Last month we discussed health concerns in overweight equines. Mobility and metabolic issues abounded. This month, we’ll learn that our ruminant species have similar problems as they pack on the pounds and cattle grow overweight.
Feeding cattle for production, be it weight gain for slaughter or to attain a good body condition for calving and milking, is a tricky operation. This explains why some folks go as far as getting doctoral degrees in ruminant nutrition. Things can get very complicated very quickly. But take heart. You’ve likely already got the basics covered.
Let’s focus today on what happens when there’s too much of a good thing, or, when is a fattened steer too fat?
Cattle with smaller frame sizes tend to have more health issues at heavier weights, simply due to mechanics. Structurally, their legs and feet aren’t robust enough to hold a frame of excessive weight. This can impact mobility to the point of causing a welfare concern.
Larger framed breeds such as Simmental or Charolais are genetically adapted to handle heavier body weights. But take care with smaller frame lineages, especially some of the heritage breeds. These “specialty” breeds lack the sturdy frames to handle heavier body weights.
While researchers have demonstrated the ease in which equine laminitis can be caused simply by feeding excess quantities of carbohydrates, the same methods have not been successful in inducing bovine laminitis. So while cattle are not quite as pre-disposed to laminitis (also called founder) as horses are, they can suffer from foot pain linked to excessive body weight.
A heavy frame exacerbates any minor conformation issue or pathology in the foot. Dietary disturbances can result in laminitic lesions such as sole ulcers and hemorrhages.
Heavier and overweight cattle are more inefficient at heat dispersion in warmer temperatures compared to their thinner cohorts. When humidity rises, this can become a serious enough issue to cause heat stress in these animals.
Decreased feed intake, higher heart rates and agitation are some early signs of heat stress in cattle. In the summer months, farmers should consider body weights when evaluating their herd management in the heat.
Over-conditioned dairy cows are at risk for relatively common metabolic challenges, including fatty liver and ketosis. Being overweight in late gestation alters these animals’ metabolic pathways such that, at time of calving and subsequent sudden switch to dramatic milk production, their bodies shunt fat stores to the liver. This confuses the metabolic pathways that require quick energy for milk production demands. This leads to a production of ketones and further fat deposits in the liver, which then typically makes the animal feel poorly.
She will then stop eating, which makes the situation worse and a negative feedback loop worsens.
The best way to stay ahead of these issues is to monitor the body condition scores of your animals on a regular basis, or at least once a season. If your herd is large enough, consider subdividing based on body condition scores. This can help you tailor feeding to the specific needs of your animals and prevent the complications that excessive body weight can wreak in cattle.