The objective of this experiment was to evaluate the effects of bovine somatotropin administration on serum concentrations of glucose, insulin, NEFA, IGF-I, and progesterone (P4) in ovariectomized non-lactating dairy cows receiving exogenous P4, as a model to estimate treatment effects on hepatic P4 degradation. Ten non-lactating, non-pregnant, and ovariectomized Gir Holstein cows were assigned...

The objective of the study was to evaluate the uterine histopathological changes in Holstein dairy cows, within the range of 90-145 day in milk, with or without clinical history of reproduction system disorders. Lactating Holstein cows (n =133) with (n=92, 69.17%) or without (n= 41, 30.82%) recorded clinical signs of reproduction diseases were examined for uterine histopathological lesions. The...

The objective was to determine whether transfer of fresh or vitrified embryos produced in vitro with sex-sorted semen improves pregnancy and calving rates during summer in lactating dairy cows compared with artificial insemination (AI). Lactating dairy cows (n=722) were enrolled during summer months at 2 commercial dairies in Central Texas and randomly assigned to 1 of 3 treatments: AI with con...

Four experiments were performed to determine whether cooling cows during final maturation of oocytes and early embryonic development or injection of vitamin E at AI prevented adverse effects of heat stress on pregnancy rates in lactating Holstein dairy cows. In Experiment 1, cows were placed in a cooling facility containing sprinklers and forced ventilation or received shade only from 2 to 3 d ...

T cells play a central role in specific immunity; their populations and phenotypes could be affected by number of lactation in high-yielding dairy cows. To investigate the effects of parity on the dynamics of T lymphocytes, lymphoproliferative capacity, T lymphocyte subsets and CD4+/CD8+ ratio were studied in peripheral blood of primiparous and pluriparous dairy cows during mid-late lactation. ...

Objective-  To study the effect of digit amputation on animal survival, and distribution of   lesions on limbs, days in milk and parity in operated cows.   Design- Retrospective descriptive study.   Animals- Thirteen cows in a dairy herd consisting 1100 lactating Holstein cows.   Procedures- Digit amputation by using a loop wire after inducing local intravenous anesthesia. Results- Digits of ...

A total of 226 out of 245 postpartum lactating dairy cows in a commercial dairy farm were allocated to two groups of oestrous synchronisation protocols in order to evaluate reproductive performance. One group was treated with oestradiol benzoate (ODB) and PGF2α on day 10 of the oestrous cycle with insemination at the detected oestrus, the second group underwent the Ovsynch (OVS) protocol (GnRH ...

The term ‘bio-diesel’ is used to describe the methyl or sometimes ethyl esters produced from oilseed crops. Every 10 gallons of biodiesel produced generates about 7.6 lb of crude glycerol. According to the National Biodiesel Board, the production of biodiesel in the U.S. over the next decade is expected to grow (http:// www.biodiesel.org/). Current annual production is 395 million gallons and p...

this study was conducted to evaluate the effects of alfalfa hay (ah) particle size and soybean hull (sh) on physical effective fibre (pendf), particle size distribution in diets, chewing activity as well as milk composition and production in early lactating dairy cows. eight lactating holstein cows averaging 590±33 kg of bw and 47±13 days in milk were assigned in a 4×4 latin square design to a ...

The present study was designed to assess progesterone profiles at the secreted (caudal vena cava) and circulating levels (jugular vein) and luteinizing hormone (LH) secretion pattern in lactating and non-lactating cows with reference to feeding. Four lactating and four non-lactating cycling Holstein cows were examined. Blood samples were collected simultaneously from the caudal vena cava (via a...