Friday, July 8, 2022

Pregnancy nutrition targeted

Even on the best pasture, healthy lambs just won’t grow sometimes.

Similarly, at lambing, some newborn lambs just don’t survive and there is no apparent reason.

Both examples occur regardless of genetic base.

The answer may lie in work being done on a relatively new frontier. Foetal programming, also known as developmental programming, is a concept often associated with human research. In recent times obesity and diabetes in children have been linked to the diet of mothers during pregnancy.

Dr Sue McCoard, senior research scientist with the animal nutrition team at AgResearch Grasslands, said some key trends emerging from human research internationally had major implications for our sheep, beef and dairy industries.

Nutrition is the key area in the sheep research programme with focus on the importance of nutrient intake by multiple-bearing ewes. McCoard and her team are investigating how specific amino acids can “programme” the organs and tissues in the developing foetus to operate a certain way. This programming affects survivability, body (muscle) composition, lactation and future productive performance.

Using the proverb of “we are what we eat”, McCoard said the research could be expanded to include that “we also are what our mother’s ate”.

Farmers are well versed on how feed supply in early gestation, via placental development, determines the size and timing of birth of newborn lambs. It has also been reported since 2004 how ewe nutrition levels during pregnancy determine the lactation ability of the female offspring. By comparing singleton and twin pregnancies, McCoard’s team has also highlighted the importance of foetal nutrient supply (via the placenta) in late gestation for muscle development, lamb birthweight and post-natal growth even in well-fed ewes.

These examples give an indication of how nutrition during gestation can dictate outcomes. McCoard’s team is now taking this research to a new level by trying to explain how these developmental programming events occur.

McCoard said it appeared that some amino acids regulated metabolic pathways and thereby influenced foetal development.

“Because the amino acid supply is linked to nutrition, this opens opportunities for manipulation by farmers.”

Her research aims to find out if supplementation with specific amino acids can programme the development of organs and tissues in the foetus and the impact on lamb survival, growth and meat production.

Knowledge generated from this research may also provide insights into how stressors during critical periods of development affect the developing foetus, particularly those of multiple-bearing ewes. Stressors are often associated with nutrition but can be brought on by things other than feed supply such as bad weather, yarding, shearing or even competition from other ewes. Standing ewes off feed, for example, for even a short time during early gestation, is known to affect foetal survivability.

The aim of the research is to provide farmers with the opportunity to deliver targeted nutrition (e.g. specific nutrient supplementation) within a short window of time during pregnancy, and get a major response in terms of lamb survivability, health, growth rates and productivity.

“Can we do it? I think we can,” McCoard said.

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