Ultrasonic Carcass Assessment of Dorper and Dorper x Merino Lambs Using MLD and Body Measurements

Abstract

Ultrasonic measurements of Musculus longissmus dorsi thoracis et lumborum (MLD)were taken of Dorper (n=99) and Dorper x Merino (n=65) lambs at 156 days of age and comparisons made to various body dimensions to ascertain whether sex, genotype, birth type and live weight had any effect on these parameters. Lambs were weaned two months after birth and placed ad libitum on basic dry land pasture during the draught spring and summer months of 2014 in the arid southeastern region of Turkey. Least square means of backfat thickness, skin+backfat thickness, muscle depth, body length, chest girth and live weight, at the mean age of 156 days, were 0.17 cm, 0.32 cm, 1.75 cm, 63.30 cm, 72.37 cm and 25.16 kg, respectively. Genotype was a statistically significant factor in terms of back fat thickness (BFT), skin and backfat thickness (S+BFT), muscle depth (MD), body length (BL) and live weight (LW). The study showed that Dorper and Dorper x Merino genotypes into Turkey show a clear advantage over the native breeds in terms of meat production and quality not to mention the high potential for lean carcass production. Ultrasonic measurements of Longissimus thoracis et lumborum (MLD) will provide an important contribution to selection index in breeding programs for Dorper and Dorper crossbred genotypes. However estimation of genetic parameters are required in containing a pedigree database in order to establish an effective selection index.

The relationship of ultrasound measurements taken from two different anatomical regions to carcass traits and chemical composition of the carcass in Karayaka lambs

“…From the measurements taken from the 3-4L region, only UFT had a high positive correlation with live weight, warm carcass weight, cold carcass weight, and the meat and bone amounts in the carcass, while other ultrasound measurement correlation coefficients were found to be insignificant. Supporting the current results, various authors have noted high positive correlations of UFT with live weight (7,22,23,28), cold carcass weight, bone amount (10), and meat amount (2,10). The fact that UFT measured from both regions in this study had a high correlation with live weight, warm carcass weight, cold carcass weight, and bone and meat amounts means that UFT may be used for a primary estimation of carcass traits (4,9).…”