The optimum starch content of diets fed to lactating cows is not well defined, but 24% to 26% starch (DM basis) has been suggested (Staples, 2007). Kaiser and Shaver (2006) and Bucholtz (2006), from surveys of high producing (>13,650 kg RHA) dairy farms in Wisconsin (n = 9) and Michigan (n = 18), respectively, reported starch concentrations of diets fed to lactating cow groups ranging from 25% ...

OBJECTIVE To estimate seroprevalence of Mycobacterium avium subsp paratuberculosis (MAP) infection among adult dairy cows in Colorado and determine herd-level factors associated with the risk that individual cows would be seropositive. DESIGN Cross-sectional observational study. ANIMALS 10,280 adult (> or = 2 years old) dairy cows in 15 herds in Colorado. PROCEDURE Serum samples were test...

Heat stress has negative effects on pregnancy rates of lactating dairy cattle. There are genetic differences in tolerance to heat stress; Bos taurus indicus (B. t. indicus) cattle and embryos are more thermotolerant than Bos taurus taurus (B. t. taurus). In the present study, the effects of sire and sire breed on conception and embryonic/fetal loss rates of lactating Holstein cows during the Br...

BACKGROUND: Dairy cows undergo physiological changes during pregnancy and lactation and cardiovascular system may alter during these periods. OBJECTIVES: Understanding the physiological effects of production periods of dairy cows on heart electrical activities can aid to better monitoring the cardiovascular system in these animals. METHODS: Five multiparous Holstein dairy cows were studied from...

a field study was conducted around pb slag contaminated sites in ibadan, nigeria to assess theintake of trace metals by cows reared around the contaminated sites as indication of heavy metals contamination.levels of pb, cd, cu and zn in blood, milk and faeces were determined in 20 cows exposed to the sites and 20reference cows from uncontaminated areas. chemical analysis of pasture grasses and ...

Lupines (Lupinus spp.) are widespread range plants that are often toxic to livestock. Some reports suggest that naı̈ve, younger animals might consume more lupine than more experienced, older cattle. Further, lactational stress might alter forage selection, and lactating cows might eat more lupine than nonlactating cows. Thus, the objectives of these trials were to examine the influence of experi...

The nutrient contents of perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.) are reasonably similar. Despite similarities, the lactation performance of dairy cows fed perennial ryegrass has not been compared with the lactation performance of dairy cows fed alfalfa. The present study was implemented to compare the performance of lactating cows fed alfalfa or perennial ryegras...

Abstract Data used in these studies were part of another project described by Parsons et al. (2021). These evaluated heifer post-weaning intake classification on performance measurements two-, five- and eight-year-old lactating or non-lactating Angus females. We analyzed production data 57 pregnant, (Study 1) 54 lactating, non-pregnant 2) Heifer was calculated over 80 test days following weanin...

Glucose uptake in the mammary gland is a rate-limiting step in milk synthesis. To study glucose transporters in the bovine mammary gland, the erythrocyte-type glucose transporter (GLUT1) and the insulin-responsive glucose transporter (GLUT4) proteins were assessed by Western blotting and immunohistochemical staining, using polyclonal antibodies against the C-terminal peptide of GLUT1 and GLUT4....

1. The hepatic concentrations of the ketone bodies and of metabolites and activities of enzymes involved in gluconeogenesis were measured in healthy lactating and non-lactating cows 48h after administration of Voren, an ester of dexamethasone, and compared with those found in control animals given saline. Parallel measurements were also made of the blood concentrations of several of the metabol...