Effects of early versus late spring calving on beef cow-calf productivity

Abstract

Pang, H., Makarechian, M., Goonewardene, L. A. and Berg, R. T. 1998. Effects of early versus late calving on beef cow-calf productivity. Can. J. Anim. Sci. 78: 249-255. Early (April) vs. late (May/June) calving was compared over 3 yr at the University of Alberta Ranch at Kinsella, Alberta, Canada. Three synthetic lines, two of which were predominantly beef breeds (BS1 and BS2) and one with approximately 60% dairy breeding (DS), were used and 995 records were analyzed. Cows from each line were randomly allotted to the early or late breeding schedules at the time of breeding. The same bulls bred cows in their own line, beginning in June and in August for two 6-wk periods. Calving season had no significant effect (P > 0.05) on pregnancy rate (%), calving assistance, calving and weaning rate (%), adjusted off-test weight or post-weaning ADG, suggesting that late calving can be a viable management option. Birth weights of all calves were significantly lower in the early group than in the late group (38.9 vs. 41.2 kg, P < 0.01). In the BS1 and BS2 lines, early calves had higher adjusted pre-weaning ADG: BS1 (1.18 vs. 1.11 kg d -1 , P < 0.01), BS2 (1.12 vs. 1.05 kg d -1 , P < 0.01) but the differences in the DS line were not significant (P > 0.05). The early calves were older at weaning and therefore were expected to have higher pre-weaning ADG. The fact that the late-born calves in the DS line equalled the early calves in pre-weaning ADG indicates that they were growing relatively faster. Late calving DS heifers had significantly higher weights (P < 0.01) at breeding in June, higher ADG to breeding, and cows had higher body condition scores at calving and weaning (P < 0.01), suggesting that DS cattle benefited more by late calving. The late-calving management system appears to be a viable option for cow-calf production in Alberta.Key words: Calving season, reproductive traits, weight and growth, beef cattle Pang, H., Makerechian, M., Goonewardene, L. A. et Berg, R. T. 1998. Effets comparatifs de la précocité du vêlage de printemps sur la productivité des élevages de veau d'embouche. Can. J. Anim. Sci. 78: 249-255. Nous avons comparé pendant trois ans les effets du vêlage précoce (avril) et du vêlage tardif (mai-juin) au ranch de l'Université de l'Alberta à Kinsella en Alberta (Canada). Nous utilisions pour cette analyse 995 relevés de production concernant trois souches synthétiques, dont deux à dominance bouchère (BS1 et BS2) et une à 60 % d'ascendance laitière (AL). Les vaches de chaque souche étaient assignées au hasard à un protocole de mise à la reproduction, précoce ou tardif. Les mêmes taureaux étaient utilisés sur les vaches de même souche, à partir de juin ou d'août, chaque fois pour une durée de six semaines. La saison de vêlage n'avait pas d'effets significatifs (P < 0,05) sur le taux de gravidité (%), sur l'assistance requise au vêlage, sur le taux de vêlage et de sevrage (%), ni sur le poids corrigé en fin de test ou sur le GMQ en post-sevrage, ce qui porte à considérer le vêlage tardif comme une option d...

Post-Weaning Performance of Steers from Varying Calving and Weaning Strategies in Montana

“…Feed efficiency during the growing phase was not measured. Results are consistent with Pang et al (1998) who reported no difference in postweaning ADG in male calves born in early or late spring and with Lardy et al (1998) who reported no effect of spring vs. summer calving season on post-weaning ADG or feed efficiency. Feed efficiency has been reported to be improved in early weaned cattle (Myers et al, 1999a,b;Story et al, 2000;Shoonmaker et al, 2002), but this may be related to lighter weights and decreased maintenance energy requirements of early weaned calves early in the growing phase.…”

“…A number of authors have found age at weaning to affect efficiency of gain in feedlot steers (Fluharty et al, 2000;Barker-Neef et al, 2001;Schoonmaker et al, 2002). Date of calving may have less of an effect; Pang et al (1998) reported that male calves born in Alberta in either April or May and June did not differ in post-weaning gain. Lardy et al (1998) reported no effect of spring vs. summer calving season on post-weaning ADG or feed efficiency of steers, but post-weaning management of summer-born steers did influence several carcass traits.…”

Comparison of FTAI and Natural Service Breeding Programs on Beef Cow Reproductive Performance, Program Cost and Partial Budget Evaluation

“…The calving rates of both programs did not match the pregnancy rates, because two cows in each program aborted. The calving rates of the NSB program reported in the current study (80%) are similar with Pang et al (1998), who reported 82%, but lower than those reported by Durunna et al (2014), who reported a 94% calving rate. The pregnancy rate for cows in the NSB program are within the range of that reported by Damiran et al (2016) (93±3%), a study conducted at the same location (Lanigan, Saskatchewan, Canada).…”

“…The average length of calving season was 5 d shorter in FTAI (64 d) program, compared to the NSB (69 d) program. Pang et al (1998) reported a calving span of 53 d, which was shorter than that of the current study, presumably because of the shorter breeding season evaluated in their study. The recommended breeding season length is 63 d, which results in a similar 63 d calving season length (BCRC, 2019).…”

Calving system and weaning age effects on cow and preweaning calf performance in the Northern Great Plains1,2

“…observed by Smith et al (2001) for early vs. late springborn calves on the short-grass prairie of southern Wyoming. Pang et al (1998) reported decreased preweaning ADG by calves with an average birth date of April 14 compared with May 27 when grazing rangeland in eastcentral Alberta. The decrease in weaning weights for later-born calves is related to declines in forage quality and different environmental conditions (Figure 1; NOAA, 1998NOAA, -2001 than those for calves born earlier in the year.…”