We examined whether infrequent milk sampling for progesterone analysis could be used as a management or diagnostic tool by the dairy farmer to predict delayed ovarian cyclicity in dairy cows. The data included 1040 lactations from 324 Swedish Red cows and 183 Swedish Holstein cows and were randomly divided into two datasets. A logistic regression model was fit to the first dataset and the model...

OBJECTIVE To compare milk yield among cows classified as nonlame, moderately lame, and lame and to examine the relationship between severity of lameness and milk yield in cows classified as lame during the first 100 days after parturition. DESIGN Longitudinal study. ANIMALS 465 Holstein cows. PROCEDURE Cows were examined weekly during the first 100 days after parturition and assigned a la...

The purpose of the study is to relationship between rates dairy productivity and reproduction cows in highly productive Ayrshire herds Republic Karelia. Materials methods. work was performed on basis four Stud Airshire rock at "Megrega" trivial, "Ilyinskoe", Mayak LLC, Agrocomplex OJSC. V. M. Zaitseva "(Republic Karelia). Data reproductive ability are collected processed 24,720 cows. zootechnic...

This study was designed to evaluate serum and milk amyloid A (SAA) as an inflammatory indicator in inflammatory diseases. Twenty clinically healthy cows and 100 cows with various inflammatory diseases were selected for this study. Blood samples were collected from the coccygeal vein of both healthy and diseased groups. Milk samples were taken from four quarters of both groups. Milk samples of f...

JUOZAITIENE, V., A. JUOZAITIS: The influence of somatic cell count in milk on reproductive traits and production of Black-and-White cows. Vet. arhiv 75, 407414, 2005. ABSTRACT The aim of this study was to estimate the relationships between somatic cell count in milk, reproduction traits and milk production of cows of the Black-and-White breed. The research was carried out on 412 herds of the ac...

Modeling extended lactations for the US Holsteins is useful because a majority (>55%) of the cows in the present population produce lactations longer than 305 d. In this study, 9 empirical and mechanistic models were compared for their suitability for modeling 305-d and 999-d lactations of US Holsteins. A pooled data set of 4,266,597 test-day yields from 427,657 (305-d complete) lactation recor...

An animal model with a REML algorithm was used to estimate variances of additive genetic effects and interaction effects of sire and herd. Milk and fat yields were analyzed for first, second, and third lactations of Holsteins from California, New York, and Pennsylvania. Twenty samples of data were used in the study: 10 from California, 4 from New York, and 6 from Pennsylvania. Mean number of la...