AB science makes NZ a leader
Which term is correct – artificial breeding or artificial insemination? Both terms refer to the same thing – semen collection placed in the female’s reproductive tract to cause pregnancy. Overseas the term artificial insemination (or AI) is used. In New Zealand, we use call it artificial breeding (AB).
Artificial Breeding began in New Zealand in the late 1940s – one of a number of methods to get more production from dairy cows.
Other methods included herd testing (measuring the amount of milk produced by a cow and testing the components of that milk) and recording (recording the parentage and cows’ other traits).
Reasons for artificial breeding were bull management and improving cow production. A sire survey conducted in 1936 said that around 37 per cent of bulls actually lowered milk production.
Globally there was an urgency for artificial breeding to address problems caused by top sire shortage and reproductive diseases causing abortions. In those days, dairy farms carried around one bull to every 25 cows.
Herds were small, averaging around 60 to 80 cows, requiring two or three bulls for the spring mating period.
Farmers experienced all sorts of problems running bulls – from them competing for a cow’s attention, to broken gates and fences, disease (cattle can have sexually transmitted diseases which can affect health and fertility) and bull fertility.
With natural mating a farmer usually does not know how good (fertile) a bull is until his cows are checked for pregnancy – and then it’s usually too late meaning those cows will calve later than their herd mates the following calving season. (Farmers want their cows to calve within a concentrated period. Cows are pregnant for nine months leaving only three months to get pregnant again. Any delays during these three months puts the cow outside the best calving pattern for the herd.
Besides natural mating health and management problems were extra costs associated with purchasing or leasing bulls coupled with the cost of grazing them – taking grass (milk profit) from cows. And risk from handling the occasional wild bull.
Artificial breeding provided an answer to these problems with the attraction of getting progeny from some of the best bulls in the world.
Not surprisingly, farmers were keen to make use of this new science which promised so much in terms of farm management and herd improvement. In 1939 research into artificial breeding began in Ruakura, Hamilton, funded by the NZ Dairy Board and led by Dr John James.
This AB centre was the forerunner of today’s Livestock Improvement Corporation, the largest artificial breeding company in New Zealand. Its research and technologies have led the development of AB internationally and made New Zealand’s rate of genetic gain one of the highest in the world.
Artificial breeding results in the semen from one bull with superior genes being inseminated into thousands of cows each year – compared to a mere 100 if he was simply a herd bull, siring one calf from each cow each year by natural mating.
Artificial breeding sires are bred from the best genetics from New Zealand and around the world and their use here has, over the years, increased the profitability and productivity of dairy cows.
One of New Zealand’s most prominent scientists and cow production researchers, Dr Colin Holmes of Massey University, has been quoted as saying you couldn’t farm today with 1950s cows.
This describes the efficiency improvements in genetic gain through artificial breeding. (Genetic gain is the result of breeding increasingly superior bulls to increasingly superior cows and can be measured by the increased milk production of these cows year after year.)
The rate of genetic gain is said to be worth three kilograms of milksolids a cow annually.
A kilogram of milksolids is worth around $4 to the farmer, so each year there is increased value to the farmer of $12 per cow.
On a national scale, the value of genetic gain is in the region of $30 million each year.
This level of genetic gain, or improvement, in the national herd would not have happened without the widespread uptake of artificial breeding.
Moo: With calving season over farmers are now looking at preparing cows for calving season next year.