Feeding for fertility tightens calving pattern

William Dean took responsibility for running the herd several years ago and in December 2010, he mentioned to John Taylor, his Harbro sales specialist, he wanted to have a stronger focus on the calving pattern of the cows.

"My father and I run the contracting business, which is busy from sowing to harvesting time. The herd was calving over too long a period, up to nine months and encroaching on the time when I need to concentrate on ground work," says Mr Dean.

He observed that cows were coming into heat but not staying in heat for long enough, or they were not displaying sufficiently visible heat signals. He also found that one of his bulls was sterile.

"My aim was to have two calvings over a five-month period, the bulk of the cows calving in October and November, with a small number calving in January and February to suit the business," he says.

Mr Taylor suggested looking at the silage quality, focusing in particular on the trace element levels.

"The results from the silage analysis showed that the silage was low in zinc, cobalt, selenium, copper and iodine and high in iron, aluminium and molydenum. In fact, the molybdenum level in the silage was one of the highest that I have ever seen," says Mr Taylor.

Iron and aluminium are copper antagonists, putting pressure on the already low level but it was the extremely high molybdenum which had the major effect, locking up the remaining copper.

Copper deficiency has long been recognised as a factor in sub-optimal fertility, particularly in Scottish upland farms. Selenium also plays a role in fertility and again, the combination of low levels and low availability means that sources need to be carefully considered. Iodine, a key component of many hormones, is essential for calf vitality and viability.

A course of action was planned to overcome the supply of these key trace elements and this included the use of Harbro's Grampian Super Suckler SEC mineral. This contains elevated levels of iodine, zinc, selenium (some of which is Sel-Plex, a selenium enriched yeast which is more available source) and copper in the form of Cu-tek.

Cu-tek, a new product, which is exclusive to Harbro, contains copper which has been treated in a way that allows it to bypass the rumen into the intestine for absorption, unaffected by molybdenum (which locks up copper in the rumen).

The minerals were fed in conjunction with Agrimin's High Iodine bolus which was administered just before calving time to cover the calving and bulling period.

While much of the focus goes on meeting the mineral and nutritional requirements of the breeding female, a deficient bull can have a bigger impact on the profitability of the breeding herd. Mr Dean has also paid attention to the condition of his bulls – two Simmentals and one Limousin – by feeding them with Harbro Bull Fertility 50 days prior to bulling. This is high in fish oils, and minerals, particularly copper, zinc and Selenium, as Sel-Plex for improved health, vitality and sperm production. Mycotoxins in mould from forage and bedding can destroy semen quality in normally fertile animals so it also contains Mycosorb to prevent this from occurring.

"I have managed to get the cows calving in two six to eight-week periods and am very pleased with the performance of the cows which is improving all the time," he says.

"There are still a few cows calving in December and March so there is still a bit to go. These cows are primarily first and second calvers and this was due to the Limousin bull becoming infertile," says Mr Dean.

Alongside the cows, there are 600 acres where malting barley is grown and some ground is rented out for growing carrots. Services provided by the contracting business include crop spraying using four self-propelled sprayers, ploughing, three one-pass seed drilling machines, silage making with a forage wagon and harvesting with three combine harvesters.