Confusion is an apt summary. A recently published article states in its summary, “the increase in milk production is through a combination of great body condition score loss and less energy partitioning in body condition score gain, and a lower substitution rate of supplements for pasture”.
It goes on to say “supplements will not improve reproduction unless cows have restricted access to pasture”.
I think the point being made is that increased production is in part because of eating more grass but if you want to improve reproduction rates, supplements help only if access to grass is limited or increased milk production and improved reproduction are mutually exclusive.
The article quoted above didn’t address the reproduction issue, leaving hanging the faintest of suggestions that high-performing cows are not suited to New Zealand farming systems.
could be wrong but that’s my take. Is it more accurate to say high-performing cows are not suited to poorly run, predominantly pasture-based systems that some have an enduring fondness for? Progressive farmers won’t wait around for the answers.
Other advice is available for farmers to consider that would let them grow grass and have cows eat it.
There’s some thought the pursuit of genetics to enhance production compromises reproductive performance and revisiting genetics is part of the answer, or as noted by the University of Missouri’s Animal Sciences Research Center, “the fundamental need for correcting the underlying genetics for reproduction in high-producing dairy cows”.
A Spanish study suggests “the need to improve management practices by attempting to reduce the effects of factors provoking stress” and “in addition to milk production, other factors are probably decreasing reproductive efficiency in our dairy herds”.
A paper from the United States National Library of Medicine suggests, “diets high in crude protein support high milk yield, but are also associated with lower reproductive performance”. That seems to offer a practical course to follow. From a Journal of Dairy Science paper, “daily managerial decisions to obtain efficient reproductive performance have considerable impact”. That works for me.
Who do you believe? It doesn’t matter if you derive value from the advice considered. Being practical people, many farmers have probably worked it out.
Upskilling management and staff is a good start. Farmers measure the effect in real-time operating conditions. It is found in the vat, the bank or the number of pregnant cows. Such experience and sources of advice can’t be levied for.
It seems to me the global dairy advisory sector can be singular in the analysis of data. Take the NZ example as a case in point. There was no data provided for the effect of changing diets on replacement rates and milk output. What is the financial trade-off between milk production and herd replacement rates? Ask a farmer?
Maximising income and minimising cost of production is the objective. More milk isn’t fun when money is lost on every litre. Is it as simple as changing management and upskilling staff?
From a pragmatic operational and commercial perspective looking at the information available isn’t overly helpful. It may be that high-performing producers – not to be confused with high-performing cows – could be useful in the production-versus-reproduction debate and support it with commercial reality.
Perhaps it’s time for science to study the good operators and catch-up with the market?
• Ray McLeod is an economist and engineer for Landward Management in Dunedin.
