Ewe live iveights were recorded 4 weeks prior to mating, at the beginning of mating and 22 to 23 days later over a period of 3 years in a flock of some 300 breeding ewes comprising approximately equal numbers of Australian Merino, Ideal (Polwarth), Merilin and Corriedale breeds in a pastorally based grazing system in Uruguay. Multiple-bearing ewes were generally heavier than single-bearing ewes which in turn were heavier than ewes which did not conceive, these differences being greatest in 3-and 4-year-old ewes (i.e. in their second and third breeding seasons). Body condition scores of non-pregnant ewes were lower than those of pregnant ewes, particularly in the 3and 4-year-old age groups. Ewe live weights achieved prior to, during and at the end of the mating period and the body condition score achieved 4 weeks prior to mating all had significant influences on the number of lambs born (P < 0-01) but there were no significant effects of changes in either live weight or body condition over the 4 weeks prior to mating or during the mating period. The effect of body condition score over the range from 2-0 to 4-0 was to increase the proportions of single-and multiple-bearing ewes and to decrease the proportion of non-pregnant ewes such that the number of lambs born per ewe mated increased from 0-94 to 1-38. Fleece weights differed significantly between breeds, Corriedales having the heaviest fleeces and Merilins the lightest (4-26 and 3-22 kg respectively). Wool production was also significantly and positively affected by age (P < 0-01) and by ewe weight at mating (P < 0-01). The results demonstrate the importance of giving preferential nutritional treatment to younger ewes to ensure a satisfactory subsequent lambing performance and improved wool production.
Medium-wool Australian Merino rams were sampled in 1978 and 1979 to estimate the relationships between the follicle curvature score, fleece and body characteristics.As a high correlation coefficient between two independent observers was found in both years, only one observer was used to correlate follicle curvature score with wool production.
Differences in the productivity of twin- and single-bearing, spring-lambing Corriedale ewes and their progeny were studied over 8 years at the Experimental Station, Faculty of Agriculture, Paysandu, Uruguay. Lambing ewes, grazing improved pastures during late pregnancy and early lactation, produced 9.7% less wool than dry ewes, gestation and lactation accounting for 4.5 and 5.2% of this difference, respectively. No difference in wool production was found between ewes rearing 1 or 2 lambs. Twin-born sheep produced 1.8% less wool than singles, but the difference decreased with age. Twin-born ewes had a 7.5% higher lambing rate than single-born ewes, but the mortality rate among their lambs was higher (37.1 v. 20.4%). The liveweight of single-born sheep was higher than that of twins by 20.4%, 16.0% and 11.4% at marking, weaning and 11 1 days of age, respectively. We suggest that the difference in productivity between twin- and single-bearing ewes, and their lambs, can be minimised by adequate nutrition in late pregnancy and early lactation.
A modular torque measuring instrument capable of performing tapping torque tests (TTT) according to the ASTM D-5619 standard was designed, developed, and validated. With this new instrument, the performance of different lubricants can be evaluated in terms of frictional torque and energy consumption during tapping processes. This instrument can adapt onto any conventional milling machine or CNC machine and operate under various machining operations such as tapping, drilling, and other processes. To validate the design and performance of this new device, three commercially available lubricants were evaluated. From the three tested conditions, the results showed good repeatability, with consistent results throughout the different tests for each lubricant. The impact of such a proposed instrument ranges from academic use to industrial business use.
Total follicle density, primary follicle density, secondary follicle density, secondary/primary ratio and incidence of medullated fibres were studied in skin specimens from 78 2-year-old Merilin rams representing nine parent studs in Uruguay. The limited data available suggest that the studs sampled may fall into various groups, although separation into distinct groups is not equally well defined for all variables measured. Consequently, a firm conclusion about the Merilin awaits further information on fleece weight, staple length and body weight.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.