in herd animals. objectives: this study investiga...

Five experiments evaluated the effects of supplemental Ca salts of PUFA on reproductive function of Bos indicus beef cows. In Exp. 1, nonlactating and multiparous grazing cows (n = 51) were assigned to receive (as-fed basis) 0.1 kg of a protein-mineral mix + 0.1 kg of ground corn per cow/d, in addition to 0.1 kg per cow/d of 1) Ca salts of PUFA (PF), 2) Ca salts of SFA (SF), or 3) kaolin (contr...

Alfalfa was harvested from alternate windrows as 40% DM silage or hay in small rectangular bales and fed in two 12-wk 4 x 4 Latin square trials, each with 20 multiparous lactating cows (4 with ruminal cannulas). Diets contained (DM basis) 69 (trial 1) or 66% (trial 2) alfalfa, 26 to 33% high moisture corn, 1.3% minerals and vitamins, and about 1.6 Mcal of NEL/kg of DM. In trial 1, second-cuttin...

This study was conducted to estimate the potential acid production value (PAPV) of major diets and to determine the relationship between dietary PAPV and dairy production traits. Estimation of PAPV of major cattle feeds was based on an in vitro technique, which determined the degree of Ca dissociation from CaCO3. Data on feeds and production traits were collected on 744 multiparous lactating Ho...

Two experiments were conducted to evaluate responses of primiparous and multiparous Holstein cows to diets containing wet corn gluten feed (WCGF). In both experiments, WCGF replaced a mix of alfalfa hay, corn silage, and corn grain. In experiment 1, 32 primiparous Holstein cows (four pens with eight cows/pen) were used in two 2 x 2 Latin squares with 28-d periods. Cows were housed in free stall...

The objective of this study was to compare the effects of soybean (SB) meal (SBM) with increased rumen undegradable protein as roasted SB (RSB), extruded SB (ESB) or their equal blend (RSB + ESB) on production performance, nutrient digestibility, N-utilization efficiency, and blood metabolites in mid-lactation dairy cows. Eight lactating Holstein cows (BW = 534 ± 52 and DIM = 104 ± 5; mean ± SD...

The effect of calf weaning age on cow and calf performance and feed utilization was investigated over 2 yr. Multiparous, crossbred, lactating beef cows (n = 156) with summer-born calves were blocked by prebreeding BW, stratified by calf age, and assigned randomly to 1 of 4 treatments within strata. The experiment was a randomized complete block design with a 2 × 2 factorial arrangement of treat...

Th e aim of this study was to establish the prevalence of repeat breeder syndrome (RBS) in diff erent breeds and reproductive ages of cattle in central Croatia and to assess the eff ectiveness of hormone therapy as a treatment option. A total of 1088 dairy cows were observed, 218 heifers and 870 multiparous cows. Aft er the third unsuccessful artifi cial insemination (n = 164) and a thorough cl...