AB sci­ence makes NZ a leader

Matamata Chronicle - - Rural Delivery -

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.

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