Apparent Digestibility Of Fatty Acids Research Articles

Effects of abomasal infusions of fatty acids and 1-carbon donors on apparent fatty acid digestibility and incorporation into milk fat in cows

Our primary objective was to determine the effects of the abomasal infusion of 16-carbon (16C) and 22-carbon (22C) fatty acids (FA) on apparent FA digestibility, plasma FA concentrations, and their incorporation into milk fat in cows. Our secondary objective was to study the effects of 1-carbon donors choline and l-serine on these variables. Five rumen-cannulated Holstein cows (214 ± 4.9 d in milk; 3.2 ± 1.1 parity) were enrolled in a 5 × 5 Latin square experiment with experimental periods lasting 6 d. Abomasal infusates consisted of (1) palmitic acid (PA; 98% 16:0 of total fat), (2) PA + choline chloride (PA+CC; 50 g/d of choline chloride), (3) PA + l-serine (PA+S; 170 g/d of l-serine), (4) behenic acid (BA; 92% 22:0 of total fat), and (5) docosahexaenoic acid algal oil (DHA; 47.5% DHA of total fat). Emulsions were formulated to provide 301 g/d of total FA and were balanced to provide a minimum of 40 and 19 g/d of 16:0 and glycerol, respectively, to match the content found in the infused algal oil. Apparent digestibility of FA was highest in DHA, intermediate in PA, and lowest in BA. Digestibility of 16C FA was lowest in BA and highest in PA. The digestibility of 22C FA was highest in DHA relative to BA (99 vs. 58%), whereas 1-carbon donors had no effect on 22C FA digestibility. Plasma 16C FA concentrations were greatest with PA treatment, and 22C FA concentrations were ~3-fold greater in DHA-treated cows relative to all other treatments. Milk fat 16:0 content was highest in PA relative to BA and DHA (e.g., 37 vs. 27% in PA and DHA), whereas the milk yield of 16:0 was higher in PA relative to DHA (i.e., 454 vs. 235 g/d). Similarly, milk 22:0 content and yield were ~10-fold higher in BA relative to all other treatments, whereas DHA treatment resulted in higher content and yield of 22:6 in milk fat relative to all other treatments (41- and 38-fold higher, respectively). Consequently, the content of FA >16C (i.e., preformed) was higher in milk fat from cows infused with BA and DHA relative to PA. De novo FA content in milk did not differ between PA, PA+CC, and PA+S (~16% of milk fat) but was higher in BA and DHA treatments (19 and 21%, respectively). We conclude that FA carbon chain length and degree of saturation affected FA digestibility and availability for absorption as well as their incorporation into milk fat. The abomasal infusion of choline chloride and l-serine did not modify these variables relative to infusing palmitic acid alone.

Effects of dietary deoiled soy lecithin supplementation on milk production and fatty acid digestibility in Holstein dairy cows

Deoiled soy lecithin is a feed additive enriched in phospholipids. Our study evaluated the effects of dietary deoiled soy lecithin supplementation on (1) milk production and composition, (2) plasma and milk fatty acid (FA) content and yield, and (3) apparent FA digestibility and absorption in lactating dairy cows fed fractionated palm fat. In a split-plot Latin square design, 16 Holstein cows (160 ± 7 days in milk; 3.6 ± 1.2 parity) were randomly allocated to a main plot receiving a corn silage and alfalfa haylage-based diet with palm fat containing either moderate (MPA) or high palmitic acid (HPA) content at 1.75% of ration dry matter (72 or 99% palmitic acid, respectively; n = 8/palm fat diet). On each palm fat diet, deoiled soy lecithin was top-dressed at 0, 0.12, 0.24, or 0.36% of ration dry matter in a replicated 4 × 4 Latin square design. Following a 14-d covariate period, lecithin supplementation spanned 14 d, with milk and blood collected during the final 3 d. Milk composition and pooled plasma markers were measured. The statistical model included the fixed effects of palm fat type, lecithin dose, period, and the interaction between palm fat type and lecithin dose. The random effect of cow nested within palm fat group was also included. Lecithin linearly decreased dry matter intake. In cows fed HPA, lecithin feeding reduced milk fat content and tended to decrease milk fat yield. Although no changes in milk yield were observed, a quadratic reduction in 3.5% fat-corrected milk was observed with increasing lecithin dose. Lecithin linearly increased energy-corrected milk efficiency in cows fed MPA. Lecithin supplementation also decreased milk urea nitrogen, relative to unsupplemented cows. The proportion of 16-carbon FA in milk fat decreased linearly with lecithin dose, whereas 18-carbon FA increased linearly. Lecithin reduced de novo FA (<16-carbon) content and tended to increase preformed FA (>16-carbon) content in a linear manner. Compared with MPA, HPA diets reduced apparent total and 16-carbon FA digestibility and absorption. Deoiled soy lecithin feeding did not modify FA digestibility or absorption. Our observations suggest that soy lecithin feeding modifies rumen digestion to reduce dry matter intake and change milk composition.

Interactive effects of dietary fibre and lipid types modulate gastrointestinal flows and apparent digestibility of fatty acids in growing pigs.

A total of eight ileal and caecal cannulated Yorkshire barrows were used to determine the interactions of dietary fibre (DF) and lipid types on apparent digestibility of DM and fatty acids (FA) and FA flows in gastrointestinal segments. Pigs were offered four diets that contained either pectin or cellulose with or without beef tallow or maize oil in two Youden square designs (n 6). Each period lasted 15 d. Faeces, ileal and caecal contents were collected to determine apparent ileal digestibility (AID), apparent caecal digestibility and apparent total tract digestibility (ATTD) of dietary components. The interactions between DF and lipid types influenced (P &lt;0·05) the digestibility of DM and FA flows. The addition of maize oil decreased (P &lt;0·05) AID of DM in pectin diets, and the addition of beef tallow depressed (P &lt;0·001) ATTD of DM in cellulose diets. Dietary supplementation with beef tallow decreased (P &lt;0·05) the AID of FA in pectin-containing diets but had no effects in cellulose-containing diets. Dietary supplementation with beef tallow increased (P &lt;0·05) AID of SFA and PUFA and the flow of ileal oleic, vaccenic, linolenic and eicosadienoic acids and reduced the flow of faecal lauric, docosatetraenoic and docosapentaenoic acids in pectin- and cellulose-containing diets. In conclusion, the interaction between DF type and lipid saturation modulates digestibility of DM and lipids and FA flows but differs for soluble and insoluble fibre sources, SFA and unsaturated fatty acids and varies in different gastrointestinal segments.

Nutrient digestibility, egg quality, and fatty acid composition of brown laying hens fed camelina or flaxseed meal

SUMMARY Flaxseed and camelina are gaining popularity as feed ingredients because of their high content of α-linolenic acid (18:3n-3), an n-3 fatty acid. The current study was designed to evaluate apparent fatty acid and CP digestibility, AMEn, egg quality, and egg yolk fatty acids of brown egg layers fed a corn-soybean diet containing 10% camelina or flax meal. Experimental diets were isocaloric and isonitrogenous. A total of seventy-five 24-wk-old Lohman brown hens were randomly allocated to 3 treatments, with 5 replicates containing 5 hens in each replicate. The hens were fed a corn-soybean basal diet (control), or control diet with 10% camelina meal (CAM10) or flax meal (FLAX10) for a period of 12 wk. The apparent digestibility of fatty acids, CP, and AMEn were measured using celite (external inert marker). Egg quality parameters were determined every 28 d during the experimental period. The CP digestibility and AMEn were decreased (P < 0.05) in CAM10 and FLAX10 compared with control. Feeding CAM10 or FLAX10 resulted in higher egg production (P < 0.05) compared with the control. The egg weights and Haugh units increased, and eggshell thickness decreased significantly (P < 0.05) in FLAX10 birds. The egg yolk content of α-linolenic acid and total n-3 polyunsaturated fatty acids was higher in CAM10 than in other treatments (P < 0.05). α-Linolenic acid digestibility was lowest in FLAX10 birds. Feeding CAM10 reduced the digestibility of linoleic acid (18:2n-6) (P < 0.05). In general, inclusion of camelina and flax meal reduced CP digestibility and AMEn while increasing egg production in brown layers.

Effect of fat type and lysophosphatidylcholine addition to broiler diets on performance, apparent digestibility of fatty acids, and apparent metabolizable energy content

A completely randomized design study with a 3×2 factorial arrangement was conducted to evaluate the effects of three different fat sources (soybean oil, tallow, and poultry fat) with or without emulsifier supplementation on performance, coefficient of total tract apparent digestibility (CTTAD) of fatty acids, and apparent metabolizable energy (AME) content in broiler chickens. Two hundred and fifty-two one-day-old male Arbor Acres broiler chickens were randomly divided into 6 different treatments: (T1) basal diet containing soybean oil without lysophosphatidylcholine (LPC) supplementation, (T2) basal diet containing soybean oil with LPC supplementation, (T3) basal diet containing tallow without LPC supplementation, (T4) basal diet containing tallow with LPC supplementation, (T5) basal diet containing poultry fat without LPC supplementation, and (T6) basal diet containing poultry fat with LPC supplementation. Body weight gains from broiler chicks fed diets containing tallow were lower (P<0.05) than the body weight gains from chicks that were fed diets containing soybean oil or poultry fat in both the starter and grower periods. Birds fed diets containing tallow had the highest FCR (P<0.05), followed by the birds that were fed diets containing poultry fat, and soybean oil. The CTTAD of C16:0, C18:2, and C18:3n3 was greater (P<0.05) for broilers fed diets containing soybean oil than for those fed diets containing tallow or poultry fat in the starter period. The addition of LPC increased (P<0.05) body weight gain of broiler chickens in the starter period and the AME of the diets in the grower period, and tended to reduce FCR (P=0.072) in the starter period. LPC supplementation increased (P<0.05) the CTTAD of C16:0, C18:1n7 and C18:1n9 in the starter period, and of C18:2, and C18:3n3 in the grower period (P<0.05). There were no significant interactions between fat sources and the addition of LPC. These data indicated that LPC supplementation can improve body weight gain of broiler chickens in the starter period. This effect may be associated with an increase of CTTAD of FA due to LPC activity.

Rumen biohydrogenation of n-3 polyunsaturated fatty acids and their effects on microbial efficiency and nutrient digestibility in sheep

The study examined the extent to which n-3 PUFA from different sources were biohydrogenated in the rumen and their effects on rumen microbial efficiency and whole tract nutrient digestibility. Four ruminally and duodenally cannulated wether lambs were used in a 4×4 Latin square design. Four iso-energetic and iso-nitrogenous diets based on dried grass were formulated to provide similar fat levels (60g/kg DM) from different sources; Megalac (palmitic acid: C16:0; Control), whole linseed (α-linolenic acid, C18:3n-3 ; Linseed) fish oil (eicosapentaenoic acid, C20:5n-3, EPA and docosahexaenoic acids C22:6n-3, DHA; Fish oil) and whole linseed plus fish oil providing equal amounts of oil (LinFish). Diets were offered at a rate of 1·2kg/day in 12 equal portions.Total fatty acid intake was similar on all diets whilst duodenal fatty acid flow varied between 101, 94, 87 and 90% of dietary intake for animals fed the Control, Linseed, Fish oil and Linfish diets respectively. Duodenal flow of C18:3 n-3 in animals fed the Linseed diet was twice that of animals fed the Control diet (P &lt; 0·01) whilst animals fed the Fish oil diet had a significantly greater flow of EPA and DHA than those fed any of the other dietary treatments. Duodenal flow of trans C18:1 in animals fed the Linfish diet was significantly greater than that in animals fed either Linseed, Fish oil or Control diets (P &lt; 0·001). Biohydrogenation of C18:3n-3 was 80 to 93% in all diets whilst that of C20:5n-3 and C22:6n-3 was 72 to 79% in diets that contained fish oil or linseed and fish oil. Apparent fatty acid digestibility (duodenum to rectum) tended to be greater for unsaturated than saturated fatty acids whilst whole tract fatty acid digestibility (mouth to rectum) was significantly greater in animals fed diets containing fish oil (P0·05). All dietary n-3 PUFA sources decreased microbial protein synthesis and efficiency when expressed as either gN/kg organic matter (OM) apparently or truly degraded in the rumen. Additionally, the inclusion of fish oil increased the proportion of propionate in the rumen whilst depressing the rumen digestibility of OM and fibre (P &lt; 0·01), but had no significant effect on whole tract OM or fibre digestibility.

Utilization of fats based on the composition of sow milk fat in the diet of weanling pigs

Three dietary fats (A, B and C) were formulated by mixing various plant oils and animal fats so that their overall fatty acid composition would be similar to the fatty acid composition of sow milk fat. Dietary fat A was formulated to have a maximum concentration of palmitoleic acid (C16 : 1) and a similar ratio of saturated to unsaturated fatty acids as sow's milk. Dietary fat B was high in myristic acid (C14 : 0) and fat C was formulated by substituting the tallow part in formulation A with lard. Twelve crossbred male pigs, weaned at 27 days of age at a mean weight of 8.0 ± 0.5 kg, were allocated for 4 weeks to three dietary treatments, containing either A, B or C fat at 5%. The main experimental period was 4 weeks and for each week the digestibility of the dietary components was determined and the pig performance for each treatment evaluated. There were no significant differences among the treatments regarding the digestibility of dry matter, organic matter, crude fiber and nitrogen free extract. The digestibility of crude protein for treatments B (84.9%) and C (85.1%), was similar, but significantly higher compared to treatment A (82.7%), while there were no significant differences in nitrogen retention among the treatments. Apparent fat digestibility was significantly ( p ≤ 0.05) higher in treatment B (82%) followed by treatment C (79.9%) and treatment A (78.9%). The apparent digestibility of both fat and protein increased with respect to the age of the pigs, reaching their maximum values during the third experimental period. Apparent digestibility of fatty acids was high for all dietary treatments (77.6–90.2%), and significantly higher ( p ≤ 0.05) for those of treatment B. In all treatments only the stearic acid (C18 : 0) showed low digestibility (33.4–57.8%). There were no significant differences in average weight gain and the respective feed conversion ratios between treatments. In all treatments there was a large increase in the overall weight gain (a mean of approximately 23 kg), combined with an overall low feed conversion ratio (a mean of approximately 1.63). The experimental results indicate that dietary fat B was the most efficient in the diets of weaned and growing pigs.

Effects of Ruminally Inert Fat and Evaporative Cooling on Dairy Cows in Hot Environmental Temperatures

Under hot summer conditions of Tucson, Arizona, 24 Holstein cows (X¯ = 80 d of lactation) were assigned for 56 d to four treatments in a randomized block design with a 2 × 2 factorial arrangement of treatments. Factors were 1) medium [4.6% of dry matter (DM)] versus high (7.4% of DM) amounts of dietary fat and 2) corral shade only versus shade equipped with evaporative cooling. The high fat diet contained 3% prilled fatty acids. The efficiency of the conversion of feed to milk tended to be better for cows fed prilled fat than for cows fed medium dietary fat, but other lactation measurements were unaffected. Cows with access to evaporative cooling had greater milk yields than did cows with access to shade only. Prilled fatty acids did not depress the percentage of milk protein, but reduced short- and medium-chain fatty acids (C6:0 to C14:0) in milk fat and increased palmitic acid. Digestibilities of DM, organic matter, crude protein, acid detergent fiber, neutral detergent fiber, and starch were unaffected by amount of fat or by cooling method, but prilled fatty acids tended to decrease apparent digestibility of fatty acids. No differences were observed among treatments in respiration rates or rectal temperatures. When rectal temperatures were determined, cows were crowded, which probably negated detection of an effect of evaporative cooling. Evaporative cooling increased milk yield of cows in hot weather, but the addition of 3% fatty acids did not increase yield, and no interactions were observed.

Fatty Acid Digestion in Lactating Dairy Cows Fed Fats Varying in Degree of Saturation and Different Fiber Sources

Six cannulated cows were assigned to six treatments in a 6 × 6 Latin square design to evaluate the effects of fat saturation and amount and source of effective fiber on fatty acid metabolism. Cows were fed a control diet with no added fat or diets with 5% added fat from saturated tallow, tallow, or animal-vegetable fat; the diets with animal-vegetable fat had three percentages of effective fiber: 40% forage, 40% forage plus 20% soyhulls, or 60% forage. Cows fed diets supplemented with fat tended to have more disappearance of total fatty acids in the rumen than did those fed the control diet. Disappearance of fatty acids from the rumen, especially C16 and C18, was higher for cows fed the low fiber diet. The apparent digestibility of fatty acids in the small intestine was higher for cows fed the control diet than for those fed supplemental fat. Apparent digestibility also was reduced as fat saturation increased, primarily because of saturated tallow. Digestibility of C18:1 in saturated tallow was reduced, apparently in association with other saturated fatty acids. Fiber source had no effects on apparent intestinal digestibility of fatty acids. Concentrations of C18:0 and C18:1 in milk fat increased as the degree of fat saturation decreased, reflecting higher unsaturated C18 intake and ruminal biohydrogenation of polyunsaturated C18 fatty acids.

Assessment of the Effects of Iodine Value on Fatty Acid Digestibility, Feed Intake, and Milk Production

Data were pooled from 11 studies evaluating supplemental fat sources differing primarily in degree of saturation (tallow, animal-vegetable fat, vegetable oil. and hydrogenated fats). Data were standardized as proportions of the respective controls to reduce variation among individual studies and were subjected to stepwise multiple regression against the iodine value of fats, the percentage increases of total fatty acids in diets above the respective controls, or the ratio of total C16 to C18 fatty acids in fats (only for hydrogenated fats). Increased iodine value (increasing unsaturation) of fats increased apparent fatty acid digestibility, especially as iodine value increased from 11 to 27. For partially hydrogenated fat sources, as the ratio of C16 to Cl8 fatty acids increased, digestibility also increased, especially with increasing iodine value (positive interaction). Beneficial effects of higher C16:C18 ratio were reduced as amount of added fat increased (negative interaction). Dry matter intake and FCM production decreased as iodine value increased, perhaps because of inhibition of fiber digestion or metabolic regulation of DMI. Milk protein percentage depression averaged .2 percentage units for most fats. However, as partially hydrogenated fat sources became more saturated, milk protein depression appeared to be less evident; increased ratio of C16:C18 of fatty acids appeared to increase milk protein percentage. Despite the lower apparent digestibility of fatty acids of hydrogenated fats, increased milk production and percentages of fat and protein appeared to make them more economical than more unsaturated fats.

Effects of Roasting, Extrusion, and Particle Size on the Feeding Value of Soybeans for Dairy Cows

Ten multiparous Holstein cows were assigned to a replicated 5 × 5 Latin square (21-d periods) approximately 116 d postpartum. Squares one and two averaged 36.4 and 24.4kg of 4% FCM/d, respectively. Diets contained 45.1% alfalfa silage, 9.2% corn silage, and 45.7% concentrate (DM basis) fed for ad libitum intake as a TMR. Treatments were 1) rolled raw soybeans, 2) finely ground raw soybeans, 3) diet 2 with distillers dried grains, 4) roasted soybeans, and 5) extruded soybeans. Treatments 1, 2, 4, and 5 contained 15.7% of the ration DM as soybeans, averaging 4.1 kg/d of soybean DMI. Treatment 3 contained 12.6% of the ration DM as soybeans, with an average intake of 3.2 kg/d of soybeans. Yields of FCM, milk fat and protein, fat percentage, DMI, and rates of DM and NDF disappearance were not significantly affected by treatment. Milk protein percentage was highest for diet 1 and lowest for diets 4 and 5. Apparent digestibilities of nutrients in the whole tract usually were highest for cows receiving treatment 1. Fatty acid digestibility was depressed on diet 4. Rumen VFA and pH were not different, except that propionate concentrations and acetate:propionate ratios were highest for diets 4 and 5. However, acetate:propionate ratios never fell below 3.4 for any diet. Although roasting depressed apparent digestibility of fatty acids, processing of soybeans had little effect on lactation performance of dairy cattle.

Duodenal Rapeseed Oil Infusion in Early and Midlactation Cows. 1. Intestinal Apparent Digestibility of Fatty Acids and Lipids

Rapeseed oil was infused continuously into the duodenum of lactating dairy cows. Five separate trials were conducted with differences in amount of oil infused (1.0 to 1.5 kg/d), in lactation stage (early to late), and in basal diet (corn or grass silages). The effects of lecithin addition (9 g/d) also were studied.Oil infusion did not affect the apparent digestibility of defatted organic matter. Fatty acid, ether extract, and total lipid digestibilities in control cows were 62 to 82%, 72 to 76%, and 59 to 73%, respectively. Intestinal apparent digestibilities of oil fatty acid and ether extract fractions were estimated to be 63 to 74% and 67 to 81%, respectively. Intestinal apparent digestibility of oil total lipids was only 20 to 57% due to a significant increase in nonfatty acid lipid excretion (160 to 750 g/d above control cows), which sharply decreased the energy value of the infused oil. Lecithin did not modify apparent digestibility in oil-infused cows.

Energy utilization and blood traits of ponies fed fat-supplemented diets.

The digestibility and heat production values for three fats of different origin were determined. Four pony geldings (225 kg) were used in a study consisting of four successive digestion trials utilizing a 4 X 4 Latin square design. The four dietary treatments were basal alone and supplemented with 15% corn oil, blended fat or inedible tallow. The blended fat was composed of a mixture of animal and vegetable fats. A 7-d preliminary period preceded a 7-d total fecal collection period for each trial. Heat production values were obtained by indirect calorimetry and calculated from oxygen consumption data. Fat supplementation increased (P less than .05) dietary metabolizable energy from a basal value of 3,224 kcal.kg intake-1.d-1 to a mean value of 3,984 kcal.kg intake-1.d-1 for the three fat diets. No difference in heat production was observed among the diets, averaging 2,883 kcal.kg intake-1.d-1. Fats increased (P less than .05) the energy balance (metabolizable energy-heat production) approximately 88% over the basal. Corn oil and blended fat produced the greatest energy balance of the fats. Utilization of energy in fats, calculated by difference, was not different, but tended to be highest in blended fat and lowest in the corn oil. Apparent fatty acid digestibility increased (P less than .05) with the addition of fat to the basal, partially due to the dilution of endogenous fecal fat, but digestion coefficients were not different (P greater than .40) among the high fat diets.