Effects of fat supplements containing different levels of palmitic and stearic acid on milk production and fatty acid digestibility in lactating dairy cows

Abstract

Fat supplements based on palmitic acid (PA) or stearic acid (SA) are expected to have different effects on milk production and nutrient metabolism in lactating dairy cows. In this study, the effects of prilled fat supplements containing different levels of PA and SA were tested in 12 high-producing multiparous cows (pretrial milk yield = 53.4 ± 8.7 kg/d; mean ± SD) arranged in a 4 × 4 Latin square design with 21-d periods. Treatments were control (CON; no supplemental fat), an enriched PA supplement (HP; 91% C16:0), an enriched SA supplement (HS; 92.5% C18:0), and a blend of PA and SA (INT) fed at 1.95% of diet dry matter. All supplements contained oleic acid at approximately 5% of fatty acids. The HP treatment decreased dry matter intake (DMI) by 1.9 kg/d and 1.1 kg/d compared with SA and CON, respectively. Milk yield was not changed by treatment, but INT increased energy-corrected milk by 2.7 kg/d compared with HS. The HP and INT treatments increased milk fat yield by 0.11 and 0.14 kg/d compared with CON, respectively. Additionally, HP decreased yield of <16 carbon fatty acids (FA; de novo synthesized) by 44 g/d and 43 g/d compared with INT and CON, respectively. The HP treatment increased 16-carbon FA (mixed source) by 155 g/d compared with CON and 64 g/d relative to INT. No effect of treatment on apparent total-tract digestibility of dry matter, organic matter, or neutral detergent fiber was detectable. The INT and HS treatments decreased total-tract digestibility of 16-carbon FA by 10.3 and 10.5 percentage units compared with HP, respectively. Total-tract digestibility of 18-carbon FA was lowest in the HS diet and highest with HP. In conclusion, supplementing PA increased milk fat yield compared with control and SA, but supplementing a mixture of PA and SA increased energy-corrected milk without decreasing intake. The FA profile of fat supple-ments influences their digestibility and effects on DMI and milk and milk fat synthesis.

Associations between Dietary Fatty Acid Profile and Milk Fat Production and Fatty Acid Composition in Dairy Cows: A Meta-Analysis

“…Preformed FA increased with most diets evaluated in our study (Groups 1, 2, and 3). These findings are consistent with those reported by dos Santos Neto et al [ 12 ] and Shepardson and Harvatine [ 22 ]. However, other studies indicate that sources with high SFA content do not affect the synthesis of preformed FA in milk [ 29 , 30 ].…”

“…In general, it is known that lipid supplementation in dairy cow diets increases milk production [ 12 , 13 , 14 ]. However, there are reports suggesting that certain lipid sources have no effect on milk production [ 22 , 23 , 24 ]. Consistent with these findings, our study showed that diets rich in UFA had no effect on milk production.…”

Abomasal infusion of different exogenous emulsifiers alters fatty acid digestibility and milk fat yield of lactating dairy cows

“…The inclusion of an almost pure C18:0 supplement (>90% C18:0) at 1.92% (Piantoni et al, 2015) and 2.30% (Boerman et al, 2017) diet DM reduced FA digestibility of lactating dairy cows by 20 and 28 percentage units, respectively. When included at 1.95% in the diet DM, a C18: 0 -enriched supplement (92.6% C18:0) decreased total and 16-carbon FA absorption compared with a C16: 0 -enriched supplement (91.0% C16:0; Shepardson and Harvatine, 2021). Our recent meta-analysis observed that diets containing mixed C16:0 + C18:0 supplements decreased FA digestibility by 5.20 percentage units compared with control diets not supplemented with FA, whereas diets with C16: 0 -enriched supplements had no effect (dos Santos Neto et al, 2021a).…”

ARID3A plays a key regulatory role in palmitic acid‐stimulated milk fat synthesis in mouse mammary epithelial cells

“…Our study found that PA promoted ARID3A protein expression and SREBP1 expression and maturation in HC11 cells in a dose‐dependent manner. It is well known that long chain fatty acids such as PA and stearic acid can promote milk fat synthesis in mammary epithelial cells (Jin et al, 2022; Shepardson & Harvatine, 2021). We observed that high concentration of PA has inhibitory effects on SREBP1 expression and maturation, in agreement with previous reports that high concentration of fatty acids may have cytotoxic effects and induce apoptosis (Ng & Say, 2018; de Sousa Andrade et al, 2005).…”