Carcass characteristics and meat quality of progeny of five Merino dam lines, crossed with Dormer and Suffolk sires

This study details the slaughter traits of lambs born from a terminal crossbreeding experiment that involved five Merino type dam lines crossed with Dormer and Suffolk sires. Dam lines included dual purpose types; South African Mutton Merino (SAMM), Dohne Merino, SAMM rams crossed to commercial Merino ewes (SAMM cross) and specialist Merino lines selected either for clean fleece weight (FW+) or for an increased fertility (Rep+). Data include between 228 and 483 individual records, depending on the trait. The unadjusted fat depth 25 mm from the midline at the 13th rib of lambs from dual-purpose ewes was between 22 and 32% greater than that of lambs from FW+ Merino ewes. Progeny from Rep+ Merino ewes showed a closer resemblance to the progeny of dual-purpose breeds than to those of FW+ Merino ewes in this instance. Adjustment for slaughter weight eliminated these differences. The initial pH of meat from progeny of FW+ Merino ewes was lower than that from progeny of dual-purpose ewes, and Rep+ Merino ewes. No differences in Warner-Bratzler shear values of the meat were found between the different crosses. Crossbred progeny of the Merino lines performed satisfactorily for all the traits considered, and will not be discriminated against in the market. No conclusive differences in favour of either sire breed were found. Keywords: Dohne Merino, meat quality, SA Mutton Merino, terminal crossbreeding South African Journal of Animal Science Vol. 38 (4) 2008: pp. 355-36

A comparison between the body composition, carcass characteristics and retail cuts of South African Mutton Merino and Dormer sheepe/pj

No Abstract. South African Journal of Animal Science Vol. 34 (1) 2004: pp.44-5

Production of five Merino type lines in a terminal crossbreeding system with Dormer or Suffolk sires

This study details the production performance of ewes and lambs that originated from a terminal crossbreeding experiment that involved five Merino type dam lines and two terminal crossbreeding sire lines from 1999 to 2002. Ewe lines were SA Mutton Merino (SAMM), SAMM rams crossed to Merino ewes (SAMM cross), Dohne Merino, as well as specialist Merino lines selected for clean fleece weight (FW+) and for an increased reproduction rate (Rep+). Dormer and Suffolk rams were used as sire breeds on these ewes. Data include 777 birth and 605 weaning records of lambs and 562 production year records of ewes. At birth the progeny of SAMM ewes were heavier than those of the other ewe lines, while FW+ ewes produced smaller lambs at birth than SAMM cross and Rep+ ewes. Lamb survival was not significantly affected by ewe line or sire breed. The progeny of the dual-purpose ewe lines (SAMM, SAMM cross and Dohne Merino) were heavier than those of Merino ewes (FW+ and Rep+) at weaning. No sire breed difference was found for birth or weaning weight. The joining weights of dual-purpose ewe lines were higher than those of Merinos. Although considerable variation was found between ewe lines in terms of lamb output (number or weight of lamb weaned per ewe joined), the only significant difference was for weight of lamb weaned between SAMM cross and FW+ Merino ewes. Means for weight of lamb weaned per joining (in kg) were 37.3 for SAMM ewes, 39.6 for SAMM cross ewes, 35.5 for Dohne Merino ewes, 28.9 for FW+ ewes and 34.6 for Rep+ ewes. No differences in ewe reproduction were found between ewes joined to Dormer or Suffolk rams. The clean wool production of SAMM ewes amounted to 46% of that recorded in FW+ ewes. Corresponding percentages were 68% for SAMM cross ewes, 74% for Dohne Merino ewes and 90% for Rep+ ewes. The wool of SAMM ewes was slightly coarser in diameter than those of SAMM cross and FW+ ewes, which in turn was coarser than those of Rep+ and Dohne Merino ewes. The economic viability of crossbreeding programs involving the respective ewe lines would depend on the ratio between the prices of wool and lamb. No conclusive advantage could be demonstrated in favour of any of the sire breeds. Keywords: Fibre diameter, Lamb growth, Lamb output, Reproduction, South African sheep breeds, Wool yield South African Journal of Animal Science Vol.33(4) 2003: 223-23

Relative performance and efficiency of five Merino and Merino-type dam lines in a terminal crossbreeding system with Dormer or Suffolk sires

The production performance of ewes was assessed in a terminal crossbreeding experiment involving five Merino and Merino-type dam lines and two terminal crossbreeding sire breeds. Dam lines were SA Mutton Merino (SAMM), SAMM rams crossed to Merino ewes (SAMM cross), Dohne Merino, as well as specialist Merino lines selected for clean fleece weight (FW+) and for an increased reproduction (Rep+). Dormer and Suffolk rams were used as sires. Dual-purpose ewes were heavier than Merinos on average and at the ultimate joining at 3.5 years. Average clean fleece weight for SAMM ewes was approximately half that of Merino ewes while clean fleece weights for Dohne and SAMM cross ewes were intermediate. Differences between progeny in slaughter age, marketing weight, dressing percentage and carcass weight could largely be attributed to the comparison of purebred Merino lines with dual-purpose lines. The slaughter age of lambs from the two Merino lines was between 14 and 21% higher than that of the dual-purpose lines. Lambs from purebred SA Mutton Merino (SAMM) dams also outperformed lambs from SAMM cross ewes for slaughter age, slaughter weight and carcass weight. Considerable variation was found between dam lines for reproduction parameters, but few significant differences were found. Lamb output, defined as total weight of lamb slaughtered per joining, averaged 42.7 kg for SAMM ewes, 44.2 kg for SAMM cross ewes, 39.3 kg for Dohne ewes, 32.9 kg for FW+ Merino ewes and 42.0 kg for Rep+ Merino ewes, but differences between lines only tended to be significant. Sire breed did not affect lamb performance or ewe productivity markedly. An economic simulation indicated large differences in gross income per small stock unit between dam lines, warranting further research on the efficiency of terminal Merino-type damlines. Key Words: Carcass yield, Fibre diameter, Gross income, Lamb output, Productivity, Reproduction, Wool yield South African Journal of Animal Science Vol.34(3) 2004:135-14

Behaviour of Merinos selected for multiple rearing ability in response to human beings.

Please help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected] Wetenskapp

Behaviour response of Namaqua Afrikaner, Dorper and South African Mutton Merino lambs towards humans

The response of Namaqua Afrikaner, Dorper and South African Mutton Merino lambs, of approximately four months of age, towards a human being situated between them and their flock mates was studied in an arena test. The objective of the study was to determine whether the unimproved Namaqua Afrikaner, with an arguably shorter history of selection, would react differently to humans in an arena test compared to commercial breeds. A total number of 305 animals, born in 2010 and 2011 and raised under extensive veld conditions, were assessed in a modified arena test when the lambs born in each year were approximately four months old. From the test results it was possible to calculate the following parameters of the behaviour of the sheep: (i) The mean distance from the human operator, (ii) the time a lamb spent in a specific zone situated either close to or far from the human, and (iii) the total number of boundaries crossed, which gives an indication of the total distance travelled by an individual lamb. Other data recorded were the number of bleats and the number of times an animal urinated or defecated. There were no significant sex and birth type differences for any of the behaviour traits. No conclusive breed differences were found for any of the traits describing the behaviour of the lambs, except for the number of bleats. Namaqua Afrikaner lambs bleated significantly (24.0 ± 1.2) more in the three minute testing period than Dorper (8.2 ± 0.9) and South African Mutton Merino lambs (11.9 ± 2.5). Further research is necessary to see if this slight indication of anxiety could be related to other traits such as lamb survival or product quality.Keywords: Arena test, distance travelled, times defecated, times urinated, sheep, stockman, temperamen

Production of five Merino type lines in a terminal crossbreeding system with Dormer or Suffolk sires

AgriwetenskappeVeekundige WetenskappePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

The effect of breed, ewe age and season on tick counts of indigenous and commercial sheep in South Africa.

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Searching for SNPs that affect sheep robustness: <I>CYP17</I> SNP affects behavioural responses to psychological stress

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Carcass composition of Namaqua Afrikaner, Dorper and SA Mutton Merino ram lambs reared under extensive conditions

This study evaluated the differences in the muscle-fat-bone yield of Namaqua Afrikaner (NA), Dorper (D) and SA Mutton Merino (SAMM) ram lambs. The breeds constituted an indigenous, hardy and late maturing, fat-tailed breed (NA), an early maturing, commercial meat breed (D) and a late maturing commercial dual-purpose breed (SAMM). Lambs were slaughtered at 35 (± 8) days post weaning. Carcasses were cooled for 24 h, separated into retail cuts (leg, loin, rib, and shoulder), weighed and deboned. Meat and fat were separated after deboning and weighed to calculate the muscle-fat-bone yield per cut. Least-square means were computed for the respective breeds, using slaughter age as covariate. Results for percentage meat indicate that, with exception of the rib, retail cuts from the NA breed contained a lower percentage of meat than D and SAMM breeds, particularly in the valuable loin and leg cuts. The shoulder of the NA had a lower percentage meat than that of the D. The percentage fat in retail cuts did not differ between breeds for any of the cuts. In comparison with both D and SAMM, NA contained a higher percentage bone in all cuts. Dorper and SAMM carcasses did not differ in terms of the percentage of bone, fat or muscle for any of the retail cuts. The lower meat yield, particularly in the more expensive loin and leg of the NA, when compared to the commercial meat breed (D) could make the former less preferred for meat production. However, the NA compared more favourably than the dual-purpose SAMM. Differences in carcass composition could be attributed to the fact that the NA is an unimproved and late maturing sheep breed.Keywords: Muscle-fat-bone yield, indigenous, early-maturing, late-maturing, retail cuts, shee