Butter fatty acid composition as a function of soybean oil supplementation and time of milking, and performance of Holstein x Gyr cows fed with chopped elephant grass-based diets

Abstract

The aim of this study was to evaluate the performance of cows fed with a total mixed ration composed of elephant grass and a concentrate containing 0.0% (control), 1.5%, 3.0% or 4.5% soybean oil on a dry matter basis. The effect of milking time (morning versus afternoon) on butter fatty acid composition was also evaluated. Twelve multiparous Holstein x Gyr cows with an average milk production of 18.0±4.6 kg day-1 and 90±25 days in milk were used in a triplicated 4 x 4 Latin square experimental design with 15-day periods. Data were analyzed using mixed models. There was no effect of soybean oil supplementation on dry matter or neutral detergent fiber intake (P > 0.05). The fat-corrected milk yield linearly decreased (P=0.0109) and the milk protein yield linearly increased (P=0.0023) in response to soybean oil supplementation. The butterfat trans-9 C18:1, cis-9 C18:1, trans-10 C18:1, trans-11 C18:1, cis-9, trans-11 CLA and trans-10, cis-12 CLA content linearly increased (P < 0.05), whereas the C12:0, C14:0 and C16:0 content linearly decreased (P < 0.001) as the level of soybean oil in the diet increased. The butter produced from afternoon milk had a lower content of C16:0 and a higher content of cis-9 C18:1 (P < 0.05). The supplementation of elephant grass-based-diets with soybean oil and, to a small extent, the selective segregation of milk obtained from afternoon milking sessions are strategies that can be used to improve the fatty acid composition of butterfat.

Ruminal parameters and fatty acid composition of omasal digesta and milk in cows fed sugarcane-based diets supplemented with sunflower oil

“…The negative effect of the dietary inclusion of vegetable oils on cow's milk fat content is well documented in the literature (C. G. S. Ribeiro et al, 2018;Lopes et al, 2019;Mahdavi et al, 2019;Rodrigues et al, 2019). Additionally, the current results corroborate Souza et al (2019) Lopes, F. C. F. et al in the productive performance trial.…”

“…The absence of an effect (P>0.05) of SO on DM and NDF ap intake and apparent digestibility (Table 2) corroborates the results of the productive performance trial, presented in our companion paper (Souza et al, 2019). Additionally, the dietary EE content (Table 1) did not exceed 60-70 g kg -1 DM (NRC, 2001), and we employed a strategy of mixing the SO with the concentrate (Lopes et al, 2019). This technique probably avoided the deposition of a layer of oil on the forage particles, which could negatively impair both the adhesion of fibrolytic microbiota and the activity of the enzymes involved in cellulose hydrolysis (Jenkins, 1993).…”

“…Ruminal parameters and fatty acid composition of omasal digesta and milk in cows fed sugarcane-based diets... hypothesis is supported by negative correlations (r = -0.55 to -0.93, P<0.03) between the sum of the milk fat C4:0 to C16:0 contents versus the milk fat contents of several C18-unsaturated FAs (e.g., oleic and rumenic acid, cis-9, trans-12 C18:2, trans-4 C18:1 to trans-16 C18:1, cis-11 C18:1, cis-12 C18:1, trans-9, cis-11 CLA, and trans-10, cis-12 CLA). The negative effect of SO on the milk fat content of de novo-synthesized FAs has also been observed in the productive performance trial (Souza et al, 2019) and in other studies (C. G. S. Ribeiro et al, 2018;Lopes et al, 2019).…”

“…These data corroborate the results of Souza et al (2019) in the productive performance trial. The linear increase in milk protein content (P=0.0242) promoted by SO supports the results from some studies (Rodney, Celi, Scott, Breinhild, & Lean, 2015;Lopes et al, 2019), although the literature commonly indicates that lipid supplementation of diets supplied to cows reduces milk protein content (NRC, 2001;Mahdavi, Mahdavi, Darabighane, Mead, & Lee, 2019). The linear reduction in milk fat content was proportionally higher than the linear increase in milk protein content.…”

Milk fatty acid composition in Holstein x Gyr dairy cows fed chopped elephantgrass-based diets containing two types of sunflower oil associated with two methods of concentrate feeding

“…In Brazil, elephantgrass (Pennisetum purpureum, Schumach) is one of the most important tropical grasses for feeding dairy cows in a cut-and-carry system (Pereira, Morenz, Ledo, & Ferreira, 2016). Studies carried out by our research group have shown that the inclusion of up to 45 g kg -1 vegetable oils rich in linoleic acid (i.e., soybean or sunflower oil) in the DM of chopped elephantgrass-based TMRs improved the nutritional quality of milk (Ribeiro, Lopes, Gama, Morenz, & Rodriguez, 2014;Ribeiro, Lopes, Gama, Rodriguez, & Morenz, 2018; F. C. F. Lopes et al, 2019). Supplementation with these oils promoted an increase in the milk fat content of oleic (cis-9 C18:1), rumenic (cis-9, trans-11 CLA) and vaccenic (trans-11 C18:1) acids, which are beneficial to human health, and a concomitant reduction in hypercholesterolemic lauric (C12:0), myristic (C14:0) and palmitic (C16:0) acids.…”