Effects of supplementation with vegetable oils, including castor oil, on milk production of ewes and on growth of their lambs1

Abstract

The objectives in this experiment were to compare the effects of castor oil, canola oil, or sunflower oil on lactation performance, milk composition, and milk fatty acid (FA) profile in Santa Inês ewes and on growth of lambs. Forty-four ewes (66.9 ± 4.7 kg of initial BW, mean ± SD) were penned individually with their lambs and used in a randomized complete block design with 11 blocks and four diets. The experimental diets were as follows: 1) basal diet without added oil (control), 2) 30 g FA/kg DM of canola oil (CAN), 3) 30 g FA/kg DM of sunflower oil (SUN), and 4) 30 g FA/kg DM of castor oil (CAS). The oils were added to a basal diet containing 50% of roughage. Once a week, from the 2nd to 8th wk of lactation, ewes were separated from their lambs, injected with oxytocin, and mechanically milked to empty the udder. After 3 h, using the same procedure, milk production was recorded, and milk was sampled for composition and FA profile determination. The growth of the lambs was monitored weekly. Ewes fed the control diet had greater (P < 0.05) dry matter intake (DMI) than those fed the oil-supplemented diets. No effect was observed on milk yield and on final BW of lambs. Milk fat and milk total solid concentrations were greater (P < 0.05) with the supply of CAS. Supplementation with CAN and SUN, but not with CAS, reduced (P < 0.05) the sum of FA with 14 or less carbon chains and increased (P < 0.05) the c9-18:1, 18:0 and most of the biohydrogenation intermediates, including the t10-18:1, t11-18:1, and c9,t11-18:2. All oil-supplemented diets reduced (P < 0.05) the content of 16:0 when compared with the control. Milk from ewes fed CAS presented only small proportion of 12-OH,c9-18:1 (0.31% of total FA) but much larger proportions of 12-OH-18:0 (1.58% of total FA) and particularly of 12-oxo-18:0 (2.95 % of total FA), which suggests that 12-OH,c9-18:1 was extensively metabolized in the rumen. Concluding, CAS increased milk fat and modified the milk FA composition by increasing the hydroxy- and oxo-FA. The potential health promoting proprieties and technological advantages of milk enriched with hydroxy- and oxo-FA are not know at present but deserve to be explored.

Narasin inclusion for feedlot lambs fed a diet containing high amounts of ground flint corn

“…Recently, Lodi et al (2019) reported that the inclusion of 12.5 mg of monensin kg -1 of DM increased ruminal pH without affecting DMI or feed behavior of lambs fed high-concentrate diets. In some cases, the use of 25 mg of monensin aims to control coccidiosis (Polizel et al, 2017;Parente et al, 2018); however, few studies evaluate whether the inclusion of lower rates can control coccidiosis in small ruminants.…”

Effect of Dietary Supplementation with Lipids of Different Unsaturation Degree on Feed Efficiency and Milk Fatty Acid Profile in Dairy Sheep

“…However, this recommendation is mostly based on knowledge gained from dairy cows and might be related to the susceptibility of this species to milk fat depression (MFD) induced by unsaturated FA (especially when high-concentrate diets are fed) [ 6 , 12 ]. On the contrary, there is evidence that dairy ewes are not prone to this MFD type [ 3 , 8 , 13 , 14 ]. Thus, in the ovine, substitution of 16:0-rich fats by oils of higher unsaturation degree (e.g., rapeseed or soybean oils) may provide advantages that go beyond enhancing production level, specifically by modulating milk FA profile [ 7 , 15 , 16 ].…”

Free Saturated Oxo Fatty Acids (SOFAs) and Ricinoleic Acid in Milk Determined by a Liquid Chromatography-High-Resolution Mass Spectrometry (LC-HRMS) Method

“…RA is not expected to be synthesized in rumen; however, it could be found in milk depending on the type of animal feeding. As a matter of fact, about 90% of the fatty acid content of castor oil is the triglyceride formed from RA, and castor oil may supplement cow feeding [ 20 , 21 ].…”