Journal of Animal Science, Vol 68, Issue 12 4039-4050, Copyright © 1990 by American Society of Animal Science

JOURNAL ARTICLE

Embryo-transfer twinning and performance efficiency in beef production

P. Guerra-Martinez, G. E. Dickerson, G. B. Anderson and R. D. Green
University of Nebraska, Lincoln 68583-0908.

Effects of twinning on efficiency of beef production were estimated from results of bilateral transfer of two Angus x Hereford (AxH) embryos into each of 241 heifers and 84 cows (H, A, HxA or Holstein x H) over 4 yr. Calves were weaned at 180 d and fed either 220 d in a feedlot (1977) or 170 d on forage and 140 d in a feedlot (1978 to 1980). Effects of parity, twinning and sex of calf were estimated as covariates within year-breed of dam. Pregnancy at 45 to 60 d of gestation was 68% in heifers (H) and 74% in cows (C), with 40% single (S) and 60% twin (T) births. Dystocia was 28% in H vs 10% in C (P less than .05), and tended to be less (P greater than .05) for T than S in H. More placentas were retained (P less than .05) for T than for S in both H (35 vs 12%) and C (24 vs 4%). Twin gestations averaged 3 d shorter and subsequent calving intervals 13 d longer (P less than .05), but total calf mortality was slightly higher (P greater than .05). Abortions were 4% in H only. Twinning females lost maternal weight during late gestation (P less than .05) when crowding limited voluntary feed intake, while fetal requirements were 60% higher (P less than .01). Twins increased milk output 25% (P less than .05), but 11% higher feed intake maintained cow weight during lactation. Twinning reduced birth weight 13% and weaning weight 17% (P less than .05), but 400-d feedlot weight only 9% because of compensating feedlot gain. Twins gained 18% faster than S during postweaning 170-d forage feeding, but 5% slower in feedlot to 8% lighter 490-d weight (P less than .05). Assuming 40% higher veterinary and labor costs for twins, estimated integrated herd costs per unit of age-constant output value would be lower for T than for S production by about 24% for marketing either at weaning or at 400 d.

This article has been cited by other articles:

				N. G. Hossein-Zadeh, A. Nejati-Javaremi, S. R. Miraei-Ashtiani, and H. Kohram An Observational Analysis of Twin Births, Calf Stillbirth, Calf Sex Ratio, and Abortion in Iranian Holsteins J Dairy Sci, November 1, 2008; 91(11): 4198 - 4205. [Abstract] [Full Text] [PDF]

				S. E. Echternkamp, R. A. Cushman, M. F. Allan, R. M. Thallman, and K. E. Gregory Effects of ovulation rate and fetal number on fertility in twin-producing cattle J Anim Sci, December 1, 2007; 85(12): 3228 - 3238. [Abstract] [Full Text] [PDF]

				S. E. Echternkamp, R. M. Thallman, R. A. Cushman, M. F. Allan, and K. E. Gregory Increased calf production in cattle selected for twin ovulations J Anim Sci, December 1, 2007; 85(12): 3239 - 3248. [Abstract] [Full Text] [PDF]

				G. Wu, F. W. Bazer, J. M. Wallace, and T. E. Spencer BOARD-INVITED REVIEW: Intrauterine growth retardation: Implications for the animal sciences J Anim Sci, September 1, 2006; 84(9): 2316 - 2337. [Abstract] [Full Text] [PDF]