Abstract
Dairy products contain bioactive fatty acids (FA) and are a unique dietary source of an emerging class of bioactive FA, branched-chain fatty acids (BCFA). The objective of this study was to compare the content and profile of bioactive FA in milk, with emphasis on BCFA, among Holstein (HO), Jersey (JE), and first generation HO x JE crossbreeds (CB) across a lactation to better understand the impact of these factors on FA of interest to human health. Twenty-two primiparous cows (n = 7 HO, n = 7 CB, n = 8 JE) were followed across a lactation. All cows were fed a consistent total mixed ration (TMR) at a 70:30 forage to concentrate ratio. Time points were defined as 5 days in milk (DIM), 95 DIM, 185 DIM, and 275 DIM. HO and CB had a higher content of n-3 FA at 5 DIM than JE and a lower n-6:n-3 ratio. Time point had an effect on the n-6:n-3 ratio, with the lowest value observed at 5 DIM and the highest at 185 DIM. The content of vaccenic acid was highest at 5 DIM, yet rumenic acid was unaffected by time point or breed. Total odd and BCFA (OBCFA) were higher in JE than HO and CB at 185 and 275 DIM. Breed affected the content of individual BCFA. The content of iso-14:0 and iso-16:0 in milk was higher in JE than HO and CB from 95 to 275 DIM. Total OBCFA were affected by time point, with the highest content in milk at 275 DIM. In conclusion, HO and CB exhibited a higher content of several bioactive FA in milk than JE. Across a lactation the greatest content of bioactive FA in milk occurred at 5 DIM and OBCFA were highest at 275 DIM.
Highlights
There is growing awareness of the physiological and metabolic health properties of bioactive fatty acids (FA) derived from milk and dairy products
Fat production differed in response to lactation stage, with cows producing less fat at 5 days in milk (DIM) than at all other time points (0.78, 1.15, 1.07, and 0.98 kg/d for 5, 95, 185, and 275 DIM, respectively; P
The reduced intake of milk fat in response to these guidelines may result in consumers lacking in various bioactive FA provided by whole-fat dairy products
Summary
There is growing awareness of the physiological and metabolic health properties of bioactive fatty acids (FA) derived from milk and dairy products. BCFA in Milk Fat (CVD) [3], while ALA has demonstrated protective effects against inflammation [4], neurological disorders [5], and CVD [6]. This is supported by several observational studies and dietintervention trials that associated milk consumption with a lower risk for CVD and type 2 diabetes [6,7,8,9,10]. Because BCFA originate from the cell membranes of rumen bacteria, dairy and meat products from ruminants are a unique source of these FA. This allows for BCFA to be used as biomarkers of dairy intake in humans and as biomarkers of rumen function in cattle [15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
