To meet the nutrition requirements of lactation, dairy cows are usually fed a high concentrate diet (HC). However, high-grain feeding causes subacute ruminal acidosis (SARA), a metabolic disorder that causes milk protein depression. This study aimed to investigate the effect of lipopolysaccharide (LPS) released in the rumen on inflammatory gene expression and casein synthesis in mammary glands ...

The objective of this study was to examine the effect of an excess intake of quickly degradable nitrogen (QDN) on ovarian follicle development. Twenty lactating dairy cows were fed mixed silage and concentrates twice daily. The control diet was a typical ration for high producing dairy cows in the United Kingdom (crude protein (CP)=17.5%; metabolizable energy (ME)=11.8 MJ/kg DM). The cows were ...

Bovine subclinical mastitis is an inflammation of the mammary gland caused by bacterial intramammary infection, accounting for large economic losses. Treatment of subclinical mastitis is not suggested for lactating cows due to the risk of milk contamination. The objectives of this study were to evaluate an antimicrobial peptide, nisin, in the treatment of subclinical mastitis in lactating cows....

The objective of this study was to investigate the effect of a partial substitution of soybean meal with field pea (Pisum sativum) in Holstein lactating dairy cow diets on dry matter intake, milk yield and composition, blood metabolites, rumen ammonia-N concentration and pH. Eighteen lactating Holstein cows were randomly assigned into three groups based on parity, days in milk, and mil...

BACKGROUND The prevalence and the clinical consequences of subacute ruminal acidosis (SARA) in dairy cows are still poorly understood. In order to evaluate the prevalence of SARA, 26 German dairy farms were included in a field study. In each herd, between 11 and 14 lactating dairy cows were examined for their ruminal pH using rumenocentesis. Milk production data and farm management characterist...

Objectives were to determine effects of lactation and pregnancy on endometrial gene expression on d 17 of the estrous cycle and pregnancy. Heifers (n=33) were assigned randomly after parturition to lactating (L, n=17) or nonlactating (NL, n=16) groups. Cows were subjected to an ovulation synchronization program for a timed artificial insemination (TAI); 10 cows in L and 12 in NL were inseminate...

The present study aimed to verify the occurrence of displacement abomasum (DA) in dairy herds from a high-yielding region Southern Brazil. Data on breed, age, lactation number, days after calving, breeding system, number animals, and lactating cows herd were obtained 135 cases DA. A total 39 herds, 6,454 cows, including 2,987 municipality Palmeira, Paraná State, included this study. overall pre...

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...

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...