Abstract #423
Section: Ruminant Nutrition (orals)
Session: Ruminant Nutrition 5: Fat and Lipid Metabolism
Format: Oral
Day/Time: Tuesday 2:45 PM–3:00 PM
Location: Junior Ballroom D
Session: Ruminant Nutrition 5: Fat and Lipid Metabolism
Format: Oral
Day/Time: Tuesday 2:45 PM–3:00 PM
Location: Junior Ballroom D
# 423
Altering the ratio of dietary palmitic and oleic acids impacts nutrient digestibility and energy intake in early lactation dairy cows.
J. de Souza*1, C. M. Prom1, A. L. Lock1, 1Michigan State University, East Lansing, MI.
Key Words: digestibility, fat supplementation, postpartum
Altering the ratio of dietary palmitic and oleic acids impacts nutrient digestibility and energy intake in early lactation dairy cows.
J. de Souza*1, C. M. Prom1, A. L. Lock1, 1Michigan State University, East Lansing, MI.
Fifty-six multiparous cows were used in a randomized complete block design and assigned to 1 of 4 treatments fed from 1 to 24 DIM. The treatments were a control diet (CON; non-fatty acid [FA] supplemented diet) and diets supplemented at 1.5% DM with FA supplement blends differing in the ratio of palmitic (C16:0) and oleic (C18:1) acids. FA treatment diets were: 80:10 (80% C16:0+10% C18:1); 70:20 (70% C16:0+20% C18:1); and 60:30 (60% C16:0+30% C18:1). Digestibility of nutrients was calculated using iNDF as a marker. The statistical model included the random effect of block and cow, and the fixed effects of treatment, time, and their interactions. Results are presented in the following sequence: CON, 80:10, 70:20, and 60:30. Compared with CON, FA-supplemented diets increased the intake of 16-carbon (54, 311, 266, and 256 g/d, P < 0.01), 18-carbon (253, 338, 360, and 417 g/d, P < 0.01), and total FA (316, 669, 643, and 688 g/d, P < 0.01). Increasing C18:1 in FA-supplemented diets increased the intake of total and 18-carbon FA (both linear, P < 0.01) and decreased the intake of 16-carbon FA (linear, P < 0.01). Compared with CON, FA-supplemented diets increased the digestibility of DM (69.2, 69.9, 70.2, and 71.0%, P < 0.01), NDF (37.6, 40.0, 39.9, and 41.3%, P < 0.01), 18-carbon (85.7, 88.0, 88.5, and 88.7%, P < 0.01), and total FA (82.3, 82.5, 83.8, and 84.9%, P < 0.01). Increasing C18:1 in FA-supplemented diets increased digestibility of DM, NDF, total FA, and 18-carbon FA (all linear, P < 0.01). Compared with CON, FA-supplemented diets increased the intake of digestible energy (DE; 57.0, 68.1, 65.3, and 69.5 Mcal/d, P < 0.01), metabolizable energy (ME; 49.3, 59.2, 56.8, and 60.6 Mcal/d, P < 0.01), and net energy of lactation (NEL; 31.2, 37.1, 36.1, and 38.6 Mcal/d, P < 0.01). Increasing C18:1 in FA-supplemented diets increased DE, ME, and NEL intake (all linear, P = 0.01). Our results indicate that feeding FA supplements containing C16:0 and C18:1 increased the digestibility of NDF, FA, and DM and increased energy intake compared with a control diet. Increasing C18:1 in the FA supplement increased DM, NDF, and FA digestibility resulting in increased energy intake.
Key Words: digestibility, fat supplementation, postpartum
