Make sure your stock bull’s set for the breeding season
Grass-based dairy and beef production demands highly seasonal calving patterns immediately in advance of or at the start of the grazing season. This requires a rapid resumption of oestrous cyclicity in cows following calving; high oestrous detection and submission rates in herds where AI is used; and high bull fertility, irrespective of using AI or natural service.
The fertility of bulls is of paramount importance. However, in herds dependent on natural service bulls to get cows pregnant, it’s simply not just about turning in a bull with a herd of cows and expecting calves to arrive 285 days later. Research data suggests that up to five per cent of bulls are infertile at any one time, with a further 20 to 25 per cent being sub-fertile. Both conditions can have major effects on herds’ reproductive, productive and economic performance, particularly where these conditions go undetected for a number of weeks.
In order to minimise or avoid economic losses within your herd as a result of infertile or sub-fertile bulls, one has to be proactive in the months approaching and during the breeding season. Some simple tips that could have a positive impact on your 2020 calving figures might include the following: If you are planning on purchasing a new stock bull for this breeding season, you should, if possible, try to purchase the bull well in advance of the breeding start date so that he will have time to adjust to his new environment and surroundings. It will also give the bull time to adjust to any changes in his diet. You will also have the option to fertility test the bull if you decide to do so in consultation with your vet.
Where you already have a bull on the farm, at least two months before the breeding season the bull should have his annual NCT. There are four main areas you need to examine to have your bull ready which include: Feeding: Your bull should be
in good condition before being let out with cows. He needs to be fit but not overly fat. If you have purchased a young bull, he will need to be kept on a good diet right up to breeding time. Similarly, after the breeding season is over, a young bull needs to kept on a high plain of nutrition to ensure he keeps growing.
Fertility: It is estimated that up to 25 per cent of stock bulls are sub-fertile at any one time.
Ahead of the breeding season, if you have any doubts about conception rates in prior years, have your bull’s fertility tested to get an estimate of his sperm count and quality. The cost of testing is very low relative to the cost of carrying empty cows for the summer, and results are available to you before the vet or technician leaves the yard.
Health: If you have bought a bull, find out from the seller what treatments he has got. A blood test might be useful to check for BVD, IBR, Johnes Disease and Leptospirosis. If vaccinating or treating for parasite, these should be administered at least six to eight weeks in advance of the breeding season as they could lead to reduced fertility. Consult your vet for advice on the health of the bull. Remember a young bull in his first season should serve no more than 20 cows.
Feet: Physically, your bull should have good legs and feet. Over the winter, he should be in a good-size pen or a dry paddock so he can get plenty of exercise to build endurance for the busy period ahead. Hiring a qualified hoof trimmer is a good idea if you are in doubt about your bull’s feet. Even if a bull shows no sign of lameness, there may still be a requirement for hoof trimming, which could lead to problems with the increased walking and mounting during breeding season.
Records: This is a very useful tool whether using a pen and notebook or recording it on the phone using an App. Keeping a record of cows that you see being served early in the breeding season will give you a good idea if your bull is working well. If a large number of your cows are repeating, you need to take action quickly to find out what is wrong. In order to achieve the best results possible from this breeding season, start early and take a small bit of time to go through some of these simple checks for your stock bull.