Fresh, stockpiled, and composted beef cattle feedlot manure: nutrient levels and mass balance estimates in Alberta and Manitoba.

The fate of manure nutrients in beef cattle (Bos taurus) feedlots is influenced by handling treatment, yet few data are available in western Canada comparing traditional practices (fresh handling, stockpiling) with newer ones (composting). This study examined the influence of handling treatment (fresh, stockpiled, or composted) on nutrient levels and mass balance estimates of feedlot manure at Lethbridge, Alberta, and Brandon, Manitoba. Total carbon (TC) concentration of compost (161 kg Mg(-1)) was lower (P < 0.

Relationships between urea dilution measurements and body weight and composition of lactating dairy cows.

The objective of the present study was to investigate the potential of the urea dilution technique, coupled with live animal measures to predict the body components of dairy cattle. The study involved 104 lactating Holstein-Friesian cows offered grass silage-based diets. Urea space volume (USV) was calculated from 2 collection periods of blood samples following infusion of urea at 12 (USV12, kg) and 30 (USV30, kg) min after infusion, and then as a proportion of live weight (LW) or empty body weight (EBW).

Fertility of dairy cows in Northern Ireland.

A comprehensive database was established on the milk production and reproductive performance of dairy cows in 19 selected herds in Northern Ireland, varying in size, management system and genetic merit. Data were obtained for 2471 cows, 1775 of which calved in a second year, and 693 were culled from the herd for specific reasons. The estimated mean rate of heat detection (assessed by the interheat interval during the main breeding season) in all the herds was 71 per cent, with a range from 53 to 92 per cent The average conception rate to first insemination was 37.

Electronic monitoring of mounting behavior in beef cattle on pasture.

An automated heatmount detection system was employed to detect estrus for artificial insemination in 57 beef cows. First service conception rate was 84.2% and the pregnancy rate was 89.

Residues of nortestosterone esters at injection sites. Part 2. Behavioural effects.

Anecdotal evidence in man suggests that abuse of anabolic androgenic steroids (AAS) is linked with increased aggression. In order to test the hypothesis that administration of nortestosterone (beta-NT) esters may increase aggression, behavioural effects following beta-NT phenylpropionate (NTPP) administration were assessed in male mice using the isolation-induced aggression paradigm. Mice (n = 80) were individually caged and randomly assigned to 'resident' or 'intruder' status.