Calcium chloride supplements such as gels and drench were studied to determine their effectiveness for increasing blood serum Ca concentrations in periparturient dairy cows. Multiparous, pregnant Holstein dairy cows (n = 36) were assigned to one of four treatments. After calving, cows in four treatments received basal diet and two doses of either control inert gel (CON), gel containing CaCl2 an...

Photoperiod manipulation during the lactation cycle alters milk yield, with long days (LDPP) increasing yield in lactation and short days (SDPP) in the dry period improving subsequent yield. Circulating prolactin (PRL) is directly related to day length, with LDPP increasing and SDPP decreasing PRL, respectively. Two blocks of 24 multiparous Holstein cows were used during two consecutive years t...

The objective of the current study was to evaluate the dynamics of infection and the immunological response to varying numbers of Escherichia coli injected into the mammary glands of primiparous cows during the periparturient period. Primiparous cows have been shown to be more resistant to intramammary E. coli challenge, and an increase of the inoculum dose by 2 log10 units induced a more rapid...

Increasing reproductive performance of post-partum lactating dairy cows is a multi-factorial challenge involving disciplines of production medicine, nutrition, physiology and herd management. Systems of programmed timed insemination have been fine-tuned to achieve pregnancy per artificial inseminations (AI) approximating 45%. Systems have optimized follicle development, integrated follicle deve...

Efficiency in laboratory mouse breeding is hampered by poor reproductive performance, including the loss of entire litters shortly after birth. However, the underlying mechanisms are not yet fully understood and establishing the cause of death in laboratory mouse pups can be complicated. Newborn mouse pups are generally hidden in nests, dead pups are often eaten by the female, and the widesprea...