Hungrier cows need a close eye
Improving their sixweek in-calf rate by just 10 per cent means the average New Zealand dairy farmer (386 cows) stands to benefit by an additional $15,440 (based on a $5.50 per kilogram milk solid payout).
And according to LIC Reproduction Solutions adviser Joyce Voogt, most farmers have the ability to do this.
Farmers reap the benefit of a high six-week in-calf rate in more ways than purely by extra days inmilk, she said.
‘‘Farmers would also benefit from improved empty rates as there is a direct relationship between them. The more cows there are calving early, the less empties there tend to be.
‘‘Cows which calve in the first three weeks of the calving period have more time to recover and start cycling before the next planned start of mating.
‘‘Cows already on their second or third cycle when first mated have better conception rates than cows on their first cycle. The effect is cumulative. ‘‘Research shows that reproductive performance in New Zealand dairy herds has declined in recent years with six-week in-calf rates dropping from 68 per cent 10 years ago to an alarming 62 per cent in 2011,’’ said Ms Voogt.
‘‘Approximately 90 per cent of the variation in reproductive performance in a herd is due to farm management practices while only 10 per cent is attributable to genetics.
‘‘The ‘ bigger fish to fry’ include heat detection efficiency, body condition score at calving and young stock growth and management.
‘‘The eight ‘ ingredients’ needed to maximise herd fertility are: A compact calving; Good young stock rearing and heifer management;
Body condition and nutrition;
Effective and accurate heat detection;
Identifying and dealing with non-cyclers; Cow health; Genetics and AB practices; Bull management. ‘‘All these fundamental principles are covered in the Dairynz Incalf book.
‘‘This invaluable resource is available free of charge to all levy paying farmers.
‘‘Industry-wide we are all aware of the gradual decline in reproductive performance of the national herd and the impact this has on farm performance – fewer days in milk, declining six-week in-calf rates, increased empty rates and increased calving spread.
‘‘Though our cows may not be much larger today than they were 10 years ago they sure are hungrier and they need to eat more because they produce more milk.’’
The national breeding objective of ‘‘identifying the most efficient converters of feed into profit’’ means that New Zealand has bred cows who will do just that, at the expense of reproduction, Ms Voogt says.
‘‘Even if management practices have remained the same over the past 10 to 15 years, where artificial breeding (AB) has been used then the cows’ and herds’ breeding worth and production will have increased and resulted in a higher producing, more profitable animal that needs more feed.
‘‘Many farmers have increased their feeding regimes and introduced supplementary feed, for example palm kernel, to replace feed shortfalls.
However, high BW (breeding worth) cows need to be fed well, Ms Voogt said. ‘‘If they are not fed enough, these high performing animals will condition-strip to put milk in the vat.
‘‘But drying off early enough, to achieve target body condition scores is crucial as well. For improved six-week in-calf rates and empty rates, we need to ensure heifer and three-year-old cows are well grown and calve down at body condition score 5.5, while the rest of the herd need to calve at body condition score 5.
‘‘Today’s cows are producing 80kg more milk solids than those of 20 years ago.
‘‘Managed well we can ‘have our cake and eat it’ with regard to our cows but we need to be constantly mindful of the feed demands on them.
‘‘More cows in-calf quicker’’ means thinking about herd reproduction throughout the year and not just at mating time, said Ms Voogt.
‘‘Recent LIC data indicates that about 70 per cent of first calvers entering our dairy herds have not been grown to their full potential.
‘‘I believe this is a major contributor to low six-week in-calf rates and high empty rates in our two- and threeyear-old cows.
‘‘Cows continue growing until they are five years old and when these youngsters are entering the herd smaller and lighter than their mature herdmates they really struggle to compete.
‘‘In a well managed herd a more condensed calving means more days in milk, more money in the bank.’’