Work at Tokanui Dairy Research Farm progressing

Work at Tokanui Dairy Research Farm progressing well

Research at AgResearch’s Tokanui Dairy Research Farm in dairy cow productivity is further examining the role and interrelationships that environmental and genetic influences play in milk production.

The $6.5 million Waikato-based research farm, which has been running for nearly 12 months, was established by AgResearch to further research and development into environmental management, productivity gains and differentiated or speciality milks that will support a healthy, sustainable dairy industry.

Among the range of research trials being conducted at Tokanui are two on milk production as part of a programme funded by the Foundation for Research, Science and Technology (FRST). Both trials are studying the influences on molecular functioning of the mammary gland and how it regulates milk production in cows.

Peter Benfell, Science & Technology General Manager - Agriculture & Environment Group, says while the results of the two milk production trials will only be known next year, the progress made so far indicates there is capacity for more related research projects that can benefit farmers and the dairy industry. ”Over the coming years Tokanui will prove to be a major asset for pastoral research in New Zealand. Not only is there a large pool of cows to select from, but this research and development facility has been designed to carry out focused studies.”

Dr Adrian Molenaar is leading one of the research projects. He is looking at ‘lactation persistency’, the volume of milk produced by cows over the whole season. Dr Molenaar says that by-and-large cows in New Zealand show poor lactation persistency, which cannot solely be explained through nutrition. However, some cows are more persistent than others and we have selected two sets of cows, one set more and one set less persistent, for more intense study to find out why they are like that. In these groups the higher persistency cows gave 5 per cent more milk over this last season than the lesser persistency cows.

‘Performance can also be influenced by different management practices such as milking frequency. Our goal is to understand the mechanisms within the udder that regulate persistency. When dairy cows are milked twice daily the increase in milk yield after calving is due to an increase in activity of each milk-secreting cell within the udder. After peak lactation, the gradual decline in milk yield is due to a loss in number of these cells.

‘Understanding the mechanisms that regulate and govern cell renewal will lead to the development of novel strategies and/or technologies to enhance productivity,’ says Dr Molenaar.

The second milk-production trial led by Dr Kuljeet Singh is an epigenetics study focussed on understanding how the mammary gland responds to different environmental influences. Epigenetics is the study of how environment and genetic information encoded in an animal’s DNA together influence different traits.

‘It’s well known that factors such as nutrition and hormones influence the number and activity of the cells within the mammary gland that secrete milk proteins which, in turn, influence levels of milk production,’ says Dr Singh

‘In this case we’re testing how nutrition affects the foetus during pregnancy. The testing looks at permanent affects on lactation performance of the daughter during its lifespan and whether affects may be passed onto its offspring. The results could have a significant effect on livestock management,’ says Dr Singh.

Cows in both trials were subjected to mammary tissue biopsies twice during the season. The tissue samples allow changes in the udder to be studied and the results will ultimately lead to strategies and/or technologies to enhance the entire lactation cycle.

The projects have both entered the data and sample analysis phase with results expected in 2011.

ENDS

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