Insulin responsiveness to glucose and tissue responsiveness to insulin, using the hyperglycemic clamp and the hyperinsulinemic euglycemic clamp techniques, were measured in lactating, late pregnant, and nonpregnant, nonlactating (NPNL) beef cows. The glucose infusion rate (GIR) in the hyperglycemic clamp technique was higher (P less than .05). in lactating cows than in NPNL cows. The plateau in...

in order to examine the effect of degradability rates of different starch sources on performance of holstein dairy cows in their early lactation, twenty multiparous lactating holstein cows (586±33.7 bw; 48.15±9.32 dim) were made use of in a randomized complete block design of four treatments during the 65 days of the experimental period. cows were fed the following diets: 1) 100% barley, 2) 67%...

Impairment of the insulin regulation of energy metabolism is considered to be an etiologic key component for metabolic disturbances. Methods for studies of insulin sensitivity thus are highly topical. There are clear indications that reduced insulin sensitivity contributes to the metabolic disturbances that occurs especially among obese lactating cows. Direct measurements of insulin sensitivity...

As the number of horses is steadily increasing in Cantabrian less-favoured areas, mostly occupied by nutritionally poor heathland communities, the objective of this research was to study and compare diet selection and performance of crossbred horses and beef cattle (Asturiana de los Valles breed) grazing these areas during the summer. A total of 20 cows (seven lactating their calves and thirtee...

A number of reproductive parameters are altered in lactating dairy cows including: twinning rate, expression of estrus, conception rate, pregnancy loss, and incidence of anovulation. We hypothesized that the high feed consumption associated with lactation has fundamentally altered reproductive physiology due to increased metabolism of steroids. We evaluated liver blood flow and steroid metaboli...

Concentrations of total cholesterol and progesterone were measured in early lactating dairy cows fed either a control diet or a diet containing a protected fat (1.8% on a OM basis) between weeks 4 and 12 post pactum. All cows were fed the control diet from parturition to week 4 post partum. Plasma samples were collected twice weekly. Plasma total cholesterol and progesterone were greater in cow...

two experiments studied the effects of canola or sunflower seed supplementation on conjugated linoleic acid (cla) concentration in milk fat of lactating cows. in each experiment, only eight cows in early lactation were available to assign to one of two treatments in a completely randomized design and were fed individually for 12 wk. experiment 1 compared similar diets with or without the additi...

The present study investigated the effects of the supplemental dietary energy source on early lactating cows in a positive energy balance. Cows in the control group were fed a basal total mixed ration containing high-quality hay as forage, and the dietary concentrate to forage ratio was 45:65. The corn supplementation resulted in a significant decrease in the milk fat content (P < 0.05) and a l...

Dairy cows enter a period of energy insufficiency after parturition. In liver, this energy deficit leads to reduced expression of the liver-specific GH receptor transcript (GHR1A) and decreased GHR abundance. As a consequence, hepatic processes stimulated by GH, such as IGF-I production, are reduced. In contrast, adipose tissue has been assumed to remain fully GH responsive in early lactation. ...

this study was conducted to evaluate the effects of alfalfa hay (ah) particle size and soybean hull (sh) on physical effective fibre (pendf), particle size distribution in diets, chewing activity as well as milk composition and production in early lactating dairy cows. eight lactating holstein cows averaging 590±33 kg of bw and 47±13 days in milk were assigned in a 4×4 latin square design to a ...