Tuesday, November 25, 2014

The Secret to Daytime Calving

Mon Nov 24, 2014 10:30 AM CST
DTN Progressive Farmer
 
Daytime calving means newborns warm up faster and are often safer from predators. (DTN/Progressive Farmer photo by Joe Link)
Whether you have 20 cows or 200, there is nothing less pleasant than crawling out of bed in the middle of a cold night to check for calving problems. What if you don't have to? It almost sounds too easy, but there's research to support the idea that when you feed cows can affect when they calve.
Kansas State University Agricultural Research Station in Hays has data showing that when cows were fed daily between 4 p.m. and 6 p.m., 85% of their calves were born between 6 a.m. and 6 p.m. the next day. The advantages for daylight calving add up quickly. It's a lot easier to spot a cow having trouble in the daylight and get her help. Newborns dry off and warm up faster in the sunlight, and you can see if they begin to nurse. Predators are less likely to strike during the day if you calve on pasture or rangeland.
John Jaeger, the Kansas State beef cattle scientist who conducted the five-year study, said researchers aren't sure why time of feeding influences calving.
"Temperature, gut fill and rumen fermentation all appear to be involved," he said "In late afternoon, temperatures tend to decline. The increase in rumen fermentation after cows are fed increases the metabolic heat that offsets the drop in nighttime environmental temperature. Gut fill and metabolic heat may also alter some blood hormone concentrations which influence calving."
Frequency of rumen contractions also appears to be involved. Research shows pressure in the rumen begins to decrease in the last two weeks of gestation and declines even more during calving. Nighttime feeding causes pressure in the rumen to rise at night because of feed volume and decline during the daytime.
Iowa State University also tested the idea. Researchers conducted a demonstration involving 15 producers and more than 2,000 cows. In the study, 85% of the cows fed in the evening (from 5 p.m. to 10 p.m.) calved between 6 a.m. and 6 p.m. the next day.
The process isn't foolproof. In a three-year study at the USDA-ARS Research Station in Miles City, Montana, scientists observed little difference in calving times between cows fed before noon or late in the evening (after 5 p.m.). And research at the station in Brandon, Manitoba, Canada, showed just a 13.5% reduction in the number of late-fed cows calving between midnight and 7 a.m.
"We did not get consistent results," admitted Julie Small, now stationed at the Nova Scotia Agricultural College. She said some think the results may hinge on the type of diets fed.
Despite the difference in findings, Oklahoma State University beef specialist Daniel Stein said he's convinced the practice has real merit.
"We have been practicing evening feeding on our ranch in northwest Oklahoma for several decades," Stein said. "It's not 100%, but I've observed that the later I feed in the day, the more likely it is cows will calve during daylight the following day.
"I will feed after watching the news at 10 o'clock," Stein continued. "If any animal comes up to the bunk to eat, it is almost guaranteed she will calve after daybreak, and we go to bed. If they don't come up to eat, they will usually calve during the night."
K-State's Jaeger added an interesting side note, saying a high percentage of those cows that initially calved during daytime hours tended to continue to do so in the future.
(VM/CZ)

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