Fenugreek is a novel forage crop in Canada that is generating interest as an alternative to alfalfa for dairy cows. To evaluate the value of fenugreek haylage relative to alfalfa haylage, six, second lactation Holstein cows (5668 days in milk), which were fitted with rumen cannulas (10 cm i.d., Bar Diamond Inc., Parma, ID, USA) were used in a replicated three3three Latin square design with 18-d...

Plasma leptin concentrations increase as growing dairy heifers approach puberty and have greater plasma estrogen. In intact and ovariectomized rodents, estrogen has been shown to modulate expression of leptin and its receptor (Ob-R). To determine if estrogen regulates the bovine leptin system, prepubertal dairy heifers were ovariectomized at 140 d of age or left intact. A month later, both grou...

Raising dairy heifers from birth to calving has been found to comprise the second largest expense on the dairy farm towards the production of milk, while deriving no revenue until the onset of lactation (Heinrichs, 1993). Therefore, many experiments involving dairy heifers have focused on ways to minimize the costs associated with the growth period or decreasing the unproductive period of the a...

OBJECTIVE To determine whether vaccination with a monovalent vaccine against Leptospira borgpetersenii serovar Hardjo strain hardjobovis would improve reproductive efficiency in Holstein cattle in a commercial dairy setting. DESIGN Randomized controlled trial. ANIMALS 1,894 Holstein cows and heifers from a Central California dairy. PROCEDURES Cattle were assigned to undergo SC administrat...

Introduction Mycoplasmas are normal inhabitants of the upper respiratory airways, urinary and genital tracts, and the digestive system; however, they can become infectious and cause high impact diseases in dairy herds including mastitis and metritis. In dairy cattle, Mycoplasma bovis is the most commonly isolated mycoplasma species (spp.). This species is very invasive and capable of colonizing...

BACKGROUND The aim of this study was to detect the associations between bovine herpesvirus 1 (BHV-1) status of a herd and respiratory disease (BRD) occurrence and reproductive performance in pregnant heifers and cows. The association between management-related factors and higher BRD occurrence was also estimated. METHODS Serum samples, collected from cows and youngstock from 103 dairy cattle ...

To establish sustainability in the dairy industry, it is important that cows become pregnant at a biologically optimal time and at an economically profitable interval after calving. In this review, the results obtained from Holstein cattle in an experimental herd for dairy research are summarized. First, the effect of age at first calving of heifers on productive and reproductive performance wa...

Seventy postpuberal dairy heifers were assigned to remain untreated (n = 26) or to receive the Syncro-Mate-B (SMB) treatment (n = 44). Untreated heifers were inseminated at 12 hr after detection of estrus, while SMB-treated heifers were inseminated either at 48 hr after implant removal (group 1) or at 12 hr after detection of estrus (group 2). Jugular blood was collected at regular intervals fr...

1. In the first trial, hourly blood samples were drawn during the light period (06.30-20.30 hours) from thirty-four dairy heifers in two groups of different ages. 2. Concentrations of serum folates were 8.2 (SE 0.1) ng/ml at the age of 18.2 (SE 0.6) d and 14.8 (SE 0.2) ng/ml at 120.7 (SE 2.9) d (P less than or equal to 0.001). 3. In the second trial, forty heifers were randomly assigned to a fa...