Milk yield, milk composition, and hepatic lipid metabolism in transition dairy cows fed flaxseed or linola

Milk production and milk fatty acid profile as a response to feeding dairy cows with flax products during the persistence period

The response of enhanced dietary dairy cows with linolenic-rich sources during the persistence period was studied to determine its effectiveness on some blood constituents, milk yield and milk fatty acid profile. A complete randomized design experiment was conducted in the spring and involved 20 Friesian cows (60 days in milk) that were divided into four groups of five animals by milk production according to different types of flax source in isonitrogenous and isoenergetic rations: a traditional diet with no flax source (CO), a diet contains flaxseed meal (FLM), a diet contains whole flaxseed (FLS) and a diet contains flax oil (FLO). DM intake and DMI% of weight were increased for cows fed FLM. However, Omega-3 intake was reduced for cows fed on CO ration. Although, blood serum metabolites did not differ among treatments (p < 0.05) except serum cholesterol which was increased with FLO cows, and serum total lipid which was reduced with FLM cows. Cows fed on flax product and control peaked in milk production at the same time (8-week post-partum), and cows fed on FLM continued in peak production for a longer period. Using flax products enhanced milk production, cows fed FLM had higher milk yield than those fed CO (20.76 vs.16.32 kg/d), and there was no difference between cows fed FLO (17.87 kg/d) and those fed FLS (18.01 kg/d). Also, energy-corrected milk yield and 3.5 fat-corrected milk yield were increased with cows fed on FLM as compared with cows fed CO ration. Flax products had no significant effect on milk fat and protein %, whereas cows fed FLM had the greatest fat% value (3.35%) and FLS had the greatest protein% value (2.66%). Moreover, fat and protein yield increased significantly in treatment groups compared to the CO group, whereas they were the greatest in FLM g (0.700 and 0.540 kg/d), respectively. Concentrations of omega-3-fatty acids in milk fat were increased by using FLO in the ration; using flaxseed meal enhanced conjugated linoleic acids in milk fat and resulted in the highest omega-6-to-omega-3-fatty-acids ratio. The data suggest that flax seed meals can be used as a fat source in the diet of dairy cows during the persistence period with a good response to milk production and its health properties. Moreover, flax oil should be protected before use in rations to prevent its components from saturation or being changed in the rumen.

Effect of Flaxseed Supplementation on Milk and Plasma Fatty Acid Composition and Plasma Parameters of Holstein Dairy Cows

The objective of this study was to determine the effect of whole flaxseed and ground flaxseed supplementation on the composition of fatty acids in plasma and milk, particularly the content of omega-3 polyunsaturated fatty acids (n-3 PUFAs). Thirty Holstein dairy cows were randomly assigned to three treatment groups. Cows were fed a total mixed ration without flaxseed (CK), 1500 g of whole flaxseed (WF), and 1500 g of ground flaxseed (GF) supplementation. There were no differences observed in dry matter intake, milk yield, energy-corrected milk, and 4% fat-corrected milk (p > 0.05). Compared with the CK group, the contents of α-linolenic acid (ALA), eicosatrienoic acid, and eicosapentaenoic acid increased in the plasma and milk WF and GF groups, and the content of docosahexaenoic acid and total n-3 PUFA was higher in GF than the other groups (p < 0.001). The ALA yield increased to 232% and 360% in WF and GF, respectively, compared to the CK group. Compared with the WF group, GF supplementation resulted in an increased milk ALA/ALA intake ratio (p < 0.001). Flaxseed supplementation increased the activity of GSH-Px and decreased the concentration of MDA in milk (p < 0.001). Plasma parameters did not differ among the treatments (p > 0.05). This result indicated that compared with the WF group, GF supplementation in the diet showed higher efficiency in increasing the total n-3 PUFA levels and the milk ALA/ALA intake ratio, and decreased the ratio of n-6 PUFAs to n-3 PUFAs in milk.

Influence of flaxseed with rumen undegradable protein level on milk yield, milk fatty acids and blood metabolites in transition ewes

An experiment was conducted to determine the effects of two levels of rumen undegradable protein (RUP) without or with whole or extruded flaxseed on milk yield, milk component, milk fatty acids (FAs) profile and plasma metabolites in transition ewes. Three weeks before and after lambing, seventy-two Baluchi ewes were used in a completely randomized design with a 3 × 2 factorial arrangement of treatments. The treatments contained 1) no flaxseed + 20% RUP (no flaxseed, low RUP [NFLR]); 2) no flaxseed + 40% RUP (no flaxseed, high RUP [NFHR]); 3) 10% whole flaxseed + 20% RUP (whole flaxseed, low RUP [WFLR]); 4) 10% whole flaxseed + 40% RUP (whole flaxseed, high RUP [WFHR]); 5) 10% extruded flaxseed + 20% RUP (extruded flaxseed, low RUP [EFLR]), and 6) 10% extruded flaxseed + 40% RUP (extruded flaxseed, high RUP [EFHR]). Ewes fed 10% extruded flaxseed exhibited higher (p < 0.001) dry matter intake (DMI) and colostrum yield (p < 0.1) compared to other treatments. Two types of flaxseed and RUP levels had no significant effect on milk yield, but milk fat and protein contents decreased and increased in diets containing 40% RUP, respectively. Ewes fed extruded flaxseed produced milk with lower concentrations of saturated fatty acids (SFA) and higher α-linolenic and linoleic acids and also polyunsaturated fatty acids (PUFA) compared to other groups (p < 0.05). During post-lambing, the ewes fed diets containing flaxseed exhibited higher concentration of serum non-esterified FAs (NEFA) compared to diets without flaxseed (p < 0.01). The concentration of serum β-hydroxybutyric acid (BHBA) decreased in the diets containing flaxseed types at pre-lambing, but increased in diets containing extruded flaxseed at post-lambing (p < 0.01). The serum glucose concentration of ewes (pre and post-lambing) which consumed diets containing extruded flaxseed or 40% RUP increased, but blood urea concentration was elevated following supplementation of diet with whole flaxseed or 40% RUP (p < 0.001). In conclusion, utilization of 10% extruded flaxseed in the diets of transition ewes had positive effects on animal performance with favorable changes in milk FAs profile. However, there is no considerable advantage to supply more than 20% RUP level in the diet of transition dairy sheep.

Glucose metabolism and the somatotropic axis in dairy cows after abomasal infusion of essential fatty acids together with conjugated linoleic acid during late gestation and early lactation

Sufficient glucose availability is crucial for exploiting the genetic potential of milk production during early lactation, and endocrine changes are mainly related to repartitioning of nutrient supplies toward the mammary gland. Long-chain fatty acids, such as essential fatty acids (EFA) and conjugated linoleic acid (CLA), have the potential to improve negative energy balance and modify endocrine changes. In the present study, the hypothesis that combined CLA and EFA treatment supports glucose metabolism around the time of calving and stimulates insulin action and the somatotropic axis in cows in an additive manner was tested. Rumen-cannulated German Holstein cows (n = 40) were investigated from wk 9 antepartum (AP) until wk 9 postpartum (PP). The cows were abomasally supplemented with coconut oil (CTRL, 76 g/d); 78 g/d of linseed and 4 g/d of safflower oil (EFA); Lutalin (CLA, isomers cis-9,trans-11 and trans-10,cis-12 CLA, each 10 g/d); or the combination of EFA+CLA. Blood samples were collected several times AP and PP to determine the concentrations of plasma metabolites and hormones related to glucose metabolism and the somatotropic axis. Liver tissue samples were collected several days AP and PP to measure glycogen concentration and the mRNA abundance of genes related to gluconeogenesis and the somatotropic axis. On d 28 AP and 21 PP, endogenous glucose production (eGP) and glucose oxidation (GOx) were measured via tracer technique. The concentration of plasma glucose was higher in CLA than in non-CLA-treated cows, and the plasma β-hydroxybutyrate concentration was higher in EFA than in non-EFA cows on d 21 PP. The eGP increased from AP to PP with elevated eGP in EFA and decreased eGP in CLA-treated cows; GOx was lower in CLA than in CTRL on d 21 PP. The plasma insulin concentration decreased after calving in all groups and was higher in CLA than in non-CLA cows at several time points. Plasma glucagon and cortisol concentrations on d 21 PP were lower in CLA than non-CLA groups. The glucagon/insulin and glucose/insulin ratios were higher in CTRL than in CLA group during the transition period. Plasma IGF-I concentration was lower in EFA than non-EFA cows on d 42 AP and was higher during the dry period and early lactation in CLA than in non-CLA cows. The IGF binding protein (IGFBP)-3/-2 ratio in blood plasma was higher in CLA than in non-CLA cows. Hepatic glycogen concentration on d 28 PP was higher, but the mRNA abundance of PC and IGFBP2 was lower in CLA than non-CLA cows on d 1 PP. The EFA treatment decreased the mRNA abundance of IGFBP3 AP and PCK1, PCK2, G6PC, PCCA, HMGCS2, IGFBP2, and INSR at several time points PP. Results indicated elevated concentrations of plasma glucose and insulin along with the stimulation of the somatotropic axis in cows treated with CLA, whereas EFA treatment stimulated eGP but not mRNA abundance related to eGP PP. The systemic effects of the combined EFA+CLA treatment were very similar to those of CLA treatment, but the effects on hepatic gene expression partially corresponded to those of EFA treatment.

Fatty Acid Profile and Enterolactone Content of Early and Commercial Milk of Dairy Cows Supplemented with Flaked Flaxseed during the Dry Period

Various supplementations in animal feeding have been investigate in order to enrich food of animal origin with n-3 fatty acids. Although the effects of flaxseeds inclusion in diets for lactating dairy have already been assessed, few studies have focused on this n-3 source supplementation during the transition period. The aim of this work was to evaluate the effects of flacked flaxseed (200 g/head/day; 2.13% DM) dietary treatment during the dry period on milk yield and quality in the 30 days after calving. In addition, the enterolactone content in plasma (before and after calving) and in milk of cows fed diets supplemented or not with flaxseed was considered. The study demonstrated that the carry-over effect on the milk profile of C18:2, C18:3 n-3, and C20:5 n-3 was significantly higher in flaxseed diet than in the control one at 4th day of lactation. A significant increase of enterolactone on milk from flaxseed fed cows was observed only at 15 sampling day. The quick modification in fatty acid (FA) profile of the milk in the first few days of lactation suggests that the carry over effect from pre-calving flaxseed feeding at this concentration was very short lasting.

Lipid Accumulation and Injury in Primary Calf Hepatocytes Challenged With Different Long-Chain Fatty Acids

Fatty liver disease is one of the most common disorders afflicting dairy cows during the postpartum period, and is associated with increased blood non-esterified fatty acid (NEFA) uptake by the liver. Major long-chain fatty acids (LCFA) in NEFA are palmitic (PA), palmitoleic (POA), stearic (SA), oleic (OA), and linoleic (LA) acid. In order to investigate the characteristics of lipid accumulation and injury caused by these NEFA, primary calf hepatocytes were isolated and challenged for 12 h with 1.2 mmol/L PA, POA, SA, OA, LA, or a mixture of these LCFA (NEFA). Compared with POA, OA, and LA, culture with PA and SA led to greater abundance of CCAAT-enhancer binding protein, glucose-regulated protein 78 mRNA, and stearoyl-CoA desaturase 1 mRNA along with greater concentrations of H₂O₂, malondialdehyde and reactive oxygen species (ROS). Although culture with POA, OA, and LA led to lower very low density lipoprotein (VLDL) concentration in cell culture medium, POA and OA led to greater concentrations of triacylglycerol, protein abundance of sterol regulatory element-binding protein 1c, fatty acid synthase, acetyl coenzyme A carboxylase 1, ApoB100, and sortilin 1 (SORT1). Compared with individual fatty acids, culture with NEFA led to an intermediate degree of lipid accumulation and hepatocytes damage. Overall, the data suggest that saturated fatty acids cause more severe oxidative and ER stress. However, unsaturated fatty acids cause serious lipid accumulation. Furthermore, a fatty acid balanced nutrient regulation was suggested useful improve liver health of transition period dairy cows.

Review: Pro-inflammatory cytokines and hypothalamic inflammation: implications for insufficient feed intake of transition dairy cows

Improvements in feed intake of dairy cows entering the early lactation period potentially decrease the risk of metabolic disorders, but before developing approaches targeting the intake level, mechanisms controlling and dysregulating energy balance and feed intake need to be understood. This review focuses on different inflammatory pathways interfering with the neuroendocrine system regulating feed intake of periparturient dairy cows. Subacute inflammation in various peripheral organs often occurs shortly before or after calving and is associated with increased pro-inflammatory cytokine levels. These cytokines are released into the circulation and sensed by neurons located in the hypothalamus, the key brain region regulating energy balance, to signal reduction in feed intake. Besides these peripheral humoral signals, glia cells in the brain may produce pro-inflammatory cytokines independent of peripheral inflammation. Preliminary results show intensive microglia activation in early lactation, suggesting their involvement in hypothalamic inflammation and the control of feed intake of dairy cows. On the other hand, pro-inflammatory cytokine-induced activation of the vagus nerve transmits signalling to the brain, but this pathway seems not exclusively necessary to signal feed intake reduction. Yet, less studied in dairy cows so far, the endocannabinoid system links inflammation and the hypothalamic control of feed intake. Distinct endocannabinoids exert anti-inflammatory action but also stimulate the posttranslational cleavage of neuronal proopiomelanocortin towards β-endorphin, an orexigen promoting feed intake. Plasma endocannabinoid concentrations and hypothalamic β-endorphin levels increase from late pregnancy to early lactation, but less is known about the regulation of the hypothalamic endocannabinoid system during the periparturient period of dairy cows. Dietary fatty acids may modulate the formation of endocannabinoids, which opens new avenues to improve metabolic health and immune status of dairy cows.

Symposium review: Decomposing efficiency of milk production and maximizing profit

The dairy industry has focused on maximizing milk yield, as it is believed that this maximizes profit mainly through dilution of maintenance costs. Efficiency of milk production has received, until recently, considerably less attention. The most common method to determine biological efficiency of milk production is feed efficiency (FE), which is defined as the amount of milk produced relative to the amount of nutrients consumed. Economic efficiency is best measured as income over feed cost or gross margin obtained from feed investments. Feed efficiency is affected by a myriad of factors, but overall they could be clustered as follows: (1) physiological status of the cow (e.g., age, state of lactation, health, level of production, environmental conditions), (2) digestive function (e.g., feeding behavior, passage rate, rumen fermentation, rumen and hindgut microbiome), (3) metabolic partitioning (e.g., homeorhesis, insulin sensitivity, hormonal profile), (4) genetics (ultimately dictating the 2 previous aspects), and (5) nutrition (e.g., ration formulation, nutrient balance). Over the years, energy requirements for maintenance seem to have progressively increased, but efficiency of overall nutrient use for milk production has also increased due to dilution of nutrient requirements for maintenance. However, empirical evidence from the literature suggests that marginal increases in milk require progressively greater marginal increases in nutrient supply. Thus, the dilution of maintenance requirements associated with increases in production is partially overcome by a progressive diminishing marginal biological response to incremental energy and protein supplies. Because FE follows the law of diminishing returns, and because marginal feed costs increase progressively with milk production, profits associated with improving milk yield might, in some cases, be considerably lower than expected.

Dietary Fatty Acids Affect Red Blood Cell Membrane Composition and Red Blood Cell ATP Release in Dairy Cows

Diets of dairy cows are often based on maize silage (MS), delivering lower amounts of n-3 fatty acids (FA) compared to grass silage-based diets. The fatty acid composition of the cell membrane can affect the cell function. We evaluated the effects of an MS-based diet on bovine red blood cell (RBC) membrane FA composition and dietary effects on controlled ATP release of RBC. In trial 1, German Holstein cows were fed an MS-based total mixed ration for 24 weeks. The FA composition of RBC membranes from repeatedly taken blood samples was analysed in addition to the abundance of the RBC membrane protein flotillin-1, which is involved in, for example, cell signalling. In trial 2, four rumen fistulated MS-fed cows were abomasally infused in a 4 × 4 Latin square model with three successively increasing lipid dosages (coconut oil, linseed–safflower oil mix (EFA; rich in n-3 FA), Lutalin®, providing conjugated linoleic acids (CLA) or the combination of the supplements, EFA + CLA) for six weeks, followed by a three-week washout period. In trial 2, we analysed RBC ATP release, flotillin-1, and the membrane protein abundance of pannexin-1, which is involved in ATP release as the last part of a signalling cascade. In trial 1, the total amount of n-3 FA in RBC membranes decreased and the flotillin-1 abundance increased over time. In trial 2, the RBC n-3 FA amount was higher after the six-week infusion period of EFA or EFA + CLA. Furthermore, depending on the dosage of FA, the ATP release from RBC increased. The abundance of flotillin-1 and pannexin-1 was not affected in trial 2. It is concluded that changes of the membrane FA composition influence the RBC function, leading to altered ATP release from intact bovine RBC.

A Review of Lignan Metabolism, Milk Enterolactone Concentration, and Antioxidant Status of Dairy Cows Fed Flaxseed

Lignans are polyphenolic compounds with a wide spectrum of biological functions including antioxidant, anti-inflammatory, and anticarcinogenic activities, therefore, there is an increasing interest in promoting the inclusion of lignan-rich foods in humans' diets. Flaxseed is the richest source of the lignan secoisolariciresinol diglucoside-a compound found in the outer fibrous-containing layers of flax. The rumen appears to be the major site for the conversion of secoisolariciresinol diglucoside to the enterolignans enterodiol and enterolactone, but only enterolactone has been detected in milk of dairy cows fed flaxseed products (whole seeds, hulls, meal). However, there is limited information regarding the ruminal microbiota species involved in the metabolism of secoisolariciresinol diglucoside. Likewise, little is known about how dietary manipulation such as varying the nonstructural carbohydrate profile of rations affects milk enterolactone in dairy cows. Our review covers the gastrointestinal tract metabolism of lignans in humans and animals and presents an in-depth assessment of research that have investigated the impacts of flaxseed products on milk enterolactone concentration and animal health. It also addresses the pharmacokinetics of enterolactone consumed through milk, which may have implications to ruminants and humans' health.

Dietary Alfalfa and Calcium Salts of Long-Chain Fatty Acids Alter Protein Utilization, Microbial Populations, and Plasma Fatty Acid Profile in Holstein Freemartin Heifers

This study presented the effects of alfalfa and calcium salts of long-chain fatty acids (CSFA) on feed intake, apparent digestibility, rumen fermentation, microbial community, plasma biochemical parameters, and fatty acid profile in Holstein freemartin heifers. Eight Holstein freemartin heifers were randomly divided into a 4 × 4 Latin Square experiment with 2 × 2 factorial diets, with or without alfalfa or CSFA. Dietary supplementation of CSFA significantly increased the apparent digestibility of dry matter, crude protein, neutral detergent fiber, organic matter, and significantly reduced N retention (P < 0.05). CSFA increased the concentration of ammonia nitrogen in the ruminal fluid (P < 0.05), but alfalfa increased the concentration of valerate and isovalerate (P < 0.05). CSFA increased the concentration of ammonia nitrogen and the relative population of Streptococcus bovis in the rumen (P < 0.05) and inhibited the relative population of Ruminococcus flavefaciens, methanogens, and protozoa (P < 0.05). Alfalfa instead of Leymus chinensis increased the relative population of Butyrivibrio fibrisolvens and Ruminobacter amylophilus in the rumen (P < 0.05) and reduced the relative population of the Ruminococcus albus and Megasphaera elsdenii (P < 0.05). Supplemental CSFA increased the concentration of cholesterol and low-density lipoprotein cholesterol in the plasma (P < 0.05). And it also altered the composition of fatty acids in the plasma, which was expressed in reducing saturated fatty acid (ΣSFA) ratio and C14-C17 fatty acids proportion except C16:0 (P < 0.05) and increasing the proportion of polyunsaturated fatty acid (ΣPUFA) and unsaturated fatty acid (ΣUFA) (P < 0.05). The results showed that alfalfa and CSFA had interaction effect on the apparent digestibility of ether extracts, plasma triglyceride concentration, isobutyrate concentration, and Ruminococcus albus relative abundance in the rumen. It was concluded that alfalfa substituting Leymus chinensis did not change the apparent digestibility of nutrients in the final stage of fattening Holstein freemartin heifers, while CSFA increased the cholesterol and the proportion of unsaturated fatty acids in plasma. Alfalfa and CSFA had mutual interaction effect on fat digestion and plasma triglycerides.

Effect of calcium salt of long-chain fatty acids and alfalfa supplementation on performance of Holstein bulls

The purpose of this study was to assess the effects of calcium salt of long-chain fatty acids (CSFA) and alfalfa on beef cattle in the late fattening. 48 Holstein bulls were selected and randomly divided into 4 groups, feeding four dietary that Leymus chinensis with (LC) or with no (LN) 2.4% CSFA, and alfalfa replaced 50% Leymus chinensis with (AC) or with no (AN) 2.4% CSFA. The results indicated that alfalfa improved the feed conversion rate (P < 0.05). CSFA increased serum low density lipoprotein cholesterol, and reduced the cooking loss of Longissimus muscle (P < 0.05). CSFA and alfalfa reduced Acetate/Propionate. Alfalfa and CASF had significant additive effects on the apparent digestibility of dry matter, crude protein, neutral detergent fiber, acid detergent fiber, organic matter and rumen fermentation for acetate, isobutyrate, butyrate, isovalerate, total volatile fatty acids (P < 0.05). CSFA increased microbial diversity index when compared with alfalfa (P < 0.05), but no significant differences were detected in bacterial genera abundances among diets. The relative abundances of rumen bacterial genera have significant correlation with apparent digestibility of nutrients, rumen fermentation characteristics and serum biochemical parameters (P < 0.05). These results comprehensively evaluated the additive effects of alfalfa and CSFA on the application in Holstein bulls.