Milk from cows grazing on cool-season pastures provides an enhanced profile of bioactive fatty acids compared to those grazed on a monoculture of pearl millet

Abstract

The demand for dairy products from grass-fed cows is driven, in part, by their more desirable fatty acid (FA) profile, containing more n-3 FA and conjugated linoleic acids (CLA) than conventionally produced dairy products. This study investigated the effects of pearl millet (PM) vs. cool-season pasture (CSP) on animal performance and milk FA in a grazing system. Eight Holstein dairy cows were used in a repeated measures design with four-week periods. Forage type had no effect on animal performance (estimated dry matter intake, milk production, fat, or protein). The contents of CLA and n-3 FA in a serving of whole milk (3.25% fat) increased when cows grazed CSP compared to PM. A serving of whole milk from cows grazing PM had a higher content of saturated FA and branched-chain FA. In conclusion, the contents of various bioactive FA were higher in milk fat of cows grazing a CSP compared to PM.

Dairy Products Intake and Endometrial Cancer Risk: A Meta-Analysis of Observational Studies

“…On the other hand, several nutrients in dairy products might inhibit carcinogenesis. Dairy products are an excellent source of calcium [ 38 ] which was reported to be significantly associated with reduced endometrial cancer risk [ 6 , 38 ]. Calcium in dairy products may be a potential cancer prevention element through vitamin D, as it is highly correlated and metabolically tied to vitamin D [ 6 ].…”

Alteration of Rumen Bacteria and Protozoa Through Grazing Regime as a Tool to Enhance the Bioactive Fatty Acid Content of Bovine Milk

“…Procedures involving animals were approved by the University of Vermont Animal Care and Use Committee. This research is part of a larger study that has been previously reported (for details see Bainbridge et al, 2017 ). Briefly, five multiparous (parity: 3.0 ± 0.7 lactations) mid-lactation (171 ± 21 days in milk) Holstein dairy cows were used in a repeated measures design with three 28-day periods.…”

“…An electronic rising plate meter (Jenquip; Feilding, New Zealand) was used to estimate DM intake three times per week as described previously (Bainbridge et al, 2017 ). Weekly forage samples for quality measurements were collected from the next pasture in the paddock rotation.…”

“…Forage samples were ground through a Wiley Mill (Arthur H. Thomas, Philadelphia, PA) with a 2 mm screen and then through an Udy Mill (UDY Corporation; Fort Collins, CO) with a 1 mm screen. Forage samples were analyzed for quality using near-infrared reflectance spectroscopy (Bainbridge et al, 2017 ).…”

“…These differences may favor a different community composition of bacteria and protozoa in the rumen compared to a cool-season pasture (CSP) diet. We have previously shown that feeding dairy cows pearl millet (PM), a summer annual, resulted in a shift in the milk FA profile, particularly increasing the content of BCFA (Bainbridge et al, 2017 ). Therefore, we hypothesized that grazing dairy cows on (PM), in comparison to a CSP, will shift the rumen microbial community structure (i.e., bacteria and protozoa) and modify their cellular FA composition, resulting in an altered milk FA profile.…”