Short-term effects of soybean oil supplementation on performance, digestion, and metabolism in dairy cows fed sugarcane-based diets

Abstract

We aimed to quantify the productive and metabolic responses, and digestive changes in dairy cows fed various concentrations of soybean oil (SBO) in high-concentrate, sugarcane-based diets. Eight rumen-cannulated multiparous Holstein cows in mid lactation (574 ± 19.1 kg of body weight and 122 ± 6.9 d in milk), averaging 22.5 ± 1.22 kg/d of milk were assigned to replicated 4 × 4 Latin squares. The experimental period lasted 21 d as follows: 14 d for adaptation, followed by a sampling period from d 15 to 21. The diets were formulated with increasing concentrations of SBO [% of dry matter (DM)]: control (0%), low (LSBO; 1.57%), medium (MSBO; 4.43%), and high (HSBO; 7.34%). Dry matter intake decreased quadratically in response to SBO addition. The greatest decrease in DM intake was observed in MSBO and HSBO diets. Both milk and energy-corrected milk yield were quadratically affected by the SBO inclusion, with a slight decrease up to MSBO and substantial decrease in the HSBO diet. The milk fat concentration linearly decreased from 3.78% in the control to 3.50% in the HSBO diet. The potentially digestible neutral detergent fiber digestibility in the rumen decreased from 55.7% in the control to 35.2% in the HSBO diet. The fractional rate of digestion of potentially digestible neutral detergent fiber in the rumen decreased linearly from 3.13 to 1.39%/h from the control to HSBO diet. The fractional rate of indigestible neutral detergent fiber passage in the rumen was quadratically affected, with the lowest value (2.25%/h) for the HSBO diet. Rumen pH increased from 6.42 to 6.67, and ammonia nitrogen decreased from 28.1 to 21.4 mg/dL, in the control and HSBO diets, respectively. Rumen volatile fatty acids decreased quadratically, with the greatest decrease observed in MSBO and HSBO diets. Serum concentrations of glucose, fatty acids, and β-hydroxybutyrate were unaffected by SBO inclusion. However, serum concentrations of total cholesterol and high- and low-density lipoproteins linearly increased with increasing concentrations of SBO in the diet. Inclusion of SBO at concentrations from 4.43 to 7.34% of the diet DM decreased DM intake, energy-corrected milk production, fiber digestibility, and rumen fermentation and was thus not recommended. Soybean oil supplementation at 1.57% of the diet DM proved to be a safe concentration for dairy cows fed high-concentrate diets with sugarcane as the sole forage.

Ruminal fermentation and degradation, kinetic flow of the digesta and milk fatty acid composition of cows fed chopped elephantgrass supplemented with soybean oil

“…The negative effect of dietary inclusion of free vegetable oils on the milk fat content of cows is well documented in the literature (LOPES et al, 2015;RODRIGUES et al, 2017). In the present work, comparing the control ration with the 4.5% SO ration, this reduction was 14%.…”

“…These results corroborate the linear reduction observed in the NDF ED (P=0.0358; Table 3) and, consequently, in the molar ratio of acetate (P=0.0741; Table 2). Moreover, the substitution of non-fibrous carbohydrates of the dietary ingredients by EE from the SO already promotes a decrease in fermentable substrate (RODRIGUES et al, 2017), limiting the development of the ruminal microbiota, which was indicated in the present study by the linear reduction in the excretion of purine derivatives (P=0.0127; Table 4). Corroborating this, negative correlations (P<0.05) of -0.69 and -0.59, were observed between the milk contents of the majority of the LECSFAs (i.e., C15:0 and C17:0) with EE intake.…”

“…Even in diets formulated with an ether extract (EE) content below the recommended maximum limit for lactating cows (< 7% of diet DM) (NRC, 2001), high dietary levels of vegetable oils rich in free polyunsaturated-FAs may cause changes in parameters of ruminal fermentation (RODRIGUES et al, 2007) and promote a reduction in digestibility and/or intake of DM and the neutral detergent fiber (NDF) (BATEMAN;JENKINS, 1998;RODRIGUES et al, 2017), with a negative effect on the milk fat content and milk yield (RODRIGUES et al, 2017). In addition, it may cause an increase in the formation of FAs intermediates of ruminal biohydrogenation, such as trans-10, cis-12 CLA (EIFERT et al, 2006) and trans-9, cis-11 CLA (RIBEIRO et al, 2014), which are associated with the inhibition of lipogenesis in the mammary gland of cows (BERNARD et al, 2008;SHINGFELD et al, 2010).…”

Effect of soya bean oil supplementation and forage type on methane production and fibre digestibility using the in vitro gas production system

“…Supplementary fat characteristics and concentration in the diet dry matter (DM) are greatly determinant on its effects on rumen fermentation and fibre digestion (Palmquist, ; Weld & Armentano, ). Soya bean oil (SBO) is a high rumen release fat source rich in α‐linolenic acid (LNA; C 18:3 cis ‐9, cis ‐12, cis ‐15) which along with its main first biohydrogenation product; linoleic acid (LA; C18:2 cis ‐9, cis ‐12) has a known inhibitory effect on ruminal fibrinolytic bacteria, protozoa populations and fibre digestion (Rodrigues et al., ; Maia, Chaudhary, Figueres, & Wallace, ; Yang et al., ). Fatty acid (FA) composition and rumen release of supplementary fats, however, are not the only determinant factors for its effects on rumen fermentation.…”

“…Tropical environments have a wide range of heterogeneous forage species and diet formulation based on studies with non‐tropical forages can lead to inefficient diets. Sugarcane is a forage commonly fed to cattle in tropical environments, and it is often used as the main dietary fibre source (Daniel et al., ; Rodrigues et al., ). Mombaça guinea grass and Marandu palisadegrass are relevant forages for livestock production in Brazil and are widely used in grazing systems (Carvalho et al., ; Gimenes et al., ).…”