Diet-induced milk fat depression is associated with alterations in ruminal biohydrogenation pathways and formation of novel fatty acid intermediates in lactating cows (original) (raw)
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Diet, rumen biohydrogenation and nutritional quality of cow and goat milk fat
European Journal of Lipid Science and Technology, 2007
The potential to modify the milk fatty acid (FA) composition by changing the cow or goat diets is reviewed. Ruminal biohydrogenation (RBH), combined with mammary lipogenic and D-9 desaturation pathways, considerably modifies the profile of dietary FA and thus milk composition. The pasture has major effects by decreasing saturated FA and increasing FA considered as favorable for human health (c9-18:1, 18:3n-3 and c9t11-CLA), compared to winter diets, especially those based on maize silage and concentrates. Plant lipid supplements have effects similar to pasture, especially linseed, but they increase to a larger extent, simultaneously several trans isomers of 18:1 and, conjugated or non-conjugated 18:2, especially when added to maize silage or concentrate-rich diets. The goat responds better for milk 18:3n-3 and c9t11-CLA, and sometimes less for c9-18:1, and is less prone to the RBH trans-11 to trans-10 shift, which has been shown to be time dependent in the cow. The respective physiological roles of most milk trans FA have not been studied to date, and more studies in rodents and humans fed dairy products modified by changing ruminant diet are required before recommending a larger use of lipid sources and how to combine them with the different feeding systems used by dairy farmers.
Animal Feed Science and Technology, 2016
Fat sources, besides the energy-rich content, have featured beneficial effects on dairy cow production, reproduction and health. This work aimed to study the biohydrogenation process and fatty acid abomasal flow in lactating dairy cows fed different fat sources. Eight rumen and abomasum cannulated cows (188 ± 27.3 days in milk, 18.9 ± 3.24 kg of milk yield, and 572 ± 59.6 kg of body weight) were used in a 4 × 4 Latin square design. Control (CON) diet without fat source, soybean oil (SO), raw soybean grain (SG) and calcium salts of unsaturated fatty acids (CS) were evaluated. Fat sources decreased dry matter (DM), crude protein and neutral detergent fiber (NDF) intake and increased ether extract (EE) intake and ruminal pH (P < 0.05). Acetate to propionate ratio was lower in animals fed diets with fat (P < 0.05). Diets had no effect on microbial protein synthesis, and energy and nitrogen balances. NDF digestibility and DM passage rate were lower in animals fed diets with fat sources (P < 0.05), while protected sources (SG and CS) tended to increase ruminal fiber digestibility (P = 0.092) in relation to SO diet. Intake and abomasal flow of FA were higher (P < 0.05) for animals supplemented with fat sources than those fed CON. Protected sources (SG and CS) promoted greater abomasal flow of linoleic acid (C18:2) and lower biohydrogenation rate compared to the SO diet. Fat sources increased unsaturated milk fatty acids and serum cholesterol concentration while protected sources (SG and CS) increased milk C18:2 cis concentration (P < 0.05). Fat sources improved ruminal fermentation without compromise nutrients digestion and increasing fatty acids abomasal flow and milk concentration. Raw soybean grain had higher ruminal biohydrogenation protection than calcium salts.
Annales de Zootechnie, 2000
After a brief survey of metabolic pathways and nutrient fluxes involved in mammary lipogenesis, this review summarises the known effects of diet on ruminant milk fat composition. Special attention is given to fatty acids that could play a positive role for human health, such as butyric acid, oleic acid, C18 to C22 polyunsaturated fatty acids and conjugated linoleic acid (CLA). The efficiency of the transfer of C18:2, C18:3, C20:5, C22:5 and C22:6, from the duodenum to the milk, is reviewed. The main dietary factors taken into account are the nature of forages, including pasture, and the supplementation of dairy rations with protected or unprotected vegetable or fish oils. Dose-response curves of milk CLA are reviewed for different fat supplements, as well as the non-linear relationship between milk CLA and trans C18:1. The potential of dietary factors to increase the mean CLA content in cow milk fat is about 300% above basal values. There is, however, a need to evaluate how the different feeding strategies could change the other aspects of milk fat quality. ruminant / nutrition / milk / fatty acids / human health Résumé-Plasticité de la matière grasse du lait de ruminant : contrôle nutritionnel des acides gras saturés, polyinsaturés, trans et conjugués. Après un bref rappel des voies métaboliques et des flux de nutriments qui concourrent à la lipogenèse mammaire, cette revue est consacrée aux principaux effets des facteurs alimentaires sur la composition des lipides du lait de ruminant. Un intérêt particulier est porté aux acides gras qui peuvent avoir des effets positifs sur la santé humaine, tels que les acides butyrique, oléique, linoléique conjugué (CLA) et les acides gras polyinsaturés, de 18 à 22 atomes de carbone. L'efficacité du transfert des C18:2, C18:3, C20:5, C22:5 et C22:6, du duodénum au lait est estimée à partir des données de la bibliographie. Les principaux facteurs alimentaires considérés sont la nature des fourrages, dont l'herbe pâturée, et la supplémentation des rations pour vaches laitières avec des huiles végétales ou de poisson, protégées ou non. L'augmentation potentielle
2015
Effects of grain type and dietary oil supplement on milk fat depression, milk fatty acid (FA) profile, and lactational performance of dairy cows were evaluated using 8 multiparous Holstein cows in a duplicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Experimental diets contained either ground barley or ground corn supplemented with either fish oil or soybean oil at 2% of dietary dry matter (DM). Experimental diets contained 28.5 and 31.2% of cereal grain in cornand barley-based diets, respectively, as the sole source of grain. The forage component of the experimental diet was a mixture of corn silage (19.0% of DM) and alfalfa hay (21.0% of DM). Treatment periods were 25 d, with the final 7 d used for sample and data collection. Data were composited within period and subjected to MIXED MODEL procedure of SAS (SAS Institute, 2003) to account for effects of square, period within square, cow within square, treatments (grain type and oil supplement), an...
Ruminal Synthesis, Biohydrogenation, and Digestibility of Fatty Acids by Dairy Cows1
Journal of Dairy Science, 1991
Ruminal synthesis and biohydrogenation of fatty acids in dairy cows were determined by sampling duodenal digesta through T-cannulas. Fatty acid digestibility in the total tract also was measured. Five diets (concentrate:alfalfa hay:alfalfa haylage:corn silage, 2:1:1:1, DM) in a 5 × 5 Latin square contained either no added fat; 3 or 6% added calcium soap; or 3 or 6% animal-vegetable blend fat. Seventy percent of dietary fatty acids were recovered at the duodenum, and 106 g/d were synthesized in the rumen regardless of diets. Fatty acids synthesized in greatest amounts were odd or branched chains, whereas more than 90% of the fatty acids shorter than 14 carbons disappeared. Fatty acids in calcium soap were biohydrogenated 57% and in animal-vegetable blend 87%. Fatty acids in calcium soap were more digestible (80.0 vs. 75.7%) than those in the blended fat due to greater unsaturation in the small intestine. Ruminal microorganisms selectively synthesized fatty acids.
British Journal of Nutrition, 2008
Based on the potential benefits of cis-9,trans-11-conjugated linoleic acid (CLA) for human health there is interest in developing sustainable nutritional strategies for enhancing the concentration of this fatty acid in ruminant-derived foods. Most evidence to date suggests that endogenous synthesis is the major source of cis-9,trans-11 in milk fat and ruminal outflow is limited and largely independent of dietary 18 : 2n-6 supply. Four lactating cows fitted with a rumen cannula were used in a 4 £ 4 Latin square with 14 d experimental periods to examine the effects of sunflower-seed oil (SFO) as a source of 18 : 2n-6 on ruminal lipid metabolism. Cows were offered grass silage-based diets supplemented with 0, 250, 500 or 750 g SFO/d. Supplements of SFO had no effect on DM intake, milk fat or protein secretion, but increased linearly (P, 0·01) milk yield and milk lactose output and shifted (P,0·001) rumen fermentation towards propionate at the expense of acetate. SFO supplements increased linearly (P, 0·05) the flow of 18 : 0, 18 : 1, 18 : 2n-6 and total CLA at the omasum and enhanced ruminal cis-9-18 : 1, 18 : 2n-6 and 18 : 3n-3 metabolism. Flows of all-trans-(D4 -16) and cis-(D9 -16) 18 : 1 isomers were elevated, while increases in ruminal CLA outflow were confined to trans-8,trans-10 and geometric 9,11 and 10,12 isomers. It is concluded that supplementing grass silage-based diets with plant oils rich in 18 : 2n-6 enhances ruminal outflow of trans-11-18 : 1 and cis-9,trans-11-CLA in lactating cows.
Animal Feed Science and Technology, 2011
This experiment studied the influence of the diet structure value (SV) on ruminal biohydrogenation and milk fatty acid (FA) responses in cows fed heterogeneous basal diets equally supplemented with FA. Eight lactating Holstein cows were used in a replicated 4 × 4 Latin square design with four dietary treatments and four 21-day periods. The iso-fat, iso-18:2 n − 6 and iso-18:3 n − 3 diets were formulated to display three different SV, using different sources and proportions of forages, energy and nitrogen concentrates. The four diets contained maize silage as the main forage (SV1.2 diet), grass hay as the main forage (SV2.0 diet), maize silage and grass hay in a 4:1 ratio (SV1.6 M diet) or maize silage and grass hay in a 1:1 ratio (SV1.6H diet). The diets also contained soya bean meal and/or urea as additional sources of nitrogen, sugar beet pulp and barley in a 1:1 ratio as additional source of energy, extruded linseed as supplemental 18:3 n − 3, a mineral and vitamin mix and a vitamin E preparation. Wheat straw was added to the diets as additional structure source, except for the SV2.0 diet. Soya bean oil was added to the diets as supplemental 18:2 n − 6 to adjust the diets for this FA, except for the SV1.2 diet. The diets were distributed as a restricted total mixed ration. The various C18 FA expressed as 100 g of total C18 FA in milk fat are relevant indicators of ruminal biohydrogenation since duodenal concentrations of C18 FA follow similar changes as those in milk fat, and since these ratios only take into account FA involved in ruminal biohydrogenation. All the various C18 FA to total C18 FA in milk fat differed among diets (P < 0.05). Milk 18:2 n − 6 + 18:3 n − 3/total C18 FA and total trans-C18 FA/total C18 FA decreased from SV1.2 to SV2.0 diets, whereas 18:0/total C18 FA increased from SV1.2 to SV2.0 diets. Subsequently, transfer efficiencies of 18:2 n − 6 and 18:3 n − 3 from diet to milk were higher for the SV1.2 diet than for the other diets (P < 0.05). These results confirm the hypothesis that ruminal biohydrogenation is more complete with higher diet SV, which is consistent with results from other published experiments where high forage diets or grass silage compared to maize silage-based diets were used. This experiment showed that the concept of diet SV is a valid tool characterizing heterogeneous basal diets differing in sources and proportions of forages and concentrates.
Animal Feed Science and Technology, 2017
The objective of this study was to evaluate the effects of dietary fat supplementation on dry dairy cows feed intake, digestion, ruminal kinetics, biohydrogenation, and abomasal flow of fatty acids (FAs). Eight Holstein rumen and abomasum fistulated dry cows (average body weight of 614 ± 59 kg), were assigned to a replicated 4 × 4 Latin square design experiment, with 21-d periods. The experimental diets were: 1) control (CON): corn-and soybean meal-based diet, with no fat source; 2) soybean oil (SO) diet with 30 g/kg dry matter (DM) of soybean oil; 3) whole raw soybean (WS) diet with 160 g/kg DM of whole raw soybean grain; 4) calcium salts of fatty acids (CS) diet with 32 g/kg DM of calcium salts of unsaturated FA. Fat-supplemented diets increased ether extract intake and digestibility without affecting DM intake. However, these diets promoted a decrease in DM and neutral-detergent fiber (NDF) total tract apparent digestibility. Fat sources decreased ruminal acetate to propionate ratio (C2:C3). In addition, SO diet increased ruminal propionate concentration and decreased C2:C3 in relation to protected sources of FA (CS and WS). Furthermore, cows fed CS diet exhibited higher ruminal pH, NH 3-N and acetate concentration compared to those fed WS diet. Fatty acid supplementation did not alter serum glucose and urea concentration, but increased the serum cholesterol concentration. Although FA supplementation increased net energy intake of cows, energy and nitrogen balances, and microbial protein synthesis were not affected by the experimental diets. Fat supplementation had no effect on ruminal digestion neither on DM and NDF passage rates. Cows fed CS and WS diets presented higher DM and NDF ruminal digestion rates whether compared to SO one. Consequently, cows fed CS and WS had higher truly digestible NDF ruminal removal rate than those fed SO. Calcium salts of unsaturated FA increased DM and NDF rumen passage rate and decreased
Italian Journal of Animal Science, 2010
The effects on milk yield and quality caused by the same amount (325 g/d/cow) of lipids provided by 3 different fat sources (hydrogenate palm fat, HF; calcium salt palm fat, CaSF; full-fat toasted soybean, TS), top dressed to a common total mixed ration, were investigated. Supplementations did not affect feed intake and milk yield, but markedly changed the acidic profile of milk fat. CaSF and TS significantly increased the proportions of unsaturated fatty acids of milk fat with respect to control and to HF. The 3 fat sources did not affect the concentrations of ammonia and VFA of rumen fluid. TS only slightly increased (P<0.10) plasma urea content because of a higher dietary protein supply, with respect to the other treatments. The use of a low amount of toasted and cracked full fat soybean seem to be interesting to increase the energy concentration of diets in replacement to commercial fat products and it can be use to modify the milk fat quality increasing the fraction with benefit effects on human health.