Meat wellness, well done
Newly published research shows overseas consumers have a strong interest in improving their wellbeing through eating red meat, highlighting opportunities to achieve a premium for products with proven health benefits.
New Zealand has an the outdoor pasture-based system.
AgResearch's Dr Sue McCoard says overseas milking sheep are often fed on a 'total mixed ration' (TMR) – a mixture of conserved forage and concentrate, or using high concentrate feeding systems.
But McCoard reckons there is a lack of scientific data on how to optimise dairy sheep production on NZ's pasture system and that we need to fully understand how our system works to get the best long term results from our milking sheep.
McCoard is working alongside Dr David Stevens' in the onfarm, MBIE-funded Competitive Sheep Dairying programme, led by Dr Linda Samuelsson; this is aimed at improving feeding, management and farming systems to enhance lifetime milk production from a ewe and optimise lamb rearing systems. The wider programme also includes understanding the unique compositional and functional attributes of the milk to support novel product development, and the environmental footprint, of dairy sheep systems.
"We are particularly focused on the impact of nutrition on the performance of the animal. Nutrition in early life is important for survival and growth of the young lamb either as a replacement animal to go into the milking flock or for meat production," she explains.
"Our research aims to optimise both artificial (i.e. by hand) and natural rearing systems, to reduce mortality and to deliver healthy lambs that grow well, and to optimise their lifetime performance. An important aspect of this is how we feed them in early life and how that impacts the future performance of that animal."
McCoard says the aim is to get more than just an adequate lamb at the end of the process. They are interested in the implications of early life nutrition on the physiology of the lamb for her future growth, health and reproduction and milk production – understanding what is going on inside the animal and how nutrition and management affects these production traits.
She says organs and tissues undergo substantial development and growth in early life (prenatal and soon after birth) and the researchers are particularly interested in the formation of the mammary gland and how nutrition pre- and post-weaning affects the development of that gland, because it can affect milk production potential.
Their research is indicating that the period after weaning (12-20 weeks) is important for mammary gland growth leading up to puberty, but the long-term implications for milk production are still being evaluated.
"We have been looking at what to feed young ewe replacements and how this affects the development of the mammary gland and what that might mean for her future reproduction performance and the implications for her milk production. The early life nutrition and rearing research is to develop systems fit for purpose, in terms of cost-benefit, production performance and practicality."
In NZ a lot of research has been done on growing lambs faster post-weaning using the 'rocket fuel' pastures plantain, chicory and red clover. While this has positive implications for growing lambs faster for slaughter, the outcomes of rapid growth may have trade-offs for mammary development in future milking ewes; so it is important to better understand what are the optimal feeding systems for young ewe replacements for dairy sheep operations, McCoard says.
"Overseas studies have shown that in terms of mammary development, growing lambs too fast when they are young can adversely affect their milk production. Whether that actually occurs in our pasture-based systems we don't know because it is harder to get animals really fat on a pasture-only diet versus grain-based concentrate feeding systems.
"Feeding during key developmental time windows, such as when the mammary gland is forming prior to puberty, is important and understanding what to feed, how to feed and when to feed is quite a big challenge," she says.
In some overseas dairy milking systems, the lambs are reared on the ewes until weaning and then the ewes are milked for commercial production. But she notes that 25% of a ewe's milk production is in the first month, so these systems can limit the yield of commercial milk.
"In addition to our research into artificial lamb rearing systems, which enables ewes to be milked soon after lambing, we have recently experimented to evaluate the potential of weaning naturally reared lambs early in lamb growth as well as commercial milk production from the ewes," McCoard adds.
"We separated the lambs from their mothers for a short time during the day from two weeks of age. This separation encourages them to eat solid feed which develops the rumen which in turn supports the transition off a milk diet onto pasture which occurs at weaning. It also enables those ewes to be milked once a day, following which they get reunited with their lambs."
McCoard says the lambs were weaned from four weeks of age versus five-six weeks for the standard system. She says their research showed that early separation of lambs from the ewes, coupled with early weaning, does not affect the pre- or post-weaning growth rates of the lambs or their survival and health.
"It's an ongoing piece of work with the ultimate goal being a system that enables natural rearing of lambs while increasing commercial milk production."
Last season they were not able to measure individual ewe milk production, but this season they will be able to. However, she says it appears that this season has resulted in an estimated 25% increase in the total commercial milk yield, consistent with overseas data.
Exciting, fun and having a real practical application is how Sue McCoard describes their work. She says working with some of the major players in the sheep milk industry is rewarding and there is a good interchange of ideas between farmers and scientists to obtain a practical and commercial outcome.
