Use of Embryo Transfer to Induce Twinning in Beef Cattle: Embryo Survival Rate, Gestation Length, Birth Weight and Weaning Weight of Calves

Abstract

Experiments were conducted in 1985 and 1986 at the Eastern Ohio Resource Development Center, Belle Valley, to examine the feasibility of using embryo transfer to induce twinning and to examine the influence of twinning on traits of the cow and calf. Embryos were collected from a total of 14 superovulated Angus donors on two dates each in 1985 and 1986 and were transferred to Angus recipients. A total of 124 embryos were transferred to 79 recipients, with 43 (34.7%) calves born alive. Seven of 45 (15.6%) recipients implanted with two embryos produced twins. In no case did both halves of the 15 embryos that were split to produce identical twins and implanted in the same recipient survive to birth. Proportion of calves born alive did not differ among transfer codes 3 (nonsplit embryos from two different donors implanted in separate uterine horns of the same recipient), 6 (nonsplit embryos from one embryo flush implanted in separate uterine horns of the same recipient) and 7 (nonsplit embryos from two different donors implanted in the same uterine horn of one recipient). Surgical transfers tended to result in a higher proportion of embryos surviving to birth (.43 vs .21; P = .16) and a higher twinning rate (.29 vs .04; P = .36) than did nonsurgical transfers. Age of recipient did not influence embryo survival (P = .98) or twinning rate (P = .99). Gestation length was 5 d shorter (P less than .01) for twin calves than for singles. Singles were 9 kg heavier (P less than .01) at birth and 32 kg heavier (P less than .01) at weaning than twins. However, cows raising twins produced 108 kg (51%) more total weaning weight than did cows raising singles.

Secondary Corpora Lutea Induced by hCG Treatment Enhanced Demi‐Embryo Survival in Lactating High‐Yielding Dairy Cows

“…The demi‐embryo survival rate here reported in untreated cows (18%) is similar to that obtained in beef cows with bilateral transfer [(21%); Davis et al. ] and indicates a low developmental competence of demi‐embryos, as previously reported (Chagas e Silva et al. ).…”

Aberrant Allocations of Inner Cell Mass and Trophectoderm Cells in Bovine Nuclear Transfer Blastocysts1

“…The reduced viability may result in an increased incidence of fetal mortality following embryo transfer. Abortion rates of in vivoproduced embryos ranged from 9% to 47% during the first or second trimesters of gestation [32][33][34][35][36]. The present cloning system shows relatively high rates of early and late abortion and neonatal and early postnatal deaths [1,4,7,[37][38][39].…”

Genetic parameters for twinning in the Maine-Anjou breed

“…Detrimental effects of twinning are: calf size reduction, higher stillbirth rates, the production of infertile females and more retained placentas under standard management (Cady and Van Vleck, 1978;Dickerson et al, 1988). On the other hand, twinning increases birth and weaning weight ouput per cow calving (Davis et al, 1989). The overall twinning effect on beef production may be positive in terms of economic efficiency if twinning rate is high (Dickerson et al, 1988).…”

“…However, twinning is rare in cattle, with only a few populations surpassing a 5% rate. Embryo transfer techniques (Davis et al, 1989;Johnson et al, 1989) have been applied in order to improve twinning rates but, as pointed out by de Rose and Wilton (1988), transferred embryo survival rates should be improved for application in the commercial beef industry. Genetic selection represents another way, not antagonistic to reproductive techniques, for improving twinning rates.…”