Purdue Extension beef specialist Ron Lemenager is adamant that body condition in gestational and lactating cows is extremely important for successful reproduction, because cows with less-than-ideal body conditions can have longer postpartum intervals, calve later or just fail to breed at all.
"If producers with spring calving herds have thin cows now, they need to put those cows on a diet that allows them to gain weight," Lemenager said. "That's challenging because those cows are approaching peak lactation, but if you don't make adjustments, fertility can suffer."
The best ways to help animals gain weight is to feed high-quality forages. If forages are of low quality, they can be supplemented with dried distillers grains, soybean hulls, corn gluten feed or grain feed.
At this point in the season, producers with fall calving herds who have thin cows have more time to make nutritional and feed adjustments before calving season. They also have time to decide whether to wean calves early or wait until calves are 7-8 months old.
"With thin, young cows in fall calving herds, it's probably best to wean calves around 7 months," Lemenager said. "Mature cows can nurse a little bit longer, until maybe June, but producers need to let young cows gain weight and body condition."
Evaluating cow body condition scores involves looking at a series of physical attributes, including any physical weakness, muscle atrophy, fat in the brisket, fat over the shoulder, visible ribs, visible vertebrae along the topline, visible transverse processes between the hooks and the last rib, visible hooks and pins, patchy fat around the tail head, and fat in the udder.
Cows are scored on a scale of 1 to 9, with 1 meaning the animal is emaciated and 9 meaning the animal is very obese.
Lemenager said mature cows need to have a body condition score of at least 5, which is moderate. A body condition score approaching 6 is considered ideal for replacement heifers and young cows.
Tables and videos for evaluating cow body condition scores are available through Purdue Extension's Beef Center website. Also see: