Common sense tells us that packing 300 cows into a 100-stall free stall barn would seriously sacrifice cow comfort. This is clearly an extreme example of overcrowding…but what about a more realistic situation? Would 120 cows be considered overcrowded? 150?
When talking about overcrowding, a term that frequently comes up is “stocking density.” But what is stocking density exactly? According to Dale Moore’s article in the Western Daily News,
“Stocking density on the dairy, also known as stocking rate, is the number of animals per unit area in a drylot pen or pasture, the number of animals per free stall in a free stall pen, or the number of feet of bunk space” (Moore).
As discussed in Part 1 of this 5-post blog series, Rick Grant’s recent Hoard’s Webinar focused on the impacts that a cow’s physical and social environments have on her productivity and health. Stocking density was an important factor in determining the quality of the social environment for a herd.
The webinar contains a wealth of valuable information that is definitely worth checking out. For now, here is a brief overview of Grant’s presentation on stocking density:
What types of behavioral changes can overcrowding produce?
- Greater aggression & displacements at feed bunk
- Greater feeding rate
- Reduced resting time
- Increased idle standing in alleys
- Decreased rumination
- Subordinate most affected
- Less milk yield
- Lower milk fat
- Greater SCC
- More health disorders
- Increased lameness
- Fewer cows pregnant
What is optimal stocking density?
- Close-up and fresh: ≤ 80% of bunk space
- Lactating cows: → 4-row barn: don’t exceed 115-120% of stalls (note – mixed heifers & older cows: 100%)
→ 6-row barn: 100% of stalls (limited research available)
Check back at 3 p.m. (CST) for Part 3 of this 5-post blog series: 4 ways to increase DMI by 1 lb.!
Sources: “Managing cow behavior for profit and performance” Hoard’s Webinar presented by Rick Grant, Miner Institute. May 9, 2011.
“Stocking density: How much?” article by Dale A. Moore. Western Dairy News, December 2010 issue. Vol. 10, No. 11.