Large herds, less lameness
Animal rights activists claim cows in large, commercial dairies aren't as well cared for and have more welfare issues than in small herds where herd owners know cows individually.
It's a nice story, but research from the University of Minnesota (U of M) strongly suggests it's simply not true. Researchers intensely studied lameness and other animal welfare issues in 15 herds averaging 5,000 cows. "There is a general perception that animal welfare in large dairy farms is probably subpar," says Marcia Endres, a professor of dairy science specializing in animal well-being issues.
"The large dairy study showed just the opposite as overall prevalence (scores of 3, 4 and 5) of lameness in the very large herds was 16.7%." Note: Severely lame cows were about 30% of this total.
That might seem high, but the average prevalence of lameness in U.S. herds (and herds around the world housed in confinement, for that matter) is 20% to 30%, she says. This is based on a 1 to 5 scale, with 1 normal and 5 extremely lame.
"A score 3 cow is not as obviously lame as a more severe 4 or 5 score cow—those with an arched back, severe head bob and reluctance to bear weight on a limb," she says. "This is probably a reason why producers tend to underestimate the overall prevalence of lameness in their herds by two to three and half times compared to researchers' averages."
Of the 15 large herds studied, seven used deep sand bedding in stalls, seven used deep, recycled manure solids and one used recycled solids on the top of mattresses. There was no difference in lameness among the bedding surfaces, Endres says.
The one factor that seemed to make a difference was whether a herd had a hoof trimmer on staff, allowing that person to deal with hoof issues on a weekly or even daily basis. "Herds that had an on-farm hoof trimmer had overall lameness prevalence of only 11.6% and very low severe lameness," she says.
The other difference researchers saw in large herds was mastitis prevalence. "The incidence of mastitis was 1.5 times greater for recycled manure solids than sand," Endres says. That suggests manure solids can be a challenge when it comes to udder health.
The large herds were very labor efficient, averaging 105 cows and 2.5 million pounds of milk per worker. But the labor is very specialized, and animals were well cared for.
Robotic herds more lame?
The U of M researchers also evaluated lameness in 53 robotically-milked herds. The herds averaged 180 cows. Somewhat surprisingly, lameness averaged about 30% in these herds. "Deep sand freestalls, pasture and bedded pack barns had a lower prevalence of lameness than mattresstype stall surfaces," Endres says. In fact, the mattresses had a lameness prevalence of 40% compared to 20% in the other systems.
"However, the severe lameness prevalence was only 2% to 4% for the deep beds and packs," Endres says.
Robotic dairies that used footbaths appeared to have lower rates of lameness. So the researchers hypothesize the higher rates of lameness in robotic herds might be associated with the difficulty of using footbaths in these facilities.
Placement of footbath is challenging because footbaths in the exit lanes of the robotic milkers can slow cow movement and robot use.
Note: This story appeared in the
