14 April 1995


Within five years, the typical black-and-white dairy herd will be almost 100% Holstein, predicts Holstein Friesian Society research analyst Mike Coffey. Have milk producers caught up with the management implications?

THE UK national dairy herd is not as far behind the rest of the world as some authorities have suggested, and the remaining genetic gap is narrowing fast. This bodes well for our ability to compete on the world semen market, and promises to reduce our dependency on overseas semen to maintain our breeding programme.

Genetic improvement in the UKs dairy herds virtually stood still in the early and middle part of the present century. It was not very good in the late sixties, seventies, and eighties. But in the past 10 years it has been astounding.

The figures speak for themselves. The average fat + protein for all animals born between 1977 and 1992 with a calculable index has gone from almost nothing to about 20kg. This is equivalent to a pedigree index range of between 500 and 700. Although absolute levels are not truly relevant, because genetic indices are relative, there can be no doubt that such an improvement has a real economic value.

At the Scottish Agricultural Colleges Langhill Herd it has been shown that each pedigree index point is worth roughly 50p in margin over all feed, health and reproductive costs. So it is fair to suggest that the average animal born in 1992 could be £100 a lactation more profitable than the average animal born in 1982.

Market signals

Closer inspection of the changes in fat and protein percentages (see graph) reveals the speed with which breeders have responded to market signals about milk quality when making their choice from a wide selection of bulls.

Most notable is a massive decline in genetic merit for fat percentage in the early 1990s. Protein has seen a small, long-term decline, but it could easily be altered by using a small number of very popular bulls. In future, ever-increasing emphasis on protein will result in the recovery of protein percentage.

During the decade, the average index improvement has been 1.6% a year, and this compares very favourably with progress in the worlds best dairying nations. In the most recent five-year period, progress has speeded up to an average rate of 1.8%, considerably better than most other countries have achieved.

The speed of the change to Holstein blood has been accelerated by two circumstances:

&#8226 Competition between world-wide semen suppliers has extended the choice of animals while reducing the price to levels that competed with the cost of using cheap, UK-bred bulls.

&#8226 Increasing use of genetic indexes as selection tools, backed by concrete evidence of the results.

Figures for the number of registrations to top bulls born in 1985 and in 1992 illustrate how quickly there has been an almost complete shift to the internationally known bulls, such as Sunny Boy, Inspiration and Linde Alfred, being used by UK breeders.

As a result, the average proportion of Holstein in females registered between 1977 and 1992 rose from about 7% to near 60%. This is entirely due to using 100% Holstein bulls on cows that were themselves bred to pure Holstein bulls.

It is important to note that this had nothing to do with the introduction of quotas. The Holstein proportion was rising before 1984 and the trend continued afterwards.

Within a very short space of time – probably less than five years from now – the national average will be approaching 100% Holstein. The number of 50% Holstein animals is already reducing, showing that more than half are first-cross Holstein, with many the result of two or three crosses to pure Holstein bulls.

The massive change has taken place in a period of less than 15 years even though the generation interval of a dairy herd is relatively long. This is significant because it means there will be a very wide range in the percentage of Holstein between the oldest and the youngest cows in the typical herd. That adds up to important conformation, dietary and performance type differences between animals in such herds.

Conformation traits are most obviously seen in stature, and this is born out by the HFS classification scheme. The average heifer assessed by classifiers has risen by a staggering 10cm (nearly 4in) in height in just 10 years. Because increases in height are proportional to other measurements, it is inevitable that length, width, depth and weight have also increased.

That is posing problems for transitional herds. Most dairy units were built to house and manage the typical cow of the seventies and early eighties. Many cubicle houses are completely unsuitable for an increasing number of the cows now being housed in them, and the problem is made worse because of the range of sizes of cows in the herd.

Cubicles that are too small create a number of problems that could have a serious economic impact on profitability.

When space is limited, cows spend more time standing, and less lying down and cudding. They spend more time with their front feet in the cubicles and their back feet out, shifting their centre of gravity on to back feet and increasing the potential for lameness. Because they have to lie too far forward, their lunging space is restricted, leading to risk of injury when standing up. And the incidence of udder disease and teat injury may be increased because they tend to dung on to one another and tread on one anothers teats.

This is a real dilemma for many milk producers. It is obviously not sound economically to tear down cubicle houses that are still in sound condition. But economic and welfare considerations demand that cows should be comfortable.

One possible solution is to split herds into groups, allowing younger, larger types to be managed in separate housing.

Urged on by economic data, many herds have made great progress towards the goal of a first calf when the heifer is close to two years old. Until 1985, the bulk of heifers still calved at or around three years old – roughly 30% calving at less than 30 months of age, and 70% when older than that. Currently, more calve before 30 months of age than after.

Advice from management consultants has helped, with suggestions that a three-year-old calving heifer has cost £180 more to bring into milk than a two-year-old. The cost of semen may also have been a factor, encouraging breeders to get high value heifers into the herd as soon as possible.

It is also likely that the trend has been encouraged by the physical size of the modern heifer. Holsteins are bigger at any given age, and therefore sooner reach the height at which the farmer perceives it is right to put them in calf.

Mike Coffey says high genetic merit cattle demand greater attention to management detail.

At a distance, theres little apparent change in the dairying scene. But bigger, more demanding Holsteins pose management problems as they come into herd.