Abstract #115
Section: Ruminant Nutrition (orals)
Session: Ruminant Nutrition I: Fat
Format: Oral
Day/Time: Monday 12:00 PM–12:15 PM
Location: Ballroom G
Session: Ruminant Nutrition I: Fat
Format: Oral
Day/Time: Monday 12:00 PM–12:15 PM
Location: Ballroom G
# 115
Changes in the omasal flow of long-chain fatty acids alters the yield of de novo and preformed milk fatty acids.
Jonas de Souza*1, Heidi Leskinen2, Kevin J. Shingfield4,2, Adam L. Lock1, Pekka Huhtanen3, 1Department of Animal Science, Michigan State University, East Lansing, MI, 2Animal Genomics, Green Technology, Natural Resources Institute Finland (Luke), Jokioinen, Finland, 3Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences, Umeå, Sweden, 4Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom.
Key Words: fatty acids, milk fat, meta-analysis
Changes in the omasal flow of long-chain fatty acids alters the yield of de novo and preformed milk fatty acids.
Jonas de Souza*1, Heidi Leskinen2, Kevin J. Shingfield4,2, Adam L. Lock1, Pekka Huhtanen3, 1Department of Animal Science, Michigan State University, East Lansing, MI, 2Animal Genomics, Green Technology, Natural Resources Institute Finland (Luke), Jokioinen, Finland, 3Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences, Umeå, Sweden, 4Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom.
We determined milk fatty acid (FA) yield response in relation to omasal flow of long-chain FA. Our analysis used individual observations (n = 132) in lactating Nordic Red dairy cows from 9 Latin square or switch-back design studies. The yield of milk FA (g/d) was classified as: < 16C (summation of FA lower than 16-carbon, de novo FA), 16C (summation of 16-carbon FA, mixed FA), > 16C (summation of FA greater than 16-carbon, preformed FA). Mixed model regressions were developed between variables of interest taking into account experiment, period within experiment, and cow within experiment as random factors. Increasing palmitic acid (16:0) omasal flow (g/d) linearly increased the yield of < 16C FA [158 ± 26.5 + 1.41 ± 0.25 × 16:0 flow, P < 0.001, R2 = 0.68], 16C FA [207 ± 36.1 + 1.60 ± 0.35 × 16:0 flow, P < 0.001, R2 = 0.73], > 16C FA [333 ± 51.9 + 1.41 ± 0.25 × 16:0 flow, P = 0.02, R2 = 0.29], and total FA [740 ± 80.5 + 3.59 ± 0.74 × 16:0 flow, P < 0.001, R2 = 0.72] in milk. In contrast, increasing stearic acid (18:0) omasal flow (g/d) did not affect the yield of < 16C and 16C (P > 0.05), but quadratically increased the yield of > 16C [233 ± 40.3 + 0.66 ± 0.14 × 18:0 flow - 0.003 ± 0.0001 × 18:0 flow2, P < 0.001, R2 = 0.84] and total FA [795 ± 75.8 + 0.87 ± 0.27 × 18:0 flow - 0.0005 ± 0.0002 × 18:0 flow2, P < 0.01, R2 = 0.48] in milk. For the flow of 18:0, maximum > 16C and total FA yields were achieved when 18:0 flow was 1065 and 943 g/d, respectively. Increasing oleic acid (cis-9 18:1) omasal flow (g/d) linearly increased the yield of < 16C [246 ± 18.5 + 1.24 ± 0.41 × 18:1 flow, P < 0.01, R2 = 0.37] and total FA [965 ± 55.9 + 2.98 ± 1.16 × 18:1 flow, P < 0.01, R2 = 0.37] in milk, and did not affect 16C and > 16C (P > 0.05). Increasing linoleic acid (18:2n-6) omasal flow (g/d) linearly increased the yield of < 16C [206 ± 17.2 + 4.46 ± 0.79 × 18:2n-6 flow, P < 0.001, R2 = 0.96], 16C [278 ± 25.2 + 3.85 ± 1.13 × 18:2n-6 flow, P < 0.001, R2 = 0.63], and total FA [888 ± 62.0 + 9.33 ± 0.25 × 18:2n-6 flow, P < 0.001, R2 = 0.65] in milk. Our results highlight the interdependence between de novo synthesized and preformed milk FA and demonstrates that effects on de novo, mixed, and preformed milk FA synthesis are dependent upon the amount and profile of absorbed FA.
Key Words: fatty acids, milk fat, meta-analysis
