Although there is increasing concern over routine administration of long-acting antibiotics to all cows at the end of lactation, the practice is required to eliminate subclinical infections that are present at drying off. Alternatives to dry cow therapy (DCT) for preventing new infections from occur...

Milk samples from 50 sheep on a single Scottish research farm were collected weekly for 10 wk postpartum. Samples were analyzed for somatic cell counts (SCC) each week and bacteriologic culture was done for 7 of the 10 wk. A total of 492 udder half samples were cultured, of which 467 had correspondi...

Effective aids to decision-making for clinical mastitis therapy are reviewed..

A total of 1317 Holstein cows from 45 farms in the Canadian provinces of Quebec, Prince Edward Island (PEI) and Ontario, Canada were enrolled in a randomized trial between 1998 and 1999 to further confirm the efficacy of a monensin controlled release capsule in preventing periparturient disease in l...

Plasma progesterone (P4) levels were assessed by radioimmunoassay in lactating dairy cows treated with a progesterone-releasing intravaginal device (PRID). Group A cows (N=6) received no treatment. PRIDs were administered to Group B1 (N=3) on day 25 after the first observed estrus (Day 0) and to Gro...

Staphylococcus aureus is the most prevalent pathogen causing intramammary infections (IMI) in dairy cattle worldwide. New treatment regimens have been evaluated to increase cure rates. A systematic review was conducted to answer this question: what is the best antibiotic treatment for S aureus IMI o...

The purpose of this study was to 1) estimate the herd prevalence of contagious mastitis pathogens in bulk milk from Prince Edward Island (PEI) dairy farms, 2) determine the association between bulk milk culture results and mean bulk milk somatic cell count (BMSCC), and 3) investigate the agreement o...

An acute onset of illness was reported in a lactating dairy herd in Canada in which monensin had been incorporated in error in its ration at almost 10 times the prescribed level. All of the lactating cows became lethargic, were inappetant, developed diarrhea, and had decreased milk production from 2...

Our objective was to describe cow and quarter-level factors associated with drying-off, and to evaluate their impacts on new intramammary infections (IMI) during the dry period. Data from 300 cows in five research herds were collected starting 2 weeks prior to scheduled drying-off. Variables of inte...

The objective ofthis study was to evaluate the efficacy of intramammary tilmicosin, administered at drying-off, for eliminating Staphylococcus aureus infection, and to identify risk factors for S. aureus cure during the dry period. A total of 219 naturally infected cows, representing 308 quarters, w...

The objective of this study was to compare the efficacy of an intramammary infusion, containing tilmicosin phosphate, to an infusion of a negative control intramammary placebo for preventing new intramammary infections (IMI) during the dry period. Cows were enrolled from 24 dairy herds from three ge...

The objective of this field trial was to compare the effect of intrauterine (i.u.) antibiotic or intramuscular (i.m.) prostaglandin F2 alpha (PGF2 alpha) on time to pregnancy in dairy cows diagnosed with clinical endometritis between 20 and 33 days in milk (DIM). The case definition of endometritis ...

The objectives of this study were to validate diagnostic criteria for clinical endometritis in postpartum dairy cows and to measure the impact of endometritis on reproductive performance. Data were collected from 1865 cows in 27 herds, including history of dystocia, twins, retained placenta, or metr...

The objective of this study was to assess the use of GnRH in a controlled breeding program (7 d prior to the second of two injections of PGF2 alpha, 14 d apart) as a means to improve the expression and detection of estrus, first service conception rate, and overall pregnancy rate of lactating dairy ...

Streptococcus agalactiae continues to be a major cause of subclinical mastitis in dairy cattle and a source of economic loss for the industry. Veterinarians are often asked to provide information on herd level control and eradication of S. agalactiae mastitis. This review collects and collates relev...

OBJECTIVE: To determine whether half-udder intramammary infusion of cloxacillin results in transfer of cloxacillin from treated to untreated mammary gland quarters within nonlactating cows, and, if so, at what concentrations, and to determine whether selection of ipsilateral versus diagonal-contrala...

OBJECTIVE: To determine whether insertion of an internal teat sealer (ITS) at the end of lactation would prevent development of new intramammary infections (IMIs) during the nonlactating period. DESIGN: Controlled clinical trial. ANIMALS: 939 Holstein-Friesian dairy cows from 16 herds. PROCEDURES: R...

A clinical trial was conducted to determine the perceived and actual utility of milk urea nitrogen (MUN) notification and interpretation as a tool for monitoring protein and energy imbalances in dairy cows. Based on MUN results during the summer of 2001, 50 farms with high MUN values and 30 with low...

The objective of this study was to determine if an internal teat sealer used in addition to dry-cow antibiotics would have a beneficial effect on the elimination of intramammary pathogens during the dry period. In total, data from 425 culture-positive quarters from 270 Holstein-Friesian dairy cows w...

To determine the effect of subclinical infection with bovine leukaemia virus (BLV), Mycobacterium avium subspecies paratuberculosis (MAP) and Neospora caninum (NC) on milk production in dairy cattle in 3 Maritime Canadian provinces, 90 dairy herds (all on monthly milk recording) were randomly recrui...

This study evaluated the ability of ultrasonic examination at entry into the feedlot to predict carcass traits. Feeder calves (487) from eight Prince Edward Island feedlots were examined with an Aloka 500 ultrasound and Critical VisionReg. image analysis software to determine carcass attributes (bac...

The objectives of this study were to evaluate microbiological quality of bulk tank milk in Prince Edward Island, to evaluate correlation among milk quality criteria, and to determine seasonal effects on milk quality parameters. Bulk tank raw milk quality was evaluated on all Prince Edward Island dai...