In spite of the difficulties in delivering PUFA to ruminants, studies have generally indicated that the PUFA of the omega-6 (linoleic acid) and omega-3 [α-linolenic acid; eicosapentaenoic (EPA), C20:5 omega-3; docosahexaenoic (DHA), C22:6 omega-3] families are the most beneficial to improving reproduction in cows. The objectives were to determine if a diet enriched in α-linolenic acid (omega-3)...

The objective of this study was to characterize the circulating concentrations of estradiol-17β (E-17β) after treatment with different types or doses of estrogens in the absence (Experiment 1) or presence (Experiment 2) of a dominant follicle in lactating cows. In Experiment 1, cows (n = 12) had all follicles > 5 mm removed by ultrasound-guided follicular aspiration every 12 h throughout the bl...

Considering different fertility traits 411 cows from 73 farms used for economic analyses. From these, 202 lactating cows were selected for evaluating the fertility status. Pre-tested data sheets were used to record the socioeconomic status of the farms including their assets, cost and return and productive and reproductive performance of the dairy cows. Targets were set considering the situatio...

A cross-sectional study was conducted to determine the prevalence of sub-clinical and clinical mastitis and the associated factors in cows from selected smallholder dairy farms in Zimbabwe. Physical examinations were conducted on all lactating cows for evidence of signs of clinical mastitis. Composite milk samples were collected from all lactating cows for bacterial culture and somatic cell cou...

The objectives were to assess incidence of pregnancy losses, associate this outcome with immunization programs against reproductive diseases, and evaluate the effects of vaccination against bovine herpesvirus-1 (BoHV-1), bovine viral diarrhea virus (BVDV), and Leptospira spp., on reproductive efficiency of Brazilian cow-calf operations. In experiment 1, 7614 lactating Nelore cows from 18 ranche...

The aim of this study was to retrospectively analyse the results of milk samples obtained from South African dairy herds during the period 1996 to April 2007 in order to identify possible trends in isolates of microorganisms and their pathogenicity under field conditions. Milk samples were obtained from 7 of the 9 provinces in South Africa where there are low numbers of dairy cows. Although the...

The objective of this study was to evaluate the effects of replacing protein sources that are commonly used in North America with triticale dried distillers grains with solubles (TDDGS) as a source of dietary N on the productivity of lactating dairy cows. Experimental diets contained 17.1% TDDGS, 17.5% Corn DDGS (CDDGS), 13.1% canola meal (CM), or 10.2% soybean meal (SBM) on a DM basis so that ...

fatty liver is a metabolic disorder of dairy cows in early lactation, and approximately half of multi-parous dairy cows experience a moderate to severe fatty liver at calving. since the occurrence of fatty liver in buffalo is not known, the aim of this study was to evaluate the hepatic content of triacylglycerols (tag) and total lipids (tl), and the serum content of non-esterified fatty acids (...

Our objective was to compare mammary tissue gene expression profiles during a Streptococcus uberis (S. uberis) mastitis challenge between lactating cows subjected to dietary-induced negative energy balance (NEB; n = 5) and cows fed ad libitum to maintain positive energy balance (PEB; n = 5) to better understand the mechanisms associated with NEB and risk of mastitis during the transition period...

This study aimed to evaluate the effect of short-term forage substitution with ensiled olive cake (OC), on yield, composition and fatty acid (FA) profile cows’ milk. Mid-lactating Holstein-Friesian cows were randomly assigned for 21 days two isoenergetic isoproteic feeding treatments (12 animals per treatment), containing 0 10% DM OC (C groups, respectively). Milk yield was recorded daily, milk...