Effects of soybean oil supplement to diets of lactating dairy cows, on productive performance, and milk fat acids profile: a meta-analysis

Quantifying the Impact of Different Dietary Rumen Modulating Strategies on Enteric Methane Emission and Productivity in Ruminant Livestock: A Meta-Analysis

A meta-analysis was conducted with an aim to quantify the beneficial effects of nine different dietary rumen modulating strategies which includes: the use of plant-based bioactive compounds (saponin, tannins, oils, and ether extract), feed additives (nitrate, biochar, seaweed, and 3-nitroxy propanol), and diet manipulation (concentrate feeding) on rumen fermentation, enteric methane (CH4) production (g/day), CH4 yield (g/kg dry matter intake) and CH4 emission intensity (g/kg meat or milk), and production performance parameters (the average daily gain, milk yield and milk quality) of ruminant livestock. The dataset was constructed by compiling global data from 110 refereed publications on in vivo studies conducted in ruminants from 2005 to 2023 and anlayzed using a meta-analytical approach.. Of these dietary rumen manipulation strategies, saponin and biochar reduced CH4 production on average by 21%. Equally, CH4 yield was reduced by 15% on average in response to nitrate, oils, and 3-nitroxy propanol (3-NOP). In dairy ruminants, nitrate, oils, and 3-NOP reduced the intensity of CH4 emission (CH4 in g/kg milk) on average by 28.7%. Tannins and 3-NOP increased on average ruminal propionate and butyrate while reducing the acetate:propionate (A:P) ratio by 12%, 13.5% and 13%, respectively. Oils increased propionate by 2% while reducing butyrate and the A:P ratio by 2.9% and 3.8%, respectively. Use of 3-NOP increased the production of milk fat (g/kg DMI) by 15% whereas oils improved the yield of milk fat and protein (kg/d) by 16% and 20%, respectively. On the other hand, concentrate feeding improved dry matter intake and milk yield (g/kg DMI) by 23.4% and 19%, respectively. However, feed efficiency was not affected by any of the dietary rumen modulating strategies. Generally, the use of nitrate, saponin, oils, biochar and 3-NOP were effective as CH4 mitigating strategies, and specifically oils and 3-NOP provided a co-benefit of improving production parameters in ruminant livestock. Equally concentrate feeding improved production parameters in ruminant livestock without any significant effect on enteric methane emission. Therefore, it is advisable to refine further these strategies through life cycle assessment or modelling approaches to accurately capture their influence on farm-scale production, profitability and net greenhouse gas emissions. The adoption of the most viable, region-specific strategies should be based on factors such as the availability and cost of the strategy in the region, the specific goals to be achieved, and the cost-benefit ratio associated with implementing these strategies in ruminant livestock production systems.

Associations between Dietary Fatty Acid Profile and Milk Fat Production and Fatty Acid Composition in Dairy Cows: A Meta-Analysis

This meta-analysis aimed to investigate the effect of dietary fatty acid (FA) profile on milk fat production and FA profile in dairy cows. The study also aimed to develop prediction models using a meta-regression approach. The database included 217 peer-reviewed articles on lactating dairy cows (n = 12,892), consisting of 515 treatment means. Effect size was assessed using the raw mean differences between diets with supplementary lipid sources and those without. Subgroup analyses were employed to assess heterogeneity. Diets rich in saturated FA (SFA) increased milk fat production and proportion, while reducing de novo FA in milk. Diets high in monounsaturated FA and polyunsaturated FA decreased mixed FA in milk. Most lipid-supplemented diets increase preformed FA in milk, except those rich in SFA. Prediction models were developed using meta-regression. Key predictors of milk fat production included neutral detergent fiber (NDF), dietary myristic acid, and milk production. Milk fat proportion was best predicted by dietary unsaturated FA, NDF, and forage. De novo FA in milk was predicted by dry matter intake (DMI) and dietary FA, while preformed FA was predicted by DMI, dietary oleic and linoleic acids. In conclusion, this study emphasizes the importance of the dietary FA profile in evaluating the effects of lipids on milk fat production and FA profile. Accurate and precise predictions of milk fat production, proportion, and FA profile can be achieved by considering cow production and dietary characteristics.

Effect of whole oilseeds in the diet on bacterial diversity in the solid fraction of the ruminal content of steers

Our hypothesis was that different whole oilseeds included in the diet for steers confined could alter the diversity of rumen bacteria compared to a diet without oilseeds or an exclusively forage diet. It was aimed to evaluate the effects of oilseeds inclusion in the diet on bacterial diversity in the solid fraction of the ruminal content of steers, by gene sequences of the conserved 16S rDNA region. Six crossbred steers castrated males, fitted with ruminal cannula were used in a 6 × 6 Latin square design, using 21-day period. At the start of the experiment, the live weight of the animals averaged 416 ± 9.7 kg (mean ± SD). A total of 2,180,562 16S rDNA sequences were generated for the Bacteria domain by MiSeq sequencing. The bacterial diversity was composed of 24 bacterial phyla, with the most abundant being Firmicutes, Bacteroidetes, and Proteobacteria. Other phyla with less diversity were also identified including Eurychaeota, Tenericutes, SR1 Absconditalbacteria, Synergistetes, Actinobacteria, Saccharibacteria, Elusimicrobia, Cyanobacteria, Verrucomicrobia, Fusobacteria, Lentisphaerae. The similarity in the bacterial community averaged 50% for all the experimental diets. Steers-fed corn silage exhibited a great diversity of bacteria of the Firmicutes phylum. The steers-fed oilseeds in the diet had a great diversity of bacteria from the phylum Bacteroidetes and Proteobacteria. The inclusion of whole oilseeds in the steer diets can alter the rumen bacteria population by up to 50% of total diversity.

Dietary Effect of Palm Kernel Oil Inclusion in Feeding Finishing Lambs on Meat Quality

This study evaluated the effects of palm kernel oil (PKO) in the diet of lambs on carcass characteristics, quality, and fatty acid profile of the meat. Forty uncastrated male Santa Inês lambs were used and divided among the treatments: PKOzero without inclusion; PKO1.3—added 1.3%; PKO2.6—added 2.6%; PKO3.9—added 3.9%; PKO5.2—added 5.2%. The carcass characteristics, the variables related to meat color, and the chemical composition of the Longissimus lumborum of lambs were not affected by the PKO inclusion. The weight of the carcasses at slaughter, hot and cold, half carcass, loin-eye area, and commercial cuts decreased linearly when PKO was added to the lamb diet (p < 0.01). CCY decreased linearly to the inclusion level of 2.66% PKO (RMSE 2.204). Total conjugated linoleic acid CLA and C18:3 n-3 GA concentrations remained stable until the inclusion levels of 3.44% PKO (RMSE 0.0956) and 2.17% (RMSE 0.0637), decreasing its concentrations as the increased level of PKO. The presence of PKO in the lambs’ diet up to the level of 5.2% did not change the meat quality characteristics; thus, from the point of view of lamb meat production and fatty acid profile, the inclusion of PKO is not beneficial.

The Blood Immune Cell Count, Immunoglobulin, Inflammatory Factor, and Milk Trace Element in Transition Cows and Calves Were Altered by Increasing the Dietary n-3 or n-6 Polyunsaturated Fatty Acid Levels

Transition dairy cows experience sudden changes in both metabolic and immune functions, which lead to many diseases in postpartum cows. Therefore, it is crucial to monitor and guarantee the nutritional and healthy status of transition cows. The objective of this study was to determine the effect of diet enriched in n-3 or n-6 polyunsaturated fatty acid (PUFA) on colostrum composition and blood immune index of multiparous Holstein cows and neonatal calves during the transition period. Forty-five multiparous Holstein dairy cows at 240 days of pregnancy were randomly assigned to receive 1 of 3 isoenergetic and isoprotein diets: 1) CON, hydrogenated fatty acid (control), 1% of hydrogenated fatty acid [diet dry matter (DM) basis] during prepartum and postpartum, respectively; 2) HN3, 3.5% of extruding flaxseed (diet DM basis, n-3 PUFA source); 3) HN6, 8% of extruding soybeans (diet DM basis, C18:2n-6 PUFA source). Diets containing n-3 and n-6 PUFA sources decreased colostrum immunoglobulin G (IgG) concentration but did not significantly change the colostrum IgG yield compared with those with CON. The commercial milk yield (from 14 to 28 days after calving) was higher in the HN3 and HN6 than that in the CON. Furthermore, the n-3 PUFA source increased neutrophil cell counts in blood during the prepartum period and increased neutrophil percentage during the postpartum period when compared with those with control treatment. Diets containing supplemental n-3 PUFA decreased the serum concentration of interleukin (IL)-1β in maternal cows compared with those in control and n-6 PUFA during prepartum and postpartum. In addition, the neonatal calf serum concentration of tumor necrosis factor (TNF) was decreased in HN3 compared with that in the HN6 treatment. The diet with the n-3 PUFA source could potentially increase the capacity of neutrophils to defend against pathogens in maternal cows by increasing the neutrophil numbers and percentage during the transition period. Meanwhile, the diet with n-3 PUFA source could decrease the pro-inflammatary cytokine IL-1β of maternal cows during the transition period and decline the content of pro-inflammatary cytokine TNF of neonatal calves. It suggested that the highest milk production in n-3 PUFA treatment may partially be due to these beneficial alterations.

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.

Effect of soybean grain (Glycine max L.) supplementation on the production and fatty acid profile in milk of grazing cows in the dry tropics of Mexico

Improving the lipid profile in milk of cows with the use of soybean grain (Glycine max L.) can be favored in the grazing systems in the dry tropics of Mexico. The objective was to evaluate the milk production, the chemical composition, and the fatty acids profile (FAs) of the milk of cows in continuous grazing and supplemented with and without ground roasted soybean in the dry tropics of Mexico. Ten cows randomly distributed in two equal groups were used. Daily during confinement for milking, the cows individually received the treatments on dry basis T0: supplement with 4.6 kg commercial concentrate® without soybean, T1: supplement with 3.7 kg commercial concentrate® with 380 g of soybean. During the 78 days of the experiment, milk production was measured in all cows, and samples were collected to determine the chemical composition and FAs profile. Milk production, protein, milk total fat, lactose, and non-fat solids did not vary with treatment (p >0.05). Linoleic acid content (C18: 2, cis, cis-∆9, ∆12) increased by 22% in milk fat of cows of the T1 (p ˂0.05). The sum of the mono- and polyunsaturated FAs 29.1%, the ratio of saturated-unsaturated FAs (1.65), and the atherogenicity index (1.71) also improved in the milk of cows supplemented with T1 (p ˂0.05). It was concluded that ground roasted soybean supplement in the diet of grazing dairy cows did not affect production and did improve the lipid profile in milk fat with favorable index to promote human health.