A case-based learning approach for teaching undergraduate veterinary students about dairy herd health consultancy issues.

A case-based learning (CBL) format was implemented at the Veterinary School of Nantes, France, for veterinary students in their last year of the curriculum who had chosen to track toward a farm animal career. The focus of the CBL format was learning about dairy herd health consultancy. The goal was to emphasize teamwork among students, introduce professional communications and advisory relationships with clients, and work within the technical and economic limitations of participating farms. These farms volunteered to participate and had identified a problem. The learning objectives included gaining basic knowledge of herd-level diseases and the methods to control these within herds. The program focused on health audits of dairy farms performed by teams of four to five students, culminating in submission of a herd health management action plan specific for the farm visited by each team. The CBL program was comprised of defined learning objectives for each team. The learning process was supervised, from orientation through to validation, by a panel of experts from within the veterinary school and from local industry. Teams submitted written reports that listed recommendations and an action plan for implementation. This report was defended by each team in front of the farmers, their professional partners, and the panel of supervisors. Assessment of the program by students, participating farms, and industry professionals was positive.

Effect of feeding program during rearing and age at first insemination on performances during subsequent reproduction in young rabbit does.

An experiment was performed to study the effect of the feeding program and age at first mating on body growth, feed intake, reproductive performance, and culling of rabbit does over three parities, using 155 does of a strain of New Zealand white rabbits. Three treatments were applied. Ad libitum feeding until first insemination at 14.5 wk (AL-14.5) or 17.5 wk of age (AL-17.5), and restrictive feeding from five wk of age until first insemination at 17.5 wk of age (R-17.5). At first insemination, the BW of AL-14.5 and R-17.5 was similar (3 907 vs. 3 791 +/- 46 g, respectively), whereas AL-17.5 does were heavier (4 390 +/- 46 g, P < 0.001). During reproduction, performance of AL-17.5 was not improved compared to AL-14.5 and R-17.5 does. Al-17.5 does showed a lower feed intake during the first gestation (-25%) and first parity (-10%) than R- 17.5, resulting in weight loss (-6%) during the first gestation and decreased litter weights (-19%) and litter growth (-14%) in the first parity. Extended first mating by three wk (17.5 vs. 14.5 wk) but similar BW at first mating did not affect feed intake and BW development during the first three parities. However, the number of live born kits and weight at first kindling, and litter growth in the first parity were improved in R-17.5 (+23%, +18%, and +14%, respectively). Reproductive performance can be improved by restricted feeding during rearing and extended first insemination to 17.5 wk of age. However, the culling rate was not affected by the rearing strategy.

Metabolic changes in early lactation and impaired reproductive performance in dairy cows.

This review addresses the suggestion that the decline in dairy reproductive performance, as increasingly observed these days, may be due to a hampered process of metabolic adaptation in early lactating cows. In our opinion, adaptation to the negative energy balance is a gradual process. Because almost all cows do adapt in the long run, it is not possible to classify animals as adapted or non-adapted. The use of risk factors is more appropriate in this case and is discussed in this review. Among them are the body condition score and its derivatives, feed intake, the calculated negative energy balance, and metabolic parameters like the plasma concentration of insulin or the triacylglycerol content in the liver. Moreover, factors that play a role in the link between declined reproductive performance and the metabolic situation of the cow during the early lactating period are discussed. Among these are insulin, insulin-like growth factors, leptin, neuropeptide Y, non-esterified fatty acids, thyroïd hormones, urea, and ammonia.

The effects of a single injection of dexamethasone-21-isonicotinate on the lymphocyte functions of dairy cows at two weeks post partum.

Dexamethasone is a potent therapeutic for treatment of the fatty liver syndrome or primary ketosis in post partum dairy cows. Reservations exist, however, among practitioners with respect to the risk of immunosuppression induced by corticosteroids. The aim of this study was to investigate the effect of a single injection of dexamethasone-21-isonicotinate on distinct immune functions of postpartum dairy cows because only scarce information is available on the effects of corticosteroid preparations when administered at a dosage and frequency for treatment of the fatty liver syndrome or primary ketosis. Sixteen Swedish red-pied dairy cows, between days 9 and 15 post partum, were allotted to either a control group (n = 8) or a treatment group (n = 8). The cows in the treatment group received a single intramuscular injection of a dexamethasone-21-isonicotinate suspension at a dosage of 0.02 mg/kg i.m. at the start of the experiment. White blood cell counts and selected lymphocyte functions (lymphocyte proliferation, expression of lymphocyte markers and the b2 and a4 chain of adhesion molecules belonging to the integrin family) and some parameters of the energy metabolism (glucose, insulin) were determined before the administration of corticosteroids (day 0) and subsequently at days 2, 4, 7 and 9 of the experiment. Changes in glucose and insulin were within the target range for treatment of the fatty liver syndrome or primary ketosis. Significant (P < 0.05) increases in the number of circulating white blood cells were observed in treated cows on the second day following treatment which was exclusively caused by an increase in the number of circulating neutrophils. Lymphocyte blastogenesis in response to ConA and the percentages of lymphocytes positive for CD2, CD4, CD8, CD49d and CD18 as well as the intensity of CD49d expression did not differ between the treatment and control groups. There was, however, a significant reduction (P < 0.01) in the intensity of CD18 expression on lymphocytes in the treated animals on the fourth day after treatment. In conclusion, a single administration of dexamethasone-21-isonicotinate in a dosage of 0.02 mg/kg i.m. at two weeks post partum in healthy cows had a significant but highly transient effect on CD18 expression on lymphocytes and the number of peripheral blood neutrophils, but did not affect lymphocyte blastogenesis or lymphocyte subpopulation patterns in peripheral blood.