The objective of this study was to estimates the genetic and environmental components for the lactation curve parameters, milk yield, age at first calving (AFC), calving interval (CI) and somatic cell count (SCC) in Iranian Holstein cows. The dataset consisted of 210625 test day records from 25883 cows with milk yield in the first parity recorded from July 2002 to September 2007 in a total of 9...

Polymerase chain reaction-based DNA fingerprinting was used as a tool to differentiate new and persistent Streptococcus uberis and Streptococcus dysgalactiae intramammary infections (IMI) in dairy cows. The same subtype of S. uberis or S. dysgalactiae was detected from some infected mammary glands from one lactation to the next documenting the persistence of these infections. Conversely, some s...

Two experiments were conducted to investigate the effects of a corn-soybean meal (C-SBM) and a sorghum-soybean meal (S-SBM) diet on reproductive performance and nutrient utilization by sows. In Exp. 1, 75 sows (39 gilts; 36 primiparous) were fed either a C-SBM or a S-SBM gestation diet from breeding to d 109. On d 110, sows were assigned to lactation diets; half of the sows from each dietary tr...

In dairy cows, increased milking frequency (IMF) during early lactation stimulates an increase in milk yield that partially persists through the remainder of lactation. However, the effects of IMF on lactation performance and udder health of primiparous heifers have not been clearly established. The objective of this study was to determine the effects of IMF during early lactation on milk yield...

This study was conducted to determine the effects of orally administered borax on milk yield and on several blood variables related to metabolism in early lactation in Austrian Simmental cows (Fleckvieh). Twenty primiparous cows were selected at parturition and then assigned to one of two groups, the control group or the borax group. The study lasted for four weeks. Borax was administered orall...

The purpose of this study was to evaluate the effect rumination times and days spent in a close-up group before calving (DCU) on early-lactation health reproductive outcomes dairy cows. Data were gathered for 719 cows located single herd. Herd management records analyzed receiving treatment first 30 d lactation (days milk; DIM) clinical mastitis, tract disease, ketosis, milk fever, displaced ab...

Most of the metabolic diseases of dairy cows milk fever, ketosis, retained placenta (RP), and displacement of the abomasum occur within the first 2 wk of lactation. And, the etiology of many of those metabolic diseases that are not clinically apparent during the first 2 wk of lactation, such as laminitis, can be traced back to insults that occurred in early lactation. In addition to metabolic d...

Mastitis is a complex disease with critical outcomes. Subclinical mastitis (SCM) although lacks clinical signs but it has a profound effect on milk production if occurs during early lactation. The purpose of the study, was to investigate the changes that occur in plasma metabolite levels before development of mastitis during early lactation. To evaluate the association, blood samples were colle...