Abstract
Butteroil from mixed herd milk collected weekly was steam-deodorized and the C-10, C-12, and C-14 aliphatic delta-lactones quantitated. The samples, representing 276 animals, averaging 96.0ppm of lactone (range 58.6–139.0) and 67.2ppm of lactone (range 47.7–100.2) while on barn feed and pasture feed, respectively, exhibited a pronounced seasonal trend, being higher in the winter than in the summer.Analyses of weekly milk samples from an individual Holstein during a 310-day lactation indicated dramatic shifts in lactone potential. Following parturition the concentration was 25–30ppm, which increased to 170–180ppm at about 150 days. Throughout lactation, lactone concentration showed a negative correlation (P<1%) with the per cent fat and fat yield. Fatty acid analyses indicated a positive correlation (P<1%) between lactone content and short-chain fatty acid (4:0–14:1) composition.Analyses of milk from various breeds, on identical feeding regimens, showed a slightly higher lactone potential in Holstein fat. Ketotic animals were characterized by a marked depression in steam volatile compounds, i.e., lactones, earbonyls, and fatty acids.These data, together with other information, strongly imply that the lactone precursors are biological in origin and may be involved in fatty acid synthesis.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
