Heterosis Heterosis, or hybrid vigor, refers to the increased vitality or “doing ability” of the crossbreds as compared to the average of the parental breeds. The only way to get heterosis is through crossbreeding. Heterosis is expressed by the crossbred lamb (individual) and by the crossbred ewe (maternal). Crossbred lambs, on the average, are more vigorous and have a higher survivability than...

Ewe performance was compared for five pure breeds of sheep (Finnsheep, F; Rambouillet, R; Dorset, D; Targhee, T; Suffolk, S) and the crosses in development of two maternal composite lines (C1 = 1/2F1/4R1/4D and C2 = 1/2F1/4T1/4S). The data involved 10,959 breeding season records of 4,219 ewes by 412 sires. Ewe production and the components (fertility, litter size, neonatal and preweaning lamb s...

Thirteen crossbred ewes were used to compare weigh-suckle-weigh (WSW) and machine milking (MM) methods for determining milk production of ewes that were rearing single or twin lambs. At parturition, ewes were 13 mo of age and produced six single lambs and seven pairs of twin lambs. Milk production estimates were initiated on d 6 of lactation and a 3-d rotation of the two techniques was implemen...

This study evaluated the reproductive and productivity of local Dorper crossbred ewes in a community-based management system. We analyzed data collected from 2013 to 2021, taking into account different factors such as dam-breed, location, type birth, season, year lambing. Lambing was observed all year-round, but majority (35%) occurred September, October, December. suggests that pasture availab...

Mature pregnant crossbred ewes (n = 90) were used in a randomized complete block design experiment and were assigned to 1 of 3 winter-feeding systems differing in primary feed source: haylage (HL), limit-fed corn (CN), or limit-fed dried distillers grains (DDGS). Effects of these winter-feeding strategies on postweaning progeny performance were determined. Lamb progeny (n = 96) were weaned at 6...

The incidence of positive CMT, indicative of subclinical mastitis, was studied in a flock of purebred Targhee ewes from four selection lines. The incidence of positive CMT was found to be random at lambing with respect to age and line of ewe, number of lambs born and weaned and sex of lambs, but at docking (3 to 7 weeks after lambing) increased with increasing age of ewe and number of lambs bor...

The study aimed to assess additive breed effects for growth (birth, weaning and ewe adult weight), fitness (lamb survival tick count under natural challenge) reproduction traits per mated in Dorpers, the most common meat South Africa (SA), SA Mutton Merino (SAMM) a prominent dual-purpose extensive environments. Additionally, reciprocal crosses between two breeds were used estimate dam heterosis...