Organic Producers Welcome New Bull Selection Index

Research Found Organic Producers Put More Emphasis on Functional Traits and Calving Ease

By Frances Anderson, Ontario Farmer Staff

Guelph - Organic dairy farmers want different genetic traits in their cattle, and will soon have a new selection index to help them choose bulls.

Dairy geneticist Paola Rozzi began work on this project in late 2003, with funding from OntarBio Organic Farmers Co-op Inc. "I needed to have data that was standardized,"

Rozzi explained. She chose BCA milk as means of comparison because it's a production measure that adjusts for breed, age and stage of lactation.

Rozzi began with an in-depth survey of 18 organic dairy farmers, which was half the organic milk producers in the province at the time. She conducted two-hour interviews and got their permission to use production data from the Dairy Herd Improvement Association as well, "in order to see what they do, and how different from conventional farmers they really are."

On average, the organic farmers surveyed in Ontario produced about 20 per cent less milk per cow (1,900 kilograms less) than conventional producers. "It is the same also in other countries," adds Rozzi, who is working closely with organic dairy researchers in Germany, Switzerland, and more recently, Scandinavia.

However, Rozzi also divided the organic producers into three distinct groups, based on their production level, because there were distinct differences in breeding policies and their choice of breeds.

The four organic producers with the highest production, (about 9,500 kg milk) had lower somatic cell counts (244,000), fewer cows (average 44), and more pasture and hay acreage per cow (1.8 ha or 4.5 ac).

In comparison, the six organic producers with the least production per cow (about 7,000 kg) had higher average cell counts (368,000), more cows (55), and a half hectare (or 1.6 ac) less pasture and hay per cow (1.2 ha or 2.9 ac).

Interestingly, the low production group had been organic producers for the longest time - an average of 18 years - compared to the high production group which had been certified just four years ago, in 2000.

The three different organic groups also had different breeding practices. The high group bred 100 per cent with artificial insemination and had 100 per cent Holstein cows. However, the longer the farmers had been organic, the more they experimented with natural breeding and crossbreeding.

Nine per cent of the cows in medium production group were crossbred, mostly to Brown Swiss, and AI use dropped to 76 per cent. In the low production group, 43 per cent were crossbred, mostly to Milking Shorthorn, and AI use was down to 60 per cent.

"They are small groups, so these averages have to be taken with a grain of salt," cautioned Rozzi. "I would look at the differences only if I could see a gradient." However, when she asked the organic farmers to rank their priorities for genetic selection, the three production groups were very similar to one another, and very different from conventional farmers.

Ontario's organic producers put 70 per cent of their selection emphasis on functional traits and only 30 per cent on production. They put much more weight on calving ease, milk persistency and capacity than conventional producers, who select 60 per cent on the basis of production and 40 per cent on function.

Ontario's organic producers had very similar selection priorities to the Swiss organic producers, who have been using a organic selection index for two years now.

"Conventional farmers in Scandinavian countries have been selecting for function for the longest time," added Rozzi. "Now we know what they want," said the geneticist. It's too small a group to ask for a specialized breeding program. The only thing we can do is sort the bulls by an index which reflects the desires of the organic farmers."

Calving ease, capacity, and a long flat lactation curve (milk persistency) are priorities. "We are still trying to figure out a measure for capacity," said Rozzi, suggesting that it may be a combination of traits including frame score.

Rozzi has already presented her research in both Germany and FiBL, the centre for organic research in Switzerland, as well as at the organic conference in Guelph. She will be speaking at the organic dairy seminar at Alfred College in early April.

Rozzi said she wants to meet again with dairy farmers to work on the capacity question before she develops a ranking of AI bulls for organic farmers. Still, she said, she may have a list of recommended bulls by summer, 2005.

Organic dairy farmers won't be the only ones to benefit from this information. It should also help conventional milk producers with intensive pasture systems.

OACC gratefully acknowledges Ontario Farmer for permission to post this article on our website.

Posted on the OACC website, April 2005