Finley dairy farmers use simple crossbreeding system to lift herd fertility

Implementing a simple, visual system ensures that three-way crossbreeding takes place with ease, achieving consistently outstanding results.

The Kydds have not always milked crossbred cows; originally, their herd was all Holstein-Friesian.

However, Mrs Kydd became concerned about inbreeding within their purebred herd and consequently was spending a large amount of time matching semen choices for their cows.

The Kydds Neville were also unsatisfied with their reproductive performance as they were consistently achieving a 20 per cent empty rate, despite a long mating.

In 1992, the Kydds made the decision to start inseminating their Holstein-Friesian heifers using Jersey semen. In 1995, when the Jersey-Friesian heifers had entered the milking herd, their records indicated that they were getting in calf much easier and appeared as though they were producing as well as the pure Holstein-Friesian heifers. This gave the Kydds the confidence to start crossbreeding their whole herd with Jersey semen.

There was, however, always a dilemma as what breed of sire to use on the first generation of crossbreds.

This decision was made easier in 2006 when the Kydds started using a 3-way crossbreeding strategy.

The Kydds have adopted a visual cow identification system. With only a glimpse of the cow or herd ID system, they instantly know the breed of the sire of the cow and the breed to which it will be mated. Ear-tags, tail paint, markers within their artificial insemination semen tank and even cow numbers on their computer program are all colour-coded.

Their AI technician is also on board with their ID system as he has colour-coded his AI guns.

For instance, a cow with an Ayrshire sire will have an eartag with the sire breed written on it. The back of the eartag will be red and the cow's number will also come up as red on their herd data system ("Identity"). At mating time the cow will be painted red, and the Jersey semen that will be used on the cows with an Ayrshire sire will be identified with a red marker in the AI tank. At mating time, the Kydds don't talk about breeds they only talk colours.

The Kydds' herd has exceptional reproductive performance. This is the result of years of selective breeding by the Kydds for high reproductive performance combined with the benefits of heterosis (hybrid vigour).

Heterosis is the reason why the fertility of crossbreed cattle is generally superior to the fertility of their purebred parents.

However, the Kydds have not simply relied on heterosis to improve their herd's fertility. When they select their AI sires, they heavily weight their sire selections for high daughter fertility ABV.

To simplify their mating system even further, the Kydds only choose one sire for each of the three breeds each year (that is, each year they only have one Holstein-Friesian sire, one Jersey sire and one Ayrshire sire).

To offset the risk of using only a small number of sires, the Kydds ensure that the sires chosen have highly reliable data for the characteristics that they are most interested in, especially daughter fertility.

The AI period for the milking cows in the Kydds' herd is only 14 days. Three weeks before mating start date, all cows receive a prostaglandin injection.

Once mating starts, the Kydds AI cows with detected heats. Any cow not joined by the end of the first week is given another injection of prostaglandin.

By the end of the 14 days of AI mating, the Kydds will submit 90pc of their cows and achieve a 70pc conception rate.

Jersey bulls are then run with the herd for nine weeks with 15 bulls in the herd during the day and another 15 during the night.

Although only AI calves are reared as replacements, the Kydds rear 35 Jersey bull calves out of the heifers each year as future mop-up bulls to minimise calving issues in the naturally bred cows.

The mating program has led to the Kydds achieving an empty rate of 4.5 to 5.5pc for several years.

Given their large herd size, all heat detection has been undertaken in the dairy. The Kydds have some rules to maximise the number of cows detected that are on heat.

Firstly, the same person does all of the heat detection for the two-week joining period.

Secondly, tail paint and Kamars are used simultaneously.

Mrs Kydd is adamant that this is of crucial importance in their system.

Despite the exceptional reproductive performance within the milking herd, the Kydds continue to undertake a fixed-timed AI program for their maiden heifers.

Heifers are mated to start calving about two weeks before the milkers, to ensure that they have time to recover from calving by the next joining period.

Currently they use Jersey, Ayrshire and Norwegian Red easy-calving sires but not Holstein-Friesian sires to join the heifers. Although many farmers find this strategy successful, the Kydds choose smaller sires as they want to maximise the chance of their heifers getting back in calf quickly.

This story first appeared on Australian Dairyfarmer