Novel dietary fat source for broiler chicks

Based on an extensive body of research on how a lipid-containing component of cow’s milk called milk fat globule membrane (MFGM) benefits development and health, Nukamel has investigated the benefits of its inclusion in broiler chick diets and the diets of other young livestock.

As its full name suggests, MFGM is a membrane that surrounds the lipid core of milk fat globules with 3 layers of various lipid types. It’s studded with proteins – over 500 types, mainly glycoproteins that resist digestion – and carbohydrates, mainly glycoproteins or glycolipids.

Some of these specific MFGM components are bioactive, notes Nukamel R&D manager Dr Evi Croes, adding that they also provide synergistic benefits in their combinations and because of their structural organisation. “The lipid-lipid and lipid-protein interactions within the MFGM structure afford these molecules a degree of persistence in the gastrointestinal lumen,” she explains. “Because of this, they are conveyed to the large intestine where they perform specific roles, such as strengthening immune response, promoting intestinal development and providing direct antimicrobial effects.”

Inspiration

In infants, consumption of MFGM-enriched formula has been shown, for example, to reduce the number of days with fever and help prevent infections through actions such as prevention of pathogen adhesion to gut epithelium. “Similarly, studies on rodent and piglet models have shown benefits of MFGM on infection, inflammation, brain composition, and gut barrier integrity, as well as intestinal development,” says Croes.

“In rat pups, MFGM-supplemented diets fed from day 5 resulted in a better restoration of the intestinal villus and crypt architecture and improved expression of tight junction proteins, which help prevent pathogen entry,” she said. “Inflammatory response with a MFGM-rich diet was significantly lower, and serum levels of different cytokines were decreased and signify a reduced stress on the gut barrier.”

Although these first studies weren’t numerous, they caught the attention of Croes and her colleagues. “As we specialise in young livestock animal nutrition, we are always keeping up with infant nutrition research and research on dairy ingredients,” she explains.

“We looked into where we could get MFGM raw materials. MFGM-enriched dairy ingredients can be produced commercially from either whey or cream concentrates, and they only became available in the last 5 years or so as interest in using MFGM in infant formula increased. We analysed the different raw materials and sought those treated only with low heat to maintain as much of the biological value as possible. In 2019 we did our first trials with broiler chicks and calves, testing different formulations and percentages of MFGM,” she said.

Research results

Steven Cools, Nukamel poultry product manager: “With regard to fat metabolism, there is always the concern that the chick’s liver health is good, and also that the fat is used in the body in the direction of muscular growth and not into fat accumulation.”

His team noted trials where inclusion of dairy fats in rodent and human diets resulted in lower levels of IGF-1 gene expression, as well as less hepatic fat accumulation, de novo fatty acid synthesis and hepatic lipidosis. Fat deposition was lower and muscle growth was higher. In addition, adipocyte cell number and/or cell size was lower, and there was a beneficial re-programming effect on long-term visceral fat accumulation and metabolic health, if supplementation is initiated early enough, which is defined as ‘metabolic programming’.

“So in our broiler chick studies, we were focused on seeing how different levels of MFGM inclusion in the diet would support good fat metabolism but also good fat digestion (emulsification) and absorption (micelle formation),” says Cools. “This, in turn, should result in better overall chick health, faster growth and lower feed conversion.”

The initial trials were done in ground floor pens in different academic trial farms (Ross 308 in Belgium, Cobb 500 in Vietnam) and found that an inclusion rate of 500 ppm provided better health and growth rates. Based on this knowledge, Nukamel launched Volamel Compass (VC), but continues its research to further optimise and differentiate advise.

A trial at Belgium’s University of Leuven, for example, involved Ross 308 broiler chicks (135 broilers per treatment) fed a wheat-soy based diet with soybean oil and lard as added oils, without (control) or with 500 ppm VC.

“To increase the challenge, we reduced the ME content with 50 (starter) and 90 kcal (grower/finisher) when VC was supplemented,” says Cools. “Nevertheless ME content was reduced, VC was increasing slaughter weight at 38 days of age (DOA) by 100 g (after fasting; 2184 vs. 2283 g), while feed conversion rate (FCR) stays the same (1.42), resulting into an increase of 18 points in EPEF (393 vs. 411). A nice effect on carcass conformation was that while carcass weight was increasing, hepatic lipidosis and abdominal fat pad were significantly reduced by at least 10%, resulting in an increase in dressing (%). Up until now, these dynamics (i.e., leaner growth) were confirmed by 2 other trials.”

Metabolic programming

Nukamel also focused on the metabolic programming effect in chicks, because in mammals, MFGM can induce long-lasting modifications in metabolism. So far, at ILVO’s trial facility in Belgium, a trial with Ross 308 (243 broilers/treatment) was done with diets similar to the Leuven trial. VC supplementation was limited to the starter phase (10 DOA) and resulted in a significant increase in slaughter weight (43 DOA) and dressing (1.5-2%). Broilers were also growing leaner (increased ratio between breast meat-abdominal fat pad by 2-3%). Feed conversion decreased and flock homogeneity increased from 81-91%.

“Overall, we can conclude that using VC provides benefits, and while it is not the cheapest product, the low inclusion rate adds only a small cost at MT of feed-level,” says Cools. “There are savings through better health outcomes and faster growth rates, but also in the fact that you can reduce the amount of fat in the diet. There is ROI between 3 and 6 depending on the diet, housing and application.”

*Nukamel’s white paper on MFGM can be found here.