Use of medium-chain fatty acids to promote production performances and gastrointestinal tract health in calves
Newborn dairy calves are susceptible to many pathological conditions that are reflected in their production life. Heinrichs and Heinrichs (2011) reported that the number of days when calves are suffering diarrhea during the first months of life has a significant negative impact on milk production, milk composition and milk production cycle during the first lactation. The gastrointestinal tract (GIT) of calves represents the first defense barrier against exogenous pathogens such as bacteria, toxins and viruses (Steele et al., 2016). However, the GIT of newborn calves is not fully developed, particularly the forestomach, which makes the calves not adapted to consume solid feeds. For this reason, the early preweaning development of the GIT of calves is important to enhance their productive performance and health status.
For a long time, antibiotics were used as growth promoters in animals, however, the development of antibiotic resistance among animals and in humans has led to banning this practice in many countries. Supplying medium-chain fatty acids (MCFA) to milk replacer and starter feed resulted in better development of the GIT epithelium, reducing health disorders and improving growth parameters (Hill et al., 2011; Quigley et al., 2019); it is, hence, an alternative to the use of antibiotics that will keep a low rate of morbidity and mortality in newborn calves.
Medium-chain fatty acids present a valuable energy source for young calves and influence their energy metabolism (Klopp et al., 2022). It was observed that MCFA supply decreased NEFA levels in blood in comparison to control calves. The MCFA represents a rapid source of energy, they are absorbed quickly by the abomasum and in the small intestine, being conducted directly to the liver, contrary to long-chain fatty acids that need to be incorporated into chylomicrons. Subsequently, high energy availability for calves leads to higher performances, increasing growth rate, average daily gain and feed efficiency (Hill et al., 2009; Quigley et al., 2019; Murayma et al., 2023).
In addition, supplying MCFA affects animal microbiota (Zentek et al., 2011; Bortoluzzi et al., 2018), with antimicrobial activity against gram-negative and gram-positive bacteria (Sol et al., 2017). Murayma et al. (2023) reported that supplementing MCFA on dairy calves during the preweaning period decreased diarrhea incidence by 55%. The authors also observed higher Beta-hydroxybutyrate levels in the blood, which indicates higher rumen epithelial metabolic activity and development (Lane et al., 2000). Furthermore, feeding a blend of sodium butyrate and MCFA increased antibody response and decreased immune and inflammatory response which simultaneously improved GIT health of claves, reducing the incidence of scours and clostridium sickness (Fokkink et al., 2009; Hill et al., 2011). These data indicate the effect of MCFA on the intestinal level, that have a stimulating effect on rumen papillae and inhibits pathological bacteria in the intestine.
In conclusion, MCFA supply into dairy calves diet is highly recommended and represents an efficient strategy to boost gastrointestinal development, stimulating young calves to have higher solid feed intake and providing protection against pathogens and reducing scours. These conditions guarantee healthier calves with improved growth performances and well-prepared for the further production cycle.