Begin flushing three weeks before breeding and, if possible, continue through the first cycle (approximately 17 days).įlushing ewes is most effective when they are mated early in the breeding season. They can be flushed with rested pastures or by supplementation. Ewes kept in acceptable condition before breeding normally produce more lambs if they are flushed, or given the chance to gain weight before and during the breeding season. Nutrition has a direct bearing upon reproductive performance. The stimulation does not occur when rams are placed with ewes earlier, or when rams are simply left with the ewes continuously. Then, at the beginning of the breeding season, rested fertile rams that are intended to sire the lamb crop can be introduced. Rams should be kept with the ewes for about 10 to 14 days and removed from the flock before breeding begins. The ram can be either fertile or surgically sterilized. It brings about earlier ovulation and estrual activity. The introduction of a ram near the end of the anestrous period appears to psychologically stimulate ewes. Heat stress during gestation impairs fetal development and can cause lambs to be significantly smaller at birth. High temperatures at breeding can reduce conception rate.
This is the biggest objection to fall lamb production. High temperatures are detrimental to fertility, embryo survival, and fetal development. In general, fertility is highest and most efficient when ewes are bred in September, October, or November ewes bred at this time generally produce the highest percentage of multiple births. Estrus becomes more frequent as the days become shorter. Sexual activity in sheep is primarily controlled by the ratio of daylight to dark. In some cases, it may be better to use rams of smaller breeds on young ewes to minimize the chance of lambing difficulties. For best results, breed them separate from older ewes. Separate ewes that lamb as yearlings from mature ewes, and manage and feed them so that the yearling ewes can grow to their maximum potential size.Įwe lambs and yearlings are normally rather shy breeders. Also, lambs born in winter or early spring are more likely to exhibit heat the first year than are lambs born later. Since the onset of puberty depends largely upon body weight, ewe lambs should be provided adequate levels of nutrition to reach at least two-thirds of mature weight before breeding. Ewe lambs that breed and lamb as yearlings generally have a greater lifetime production than ewes that have their that first lamb as 2 year olds. Ewes bred to white-faced, wool-breed rams may have a slightly longer gestation period than those bred to black-faced, meat-type rams.īreeding Ewe Lambs. High temperatures and high nutrition levels may shorten the gestation period two or three days. The medium-wool breeds and meat-type breeds ordinarily have a shorter gestation period than do the fine-wool breeds. The normal gestation period of ewes is approximately 147 days, ranging from 144 to 152 days.
The heat period usually lasts 30 to 35 hours, with a range of 20 to 42 hours. However, it can vary from 14 to 19 days.ĭuration of estrus, or heat period. The normal cycle for ewes is approximately 17 days between heat periods. Length between estruses, or heat periods. Three types of anestrous are observed in ewes: seasonal (influenced by length of day), lactation (influenced by the sucking stimulus of lambs), and postpartum. This is the period when ewes normally do not demonstrate estrus (heat). Ewes typically reach puberty at 5 to 12 months, depending on breed, nutrition, and date of birth.Īnestrous Period (reproductive inactivity).
0 kommentar(er)
