MANAGEMENT during the calving period can have a big impact on the ability to get back in-calf, according to DairySA Innovation Day keynote speaker Jim Spain.
Dr Spain, from the University of Missouri in the United States, addressed the large group of dairyfarmers and industry service providers gathered at Mount Gambier on Thursday last week, discussing the importance of caring for transitioning cows to ensure the most returns.
He said the 100 days surrounding birth were pivotal to the next conception.
In the lead-up to calving, cows will undergo a tremendous hormone shift, which can lead to a crash in appetite, just at a time they need the most energy.
This can then lead to fat laid on the liver.
“If we allow the liver to be filled full of fat, it’s like harvesting half the crop,” he said.
Dr Spain said breeding at 70 days could be influenced from as early as 14 days after calving.
He said this stressed the importance of preparing close-up, dry cows appropriately in the lead-up to calving, with management playing a big part.
He said transitioning cows could often experience changed diets and social environment up to four times, within 60 to 70 days, as they moved from dry cows to lactating.
“We know cows don’t like change,” he said.
One option to deal with this was to manage the cows as a group, to limit the social change, while also minimising the difference in diet.
Dr Spain also spoke about the importance of keeping cows cool.
Statistics from the US showed in 1924, the average cow production was 2000 kilograms of milk solids a year, while in 2008 it was more than 9000kgMS.
He said this improvement in production could also lead to changes in the metabolism, with cows generating more heat.
Overheating can also come from crowding in holding pens, as well as from general ambient temperatures and humidity.
“You need to look if cows are ruminating or panting in the milk pen,” he said.
“Panting is the easiest way to monitor heat in cows. If they’re panting and not chewing, they won’t have an appetite for grain.”
The lack of salivary production could also have an impact on the pH in the rumen, he said.
University of Missouri trials have shown one of the most effective ways to cool cows was within the holding pen, by wetting skin, then directing a fan.
“Don’t just look at the air temperature, look at the cow temperature,” he said.
Dr Spain said heat should also be considered when dealing with close-up, dry cows. He said the foetus could generate twice the body heat of the mother.
Because of this, Dr Spain recommends appropriate shade for cows in late gestation.
He said if holding pens already had fans and sprinklers to cool lactating cows, there was potential for them to be used, post milking time, for close-up cows.
Elizabeth Anderson
Editor of Stock Journal.
Editor of Stock Journal.
