By D. Peter Stonehouse, Lan Gao, Department of Agricultural Economics & Business, University of Guelph and Tom Hamilton, OMAFRA, New Liskeard Research Station

Traditionally beef cow herds in Ontario are set to calve in the winter months. The cold weather raises the appeal of confinement calving, not just for the sake of the dam and her calf, but also for the sake of the farm operator. Confinement means that we need a building with individual calving pens, bedding, in-door feeding, and lots of labour looking after the animals. It's a labour-intensive and high-cost way of calving cows.

As an alternative, have you ever thought about having your herd calve in the summer when the weather is pleasant so that it can all happen naturally on pasture? Tom Hamilton and his colleagues at the New Liskeard Research Station have. Starting in 1993, the herd of 150 cows was split into two even groups, one group of 75 set to calve in February-March, the other in June-July. For five years, data were carefully compiled on these groups, so that traditional winter calving could be compared with the alternative summer calving. Data were kept on everything from pregnancy, culling and calving rates, to feed consumption, health treatments for the calves, and labour requirements.

Key findings have been reported before but they are worth repeating if only to emphasize which factors were roughly the same and which were different between winter and summer calving. No or very little difference was found in a) body condition of dams at breeding; b) pregnancy rates of cows; c) culling rate for cows; d) calf survival rate; and e) calf weaning rate. In contrast, differences were found in a) pregnancy rates of heifers (summer calvers were higher); b) culling rate for heifers (summer calvers were lower); c) calving ease score (summer calvers were lower, so had an easier time); d) assisted births (summer calvers needed fewer for both cows and heifers); e) calf birth weights (these were lower for summer calvers, both cows and heifers); and f) calf health treatments (lower for summer calvers, whether measured in percentage terms or in number of treatments per calf born). Hamilton suggests that the lower calf birth weights for summer calvers worked in favour of fewer assisted births needed and superior calving ease scores, especially for heifers. He also reasons that summer calves born on open pasture get a head start on general health and well-being, leading to fewer health treatments required.

Moreover, the lower birth weight for summer calvers did not appear to detract from calf performance through to weaning. Although still lighter at 531 lb. weaning weight than winter-born calves at 558 lb., the summer-born calves achieved their weight gain over a shorter period of time and at slightly higher daily gain rate . On the feed requirements front, the summer-calving cows required less concentrates, straw, and mineral supplement, but more hay and pasture for grazing (Table 1). In addition, the calves born in summer consumed more concentrates than winter-born calves, because summer calves are in confinement at an older age (4 to 7 months from October to January) when their appetites are bigger. Total feed requirements for cows and calves combined are therefore higher for summer calvers than for winter calvers.

Summer calvers will, however, save you some labour time. Between the fewer assisted births and the fewer health treatments, you can shave nearly an hour per cow. True you have to spend more time looking after summer-born calves after the herd has been confined in October, but summer calvers take a little less labour time overall.

Agricultural economists Peter Stonehouse and Lan Gao at the University of Guelph took Tom Hamilton's bio-physical data and applied market prices for beef animals and market costs for feeds, labour and other inputs, to give an economics performance comparison. Market prices for weaned calves were based on 12-year averages for the months when offspring were sold (October for winter calvers, January for summer calvers), using OMAFRA data. Prices were slightly higher for winter calvers at $1.06 per lb. than for summer calvers at $0.99 per lb. (Table 2). The higher price combined with a heavier weaned calf provided higher gross revenues by about $40 per beef cow for winter calvers. Total expenses for winter calvers were higher by about $23 per cow ($586.21 for winter calvers vs. $562.85 for summer calvers). Every category of cost was lower for summer calvers except for pasture and stored feeds (Table 2). The bottom-line net return (to other omitted costs, equity capital invested and management) was less negative for winter calvers, at -$68.10 per cow exposed to breeding, than for summer calvers, at -$83.04.

It's perhaps significant that this bottom line was found to be negative for both winter calvers and summer calvers; it shows how tough it is to make a buck in the beef cow-calf business. Although you're not any further ahead financially with the summer calving program, it's suggested that it is worth trying out the alternative to traditional winter calving. It's pleasanter work looking after a herd that's calving naturally at pasture during warmer weather, and it's less work with fewer calf losses and health problems. It's easier on the cows too.