The objective of this study was to evaluate the effect of ruminally protected amino acids (RPAAs) and ruminally protected fat (RPF) supplementation on ruminal fermentation characteristics (in vitro) and milk yield and milk composition (in vivo). Fourteen mid-lactating Holstein dairy cows (mean weight 653±62.59 kg) were divided into two groups according to mean milk yield and number of days of p...

Three-year-old Angus x Gelbvieh beef cows nutritionally managed to achieve a BCS of 4 +/- 0.07 (479.3 +/- 36.3 kg of BW) or 6 +/- 0.07 (579.6 +/- 53.1 kg of BW) at parturition were used in a 2-yr experiment (n = 36/yr) to determine the effects of prepartum energy balance and postpartum lipid supplementation on cow and calf performance. Beginning 3 d postpartum, cows within each BCS were assigne...

Due to the great demand for buffalo milk by-products the interest in technical-scientific information about this species is increasing. Our objective was to propose selection criteria for milk yield in buffaloes based on total milk yield, 305-day milk yield (M305), and test-day milk yield. A total of 3,888 lactations from 1,630 Murrah (Bubalus bubalis) cows recorded between 1987 and 2001, from ...

Calf weaning weights and estimates of 205-d milk yield (n = 317) were obtained from 90 Polled Hereford (PH) and 80 Simmental (SM) cows to evaluate the relationship of these measures with maternal milk and total maternal EPD from national cattle evaluations. An inverse parabolic exponential function predicted 205-d milk yields for each cow from five estimates of daily milk yield taken once per m...

This article is a review of the factors that influence the sow’s colostrums and milk yield. Colostrum is secreted from the udder immediately after farrowing and is a rich source of highly digestible nutrients, which are critical to the survival of the newly born piglet. Colostrum contains natural growth factors for the normal development of vital life-sustaining organs. The litter performance b...

Serotonin (5-HT) is a homeostatic regulator of lactation. Selective 5-HT reuptake inhibitors (SSRI) are commonly prescribed pharmaceuticals that inhibit activity of the 5-HT reuptake transporter, increasing cellular exposure to 5-HT. Use of SSRIs has been shown to alter lactation performance in humans and 5-HT has been shown to reduce milk yield in cattle. However, it has not been determined ho...

The objective of this study was to examine the effects of concentrates containing different levels of a vitamin-trace elements premix on milk yield and composition of dairy cows. The trial, which lasted 14 weeks, was conducted from January to March and used 45 multiparous Brown cows in the early phase of lactation. Cows (n = 15 per treatment) were randomly allocated to three dietary treatments:...

Twenty-four lactating Holstein dairy cows were used in a completely randomized design to investigate the effect of soybean meal (SM) and xylose protected soybean meal (XSM) in combination with ground (GB) or steam flaked (FB) barley on dry matter intake, milk production, rumen fermentation and blood responses. The experimental period lasted for 30 days. The diets consisted of the provision of 1...

When linear programming is used to rank sires on daughter profits, coefficients of input are required for representative daughters of each sire. Within herdyear-season regressions of daughter's actual 305-day milk, fat percent, days open, 2-min milk yield adjusted for total yield, total milking time, and body weight at birth and first calving on sire's proofs for production, conformation, milki...

On a short-term basis, the efficiency of nutrient use for milk production is primarily dependent on the milk production level. As milk yield increases, a lower proportion of total feed intake is used for maintenance (a non-productive requirement that is more or less constant) of the cow. A cow producing 12 kg/d of milk is using about 50% of available nutrients for milk synthesis, whereas the co...