test day milk records of a holstein dairy farm collected during years 2004 to 2006 on 142 cows in the 1st lactation vs. 140 cows in the 2nd lactation were used in this research. there were real milk yields of cows available in each part of lactation in this farm making it possible to compare functions based on the new criteria (squared error of estimation). five functions were compared to estim...

The physiological roles of TRH in pituitary lactotrophs, particularly during lactation, remain unclear. We studied the prolactin (PRL) status, including serum PRL and PRL mRNA levels in the pituitary, in nonlactating and lactating TRH-deficient (TRH(-/-)) mice with a rescue study with thyroid hormone and TRH. We found that, as reported previously for male TRH(-/-) mice, neither the morphology o...

The records of 1085 crossbred cattle daughters of 57 sires maintained during 1974-2004 at Instructional Dairy Farm of Govind Ballabh Pant University of Agriculture & Technology, Pantnagar, Uttarakhand, India were used to evaluate sires for first lactation performance traits. The data were analyzed to estimate the breeding values of sires using least squares methods (LSM), best linear unbiased p...

Reproduction continues to be a critical component to maintain a dairy farm economically viable. For every farm and for every cow, there is an optimum time for pregnancy, which is mostly influenced by level of production, persistency of lactation, and parity. In general, as production decreases, lactation number increases, and persistency of lactation decreases, cows should be bred sooner postpa...

The aim of this study was to determine the effects of restricted feeding before puberty on reproduction, lactation and offspring growth performance in replacement ewe lambs over two breeding seasons. At weaning, 41 Dorset ewe lambs were assigned to one of three diets: an ad libitum control diet with medium-quality forage (MQF; 13.3% crude protein (CP), 1.81 Mcal metabolizable energy per kg, 42....

Significant variation exists for maternal nurturing ability in inbred mice. Although classical mapping approaches have identified quantitative trait loci (QTL) that may account for this variation, the underlying genes are unknown. In this study, lactation performance data among the mouse diversity panel were used to map genomic regions associated with this variation. Females from each of 32 inb...

Lactating dairy cow diets with more than 24% starch (DM basis) are common, but recent high corn prices have fueled a desire to feed lower-starch diets. The potential for using digestible neutral detergent fiber or pectin from byproduct feeds or sugars to partially replace starch from corn grain in diets fed to lactating dairy cows was reviewed. Potential modifying effects of corn silage, starch...

The objective was to study the effect of maternal supplementation with a yeast cell wall-based product containing a mannan-rich fraction (MRF) during gestation and lactation on piglet intestinal gene expression. First parity sows were fed experimental gestation and lactation diets with or without MRF (900 mg/kg). After farrowing, piglets were fostered within treatment, as necessary. Sow and lit...

An inverse correlation between the concentration of DDE in human breast milk samples and the duration of breast feeding prompted the present study of the effects of DDE administration on the lactational performance of primiparous rats. Daily doses of 10 mg p,p'-DDE/kg body weight were given to virgin female Sprague-Dawley rats 5 d/wk for 5 wk prior to mating and continued throughout the gestati...