BACKGROUND Objectives of the study were to document the impact of some management factors on the occurrence of clinical mastitis in primiparous dairy cows and to identify common udder pathogens of clinical mastitis in freshly calved heifers and multiparous cows on the day of calving. METHODS A one-year study was conducted during 2004 and 2005 in 11 selected Estonian dairy herds. Data consiste...

The production traits of Red Chittagong Cattle (RCC) were studied using two diets: A [Urea-molasses-rice straw (UMRS), Green Grass and Concentrate] and B [Rice straw, Green Grass and Concentrate]. In cows fed diets A and B, birth weights of calves were 15.2 and 14.1 kg (P<0.05), daily milk yield 2.0 and 2.0 kg (P>0.05), lactation length 254.8 and 247.1 days (P>0.05), age at first oestrus 28.4 a...

The main objective of this study was to estimate the genetic parameters for multi-trait evaluation of birth weight (BW), gestation length (GL) and calving difficulty (CD) in first-parity Iranian Holstein dairy cattle. The data included 29,950 calving records collected during 1995 to 2014 by the Animal Breeding and Improvement Center of Iran. A threshold-linear sire-maternal grandsire model was ...

An association analysis between T19C polymorphism in bovine PPARGC1A and productive and reproductive traits was performed in a population of 620 and 279 Polish Holstein-Friesian cows, respectively. No relationship was found with milk yield and composition. PPARGC1A genotypes had, however, a significant effect on lengths of calving interval and calving to conception interval, and the T allele wa...

The aim of this paper was to determine effects of selected genetic and environmental factors on the concentration of acetone in blood of cows in the first trimester of lactation. The study included 124 Polish Holstein-Friesian primiparous cows born, reared and managed on the same farm. The samples of blood were collected on day 2, 5, 30, 60 and 90 after calving. The highest serum acetone concen...

Weight gain of young dairy replacement heifers, even over several months, is highly variable, lowly heritable, and a poor indicator of either weight at calving or first lactation milk yield. Voluntary forage consumption is much less variable, more heritable, and a better predictor of weight at calving and milk yield. Weight at calving is highly heritable but not correlated genetically with milk...

When Rumensin (monensin sodium) was fed to dairy cows: • Services per conception, days open and calving interval were increased, and firstservice conception rate was reduced in the 22 g/ton group. Pregnancy rates and successful calving rates were similar for all treatment groups. All measures of reproductive efficiency for all doses were well within accepted industry standards. • The incidence ...

The objective of this study was to identify risk factors for repeat breeder dairy cows and their impact on reproductive performance. characteristics 1,504 cows, including peripartum health, nutrition, production, reproduction, were collected. Cows with metabolic disorder significantly more likely (odds ratio [OR], 2.47; p &lt; 0.001) clinical endometritis tended be (OR, 1.35; 0.1) become breede...