An empty mare at the 14-day scan is always disappointing, especially as the breeding season winds down. Farms face increasing frustration when mares struggle to get in foal, particularly older mares who require all possible assistance to ensure conception. In a promising development, a research team supported by AgriFutures Australia is exploring a potential game-changer for studmasters: niacin.
The research, conducted by teams from the University of Sydney, the University of Newcastle, and Charles Sturt University, focuses on the end product of niacin, or vitamin B3. This compound, known as nicotinamide adenine dinucleotide (NAD), is produced by cells and plays a crucial role in fertility, as demonstrated in other mammals.
Understanding the Role of NAD in Fertility
Professor Christopher Grupen of the University of Sydney, a veteran in reproductive technology research, explains the significance of NAD. “There’s mounting evidence in other species, including humans and mice, that the levels of this important factor NAD decline as we advance in age,” he said. Grupen, who heads the Gamete and Embryo Technologies Group at the university, has been leading the inter-university research team in this endeavor.
“NAD is a key regulator of many cellular processes, including energy production, the immune response, and DNA repair,” Grupen elaborated. “Studies in humans and mice have shown that the NAD decline can really impact female fertility. The mouse studies have gone even further and have shown that it affects the quality of the eggs that they ovulate.”
“NAD decline can really impact female fertility.” – Prof. Christopher Grupen
Just as stallions over the age of 15 are more at risk of testicular degeneration, mares in the same age bracket face lowered fertility as the quality of their eggs declines. The research team hypothesized that the results from trials in mice could be replicated in horses, potentially leading to better quality eggs and a higher chance of successful conception.
Initial Trials and Promising Results
The initial trial in late 2023 involved supplementing nicotinic acid, a form of niacin, into the feed of a group of Standardbred mares aged 15 or over. Researchers collected blood and follicular fluid to assess absorption levels. The study herd was divided into groups: a control group receiving no supplement, one group receiving 1.5g nicotinic acid per day, and another receiving 3g per day.
Using mass spectrometry, researchers detected changes in metabolite levels, indicating the transformation of niacin into NAD. “We were quite amazed by the metabolite changes, especially in the follicular fluid,” said Grupen. This confirmed that nicotinic acid could reach its intended destination and be converted into the essential NAD, mirroring results from laboratory research.
Grupen noted, “In our previous in vitro studies looking at the quality of eggs from pigs, when adding factors like nicotinic acid or niacin for two days, we found slight improvements in the quality of the eggs.” This led the team to hypothesize that a short supplementation window might suffice.
Field Trials and Future Implications
The next phase of research involves a large-scale study in collaboration with several studs in the Hunter Valley. “We’ve partnered with a number of studs and tried to recruit as many mares as possible,” Grupen explained. “Half of the mares in the study receive the supplement, half don’t, and then studs will be collecting their breeding data as normal all the way through to foaling.”
Mares selected for the study are 15 years or older and receive supplementation as an oral paste for four to eight days leading up to ovulation. “We’re hoping that a targeted supplement for at least four days will be beneficial,” said Grupen. “If we get results showing it’s beneficial, we will then discuss with AgriFutures about the next steps for sharing this information with industry.”
“If you can get the mare to conceive on her first or second mating, then it’s much less stress on her.” – Prof. Christopher Grupen
The hope is that supplementation will lead to a higher incidence of pregnancy in the study group, reducing the number of cycles needed to achieve it. “It would improve the welfare of the animals, as well as reduce the cost and time spent by management to get these mares in foal,” Grupen emphasized.
Looking Ahead: The Potential Impact of Niacin
If results are promising, there could be a market opportunity for a supplement backed by research. “The good thing about niacin is that we know it’s very safe, it’s tolerated very well by the horses,” Grupen noted. “To do these studies properly and show that a specific compound will lead to clear benefits means we’ll overcome that confusion.”
Grupen believes that niacin could become a crucial part of farm management. “I’ve been doing research in this space for 30 years and this is probably one of the most exciting advancements I’ve seen,” he said. “I am hopeful that in five years’ time, everyone will understand the importance of this as a supplement.”
While the focus is on older mares, Grupen suggests potential benefits for mares with poor reproductive histories for various reasons. “We’re just looking at one piece of the puzzle, so maybe it will have beneficial effects for immune response and general health as well,” he concluded.
