Medium-chain Fatty Acids In Milk Research Articles

Long-Term and Carryover Effects of Supplementation with Whole Oilseeds on Methane Emission, Milk Production and Milk Fatty Acid Profile of Grazing Dairy Cows.

Simple SummaryDairy cow diets that include oils have shown potential to decrease methane emissions, which contribute to climate change. However, there is limited information on long-term interventions for animals in grazing systems. The aim of this study was to evaluate the effects of feeding oilseeds on the persistency of methane mitigation effects and milk production of dairy cows during a spring and summer grazing season. Carryover effects into autumn were studied. Eight weeks after beginning the feeding trial, cottonseed was more effective than linseed or rapeseed in decreasing methane per kilogram of ingested feed, but the mitigation effect did not persist when evaluated 11 weeks later. All oilseeds maintained milk production in spring, but in summer, milk yield was lower with cottonseed. There were no carryover effects of feeding oilseeds, once supplementation ended. Thus, adding oils to dairy cow diets through cottonseed supplementation had only a temporary effect on methane mitigation. This long-term study, conducted under grazing conditions, can help to assess how proposed interventions to mitigate methane can affect production and sustainability aspects of grazing dairy systems.Research is ongoing to find nutritional methane (CH4) mitigation strategies with persistent effects that can be applied to grazing ruminants. Lipid addition to dairy cow diets has shown potential as means to decrease CH4 emissions. This study evaluated the effects of oilseeds on CH4 emission and production performance of grazing lactating dairy cows. Sixty Holstein Friesian cows grazing pasture were randomly allocated to 1 of 4 treatments (n = 15): supplemented with concentrate without oilseeds (CON), with whole cottonseed (CTS), rapeseed (RPS) or linseed (LNS). Oilseeds were supplemented during weeks 1–16 (spring period) and 17–22 (summer period), and the autumn period (wk 23–27) was used to evaluate treatment carryover effects. Cows fed CTS decreased CH4 yield by 14% compared to CON in spring, but these effects did not persist after 19 weeks of supplementation (summer). Compared to CON, RPS decreased milk yield and CTS increased milk fat concentration in both spring and summer. In summer, CTS also increased milk protein concentration but decreased milk yield, compared to CON. In spring, compared to CON, CTS decreased most milk medium-chain fatty acids (FA; 8:0, 12:0, 14:0 and 15:0) and increased stearic, linoleic and rumenic FA, and LNS increased CLA FA. There were no carry-over effects into the autumn period. In conclusion, supplementation of grazing dairy cows with whole oilseeds resulted in mild effects on methane emissions and animal performance. In particular, supplementing with CTS can decrease CH4 yield without affecting milk production, albeit with a mild and transient CH4 decrease effect. Long term studies conducted under grazing conditions are important to provide a comprehensive overview of how proposed nutritional CH4 mitigation strategies affect productivity, sustainability and consumer health aspects.

Untargeted metabolomic investigate milk and ruminal fluid of Holstein cows supplemented with Perilla frutescens leaf

Milk compounds are important for human nutrient requirements and health. The ruminal metabolic profile is responsible for dietary nutrition and determines milk production. Perilla frutescens leaf (PFL) is a commonly used medicinal herb due to its bioactive metabolites. This study elucidated the effects of PFL on the metabolome of two biofluids (rumen fluid and milk) of 14 cows fed a basic total mixed ration diet (CON, n = 7) and supplemented with 300 g/d PFL per cow (PFL, n = 7) by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Milk PE-NMe (18:1(9Z)/18:1(9Z)) and DG (18:0/20:4(5Z,8Z,11Z,14Z)/0:0), oleanolic acid, and nucleotides were upregulated, and milk medium-chain fatty acids (2-hydroxycaprylic acid) were down-regulated in response to PFL. The supplementation of PFL increased the abundance of pyrimidine nucleotides both in rumen fluid and milk. The pathways of pyrimidine metabolism and biosynthesis of unsaturated fatty acids were enriched both in the rumen fluid and milk. We also found the milk 2-hydroxycaprylic acid was positively correlated with ruminal uridine 5-monophosphate, and was negatively correlated with ruminal deoxycytidine, and the milk thymidine was positively correlated with ruminal icosenoic acid. This study found that the supplementation of PFL could alter the ruminal metabolic profiles and milk synthesis through regulation of the pathways of pyrimidine metabolism and biosynthesis of unsaturated fatty acids. Our new findings provide comprehensive insights into the metabolomics profile of rumen fluid and milk, supporting the potential production of Perilla frutescens milk in dairy cows.

Impact of maternal dietary n-3 and n-6 fatty acids on milk medium-chain fatty acids and the implications for neonatal liver metabolism

Levels of n-6, n-3, and medium-chain fatty acids (MCFA) in milk are highly variable. Higher carbohydrate intakes are associated with increased mammary gland MCFA synthesis, but the role of unsaturated fatty acids for milk MCFA secretion is unclear. This study addressed whether n-6 and n-3 fatty acids, which are known to inhibit hepatic fatty acid synthesis, influence MCFA in rat and human milk and the implications of varying MCFA, n-6, and n-3 fatty acids in rat milk for metabolic regulation in the neonatal liver. Rats were fed a low-fat diet or one of six higher-fat diets, varying in 16:0, 18:1n-9, 18:2n-6, 18:3n-3, and long-chain (LC) n-3 fatty acids. Higher maternal dietary 18:2n-6 or 18:3n-3 did not influence milk MCFA, but lower maternal plasma triglycerides, due to either a low-fat or a high-fat high-LC n-3 diet led to higher milk MCFA. MCFA levels were inversely associated with 18:1n-9, 18:2n-6, and 18:3n-3 in human milk, likely reflecting the association between dietary total fat and unsaturated fatty acids. High LC n-3 fatty acid in rat milk was associated with lower hepatic Pklr, Acly, Fasn, and Scd1 and higher Hmgcs2 in the milk-fed rat neonate, with no effect of milk 18:1n-9, 18:2n-6, or MCFA. These studies show that the dietary fatty acid composition does not impact MCFA secretion in milk, but the fatty acid composition of milk, particularly the LC n-3 fatty acid, is relevant to hepatic metabolic regulation in the milk-fed neonate.

Effects of a potato pulp silage supplement on the composition of milk fatty acids when fed to grazing dairy cows

This study was completed to determine the effects of potato pulp silage (PPS) as a diet supplement on the composition of milk fatty acids in grazing dairy cows in comparison to a barley grain supplement. Eight late lactation Holstein dairy cows were fed grazing based diets supplemented with 150 g/kg of PPS (‘PPS’) as a substitute for barley (‘barley’), and grazed on 4.3 ha swards, mainly containing orchard grass, for 56 days. Total dry matter (DM) and pasture DM intake and milk yields, as well as milk composition, did not differ between treatments. The linolenic acid intake did not differ (329 g/day vs. 323 g/day DM). The trans11C18:1vaccenic acid (VA) concentration in blood was higher in cows fed PPS (2.4 g/100 g FA) compared to those fed barley (1.9 g/100 g FA). There were no differences between treatments in the cis9 trans11conjugated linoleic acid (CLA) concentration in blood. The short-chain and medium-chain fatty acids in milk also did not differ between treatments. The VA concentration in milk was increased in cows fed PPS (2.32 g/100 g FA) compared to those fed barley (1.84 g/100 g FA), and CLA was higher in cows fed PPS (1.25 g/100 g FA) than those fed barley (0.95 g/100 g FA). Milk CLA concentration was positively correlated to blood VA concentration. Results suggest that an increase in milk CLA concentration is related to an increase of the VA concentration in blood by Δ 9-desaturase in mammary glands in the PPS fed compared to barley fed groups.

Dietary molasses enhancesruminal biohydrogenationand partially alleviates diet-induced milk fat depression (2008)

Milk fat depression remains a problem on dairy farms, and in recent years, incorporation of distillers grains (typically with solubles added and often dried) has contributed to this problem on some farms. In this study, we evaluated whether molasses could prevent milk fat depression in cows fed a high-risk diet. Replacing up to 5% of dietary corn with cane molasses linearly increased the yield of short- and medium-chain fatty acids in milk, indicating a positive effect on de novo fatty acid synthesis in a milk fat depression environment. Molasses, however, tended to linearly decrease milk yield and linearly decreased milk protein yield, resulting in no net effect on energy- or solids-corrected milk yield. These results indicate that the potential exists for sources of dietary sugar to prevent milk fat depression, but further research is needed to determine when sugar sources might be most effective.; Dairy Day, 2008, Kansas State University, Manhattan, KS, 2008; Dairy Research, 2008 is known as Dairy Day, 2008

Adaptations of Mammary Uptake and Nutrient Use to Once-Daily Milking and Feed Restriction in Dairy Cows

The aim of this study was to gain a clearer understanding of the different levels of regulation involved in the reduction in milk yield in response to once-daily milking and feed restriction. The treatments were designed as a 2×2 factorial arrangement of 2 milking frequencies (once- or twice-daily milking) and 2 feeding levels (70 or 98% of requirements determined 1 wk before the trial). The cows were surgically prepared to study the net mammary balance of the nutrients that are precursors of milk components. Mammary efficiency in synthesizing milk components was estimated using a milk output:mammary uptake ratio. No interaction was observed between the effects of milking frequency and feeding level on milk and blood parameters except for milk protein yield, milk fatty acid profile, and nonesterified fatty acids metabolism. Once-daily milking and feed restriction reduced milk yield by 5.1 and 2.9 kg/d and fat-corrected milk yield by 4.2 and 4.1 kg/d, respectively. Both treatments induced a decrease in mammary blood flow. Once-daily milking led to a reduction in the extraction rate of glucose but no changes to the lactose output:glucose uptake ratio. Feed restriction did not change the glucose extraction rate but tended to improve the lactose output:glucose uptake ratio. Under once-daily milking, the slight increase in milk fat content (0.34 percentage units) was linked to a depressed uptake of glucose and acetate but without any variations in the uptake of β-hydroxybutyrate and total glycerol and in the efficiency of acetate and β-hydroxybutyrate conversion to short- and medium-chain fatty acids in milk. The decline in milk fat and protein contents (−0.43 and −0.23 percentage units, respectively) under feed restriction was associated with relatively similar reductions in the mammary uptake of all nutrients and with enhanced conversion of the glucose taken up by the mammary gland and used for lactose synthesis. As a result, once-daily milking and feed restriction seem to affect milk yield through mechanisms that may be different and relatively independent.

Effect of Added Dietary Fat on Performance, Rumen Characteristics, and Plasma Metabolites of Midlactation Dairy Cows

Effects of supplemental Jet-Sploded® canola seed in the diets of dairy cows on milk yield and composition and blood metabolite concentrations were investigated. Twenty multiparous and 5 primiparous midlactation Holstein cows were assigned to treatments following a 3-wk covariate period; cows were then on the treatments for 70 d. Ten of the cows had previously been fitted with rumen cannulas. Five concentrate mixtures containing 0, 7.5, 15, 22, or 29% Jet-Sploded® canola seed (Simons Feed Co., Quimby, IA) (equivalent to 0, 2.66, 5.33, 7.81, and 10.30% added fat, respectively) were formulated by substituting Jet-Sploded® canola seed for barley and canola meal. Diets consisted of 25% alfalfa silage, 25% whole-crop oat silage, and 50% of one of the concentrate mixtures (dry matter basis). An increase in the amount of dietary fat from Jet-Sploded® canola seed did not influence feed intake, milk yield or composition, or milk component yields. The inclusion of Jet-Sploded® canola seed in the diet increased long-chain fatty acids and inhibited de novo synthesis of medium-chain fatty acids in milk. Mean total volatile fatty acids in the rumen and propionate concentration were reduced in a linear fashion by treatment. The inclusion of Jet-Sploded® canola seed in the diets of midlactation cows altered rumen and blood metabolite concentrations; however, these changes had minimal effects on yield responses with the exception of milk fatty acid composition and milk protein content.

Importance of milk and diet on the ontogeny and adaptation of the intestine.

Importance of milk and diet on the ontogeny and adaptation of the intestine.

Duodenal Infusion of Rapeseed Oil in Midlactation Cows.6. Interaction with Niacin on Dairy Performance and Nutritional Balance

Rapeseed oil and niacin, alone or in combination, were infused continuously into the proximal duodenum of ruminally and duodenally fistulated midlactation cows in a 4 × 4 Latin square design. Although niacin in plasma was higher for cows infused with niacin no significant effect occurred on milk production and composition. When cows were infused with oil, milk production and fat content were unchanged, milk protein content was decreased, and lactose content was increased. The magnitude of decrease in the percentage of mediumchain fatty acids in milk of cows infused with oil was similar to the magnitude of the increase in the long-chain fatty acids of milk. Except for the decrease in milk C4:0 and the increase in C14:0 and C14:1 percentages, niacin did not exert a significant influence on the fatty acid profile of milk. Oil-free DMI tended to decrease in the cows that were infused with oil, but nutrient digestibility was unchanged with all infusates. Energy and protein intake and energy balance were similar, but protein balance tended to be higher with oil infusion. However, body condition score was decreased by oil infusion.For midlactation cows that received oil infusion, the limitation in DMI or the direct effect of absorbed fatty acids limited milk protein synthesis and body condition score. Effectiveness of postrumind niacin (alone or with oil) at midlactation is questioned.

Effects of adding medium-chain triglycerides to sow diets during late gestation and early lactation on litter performance1

This experiment was conducted to determine whether feeding medium-chain triglycerides (MCT) to sows during late gestation and early lactation would improve neonatal pig survival. Beginning on d 91 of gestation and continuing through d 7 of lactation, sows were fed isoenergetic (7,000 kcal of ME/d) and isonitrogenous (278 g of CP/d) amounts of either control (19% starch, 2% soybean oil), long-chain triglycerides (LCT, soybean oil, 12%), or MCT (10% MCT, 2% soybean oil) diets. Sows (n = 18, 19, and 17, respectively) were induced to farrow on d 112 of gestation. Litters were weighed at birth, before suckling, and on d 1, 3, 7, and 21 of lactation. There was no effect of treatment on average pig weight at any time and no difference in the number of live pigs at birth. Beginning on d 3 (P < .05) and continuing through weaning (d 21, P < .02) survival was improved in litters from sows fed MCT relative to litters from sows fed the control diet. Overall survival rates were 80, 81, and 90% in control, LCT, and MCT groups, respectively. The greatest improvement in survival was observed in pigs weighing < 900 g at birth. Survival of pigs in this weight range was 32, 53, and 68% in control, LCT, and MCT treatments, respectively. Although feeding MCT resulted in an increase in content of medium-chain fatty acids in milk, these accounted for < 5% of the fatty acids in milk and likely cannot account for the improved survival rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in the concentration of metabolites in milk from cows fed on diets supplemented with soyabean oil or fatty acids.

Cows were fed on diets supplemented with soyabean oil or soyabean fatty acids which in some cases were protected from rumen hydrogenation. The fat-containing diets reduced the output of short- and medium-chain fatty acids in milk. Associated with this fall in short- and medium-chain fatty acids was a decrease in the concentration of 2-oxoglutarate and an increase in that of isocitrate and citrate. Protection of polyunsaturated fat from rumen hydrogenation had no significant effect. Milk yields were unaffected by diet, but the variation in milk yield among cows correlated positively with the concentration of glucose in milk.