Effect of oilseed type on milk fatty acid composition of individual cows, and also bulk tank milk fatty acid composition from commercial farms

Oil-in-Water Nanoemulsion Can Modulate the Fermentation, Fatty Acid Accumulation, and the Microbial Population in Rumen Batch Cultures

In this study, three oil-in-water nanoemulsions were tested in two stages: In the first stage, three levels (on the substrate dry matter (DM)), namely 3%, 6%, and 9%, of three different oils, olive oil (OO), corn oil (CO), and linseed oil (LO), in raw and nanoemulsified (N) forms were used separately in three consecutive rumen batch cultures trials. The second stage, which was based on the first stage's results, consisted of a batch culture trial that compared the raw and nanoemulsified (N) forms of all three oils together, provided at 3% of the DM. In the first stage, NOO, NCO, and NLO preserved higher unsaturated fatty acid (UFA) and less saturated fatty acid (SFA) compared to OO, CO, and LO, respectively; noticeably, NCO had UFA:SFA = 1.01, 1.16, and 1.34 compared to CO, which had UFA:SFA = 0.66, 0.69, and 0.72 when supplemented at 3%, 6%, 9% of DM, respectively. In the second stage, UFA:SFA = 1.04, 1.12, and 1.07 for NOO, NCO, NLO, as compared to UFA:SFA = 0.69, 0.68, and 0.72 for OO, CO, and LO supplemented at 3% of DM. In conclusion, oil-in-water nanoemulsions showed an ability to decrease the transformation of UFA to SFA in the biohydrogenation environment without affecting the rumen microorganisms.

Feeding Corn Oil in a Nanoemulsified Form Alters the Unsaturated Fatty Acids in the Milk of Zaraibi Dairy Goats

Simple Summary

Increasing the polyunsaturated fatty acid content of ruminant milk represents a much needed step to increase the functional properties of the milk. However, boosting milk fatty acids through feeding strategies has remained a significant challenge for years; it requires new solutions to deliver unsaturated fatty acids in a much safer form for rumen microorganisms than the traditional supplemented raw oil form. The goal is to target less biohydrogenation, which results in less saturated fatty acid accumulation in the rumen and milk. In the present study, the ultrasonic nanoemulsification of corn oil was introduced as a replacement for the raw form of oil supplementation; it was used at 3% of the offered feed dry matter in a trial on dairy goats. The new form of corn oil supplementation was more effective than the raw form of corn oil in increasing milk productivity and fat percentage and preserving a more significant proportion of polyunsaturated fatty acids in the milk of dairy goats. Conversely, the raw form of corn oil resulted in milk fat depression and lower total solid content in addition to milk with higher proportions of saturated fatty acid.

Abstract

Oil in water nanoemulsion represents a new and unstudied form of oil supplementation to the ruminant diet; that is why the aim was to evaluate the potential of nanoemulsified corn oil in dairy goats’ diets on milk productivity and fatty acid proportion. Twenty-four lactating Zaraibi goats in early lactation were randomly allocated to the following treatments: control—a basal diet without any supplementation, CO—the control diet + corn oil supplied at 3% on a dry matter basis (DM), NCO—the control diet + nanoemulsified corn oil provided at 3% on a DM basis. A completely randomized design that lasted 30 days (25 days of adaptation + 5 days of sampling) was used with eight goats in each treatment. The control diet consisted of 50% concentrate and 50% Egyptian berseem clover. The NCO increased the milk production, fat percentage, and yield compared to the CO and the control. The proportions of oleic, linoleic, and linolenic acids were higher in the NCO compared to the control and CO. The NCO had less effect on the biohydrogenation intermediates’ profile than the CO; noticeably, higher proportions of unsaturated fatty acid (UFA) were associated with the NCO. In conclusion, the NCO increased milk production and decreased the transformation rate of UFA to saturated fatty acids in the biohydrogenation environment.

Oilseed Supplementation Improves Milk Composition and Fatty Acid Profile of Cow Milk: A Meta-Analysis and Meta-Regression

Oilseed supplementation is a strategy to improve milk production and milk composition in dairy cows; however, the response to this approach is inconsistent. Thus, the aim of this study was to evaluate the effect of oilseed supplementation on milk production and milk composition in dairy cows via a meta-analysis and meta-regression. A comprehensive and structured search was performed using the following electronic databases: Google Scholar, Primo-UAEH and PubMed. The response variables were: milk yield (MY), atherogenic index (AI), Σ omega-3 PUFA, Σ omega-6 PUFA, fat, protein, lactose, linoleic acid (LA), linolenic acid (LNA), oleic acid (OA), vaccenic acid (VA), conjugated linoleic acid (CLA), unsaturated fatty acid (UFA) and saturated fatty acid (SFA) contents. The explanatory variables were breed, lactation stage (first, second, and third), oilseed type (linseed, soybean, rapeseed, cottonseed, and sunflower), way (whole, extruded, ground, and roasted), dietary inclusion level, difference of the LA, LNA, OA, forage and NDF of supplemented and control rations, washout period and experimental design. A meta-analysis was performed with the “meta” package of the statistical program R. A meta-regression analysis was applied to explore the sources of heretogeneity. The inclusion of oilseeds in dairy cow rations had a positive effect on CLA (+0.27 g 100 g−1 fatty acids (FA); p < 0.0001), VA (+1.03 g 100 g−1 FA; p < 0.0001), OA (+3.44 g 100 g−1 FA; p < 0.0001), LNA (+0.28 g 100 g−1 FA; p < 0.0001) and UFA (+8.32 g 100 g−1 FA; p < 0.0001), and negative effects on AI (−1.01; p < 0.0001), SFA (−6.51; p < 0.0001), fat milk (−0.11%; p < 0.001) and protein milk (−0.04%; p < 0.007). Fat content was affected by animal breed, lactation stage, type and processing of oilseed and dietary NDF and LA contents. CLA, LA, OA and UFA, desirable FA milk components, were affected by type, processing, and the intake of oilseed; additionally, the concentrations of CLA and VA are affected by washout and design. Oilseed supplementation in dairy cow rations has a positive effect on desirable milk components for human consumption. However, animal response to oilseed supplementation depends on explanatory variables related to experimental design, animal characteristics and the type of oilseed.

Effects on milk quantity and composition associated with extruded linseed supplementation to dairy cow diets

Enhanced milk composition can improve human health. The composition of milk determines its nutritional and market value. Therefore, in almost all pricing schemes the economic benefits obtained from raw milk sales are influenced by the milk yield and composition. The objective of this retrospective study was to quantify the average effects of supplementing extruded linseed, rich in α-linolenic acid, to dairy cows on milk yield and milk fat and protein content under field conditions. The study included test day records performed on cows from 1294 dairy herds during the period from 2008 to 2015 that were supplied at least 4 times with extruded linseed deliveries. Exposure statuses were defined according to the time sequence and the amount of extruded linseed distributed in the herd. The unexposed population was composed of cows being in a herd period when extruded linseed was not offered. In a linear dose-response relationship, every 100 g increase in exposure to EL was associated with an increased milk yield from 0.11 to 0.14 kg/day, decreased milk fat from 0.06 to 0.13 g/kg and decreased milk protein from 0 to 0.02 g/kg, according to the cow parity. This study provides information on the associations between estimated intakes of EL and milk production and composition using a large database obtained from commercial dairy herds.

Goats' Feeding Supplementation with Acacia farnesiana Pods and Their Relationship with Milk Composition: Fatty Acids, Polyphenols, and Antioxidant Activity

Simple Summary

The study aimed to describe the fatty acids, polyphenols, and antioxidant activity of goat’s milk from five different feeding systems: Grazing; conventional diet; and conventional diet supplemented with 10, 20, and 30 percent of Acacia farnesiana pods. Conventional diet showed the highest content of polyunsaturated fatty acids while grazing showed the healthiest fatty acid profile. Similarly, grazing and A. farnesiana boosted the polyphenol content. A. farnesiana pod meal inclusion in the goats’ diets increased the selective presence of bioactive compounds and the antioxidant activity of goat’s milk while cholesterol content was reduced.

Abstract

Background: Research efforts have focused on the evaluation of the bioactive quality of animal products (milk, cheese, meat, and other by-products) contrasting various feeding strategies coming from different ecological zones. The study aimed to describe the fatty acids (FA), polyphenols (P), bioactive compounds (BC), and antioxidant activity (AA) of goat’s milk. Methods: Dairy goats were fed with five systems: (1) Grazing; (2) conventional diet (CD); (3) CD + 10% of Acacia farnesiana (AF) pods; (4) CD + 20% AF; and (5) CD + 30% AF. The fatty acid profile, health promoting and thrombogenic indexes were calculated. Milk extracts were evaluated by HPLC to determent phenolic compounds (gallic, caffeic, chlorogenic, and ferulic acids, catechin, epicatechin, and quercetin). Antioxidant activity of goat’s milk extract was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•), oxygen radical absorbance capacity (ORAC), and the ferric reducing antioxidant power (FRAP) assays. Results: Conventional diet showed the highest content of polyunsaturated fatty acids while grazing showed the best n-6:n-3 and the linoleic:alpha linolenic acid ratio. Similarly, grazing and AF boosted the polyphenol content. Conclusions: Acacia farnesiana inclusion in the goats’ diets increased the presence of bioactive compounds and the antioxidant activity while diminishing the cholesterol content of goat’s milk.

Methane prediction based on individual or groups of milk fatty acids for dairy cows fed rations with or without linseed

Milk fatty acids (MFA) are a proxy for the prediction of CH₄ emission from cows, and prediction differs with diet. Our objectives were (1) to compare the effect of diets on the relation between MFA profile and measured CH₄ production, (2) to predict CH₄ production based on 6 data sets differing in the number and type of MFA, and (3) to test whether additional inclusion of energy-corrected milk (ECM) yield or dry matter intake (DMI) as explanatory variables improves predictions. Twenty dairy cows were used. Four diets were used based on corn silage (CS) or grass silage (GS) without (L0) or with linseed (LS) supplementation. Ten cows were fed CS-L0 and CS-LS and the other 10 cows were fed GS-L0 and GS-LS in random order. In feeding wk 5 of each diet, CH₄ production (L/d) was measured in respiration chambers for 48 h and milk was analyzed for MFA concentrations by gas chromatography. Specific CH₄ prediction equations were obtained for L0-, LS-, GS-, and CS-based diets and for all 4 diets collectively and validated by an internal cross-validation. Models were developed containing either 43 identified MFA or a reduced set of 7 groups of biochemically related MFA plus C16:0 and C18:0. The CS and LS diets reduced CH₄ production compared with GS and L0 diets, respectively. Methane yield (L/kg of DMI) reduction by LS was higher with CS than GS diets. The concentrations of C18:1 trans and n-3 MFA differed among GS and CS diets. The LS diets resulted in a higher proportion of unsaturated MFA at the expense of saturated MFA. When using the data set of 43 individual MFA to predict CH₄ production (L/d), the cross-validation coefficient of determination (R²_CV) ranged from 0.47 to 0.92. When using groups of MFA variables, the R²_CV ranged from 0.31 to 0.84. The fit parameters of the latter models were improved by inclusion of ECM or DMI, but not when added to the data set of 43 MFA for all diets pooled. Models based on GS diets always had a lower prediction potential (R²_CV = 0.31 to 0.71) compared with data from CS diets (R²_CV = 0.56 to 0.92). Models based on LS diets produced lower prediction with data sets with reduced MFA variables (R²_CV = 0.62 to 0.68) compared with L0 diets (R²_CV = 0.67 to 0.80). The MFA C18:1 cis-9 and C24:0 and the monounsaturated FA occurred most often in models. In conclusion, models with a reduced number of MFA variables and ECM or DMI are suitable for CH₄ prediction, and CH₄ prediction equations based on diets containing linseed resulted in lower prediction accuracy.

Differential effects of oilseed supplements on methane production and milk fatty acid concentrations in dairy cows

It is known that supplementing dairy cow diets with full-fat oilseeds can be used as a strategy to mitigate methane emissions, through their action on rumen fermentation. However, direct comparisons of the effect of different oil sources are very few, as are studies implementing supplementation levels that reflect what is commonly fed on commercial farms. The objective was to investigate the effect of feeding different forms of supplemental plant oils on both methane emissions and milk fatty acid (FA) profile. Four multiparous, Holstein-Friesian cows in mid-lactation were randomly allocated to one of four treatment diets in a 4×4 Latin square design with 28-day periods. Diets were fed as a total mixed ration with a 50 : 50 forage : concentrate ratio (dry matter (DM) basis) with the forage consisting of 75 : 25 maize silage : grass silage (DM). Dietary treatments were a control diet containing no supplemental fat, and three treatment diets containing extruded linseed (EL), calcium salts of palm and linseed oil (CPLO) or milled rapeseed (MR) formulated to provide each cow with an estimated 500 g additional oil/day (22 g oil/kg diet DM). Dry matter intake (DMI), milk yield, milk composition and methane production were measured at the end of each experimental period when cows were housed in respiration chambers for 4 days. There was no effect of treatment diet on DMI or milk protein or lactose concentration, but oilseed-based supplements increased milk yield compared with the control diet and milk fat concentration relative to control was reduced by 4 g/kg by supplemental EL. Feeding CPLO reduced methane production, and both linseed-based supplements decreased methane yield (by 1.8 l/kg DMI) and intensity (by 2.7 l/kg milk yield) compared with the control diet, but feeding MR had no effect on methane emission. All the fat supplements decreased milk total saturated fatty acid (SFA) concentration compared with the control, and SFA were replaced with mainly cis-9 18:1 but also trans FA (and in the case of EL and CPLO there were increases in polyunsaturated FA concentration). Supplementing dairy cow diets with these oilseed-based preparations affected milk FA profile and increased milk yield. However, only the linseed-based supplements reduced methane production, yield or intensity, whereas feeding MR had no effect.

Short communication: The effect of linseed oil and DGAT1 K232A polymorphism on the methane emission prediction potential of milk fatty acids

Several in vivo CH₄ measurement techniques have been developed but are not suitable for precise and accurate large-scale measurements; hence, proxies for CH₄ emissions in dairy cattle have been proposed, including the milk fatty acid (MFA) profile. The aim of the present study was to determine whether recently developed MFA-based prediction equations for CH₄ emission are applicable to dairy cows with different diacylglycerol o-acyltransferase 1 (DGAT1) K232A polymorphism and fed diets with and without linseed oil. Data from a crossover design experiment were used, encompassing 2 dietary treatments (i.e., a control diet and a linseed oil diet, with a difference in dietary fat content of 22 g/kg of dry matter) and 24 lactating Holstein-Friesian cows (i.e., 12 cows with DGAT1 KK genotype and 12 cows with DGAT1 AA genotype). Enteric CH₄ production was measured in climate respiration chambers and the MFA profile was analyzed using gas chromatography. Observed CH₄ emissions were compared with CH₄ emissions predicted by previously developed MFA-based CH₄ prediction equations. The results indicate that different types of diets (i.e., with or without linseed oil), but not the DGAT1 K232A polymorphism, affect the ability of previously derived prediction equations to predict CH₄ emission. However, the concordance correlation coefficient was smaller than or equal to 0.30 for both dietary treatments separately, both DGAT1 genotypes separately, and the complete data set. We therefore concluded that previously derived MFA-based CH₄ prediction equations can neither accurately nor precisely predict CH₄ emissions of dairy cows managed under strategies differing from those under which the original prediction equations were developed.

Effects of feeding extruded linseed on production performance and milk fatty acid profile in dairy cows: A meta-analysis

The objectives of this study were to quantify the effects on production performance and milk fatty acid (FA) profile of feeding dairy cows extruded linseed (EL), a feed rich in α-linolenic acid, and to assess the variability of the responses related to the dose of EL and the basal diet composition. This meta-analysis was carried out using only data from trials including a control diet without fat supplementation. The dependent variables were defined by the mean differences between values from EL-supplemented groups and values from control groups. The data were processed by regression testing the dose effect, multivariable regression testing the effect of each potential interfering factor associated with the dose effect, and then stepwise regression with backward elimination procedure with all potential interfering factors retained in previous steps. This entire strategy was also applied to a restricted data set, including only trials conducted inside a practical range of fat feeding (only supplemented diets with <60 g of fat/kg of dry matter and supplemented with <600 g of fat from EL). The whole data set consisted of 17 publications, representing 21 control diets and 29 EL-supplemented diets. The daily intake of fat from EL supplementation ranged from 87 to 1,194 g/cow per day. The dry matter intake was numerically reduced in high-fat diets. Extruded linseed supplementation increased milk yield (0.72 kg/d in the restricted data set) and decreased milk protein content by a dilutive effect (-0.58 g/kg in the restricted data set). No effect of dose or diet was identified on dry matter intake, milk yield, or milk protein content. Milk fat content decreased when EL was supplemented to diets with high proportion of corn silage in the forage (-2.8 g/kg between low and high corn silage-based diets in the restricted data set) but did not decrease when the diet contained alfalfa hay. Milk trans-10 18:1 proportion increased when EL was supplemented to high corn silage-based diets. A shift in ruminal biohydrogenation pathways, from trans-11 18:1 to trans-10 18:1, probably occurred when supplementing EL with high corn silage-based diets related to a change in the activity or composition of the microbial equilibrium in the rumen. The sum of pairs 4:0 to 14:0 (FA synthesized de novo by the udder), palmitic acid, and the sum of saturated FA decreased linearly, whereas oleic acid, vaccenic acid, rumenic acid, α-linolenic acid, and the sums of mono- and polyunsaturated FA increased linearly when the daily intake of fat from EL was increased. In experimental conditions, EL supplementation increased linearly proportions of potentially human health-beneficial FA in milk (i.e., oleic acid, vaccenic acid, rumenic acid, α-linolenic acid, total polyunsaturated FA), but should be used cautiously in corn silage-based diets.