Dairy farmers put a lot of effort into managing cows at calving, breeding and throughout lactation, but there is often less focus put on the dry period.
“If we pay more attention from drying off through to calving, we will inevitably see benefits in terms of milk production, health and particularly fertility,” said Hefin Richards, a ruminant nutritionist based in Shrewsbury, England.
Speaking during an online event organised by the Agriculture and Horticulture Development Board, Hefin presented various factors to consider as autumn calving herds approach the dry period.
He put a strong emphasis on environmental factors, such as feed space and cow comfort, pointing out that dry cow accommodation can quickly become overcrowded in block calving systems as most cows are dry at the same time.
Hefin said that dry cows “rarely” get access to enough space for adequate lying times. Giving cows access to paddocks can address this if cubicle space is tight, but it can run the risk of excessive grass intakes ahead of calving.
Feed space is also wildly underestimated by farmers
The transition group is usually the most socially unstable group of animals on the farm as there is constant change in the pecking order, and this needs to be reflected in cow management.
“Cows need access to clean water, with a minimum space of 10cm per cow, and there should be more than one trough so that bully cows are less dominant and other cows get enough to drink,” Hefin said.
“Feed space is also wildly underestimated by farmers. We should be really targeting one metre per cow during the transition period to make sure that shy feeders can get enough feed without feeling intimidated,” he added.
Farmers were urged to avoid the temptation to feed dry cows every other day, as the palatability and quality of feed will deteriorate, especially during warmer summer months. Feed passages should also be regularly cleaned out to avoid the build-up of stale feed.
Hefin acknowledged that a wide range of technologies are available to closely monitor the health and performance of cows, but he described visually observing rumen fill as “the cheapest indicator of feed intakes”.
Cows that are excessively hollow in the triangular area behind the ribs have a poor rumen fill with a score of one or two.
The target is to have dry cows with a rumen fill score of three (or above), so the triangular area is almost flat and can be just about made out.
Hefin presented recent research from UK dairy farms which found that having below optimal rumen fill scores pre-calving affected milk yields in early lactation.
“Going from rumen fill scores of one or two, to three or four was worth an extra 10 litres a day after calving. If rumen fill is below target across the group, then you need to look at feed access etc. If it is just individuals then those animals need further investigation,” he said.
Nutrition for dry cows can vary across dairying systems and climatic regions, but several key principles should apply to all dietary options.
Hefin Richards said diets need to meet but not exceed energy requirements so that cows do not put on too much condition when dry. They also need to meet protein requirements for the growing foetus, prevent milk fever and promote good rumen function so that cows achieve adequate intakes after calving.
Remember, diet formulation is only part of the story
Dedicated dry cow silage which has more stem content than usual and is made from land which received no slurry or potash fertiliser ticks the boxes for most participants on the Dairylink Ireland programme.
Farmers with autumn-calving cows usually offer this fodder to cows for the last three or four weeks before calving, along with dry cow minerals or concentrates.
“Remember, diet formulation is only part of the story.
“Presentation, delivery and trough management will make or break the dry cow programme,” Hefin said.
In most herds, heifers will be mixed with adult cows
Dairy farmers were also urged to put thought into the introduction of heifers to the milking herd. This is important in block autumn- or spring-calving systems, where heifers at 24 months of age are calving alongside a large proportion of the herd.
“In most herds, heifers will be mixed with adult cows. When is best to do that?” Hefin asked.
“Personally, I think it should be at least a month pre-calving to allow them to settle into that dynamic. Ideally, don’t do it very close to calving because it’s a further stress where they meet adult cows for the first time,” he said.