Growth patterns from birth to maturity were compared for 92 straightbred Herefords (H) and 299 Hereford crossbred (XB) cows. Crossbred cows were out of Hereford dams and were sired by bulls of two British [Angus (A) and Shorthorn (Sh)], two Continental [Charolais (C) and Simmental (S)] and two American dairy breeds [Brown Swiss (B) and Holstein (F)]. British XB and H cows differed only slightly...

In this study, the incomplete gamma function, an exponential function, a mixed-log function and a polynomial function were evaluated to describe the lactation curve in Moroccan Holstein-Friesian dairy cows. Data from 1990 to 1999, comprising 77130 monthly milk yields of 6029 dairy cows in 280 dairy herds, were used. Edits were carried out by considering the lactation length (5 d and

The study was carried out to assess whether hot seasons affect the oxidative status of transition dairy cows. Twenty Holstein cows were utilized. Eleven of those cows gave birth in spring; the remaining nine cows gave birth in summer. Oxidative status was evaluated from 21 d before to 35 d after calving, determining oxidative markers in plasma [glutathione peroxidase activity, thiol groups, rea...

Underfeeding or overfeeding CP to dairy cows can have detrimental effects on milk production, efficiency of nutrient utilization, reproduction, the environment, and the overall profitability of the dairy operation. Therefore, the amount and source of CP to feed must be determined if we are to optimize productivity, maximize nutrient utilization, avoid polluting the environment, and increase pro...

Background: Ovarian cysts are among the diseases which cause reproductive failure and economic losses in dairy herds. High yelding dairy cattles are suseptable to reproductive failure caused by ovarian cysts, as a result of their exposure to stressful coditions during lactation. OBJECTIVES: This study aimed to monitor metabolic profile tests in dairy cows with ovarian cysts in comparison with c...

protection of the mammary gland against mastitis-causing pathogens is mediated by many factors in thegland and blood circulation. the professional phagocytic cells of bovine udder, polymorphonuclearneutrophils (pmn) and macrophages, comprise the first line of defense against invading mastitis pathogens.most researchers now accept that the pmn is a key factor in the cows’ defense against intrama...

postpartum anestrous is one of the most important problems in the dairy industry in the world and especially in iran. the objective of present study was to compare the efficacy of two hormonal programs for recycling of postpartum anestrous cows. for this reason, 230 holstein cows from 4 similar dairy herds (with totally 2560 cow and unique management and feeding system) located on the suburb of...

In early postpartum, high-producing dairy cows undergo a period of extensive tissue catabolism because of negative nutrient balance. Metabolic unbalances can lead to diseases, which are known to depress fertility in dairy cows. Negative nutrient balance has been associated with compromised immune and reproductive functions in dairy cows, and a compromised immune system leads to greater risk of ...

Subacute Ruminal Acidosis (SARA) corresponds to an imbalance between lactate-producing bacteria and lactate-using bacteria, which results in a change in ruminal pH associated with a prevalent consumption of rapidly fermentable carbohydrates. In our study, 216 primiparus and multiparus dairy cows were selected from 20 Italian intensive dairy herds and were divided into three groups based on the ...

This study uses heteroskedastic Tobit and Censored Least Absolute Deviations models to examine the impacts of dairy cow ownership on selected outcomes for a sample of 184 households in coastal Kenya. The outcomes examined include gross household cash income, gross non-agricultural income, consumption of dairy products, time allocated to cattlerelated tasks, number of labourers hired and total w...