BVDV is estimated to cost an average dairy between $20 and $160 per adult cow per year. These losses include medication and labor to treat acute infections, milk production losses in lactating cows, infertility due to decreased conception and early embryonic death, abortions, loss of weak, abnormal, or persistently infected calves. Large scale herd outbreaks such as occurred in the early 1990s ...

38 Lactating dairy cows (n=1,538) were enrolled in a randomized complete block 39 design study to evaluate protocols to synchronize estrus and ovulation. Within each 40 herd (n=8), cows were divided into three calving groups: EARLY, MID and LATE 41 based on days in milk (DIM) at mating start date (MSD). EARLY calving cows 42 (n=1,244) were  42 DIM at MSD, MID calving cows (n=179) were 21 to 41...

Objectives of this study were to determine if concentrations of steroids, insulin-like growth factor -I (IGF-I), and IGF binding proteins (IGFBP) in follicular fluid and numbers of LH and IGF-I receptors change during growth of the dominant follicle. Ovarian follicular development was monitored daily via ultrasound in lactating Holstein cows. Animals underwent bilateral ovariectomy when the dom...

Group G streptococci in animals usually belong to the species Streptococcus canis and are most commonly found in dogs and cats. Occasionally, Strep. canis is detected in milk from dairy cows. An outbreak of Strep. canis mastitis in a dairy herd is described. Based on results from bacterial culture and ribotyping, a cat with chronic sinusitis was the most likely source of the outbreak. Subsequen...

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....

Previous studies in the field of acid-base and oxidative status cows have mainly focused on transition period (three weeks before three after calving). The aim this study was to determine differences parameters electrolyte balance not only during period, but also at other stages production cycle. Holstein-Friesian were divided into four numerically equal groups (n = 6): early lactating (9?2 day...

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...