Source: Novus International via Feedinfo News Service
27 February 2019 – “When we were feeding MINTREX® trace minerals to sows or hens—breeding animals—they were reporting benefits in the progeny. At first, we thought, ‘oh, we just got lucky’. [But if that was it], how would the effects carry on for so long in the progeny?” recounts Dr. Mercedes Vázquez-Añón, senior director of animal nutrition research and facilities for Novus International Inc. That, she says, was the starting point for research that opened a new world of opportunities in animal nutrition. Was it possible that nutrition at the parent level was having implications on the offspring? And if so, how could feed additives harness these effects?
As Dr. Vázquez-Añón explains, the concept of epigenetics was taking root in the scientific community when Novus began investigating this. Epigenetics is often summarized as the ability for environmental factors, including nutrition, to “switch on/off” or to “open/close” genes—not to alter the genetic code itself but to affect its expression in a way that can be passed between generations. In fact, as she clarifies, epigenetics is only one very specific way of regulating gene expression. Other techniques, including phosphorylation, affect gene expression without technically qualifying as an epigenetic change. “We started with epigenetics, but [the genetic effects of maternal feeding are] not limited to epigenetics,” she says.
Novus researchers began by studying the zinc contained in its MINTREX® trace mineral line and how it was influencing genetic expression by measuring acetylation or methylation of the genes. “We were seeing that zinc fed to hens would open or close genes in several tissues of the progeny*,” Dr. Vázquez-Añón says.
What researchers first found concerned the development of the immune system in the gut tissue of the chickens. “We were identifying genes that were being expressed or suppressed and they were all related to inflammation in the small intestine,” Dr. Vázquez-Añón asserts. At the same time, morphological effects were said to be visible with higher villi and a better expression of proteins connected to the barrier function of the enterocytes of the gut. She says this comes down to controlling the initial “cascade” of the inflammation pathway (the initial immune reaction leading to further immune reactions).
These immune system changes helped explain the “why” behind the benefits that had been reported in association with MINTREX® in young animals: greater number of offspring (more hatching chicks) and improved mortality in the first ten days of life. But it also went further than that. Dr. Vázquez-Añón says they have seen effects in chickens up to 21 days in age. “It’s not just for the newborn chicks.”
According to Dr. Vázquez-Añón, accessing these benefits is not just a question of feeding any minerals to the parent stock; the type of zinc and whether the mineral can be used by the animal both make a big difference. “More available zinc [such as MINTREX® Zn] will have greater impact than a less available zinc,” she observes. This is especially important considering there is only a 10-day window during the development of the embryo when the hen’s mineral nutrition can impact the embryo.
Researchers found the same benefits when they carried out these experiments in swine: larger litters, lowered mortality during weaning, and the higher market weights that had originally sparked the investigation. Dr. Vázquez-Añón also said researchers confirmed the same effects in terms of modulating the gene associated with the initial steps in the inflammatory cascade system.
Moreover, zinc’s power to affect intergenerational changes is not limited to gut health and immune system benefits. Looking to understand if the changes were genetic, Novus partnered with North Carolina State University (U.S.) to study the digestive system tissues and muscle tissues of piglets whose mothers had been supplemented with or without MINTREX®. “We do have some evidence that this is helping the… maturation of muscle fibers in the pig, the differentiation of the muscle fibers,” she asserted. Additionally, she acknowledges suspicions that “something is probably happening at [the level of] skeletal development,” pointing to observations from previous work where feeding MINTREX® increased the development of bones and cartilage of embryos, leading to longer tibias, for example. “We haven’t gone there yet in terms of gene expression, but we have the phenotype effect.”
Now, she says, Novus is focused on expanding its understanding of maternal mineral feeding concepts in ruminants. “We are beginning to evaluate if you can change perhaps the composition of the colostrum by feeding the mom earlier; while at the same time, changing the capacity of absorption or the immune response of the calf.”
Within monogastrics, Novus researchers are examining these effects in different breeds, different programs, and different environmental conditions. In the case of broilers, Dr. Vázquez-Añón says the focus will be on addressing some early-life health issues through selective feeding in breeders. In pigs, it will be reducing variability in litter sizes. Researchers will also focus on effects outside of the gut – in other tissue systems, particularly those involved in early development. “The sky’s the limit; many things can happen that we’re not looking at [today].”
But the key to it all is understanding just how important maternal nutrition is, how even the type of minerals fed to animals can have an impact on the progeny. “If you want to promote health and growth early on, in chickens or in pigs, you don’t have time. When they’re born, it’s already too late. If you want healthier newborns, you have to start with mom.”
*References available upon request. Please contact Novus.
Published in association with Novus International