18 January 2008

6 minute read

The cow-calf industry is characterized by a unique combination of variation and tradition. Wide variety is found in the breeds, people and scale of operations involved. It's little wonder that the sector features diversity and innovation in the organization of calving and production systems. Tradition is firmly rooted in the evolution of the beef cow enterprise from the mixed-farm, where a few dual purpose cows in the barn provided both milk and meat. With only a few head to care for, calving inside the barn made total sense from a labour efficiency standpoint. Each birth was an event, and it was easy to maintain clean pens. But barn calving and intensive management started to falter as farms became specialized and the concentration of animals increased. Calf scours became an all too common feature of calving season.

Figure 1. Cow-Calf pairs on pasture

Research on calving alternatives was carried out at the University of Guelph's New Liskeard Research Station. The objective was to compare animal performance, cost of production and labour efficiency of two very different management systems. The conventional group was bred to calve mid-February to mid-April, with access to naturally ventilated barns during winter, calving in special indoor, but unheated pens. The alternative group was wintered in a similar manner, but were bred to calve in June and July, when they were on pasture. To create the groups, the existing herd was split into two comparable sub-herds, with similar genetic make up and age structure. Each year, the same sires were used in both groups, ensuring that differences seen in performance of the groups would be due to management system, not genetics. Other experiments conducted with the herd over this time, such as estrus synchronization, were replicated in both groups. The groups were on a common health protocol, and the same culling criteria were applied to each.

A five year summary of results showed striking differences between the systems. Pasture born calves were much less likely to receive assistance during the calving process (Table 1). In fact, barn heifers had an assist rate which was over three times greater than their grass calved counterparts, while barn cows had an assist rate five times greater than pasture cows. This is likely due in part to the lower birth weights observed with the summer born calves, who averaged 6 lbs. lighter than the winter group. Another factor may have been that the location of the calving pens made it more likely for cows to be observed during the birthing process, although pasture cows were also checked at least twice daily.

The barn group of calves also experienced a much higher rate of intervention for health related issues, such as hand feeding of colostrum and treatment with anti-diarrheal products (Table 2). Interventions incur both labour and product costs. Calf survival was the same for mature cows in both groups, but the pasture group heifers had a significantly higher weaning rate (92%) than the barn heifers (80%). In this calculation, weaning rate was defined as the number of calves weaned divided by the number of pregnant females retained from the previous season, so it included aborted calves, dead on arrivals (DOAs), neonatal deaths and any calf losses from birth to weaning.

Figure 2. Calves born on pasture are healthier

It cost more to calve cows inside (Table 3). About 30% more bedding was required annually for the barn calving group, due to their requirement for calving and post maternity pens. In addition, more labour was expended in managing the indoor calving system, and the average cost of treatments per calf was much higher for the indoor group, relative to the pasture group.

The cost of raising cattle was greater for the conventional group compared with the pasture calvers (Table 3). It took about $47 more per cow with the winter calving system compared with the summer system. When costs were deducted from revenues within each system, the summer pasturing calving group was a clear winner. Net margin for the summer group was $113 per cow exposed to breeding, which was 45% higher than the $78 per cow realized for the traditional group. So it looks like the summer system was a clear winner in terms of profitability.

The above research results were based on a comparison of herds of the same size, but they may be also extrapolated to the farm level based on an analysis of the factors which limit herd size. Several issues have been identified as limiting herd size on farms, and thus overall profitability of the cow-calf enterprise. One is focused around calving time. With intensively managed cows, night time calving checks and the number of calves which need birthing assistance and health treatments can be limiting. This is the most stressful time of the year in beef cow herds, and the hours of labour and degree of stress increases with the number of pregnant cows. Another potentially limiting factor is the value of capital investment in the calving facilities required for winter-early spring calving. If herd numbers are increased without concurrent facility expansion, the chances of a devastating scours outbreak increases.

Based on these research results, theoretical calculations predicted that for a given amount of labour, 25% more cows could be kept with a pasture calving system compared with barn calving. More cows with means more total profit is generated per farming enterprise. Based on these projections, net enterprise margin would increase by about 80% if herd numbers could be expanded from 80 hd to 100 hd, when switching from barn calving to pasture calving. Expanding or establishing very large cow herds (200+ cows) is a daunting challenge with a traditional management system based on confinement calving in late winter-early spring. A move to extensive management with pasture calving during late spring and summer could be a viable and profitable option.