Editor’s note: The article was written by Peter Krawczel, graduate student at the Miner Institute and first appeared in the Miner Institute’s Farm Report.
Over the past few years we’ve conducted a series of research trials investigating the impacts of stocking densities, defined as cows per stall and feeding space, on the behavior of lactating dairy cows. These studies demonstrated a consistently negative effect on the lying time of cows in the overcrowded treatments. However, a recent study by a group of Norwegian researchers, published in the Journal of Dairy Science, suggests this may only be one of many factors which affects milk yield. This study evaluated the role of the physical layout of the barn on milk production and whether or not cows of differing parities (first lactation vs. mature cows) would respond differently to various features of the layout.
This study was conducted on 204 free-stall farms with a mean herd size of 43 ± 16 cows and mean 305-day milk production of 14,900 ± 3,500 lbs per cow. Overall, milk production ranged from 2,230 to 32,200 lbs per cow. Data were collected by five trained observers who visited each farm once between September 2006 and May 2007. Performance data (milk production, parity, and calving interval) was collected using the Norwegian Dairy Herd Recording System. Physical features (feed bunk space, milking system, insulation, ventilation, feed stalls (a physical divide between feeding spaces), separate housing for special needs cows, number of free-stall rows, location of free-stalls, dead-ends within the pen, and water trough location and capacity of the barns were measured directly by the researchers. Only data from purebred Norwegian Red Breed, accounting for 94 percent of the dairy cow population in Norway, were included in the final dataset.
This study established multiple variables affecting milk production on small farms. Surprisingly, space allocation per cow had a significant effect only on first lactation animals. Increasing space was associated with increased milk production for this group of cows. Furthermore, the milk production of first-lactation cows was increased by the location of the water troughs: Water troughs located next to a wall were associated with decreased milk production and locating the troughs in front of the first row of free-stalls was associated with increased milk production. Providing sufficient water space was also associated with milk production. Farms providing less than 47 percent of the recommended water trough space had lower milk production. Mature cows benefited when provided more than 80 percent of water trough capacity. Despite the parity-dependent responses, producers should be careful in the approach taken to provide separate pens for first-lactation cows. Farms with pens containing two or more dead-ends were associated with lower milk production. Finally, investment in insulation or a mechanical means of ventilation may be worth the cost, as both were associated with higher milk production compared with naturally-ventilated barns. The differences were greater for mature cows, suggesting a continued return on this investment.
Overall, providing more space to first-lactation cows, ensuring sufficient water capacity with troughs located at the front of free-stalls, limiting dead-ends and insulation of barns were all positively associated with increased milk production. These factors should be considered when building new facilities or refurbishing old ones to maximize the return on investment.
Source: Miner Institute Farm Report