Not a Load of Old Bull

With the bull semen debate coming up, it is interesting that a US Jersey Cow Breeding group "Jersey Expansion" are looking to breed pure strains of Jersey cows.

http://www.usjersey.com/

Jersey Expansion is an identification service for recording the offspring of Registered Jersey sires out of non-Jersey dams. Jersey Expansion is a proactive response to commercial producers' increasing use of Jersey semen to breed non-Jersey heifers and cows. What Jersey Expansion will do is provide the services required to properly record progeny of Registered Jersey sires from non-Jersey dams. The service is intended to take the guesswork out of knowing how much genetic material an animal has inherited from Jerseys recorded in the AJCA Herd Register

What is extremely interesting is the secondary reason behind their programme, which is to use selective breeding to produce cattle that are more genetically pure.

There is another reason for this program, and that is to increase the concentration of Jersey genetics in the U.S. dairy population. Many dairy producers have been buying Jerseys, but the supply of purebred live cattle is limited and it is more and more difficult to find live cattle to purchase. An alternative is breeding up using superior Registered Jersey sires. The idea is to breed systematically-generation after generation-to Registered Jersey sires to develop a herd that can produce higher solids milk

By the time an animal comes through this procedure and enters the Herd Register, the genetic make-up is at least 96.9% from Registered Jersey bulls. Geneticists consider animals developed along one breed line for five continuous generations to be essentially equivalent to a purebred. Continued use of Registered Jersey sires will further dilute the residual genes from the original J1 cow. At six generations, the percentage inherited from Registered Jersey sires is 98.4%; at seven generations, it is 99.2%

It also notes that both New Zealand and Denmark "have for many years had similar programs which have been successful in encouraging dairy producers to upgrade their herds along a Jersey-sired line."

Another report which I've been reading was published in "Heredity" in 2004, entitled "Population genetic structure of and inbreeding in an insular cattle breed, the Jersey, and its implications for genetic resource management."

This is a study of the DNA pattern of Jersey purebreds in the Island.

The authors note in their conclusion that:

Allan (1987) showed, based on pedigree analysis, that the level of inbreeding observed in Island Jersey was relatively low (around 0.06) and he concluded that it was not potentially damaging to the breed. Our conclusions (based on the ability to separate the effect of inbreeding and substructure) confirm that there is no genetic threat currently posed by keeping the island demographically isolated. Importation of semen from American and Australian Jersey cattle to increase the gene pool for selection on the island and allow genetic improvement in the breed has been suggested. However, in the absence of molecular evidence for a genetically depauperate island population there seems little scientific reason to ignore Allan's recommendations.

http://www.nature.com/hdy/journal/v92/n5/full/6800433a.html

In the face of this, I find the "push" by a large but not wholly representive vocal group of Jersey farmers, backed by the Council of Ministers, rather alarming. The trend outside Jersey by the USA group is to encourage genetic breeding towards purebred, and yet here we are doing the opposite. The gene study showed there is no scientific reason to worry about inbreeding. Against this is a lot of scaremongering rhetoric, about how the Jersey will only survive in a Museum unless we go ahead and allow semen importation. I do get the impression, not for the first time, that the Island is being bullied into taking an action that it may regret later.

Since there are almost equal numbers of those for and against, why is the Council of Ministers taking sides? This is another trend, in which almost like a three-line whip, it decides what is best, and all the Council push forcefully for it. They are not clearly listening to those who are saying "No", because otherwise the debate would be an open one, in which the States could decide at that time, rather than - at present - the Council having already made up its mind, and trying to impose its decision on the rest of the States.

In One Hundred Years of the Royal Jersey Agricultural and Horticultural Society 1833-1933. Compiled from the Society`s Records, by H.G. Shepard, Secretary, Mr Shepard notes how even in five years selective breeding was sufficient to improve the cow:

Five years of existence were marked in the Annual Report for 1838 by the following recapitulation of work accomplished. This Society set out with the design of creating a spirit of industry and emulation; it has fulfilled its object. It has improved, greatly improved, the breed of cattle. At the last Show, one hundred and sixty head of very fine cattle, in a most superior condition as compared with former exhibitions, were declared by the Judges, to evince in the most satisfactory and conclusive manner, the undeniable improvement that is manifested in form and condition.

Selective breeding requires careful work, but has been enhanced beyond measure with the ability to freeze bull semen from local bulls. I cannot help thinking that the importation of bull semen is one of those "quick fix" measures that recommends itself largely because it is so much easier, and so much cheaper.