the objective of this study was to evaluate the effects of sources of four starch on milk production and composition, nutrients digestibility and blood metabolites of lactating holstein cows. eight multiparous holstein cows (683±31 kg of body weight; 83±9 dim) were used in a replicated 4×4 latin square design with 21-d periods. the exprimental diets contained wheat, barley, corn, or potato as t...

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...

Eighteen Holstein dairy cows averaging 141 days in milk were used in a complete randomized design to determine the effects of feeding liquid acid whey (LAW) on milk production and composition. Animals received a diet consisting of berseem clover (Trifolium alexandrinum., L), wheat straw and concentrate (Control). Treatments were control and control plus 40 liters/cow/day of LAW. Daily individua...

The aim of this research was to investigate the changes in milk yield and its composition, fatty acid profile and peroxisome proliferator-activated receptors gamma (PPARG) gene expression in adipose tissue of Iranian Holstein cattle in response to feeding isonitrogenous and isocaloric diets but formulated based on different oilseeds (soybean or canola seeds). Twenty cows were tested ra...

Replacing dietary starch with sugar has been reported to improve production in dairy cows. Two sets of 24 Holstein cows averaging 41 kg/d of milk were fed a covariate diet, blocked by days in milk, and randomly assigned in 2 phases to 4 groups of 6 cows each. Cows were fed experimental diets containing [dry matter (DM) basis]: 39% alfalfa silage, 21% corn silage, 21% rolled high-moisture shelle...

The aim of this study was to compare energy consumption in dairy farms with different sizes. Sources of energy include non renewable sources such as fossil fuel, and electricity and renewable sources such as forage, concentrate, machinery, labor, and water. The required data were collected from 42 dairy farms in Tehran province, Iran and were analyzed to assess energy consumption based on diffe...

The gene encoding the brain-derived neurotrophic factor (BDNF) has been repeatedly associated with human obesity. As such, it could also contribute to the regulation of energy partitioning and the amount of secreted milk fat during lactation, which plays an important role in milk production in dairy cattle. Therefore, we performed an association study using estimated breeding values (EBVs) of b...

The objectives of this study were to measure particle size and evaluate the effect of increasing alfalfa hay particle size on production characteristics in lactating Holstein dairy cows. Ninety multiparous Holstein cows in early to mid-lactation were randomly assigned in a complete randomized design for a 30-day period. Animals were offered one of the three diets, which were identical in energy...

The objective of this study was to evaluate the effect of ruminally protected amino acids (RPAAs) and ruminally protected fat (RPF) supplementation on ruminal fermentation characteristics (in vitro) and milk yield and milk composition (in vivo). Fourteen mid-lactating Holstein dairy cows (mean weight 653±62.59 kg) were divided into two groups according to mean milk yield and number of days of p...