During lactation in the sow, mammary glands that are not regularly suckled undergo regression. This study characterizes the regression of unsuckled mammary glands and how that regression is affected by dietary nutrients and litter size. Sixty-nine primiparous sows were fed one of four diets containing combinations of two protein levels (32 or 65 g lysine/d) and two energy levels (12 or 17.5 Mca...

The adaptive response to a given metabolic load during energy deficiencies varies considerably among animals. The aim of this study was to investigate if individual cows respond in a repeated manner to a negative energy balance (NEB) in early and mid-lactation. Twenty-five multiparous Holstein dairy cows (3.0 ± 1.1 parities; mean ± SD) experienced a NEB during the first weeks of lactation, and ...

Intramammary infections in breeding age and pregnant heifers are much higher than previously thought. Many of these infections can persist for long periods of time, are associated with elevated somatic cell counts, and likely impair mammary development during gestation and affect milk production after calving. Prepartum intramammary antibiotic infusion of heifer mammary glands a few weeks befor...

Taurine is the most abundant free amino acid in the body and is present at high concentrations during development and in the early milk. It is synthesized from cysteine via oxidation of cysteine to cysteinesulfinate by the enzyme cysteine dioxygenase (CDO), followed by the decarboxylation of cysteinesulfinate to hypotaurine, catalyzed by cysteine sulfinic acid decarboxylase (CSAD). To determine...