Temporal changes in milk fatty acid distribution due to feeding different levels of rolled safflower seeds to lactating Holstein cows.
The objective of this experiment was to follow the time-course changes of the milk fatty acids (FA) and particularly conjugated linoleic acid (CLA), n-3, and n-6 FA in response to feeding whole rolled safflower seed (SS). Eighteen cows were blocked by milk production, days in milk, and parity, and randomly assigned to 1 of 3 diets by replacing whole cottonseed with SS. The control diet contained no SS (SS0), whereas the other diets contained 3% of dry matter as SS (SS3) or 6% SS (SS6). The study was conducted for 8 wk. Cows fed SS produced more milk than SS0, with SS3 producing more milk than SS6, but without a change in milk fat yield or milk fat %. Except for C8:0 FA, changes in milk FA were not observed until the third week of SS feeding. The C8:0 began decreasing during wk 1 of SS feeding and continued to decline to wk 8. Short-chain FA (C6:0 to C11:0) and medium-chain FA (C12:0 to C16:1) concentrations decreased in milk when cows were fed SS, whereas long-chain FA (C18:0 and higher) increased after wk 3. The milk long-chain FA increased from wk 3 until wk 5 and then reached a plateau with little difference between SS3 and SS6, whereas the short-chain FA decreased more in milk from cows fed SS6 than SS3. Total CLA increased slightly less than 5× in milk from cows fed SS compared with SS0. Over the same time frame, n-3 FA declined and n-6 FA increased in the milk from cows fed SS, with no difference between SS3 and SS6. This study indicated that SS fed at 3 and 6% of DM had the potential to increase milk production and the CLA in milk, but with a corresponding increase in n-6 FA.
Department of Animal Sciences, Bu-Ali Sina University, 65178-33131 Hamadan, I. R. Iran; Veterinary Physiology, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland.
Amir
A
Ahmadpour
Department of Animal Sciences, Bu-Ali Sina University, 65178-33131 Hamadan, I. R. Iran. Electronic address: h_aliarabi@yahoo.com.
Hassan
H
Aliarabi
Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan 84322.
Mohammad Ghelich
MG
Khan
Nittany Dairy Nutrition Inc., Mifflinburg, PA 17844.
Robert A
RA
Patton
Veterinary Physiology, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland.
Rupert M
RM
Bruckmaier
D000818:Animals; D031187:Carthamus tinctorius; D002417:Cattle; D004032:Diet; D005227:Fatty Acids / Q000032:analysis* / Q000378:metabolism; D005260:Female; D007774:Lactation; D044243:Linoleic Acids, Conjugated / Q000032:analysis / Q000378:metabolism; D008892:Milk / Q000737:chemistry* / Q000378:metabolism; D011247:Pregnancy; D012639:Seeds
D005227:Fatty Acids; D044243:Linoleic Acids, Conjugated
conjugated linoleic acid; safflower seed; temporal fatty acid change