Reducing the level of nutrition of twin-bearing ewes during mid to late pregnancy produces leaner prime lambs at slaughter.

The Australian prime lamb industry is seeking to improve lean meat yield (LMY) as a means to increasing efficiency and profitability across the whole value chain. The LMY of prime lambs is affected by genetics and on-farm nutrition from birth to slaughter and is the total muscle weight relative to the total carcass weight. Under the production conditions of south eastern Australia, many ewe flocks experience a moderate reduction in nutrition in mid to late pregnancy due to a decrease in pasture availability and quality. Correcting nutritional deficits throughout gestation requires the feeding of supplements. This enables the pregnant ewe to meet condition score (CS) targets at lambing. However, limited resources on farm often mean it is difficult to effectively manage nutritional supplementation of the pregnant ewe flock. The impact of reduced ewe nutrition in mid to late pregnancy on the body composition of finishing lambs and subsequent carcass composition remains unknown. This study investigated the effect of moderately reducing ewe nutrition in mid to late gestation on the body composition of finishing lambs and carcass composition at slaughter on a commercial scale. Multiple born lambs to CS2.5 target ewes were lighter at birth and weaning, had lower feedlot entry and exit weights with lower pre-slaughter and carcass weights compared with CS3.0 and CS3.5 target ewes. These lambs also had significantly lower eye muscle and fat depth when measured by ultrasound prior to slaughter and carcass subcutaneous fat depth measured 110 mm from the spine along the 12th rib (GR 12th) and at the C-site (C-fat). Although carcasses were ~5% lighter, results showed that male progeny born to ewes with reduced nutrition from day 50 gestation to a target CS2.5 at lambing had a higher percentage of lean tissue mass as measured by dual energy X-ray absorptiometry and a lower percentage of fat during finishing and at slaughter, with the multiple born progeny from CS3.0 and CS3.5 target ewes being similar. These data suggest lambs produced from multiple bearing ewes that have had a moderate reduction in nutrition during pregnancy are less mature. This effect was also independent of lamb finishing system. The 5% reduction in carcass weight observed in this study would have commercially relevant consequences for prime lamb producers, despite a small gain in LMY.

Post-fundoplication contrast studies: is there room for improvement?

OBJECTIVE: Since the mid-1990s, laparoscopic fundoplication for gastro-oesophageal reflux disease has become the surgical procedure of choice. Several surgical groups perform routine post-operative contrast studies to exclude any (asymptomatic) anatomical abnormality and to expedite discharge from hospital. The purpose of this study was to determine the accuracy and interobserver reliability for surgeons and radiologists in contrast study interpretation. METHODS: 11 surgeons and 13 radiologists (all blinded to outcome) retrospectively reviewed the contrast studies of 20 patients who had undergone a laparoscopic fundoplication. Each observer reported on fundal wrap position, leak or extravasation of contrast and contrast hold-up at the gastro-oesophageal junction (on a scale of 0-4). A κ coefficient was used to evaluate interobserver reliability. RESULTS: Surgeons were more accurate than radiologists in identifying normal studies (specificity = 91.6% vs 78.9%), whereas both groups had similar accuracy in identifying abnormal studies (sensitivity = 82.3% vs 85.2%). There was higher agreement amongst surgeons than amongst radiologists when determining wrap position (κ = 0.65 vs 0.54). Both groups had low agreement when classifying a wrap migration as partial or total (κ = 0.33 vs 0.06). Radiologists were more likely to interpret the position of the wrap as abnormal (relative risk = 1.25) while surgeons reported a greater degree of hold-up of contrast at the gastro-oesophageal junction (mean score = 1.17 vs 0.86). CONCLUSION: Radiologists would benefit from more information about the technical details of laparoscopic anti-reflux surgery. Standardised protocols for performing post-fundoplication contrast studies are needed.