Review of Huang-huai sheep, a new multiparous mutton sheep breed first identified in China.

Huang-huai sheep are a new multiparous mutton sheep breed that has been cultivated by domestic scientific research institutes, governments, and sheep farms in China. Huang-huai sheep were bred using Dorper sheep as a sire and Small-tailed Han sheep as a dam. The breeding of Huang-huai sheep started in 2003, and three stages have been carried out: crossbreeding innovation, fixation in a two-way-crossbred closed flock, and herd propagation. A pilot test of Huang-huai sheep was conducted on 6 sheep farms from 2017 to 2018, and hereditary properties and production performance were evaluated in 2019. Huang-huai sheep were identified on site by the National Livestock and Poultry Resources Committee of China in December 2019 and approved as a new multiparous mutton sheep breed in China. The genetic distance showed that Huang-huai sheep are most closely related to Dorper sheep, Luxi black-headed sheep, and Small-tailed Han sheep, but the genetic distances are subspecies (0.02-0.20) each other. The body weights of adult Huang-huai sheep are 98.1 ± 5.2 kg (♂) and 71.7 ± 3.5 kg (♀), and those of 6-month-old Huang-huai sheep are 58.50 ± 6.55 kg (♂) and 52.45 ± 5.67 kg (♀). The slaughter rates of 6-month-old sheep are 56.02 ± 1.25% (♂) and 53.19 ± 1.19% (♀). The estrus cycle of Huang-huai sheep is 19.32 ± 2.8 days, the first estrus cycle occurs at 168 ± 12 days, the annual lambing rate of ewes is 252.82% ± 10.69%, the survival rate of lambs is 95.79 ± 0.95%, and the number of weaned lambs per ewe per year is 2.38 ± 0.14. The growth performance, carcass quality, and reproductive performance of Huang-huai sheep have been improved, resulting in considerable economic and social benefits and broader market prospects. This breed represents a new multiparous mutton sheep breed adapted for industrial sheep farms in China.