Consequences of Maternal Essential Fatty Acid and Conjugated Linoleic Acid Supplementation on the Development of Calf Muscle and Adipose Tissue

SIMPLE SUMMARY: Cows in modern dairy production systems are fed with silage and concentrate-based diets, resulting in a low essential fatty acid and conjugated linoleic acid status in body tissues and milk. During the late pregnancy and early postnatal period, a reduced maternal fatty acid supply might negatively affect calf development. This study investigated the effects of a maternal re-substitution with essential fatty acids and conjugated linoleic acids on muscle and fat tissue development of neonatal calves. The maternally-supplemented fatty acids were found to be elevated in calf skeletal muscle and fat tissues, but no short-term effects on tissue structure were observed. Nevertheless, the possibility to change offspring fatty acid status via maternal nutrition has been confirmed that could influence offspring development and health in the long-term. ABSTRACT: Common silage and concentrate-based diets in dairy and beef production may deliver insufficient amounts of essential fatty acids (EFA), thereby also reducing conjugated linoleic acids (CLA) in body tissues and milk. An impaired maternal EFA and CLA supply can have an important impact on calf postnatal development. The current study investigates how maternal supplementation with EFA and CLA affects muscle and adipose tissue development in neonatal calves. Holstein cows (n = 40) were abomasaly supplemented with coconut oil (control), CLA or EFA, or both combined during the transition period. Calves were fed their dam’s colostrum until slaughter at day 5 of life. Fatty acid composition and tissue morphology were analyzed. In muscle and adipose tissues, EFA, CLA, and metabolites were elevated, indicating the effective transfer of maternally-supplemented FA to the offspring. Muscle fiber types, fiber nuclei, myosin heavy chain isoform distribution, capillarization, and fat cell size of intramuscular and other adipose tissues did not differ among groups. The results confirm that maternal nutrition during the transition period can alter the FA composition of the calf tissues. This could influence the offspring’s development and health in the long-term, even though only minor effects were observed in the neonatal calves’ tissue morphology.