TY - JOUR
T1 - Effects of ruminal or duodenal supply of fish oil on milk fat secretion and profiles of trans-fatty acids and conjugated linoleic acid isomers in dairy cows fed maize silage
AU - Loor, J. J.
AU - Doreau, M.
AU - Chardigny, J. M.
AU - Ollier, A.
AU - Sebedio, J. L.
AU - Chilliard, Y.
N1 - Funding Information:
The authors thank J.P. Pezant and his team (“Les Cèdres” experimental Unit) for the care given to cows and help in milk and blood sampling, as well as J. Chabrot, R. Lefaivre and M. Tourret for laboratory analyses, and P. Juaneda for his advice during HPLC analyses. This study received a grant from the Groupement Coopératif de Recherche sur la Vache Laitière (UCANOR-Caen, CCPA-Osny and UNICOPA-Morlaix, France).
PY - 2005/4/4
Y1 - 2005/4/4
N2 - Milk fat secretion and profiles of conjugated linoleic acids (CLA) and trans-18:1 isomers in milk fat due to a ruminal or duodenal supply of fish oil (FO; EPA = 22% of total fatty acids, DHA = 7%) were evaluated using six lactating Holstein cows with cannulas in their rumen and duodenum. Cows were fed a control diet based on corn silage (66% of DM), or the control plus 300 mL FO/d into the rumen (FO-R) or duodenum (FO-D) for 4 weeks in a replicated 3 × 3 Latin square design. Dry matter intake was higher with the control (19.8 kg/d), intermediate with FO-D (18.0 kg/d), and lower with FO-R (16.2 kg/d). Yield of milk (22.7 kg/d), lactose (1.09 kg/d), or crude protein (0.70 kg/d) was not affected by treatments. Content of crude protein, true protein, and casein was lower in response to FO-R compared with the control. Despite similar jugular concentration compared with the control, jugular-mammary venous difference for β-OH-butyrate was 54% lower with FO-R or FO-D. Milk fat content and yield were lowest with FO-R (25 g/kg, 567 g/d) compared with FO-D (32 g/kg, 737 g/d) or the control (35 g/kg, 783 g/d). Percentage of trans5-, trans6 + 7 + 8-, trans9-, trans10-, trans11-, trans12-, and trans13 + 14-18:1 in milk fat was greater due to FO-R (0.05, 0.44, 0.48, 1.8, 9.2, 0.70, and 0.82%, respectively) compared with the control or FO-D (0.02, 0.22, 0.19, 0.27, 1.1, 0.35, and 0.40%). Although 18:0 and cis9-18:1 percentage was markedly lower in response to FO-R, percentage of cis11-, cis13-, and cis15-18:1 was greater compared with the control or FO-D. Cis9,trans11-CLA (87-95% of total CLA) averaged 3.2% in response to FO-R compared with 0.51% for control or FO-D. Trans10,cis12-18:2 was not detected. Among non-conjugated 18:2 isomers, cis9,cis12-18:2 was lower but cis9,trans13-, trans9,cis12-, and trans11,cis15-18:2 greater when FO-R was compared with the control or FO-D. There was high correlation (r = 0.94-0.99) among data obtained by GLC versus HPLC for most trans-18:1 isomers and cis9,trans11-18:2, suggesting GLC alone with our chromatographic conditions provided adequate separation of isomers. Milk 20:5n-3 (EPA) and 22:6n-3 (DHA) were 0.08 and 0.04% with the control, increased to 0.36 and 0.17% with FO-R, and were 1.47 and 0.47% with FO-D. Data indicate, ruminal supply of FO led to hydrogenation of EPA and DHA and enhanced percentage of various trans-18:1, cis-18:1, non-conjugated 18:2, and cis9,trans11-18:2 in milk fat. Combined increases in trans-18:1 along with reduced availability of 18:0 for endogenous synthesis of cis9-18:1 may play a key role in reduced milk fat synthesis in cows fed fish oil.
AB - Milk fat secretion and profiles of conjugated linoleic acids (CLA) and trans-18:1 isomers in milk fat due to a ruminal or duodenal supply of fish oil (FO; EPA = 22% of total fatty acids, DHA = 7%) were evaluated using six lactating Holstein cows with cannulas in their rumen and duodenum. Cows were fed a control diet based on corn silage (66% of DM), or the control plus 300 mL FO/d into the rumen (FO-R) or duodenum (FO-D) for 4 weeks in a replicated 3 × 3 Latin square design. Dry matter intake was higher with the control (19.8 kg/d), intermediate with FO-D (18.0 kg/d), and lower with FO-R (16.2 kg/d). Yield of milk (22.7 kg/d), lactose (1.09 kg/d), or crude protein (0.70 kg/d) was not affected by treatments. Content of crude protein, true protein, and casein was lower in response to FO-R compared with the control. Despite similar jugular concentration compared with the control, jugular-mammary venous difference for β-OH-butyrate was 54% lower with FO-R or FO-D. Milk fat content and yield were lowest with FO-R (25 g/kg, 567 g/d) compared with FO-D (32 g/kg, 737 g/d) or the control (35 g/kg, 783 g/d). Percentage of trans5-, trans6 + 7 + 8-, trans9-, trans10-, trans11-, trans12-, and trans13 + 14-18:1 in milk fat was greater due to FO-R (0.05, 0.44, 0.48, 1.8, 9.2, 0.70, and 0.82%, respectively) compared with the control or FO-D (0.02, 0.22, 0.19, 0.27, 1.1, 0.35, and 0.40%). Although 18:0 and cis9-18:1 percentage was markedly lower in response to FO-R, percentage of cis11-, cis13-, and cis15-18:1 was greater compared with the control or FO-D. Cis9,trans11-CLA (87-95% of total CLA) averaged 3.2% in response to FO-R compared with 0.51% for control or FO-D. Trans10,cis12-18:2 was not detected. Among non-conjugated 18:2 isomers, cis9,cis12-18:2 was lower but cis9,trans13-, trans9,cis12-, and trans11,cis15-18:2 greater when FO-R was compared with the control or FO-D. There was high correlation (r = 0.94-0.99) among data obtained by GLC versus HPLC for most trans-18:1 isomers and cis9,trans11-18:2, suggesting GLC alone with our chromatographic conditions provided adequate separation of isomers. Milk 20:5n-3 (EPA) and 22:6n-3 (DHA) were 0.08 and 0.04% with the control, increased to 0.36 and 0.17% with FO-R, and were 1.47 and 0.47% with FO-D. Data indicate, ruminal supply of FO led to hydrogenation of EPA and DHA and enhanced percentage of various trans-18:1, cis-18:1, non-conjugated 18:2, and cis9,trans11-18:2 in milk fat. Combined increases in trans-18:1 along with reduced availability of 18:0 for endogenous synthesis of cis9-18:1 may play a key role in reduced milk fat synthesis in cows fed fish oil.
KW - Conjugated linoleic acids
KW - Fish oil
KW - Long-chain n-3 fatty acids
KW - Milk fat
KW - Trans-fatty acids
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U2 - 10.1016/j.anifeedsci.2004.12.016
DO - 10.1016/j.anifeedsci.2004.12.016
M3 - Article
AN - SCOPUS:13844271190
SN - 0377-8401
VL - 119
SP - 227
EP - 246
JO - Animal Feed Science and Technology
JF - Animal Feed Science and Technology
IS - 3-4
ER -