the precision and accuracy of national research council (nrc 2001) vs. cornell pennsylvania miner (cpm) softwares were evaluated. sixteen lactating dairy cows (8 in second lactation and 8 in third, with days in milk of 55 ± 31, body live weight = 641 ± 53 kg, milk yield =31.2 ± 2.5 kg/day), were assigned to individual pens in a randomized complete block design, with two blocks of two ration tre...

Twenty multiparous Holstein cows in midlactation grazed pastures of 4 forage mixtures in a 12-wk study repeated during 2 grazing seasons to determine if forage mixture complexity affected intake and productivity of lactating dairy cows. The forage mixtures were 1) orchardgrass plus white clover [2 species (SP)]; 2) orchardgrass, white clover, and chicory (3SP); 3) orchardgrass, tall fescue, per...

To meet the nutrition requirements of lactation, dairy cows are usually fed a high concentrate diet (HC). However, high-grain feeding causes subacute ruminal acidosis (SARA), a metabolic disorder that causes milk protein depression. This study aimed to investigate the effect of lipopolysaccharide (LPS) released in the rumen on inflammatory gene expression and casein synthesis in mammary glands ...

Data from six experiments (two with dry cows) were used to predict partitioning of gross energy to CH4 in Holstein cows using selected independent variables, some of which were intercorrelated, and a stepwise backward elimination regression procedure. Methane outputs ranged from 3.1 to 8.3% (mean 5.5) of gross energy intake for 134 dry cow balance trials and from 1.7 to 14.9% (mean 5.2) of gros...

The scientific literature contains evidence that the nutrient status of lactating dairy cows can have a direct bearing on reproductive status. Pregnancy rate has been improved by manipulating the mineral (Hurley and Doane, 1989), vitamin (Seymour, 2001), energy (Butler, 2001), protein (Butler, 1998), and lipid fractions (Staples et al., 1998) of the diet. Nevertheless the amount of knowledge in...

After parturition, dairy cows suffer from an intense energy deficit caused by the onset of copious milk secretion and an inadequate increase in voluntary food intake. We previously showed that this energy deficit contributes to a decline in plasma leptin. This decline mirrors that of plasma insulin but is reciprocal to the profile of plasma growth hormone (GH), suggesting that both hormones may...

Administration of recombinant bovine somatotropin (bST) to lactating dairy cows during heat stress increases milk yield, but it also can increase body temperature and may therefore compromise fertility. However, it is possible that bST treatment could increase fertility during heat stress because it has been reported to increase fertility in lactating cows. In addition, bST increases secretion ...

A field study was conducted in nine villages, three each from Kupwara, Handwara and Karnah Tehsils of Kupwara district, to find out the nutritional value of feeds and fodders, existing feeding practices and nutritional status of dairy cattle. Data was collected from the fifteen farm families from each of the nine were randomly selected through a common questionnaire. All the farmers were found ...

The objective of this study was to investigate the effects of a flaxseed-supplemented diet on archaeal abundance and gene expression of methanogens in the rumen of dairy cows. In all, 11 non-lactating dairy cows were randomly divided into two groups: group A (five cows) and B (six cows). The two diets fed were: (1) the control diet, a conventional dry cow ration; and (2) the flaxseed-supplement...

The objective of this study was to evaluate the effects of replacing protein sources that are commonly used in North America with triticale dried distillers grains with solubles (TDDGS) as a source of dietary N on the productivity of lactating dairy cows. Experimental diets contained 17.1% TDDGS, 17.5% Corn DDGS (CDDGS), 13.1% canola meal (CM), or 10.2% soybean meal (SBM) on a DM basis so that ...