New insights on the metabolism of ricinoleic acid in ruminants

Effect of coconut processing by-product graded feeding on carcass traits and meat quality of lambs

The inclusion of by-product coconut mesocarp skins (CMS) in diets was evaluated in feedlot lambs. The objective of this study was to evaluate CMS levels effects on carcass traits and meat quality of lambs. Thirty-five male lambs with an initial body weight of 16.9 ± 2.93 kg were distributed in a completely randomized design with five CMS levels in total dry matter (0; 4.8; 9.6; 14.4 and 19.2%) and fed during 71 d until slaughter. High levels of CMS decreased the intake of dry matter and negatively affected the performance of lambs. Fat and protein contents of Longissimus lumborum muscle (P < 0.05) and the saturated fatty acid (FA) decreased (P < 0.001) whereas polyunsaturated FA increased (P < 0.01) with the inclusion of CMS. The ratio t10/t11-18:1 increased with the inclusion of CMS (P < 0.001). The instrumental color descriptors were unaffected by CMS levels. According to the effects on the investigated meat quality traits we recommend up to 4.8% CMS in diets of confined lambs.

Quality and sensory milk traits of goats grazing Caatinga or confined receiving either corn or spineless cactus-based diets in the Brazilian semiarid environment

This study aimed to evaluate the yield, physical-chemical properties, fatty acid (FA) profile, and sensory traits of goat milk under different nutritional strategies in a Brazilian semiarid environment. Eighteen lactating crossbred dairy goats were distributed in a completely randomized design with three nutritional strategies: Caatinga strategy (1.5% of body weight with a concentrate supplementation), Corn-based confined strategy, and Spineless Cactus confined strategy. Daily milk yield was recorded, and milk samples were collected from all animals. Goats fed the spineless cactus-based diet presented a higher milk yield than goats feed the other strategies. Moreover, milk from goats fed with a spineless Cactus confined strategy presented higher saturated FA (SFA), and a lower proportion of cis- monounsaturated FA, trans-monounsaturated FA, and c9,t11-18:2 than milk from goats feed the other strategies. Milk from goats in the pasture system presented the highest proportions of 18:2n-6, 18:3n-3, and thus of polyunsaturated FA, when compared with milk from confined goats. We assume that milk from goats grazing in Caatinga pastures presents more benefits to human health due to the positive effects of this diet on the milk's fat content and FA profile, and this feeding strategy also results in a better sensory evaluation that may increase the acceptability of goat milk by consumers. All nutritional strategies evaluated herein and adopted in the semiarid region of Brazil are recommended for maintaining the yield, physical-chemical properties, and acceptability of milk goats.

JE, Oliveira ERD, Gandra ERDS, Pedrini CA, Mendes PVC. Effects of ricinoleic acid from castor oil and cashew nutshell liquid on nutrient digestibility and ruminal fermentation in dairy heifers

ABSTRACT This study aimed to evaluate the effects of combining functional oils (FO) [ricinoleic acid (RA) and cashew nutshell liquid (CNSL)] on nutrient intake and total-tract apparent digestibility, ruminal fermentation, nitrogen utilization, and predicted rumen microbial protein (Pmic) in heifers. Twelve Jersey heifers (14±0.6 months and 264±18.7 kg BW) were assigned to a 4 × 4 Latin square experiment with the following treatments: Control (CON), diet without feed additives; Ricinoleic acid, dietary inclusion of RA at 2 g kg-1 dry matter (DM); Cashew nutshell liquid, dietary inclusion of CNSL at 2 g kg-1 DM; and a mixture of 1 g kg-1 DM of RA and 1 g kg-1 DM of CNSL (RA+CNSL). Heifers were allowed 14 d for treatment adaptation followed by 5 days of sampling. Total feces collection was performed to determine digestibility. Rumen fluid was collected to determine short-chain fatty acids (SCFA) concentration. Urine samples were collected for nitrogen and purine derivatives analyses. Feeding RA decreased intake of DM, but increased crude protein (CP) digestibility and ruminal acetate concentration. Feeding CSNL increased NDF digestibility and lowered Pmic. The association of RA+CNSL increased neutral detergent fiber (NDF) digestibility and ruminal concentration of total SCFA without affecting DM intake. Feeding RA treatment decreased N intake and N excreted in feces and urine. CNSL group had the highest values of N balance. Heifers fed RA had lower Pmic than CNSL and RA+CNSL. The association of RA+CNSL improved digestibility of fiber and increased ruminal concentration of SCFA without altering N balance and Pmic.

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

Oxidized saturated fatty acids, containing a hydroxyl or an oxo functionality, have attracted little attention so far. Recent studies have shown that saturated hydroxy fatty acids, which exhibit cancer cell growth inhibition and may suppress β-cell apoptosis, are present in milk. Herein, we present the application of a liquid chromatography-high-resolution mass spectrometry (LC-HRMS) method for the detection and quantification of various saturated oxo fatty acids (SOFAs) previously unrecognized in milk. This robust and rapid analytical method, which involves simple sample preparation and a single 10-min run, revealed the presence of families of oxostearic acids (OSAs) and oxopalmitic acids (OPAs) in milk. 8OSA, 9OSA, 7OSA, 10OSA and 10OPA were found to be the most abundant SOFAs in both cow and goat milk. Higher contents of SOFAs were found in cow milk in comparison to goat milk. Together with SOFAs, ricinoleic acid, which is isobaric to OSA, was detected and quantified in all milk samples, following a “suspect” HRMS analysis approach. This unique natural fatty acid, which is the main component (>90%) of castor oil triglycerides, was estimated at mean content values of 534.3 ± 6.0 μg/mL and 460 ± 8.1 μg/mL in cow and goat milk samples, respectively.

Microbial Production of Conjugated Linoleic Acid and Conjugated Linolenic Acid Relies on a Multienzymatic System

Conjugated linoleic acids (CLAs) and conjugated linolenic acids (CLNAs) have gained significant attention due to their anticarcinogenic and lipid/energy metabolism-modulatory effects. However, their concentration in foodstuffs is insufficient for any therapeutic application to be implemented. From a biotechnological standpoint, microbial production of these conjugated fatty acids (CFAs) has been explored as an alternative, and strains of the genera Propionibacterium, Lactobacillus, and Bifidobacterium have shown promising producing capacities. Current screening research works are generally based on direct analytical determination of production capacity (e.g., trial and error), representing an important bottleneck in these studies. This review aims to summarize the available information regarding identified genes and proteins involved in CLA/CLNA production by these groups of bacteria and, consequently, the possible enzymatic reactions behind such metabolic processes. Linoleate isomerase (LAI) was the first enzyme to be described to be involved in the microbiological transformation of linoleic acids (LAs) and linolenic acids (LNAs) into CFA isomers. Thus, the availability of lai gene sequences has allowed the development of genetic screening tools. Nevertheless, several studies have reported that LAIs have significant homology with myosin-cross-reactive antigen (MCRA) proteins, which are involved in the synthesis of hydroxy fatty acids, as shown by hydratase activity. Furthermore, it has been suggested that CLA and/or CLNA production results from a stress response performed by the activation of more than one gene in a multiple-step reaction. Studies on CFA biochemical pathways are essential to understand and characterize the metabolic mechanism behind this process, unraveling all the gene products that may be involved. As some of these bacteria have shown modulation of lipid metabolism in vivo, further research to be focused on this topic may help us to understand the role of the gut microbiota in human health.

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

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.