Comparison of Fatty Acid Content of Milk from Jersey and Holstein Cows Consuming Pasture or a Total Mixed Ration

Abstract

Holstein (n = 19) and Jersey (n = 18) cows were used to study effects of two feeding systems on fatty acid composition of milk. Confinement cows were fed a total mixed ration with corn silage and alfalfa silage and pastured cows grazed a crabgrass (90%) and clover (10%) pasture and were allowed 5.5 kg of grain per head daily. Two milk samples were collected from each cow at morning and afternoon milkings 1 d each week for four consecutive weeks in June and July 1998. One set of milk samples was analyzed to determine fatty acid composition, and the second set was used for crude protein and total fat analyses. Data were analyzed by the general linear models procedure of SAS, using a split-plot model with breed, treatment, and breed x treatment as main effects and time of sampling and week as subplot effects along with appropriate interactions. Milk from pastured cows was higher than milk from confinement cows for the cis-9, trans-11 octadecadienoic acid isomer of conjugated linoleic acid (CLA). Also, milk from Holsteins was higher than milk from Jerseys for C16:1, C18:1, and CLA and lower than Jerseys for C6:0, C8:0, C10:0, C12:0, and C14:0. Several treatment x week interactions existed, but main effects were still important; for example, proportions of CLA in milk of grazed cows were relatively constant across weeks (0.66, 0.64, 0.64, and 0.69% +/- 0.02%, respectively), but the CLA in milk of confinement cows increased in wk 4 (0.35, 0.31, 0.31, and 0.48% +/- 0.02% for wk 1 to 4, respectively). There are potentially important differences in fatty acid composition of milk from cows consuming a warm season pasture species compared with milk from cows consuming a total mixed ration, as well as differences between Holstein and Jersey breeds.

Genetic variability of milk fatty acids

“…Holstein and Jersey milk fats present the greatest differences. Higher concentrations of SFAs, especially of FAs with short and medium carbon chains, are observed in Jersey milk fat (e.g., Hermansen and Lund 1990;Beaulieu and Palmquist 1995;White et al 2001; Table 1). However, DePeters et al (1995) reported that the concentrations of FAs with short and medium chains did not differ.…”

Efecto de la edad de rebrote sobre el perfil de ácidos grasos en gramíneas tropicales

“…La composición de los ácidos grasos (AG) en gramíneas tiene especial importancia por su efecto sobre el perfil lipídico en la carne y la leche de los rumiantes (Dhiman et al 1999;White et al 2001;Ward et al 2003;Loor et al 2003;Shingfield et al 2013). En humanos, la grasa de la leche ha sido relacionada con problemas de salud, especialmente, con enfermedades coronarias, niveles altos de lipoproteínas de baja densidad (LDL) y arteriosclerosis, debido a su contenido alto de ácidos grasos saturados (70 %) y al contenido bajo de ácidos grasos insaturados (30 %) (Jensen 2002).…”

Dietary Manipulation to Increase the Concentration of N-3 Fatty Acids in Milk Fat

“…The fatty acid (FA) composition of cow's milk has become less favourable to human health due to changed feeding and management practices, notably higher proportions of concentrates and silages in diets with less grazing (Elgersma et al, 2006). Although there are differences in the fatty acid composition of milk fat from cows consuming warm season pasture species compared with milk from cows consuming a total mixed ration (White et al, 2001), there are several other factors influencing the behaviour of the animal on rangeland, for example weather (Halasz et al, 2016), and through this the choice of pasture species.…”