Effect of Soybean Oil Supplementation on Milk Production, Digestibility, and Metabolism in Dairy Goats under Thermoneutral and Heat Stress Conditions

Abstract

In a previous work, we observed that heat-stressed goats suffer reductions in milk yield and its contents of fat and protein. Supplementation with soybean oil (SBO) may be a useful strategy to enhance milk quality. In total, eight multiparous Murciano–Granadina dairy goats (42.8 ± 1.3 kg body weight; 99 ± 1 days of lactation) were used in a replicated 4 × 4 Latin square design with four periods; 21 d each (14 d adaptation, 5 d for measurements and 2 d transition between periods). Goats were allocated to one of four treatments in a 2 × 2 factorial arrangement. Factors were no oil (CON) or 4% of soybean oil (SBO), and controlled thermal neutral (TN; 15 to 20 °C) or heat stress (HS; 12 h/d at 37 °C and 12 h/d at 30 °C) conditions. This resulted in four treatment combinations: TN-CON, TN-SBO, HS-CON, and HS-SBO. Compared to TN, HS goats experienced lower (p < 0.05) feed intake, body weight, N retention, milk yield, and milk protein and lactose contents. However, goats in HS conditions had greater (p < 0.05) digestibility coefficients (+5.1, +5.2, +4.6, +7.0, and +8.9 points for dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber, respectively) than TN goats. The response to SBO had the same magnitude in TN and HS conditions. Supplementation with SBO had no effects on feed intake, milk yield, or milk protein content. However, SBO supplementation increased (p < 0.05) blood non-esterified fatty acids by 50%, milk fat by 29%, and conjugated linoleic acid by 360%. In conclusion, feeding 4% SBO to dairy goats was a useful strategy to increase milk fat and conjugated linoleic acid without any negative effects on intake, milk yield, or milk protein content. These beneficial effects were obtained regardless goats were in TN or HS conditions.

Effects of oil and grape seed tannin extract on intakes, digestibility, milk yield and composition of Saanen goats

“…The greater EE digestibility in SFO and OCT goats was expected in this study, because with the higher EE digestibility, the animals will have more energy to supply body requirements and compensate the daily loss of energy via milk. Hamzaoui et al (2021) reported that oil supplementation in the diet did not affect the N retention of goats, and our study detected the similar result. This may be explained partly that after dissociation of the tannin-protein complex, the tannins released in the abomasum can bind again to the non-degraded proteins in the rumen (Naumann et al, 2017), microbial proteins or endogenous proteins when they reach in the small intestine (Waghorn, 2008).…”

“…That no change of total DM intake in this study was supported by some previous studies, in which soybean oil was supplemented at 2 to 5% DM in the diets of dairy goats (Bouattour et al, 2008;Mele et al, 2008;Hamzaoui et al, 2021) and cows (Qin et al, 2020). Nutrient intakes such as DM, OM, CP, NDF, ADF, GE, ME were not affected by the experimental diets.…”

“…However, our study could not detect the significance of weight gain. Hamzaoui et al (2021) suggested that soybean oil supplementation had no effect on the weight change of goats.…”

Reducing carbon emission in the goat farms by switching from conventional goat farming to green goat farm typology

“…Extreme environmental conditions affect the accessibility of goat farmers to appropriate pastures (Marino et al, 2015). Heat stress can negatively affect milk yield and the contents of total protein, casein, and fat of milk in goats (Sevi et al, 2001;Hamzaoui et al, 2012;Salama et al, 2014). Marino et al (2015) emphasized that even if the goat was a heat-tolerant species, climate change and other stress factors result in the impairment of production and reproduction performance.…”