Supplemental Tables for Journal of Dairy Science 2020-19985
Creators: name: Prom, Crystal M.
name: Lock, Adam L.
Publisher: name: Zenodo
Year: 2021
Subjects: absorption
fat supplementation
milk fat
nutrient partitioning

description: The objective of our study was to determine the effects of altering the ratio of stearic (SA) and oleic (OA) acids in supplemental fatty acid (FA) blends on FA digestibility and milk yield of dairy cows. Eight multiparous Holstein cows (mean ± SD; 157 d in milk ± 11.8) were randomly assigned to treatment sequence in a replicated 4x4 Latin square design with 14-d periods. Digestibility and production data were collected during the last 4 d of each period. The treatments were a non-FA supplemented control diet (CON), and 3 diets incorporating FA supplement blends at 1.4% of diet dry matter (DM) containing (as a % of total FA) 50% SA and 10% OA (50:10), 40% SA and 20% OA (40:20), or 30% SA and 30% OA (30:30). FA blends were balanced to contain 33% palmitic, 5% linoleic, and &lt;0.5% linolenic acids. The FA supplements replaced soyhulls in the CON diet. Preplanned contrasts were: 1) overall effect of FA treatments [CON vs. the average of the FA treatments [control vs. FA-supplemented diets; (50:10 + 40:20 + 30:30)/3], 2) the linear effect of <em>cis</em>-9 C18:1 inclusion in the supplemental FA blend, and 3) the quadratic effect of OA inclusion in the supplemental FA blend. There was no effect of treatment on dry matter intake, but the replacement of soyhulls in the FA treatments decreased neutral detergent fiber intake. Overall, compared to CON, FA treatments increased dry matter and neutral detergent fiber digestibility, and increasing OA within FA treatments quadratically increased digestibility of dry matter and neutral detergent fiber. Overall, FA treatments increased the intake of total, 16-carbon, and 18-carbon FA, decreased the digestibility of total and 18-carbon FA, but increased absorption of total, 16- carbon, and 18- carbon FA. Within FA treatments, increasing OA linearly increased the digestibility of total, 16- carbon, and 18- carbon FA, as well as the absorption of total, 16- carbon, and 18- carbon FA. Overall, FA treatments increased the yields of milk, energy-corrected milk, and milk fat and tended to increase milk protein yield. Compared to CON, FA treatments had no effect on the yield of de novo milk FA and increased the yields of mixed and preformed milk FA. Within FA treatments, increasing OA did not affect the yields of milk or milk components, linearly decreased the yield of de novo FA, and quadratically affected the yield of mixed and preformed milk FA. Overall, FA treatments increased plasma non-esterified fatty acids but did not affect β-hydroxybutyrate or insulin. Within FA treatments, increasing OA, quadratically affected plasma non-esterified fatty acids, and tended to linearly increased β-hydroxybutyrate and quadratically affect insulin. In conclusion, supplemental FA blends containing different ratios of SA and OA did not affect DMI but increased the yields of milk and milk components. Supplemental FA blends also increased digestibility of dry matter and neutral detergent fiber and decreased digestibility of total and 18-carbon FA compared to the non-FA supplemented control diet. Although increasing OA within FA supplements did not alter milk production, increasing OA within FA supplements increased total, 16- carbon, and 18- carbon FA digestibility and FA absorption. Further research is required to determine longer term effects of SA and OA on nutrient digestion and partitioning and opportunities for maintaining or improving FA digestibility with increasing SA intake and availability in the small intestine.