Resources

Mating management

Heat detection: Make the efort

Cows are more likely to have silent heats or shortened heats in the hot season so accurate heat detection is critical to achieving high submission rates. Expect cows calved in summer to take longer to start cycling than cows calved in winter. The key is to increase your heat detection efforts over the summer months and manage cows not detected on heat. See chapter 10 of The InCalf Book for more information.

AI practices: It is hard to beat the heat

Increased heat loads during periods of continuously hot, humid weather can be severe on conception rates particularly in higher producing cows. Herd managers should consider use of cheaper semen at these times or possibly even bulls at these times. 

Make sure you are not blaming the hot weather for problems caused by poor procedures. Ensure that all AI practices are up to scratch including general preparation and cow handling, semen storage and handling, insemination techniques and timing. Assess your herd using the InCalf AI practices tool and see Chapter 11 of The InCalf Book for more information. 

If using embryo transfer, implanting embryos collected in winter during the hot season may be successful.

Bull management practices: They get hot too!

If well managed, running bulls with the herd during the hot season may be an effective way to achieve higher submission rates, but don’t expect it to improve your conception rates. AI and natural services have been found to be equally susceptible to the depressing effects of heat loads on conception.

Good bull management means running adequate numbers of healthy, fertile, well-grown bulls with the herd, reducing the stresses caused by heat, over-working or dominant animals, and handling bulls to minimize the risk of injury to people and animals. Assess your herd using the InCalf bull management practices tool and see Chapter 12 of The InCalf Book for more information.

Heifer management: Consider mating more

Mating more heifers during the hot season can help compensate for lower in-calf rates expected in the milker herd, thereby helping to maintain the desired calving pattern in seasonal / split calving herds, and the number of calvings per month in year round calving herds. Of course, you need to ensure that yearling heifers have achieved the required target mating weight, and use AI sires with low calving ease scores or a breed of bull known to be easy calving. For advice on planning heifer mating, see chapter 8 of The InCalf Book.