Effect Of Fat Supplementation Research Articles

Effects of different fat sources and levels on the fatty acid composition in different tissues of laying hens

To examine the effects of supplemental fat on fatty acid (FA) compositions of some tissues, laying hens were fed diets containing different fat sources (tallow, mixture of tallow and flaxseed oil [1:1], sunflower oil, flaxseed oil) and levels (2% or 4%); 360 Isa Brown hens were assigned to one of the nine diets. The dietary FA composition was reflected in the FA composition of tissue lipids. The supplemental tallow oil increased concentrations of saturated fatty acids. The proportions of linoleic and arachidonic acids in all tissues for laying hens fed a diet containing sunflower oil (SO) were higher than the other diets. Moreover, increasing the SO level increased the n-6 FAs content. Also, dietary flaxseed oil significantly increased the content of linolenic and other n-3 FAs in most studied tissues. These results indicated that desirable changes can be achieved in FA compositions of poultry meats by using various animal and plant fats in poultry diets.

The value of different fat supplements as sources of digestible energy for lactating dairy cows

The effects of fat supplements that differed in fatty acid composition (chain length and degree of saturation) and chemical form (free fatty acids, Ca salts of fatty acids, and triacylglyceride) on digestible energy (DE) concentration of the diet and DE intake by lactating cows were measured. Holstein cows were fed a control diet [2.9% of dry matter (DM) as long-chain fatty acids] or 1 of 3 diets with 3% added fatty acids (that mainly replaced starch). The 3 fat supplements were (1) mostly saturated (C18:0) free fatty acids (SFA), (2) Ca-salts of fatty acids (CaFA), and (3) triacylglyceride high in C16:0 fatty acids (TAG). Cows fed CaFA (22.8kg/d) consumed less DM than cows fed the control (23.6kg/d) and TAG (23.8kg/d) diets but similar to cows fed SFA (23.2kg/d). Cows fed fat produced more fat-corrected milk than cows fed the control diet (38.2 vs. 41.1kg/d), mostly because of increased milk fat percentage. No differences in yields of milk or milk components were observed among the fat-supplemented diets. Digestibility of DM, energy, carbohydrate fractions, and protein did not differ between diets. Digestibility of long-chain fatty acids was greatest for the CaFA diet (76.3%), intermediate for the control and SFA diets (70.3%), and least for the TAG diet (63.3%). Fat-supplemented diets had more DE (2.93Mcal/kg) than the control diet (2.83 Mcal/kg), and DE intake by cows fed supplemented diets was 1.6Mcal/d greater than by cows fed the control, but no differences were observed among the supplements. Because the inclusion rate of supplemental fats is typically low, large differences in fatty acid digestibility may not translate into altered DE intake because of small differences in DM intake or digestibility of other nutrients.

Effect of Fat Supplementation on the Maintenance of Gut Integrity in Elemental Diet-Fed Rats

The aims of this study were to investigate the mechanism of atrophic change in ileal mucosa supplied with an elemental diet (ED) and to assess the value of supplemented fat emulsion in the prevention of atrophic change. In experiment 1, 25 male Wistar rats with a body weight of 160-180 g were divided into 3 groups. The first group was fed regular rat chow (Control group, n=5). The second group was given ED containing 0.6% long-chain triglycerides (ED group, n=10). The third group was provided with fat-enriched ED (FED) containing 3.5% long-chain triglycerides (FED group, n=10). Each group received an isocaloric diet (300 kcal/kg/day). 4 weeks later, after euthanization, ileal samples were taken for light and electron microscopic examinations. The morphological changes of the intestinal mucosa and the crypt cell proliferation rate (CCPR) were determined. In experiment 2, to determine the site of fat absorption, 9 rats were fed ED for 1 week. After 24 h of food deprivation, all rats were given 2 ml of FED through a gastric tube. Then 1, 2, and 3 h(s) later, groups of 3 rats each were euthanized, and the total small intestine was obtained from each rat. The proximal and distal jejunum and distal ileum were stained with oil red O. In experiment 1, the samples had almost the same morphological appearance irrespective of the type of feeding. The CCPR was significantly diminished in the ED group compared with the Control group, while there was no statistical difference between the FED and Control groups. In experiment 2, the oil red O stain was positive in the proximal and distal jejunum, but was completely negative in the distal ileum. The introduction of ED does not soon result in an atrophic morphological change of the ileum but will decrease the CCPR. An additive fat emulsion which was rapidly absorbed by the distal jejunum could play a role in maintaining ileal mucosa integrity through some mechanism independent of absorption.

Effects of Fat Supplementation on Postprandial GIP, GLP-1, Ghrelin and IGFBP-1 Levels: A Pilot Study on Adolescents with Type 1 Diabetes

Aims: To compare the responses of GIP, GLP-1, ghrelin and IGFBP-1 between meals with different fat and energy content in adolescents with type 1 diabetes (T1DM) and to relate them to gastric emptying and glycaemia. Methods: On different days and in a random order, 7 adolescents with T1DM ingested a high- and low-fat meal (fat content: 38 and 2 g, energy content: 640 and 320 kcal, respectively). At normoglycaemia, the same prandial insulin dose was given at both meals and to all subjects. Postprandial blood samples were taken repeatedly over 4 hours. Gastric emptying was estimated by the paracetamol absorption method. Results: The area under the curve (AUC) for GIP_{0–240 min} and for GLP-1_{0–120 min} was larger, but smaller for relative ghrelin_{0–240 min}, after the high-fat meal (p = 0.002, 0.030 and 0.043, respectively). IGFBP-1 decreased significantly, but not differently, after the meals. Larger GLP-1 secretion correlated with slower gastric emptying (p = 0.029) and higher fasting ghrelin levels correlated with lower postprandial glycaemia (p = 0.007). Conclusion: In adolescents with T1DM, the postprandial responses of GIP, GLP-1 and ghrelin, but not that of IGFBP-1, depend more on meal size than on insulin.

Consumo, digestibilidade e produção de cabras leiteiras alimentadas com dietas contendo diferentes fontes de lipídios

This study used 12 Saanen goats with BW of 35 kg and daily milk production of 1.2 kg, in order to evaluate the effect of fat supplementation on the intake, digestibility and milk yield. Four animals were fistulated in the rumen for pH observation. The treatments consisted of a control diet and three diets supplemented with faveleira seed, faveleira cake and cotton seed. The data were analyzed in 4 x 4 chi squares, with three repetitions and the statistical analyses by Tukey's test at 5% probability. Fat supplementation decreases the intake of dry matter and of most nutrients, affecting milk yield and the composition of Saanen goat milk. Supplementation with faveleira cake and cotton seeds can be considered as an alternative feed for those animals.

Short-term effects of a moderate fish oil or soybean oil supplementation on postprandial glucose and insulin responses in healthy horses

The aim of this study was to investigate the effects of fat supplementation on postprandial glycaemic and insulinaemic responses in horses fed a corn meal. Four horses were fed three different diets: (1) cracked corn (CC), (2) cracked corn with soybean oil (CC+SBO), and (3) cracked corn with fish oil (CC+FO). Each diet was adjusted so there was a starch intake of 2 g/kg bodyweight (BW) and an intake of 0.2 mL/kg BW of FO and SBO. The increases in mean plasma glucose and insulin concentrations, peak values, and areas under the curve were similar for all diets (time P<0.05, diet not significant). The addition of FO or SBO at 0.2 mL/kg BW to a starchy meal did not affect acute glucose and insulin responses. To avoid high postprandial glycaemic and insulinaemic responses feeding strategies should be designed primarily to reduce starch intake rather than the addition of fat.

Effects of fat supplementation on glycaemic response and gastric emptying in adolescents with Type 1 diabetes

To compare the glycaemic response to meals with different fat content in adolescents with Type 1 diabetes mellitus (T1DM) and to investigate associations with gastric emptying. In this randomized, cross-over study, paired results were obtained from seven adolescents with T1DM who ingested on different days two meals with the same carbohydrate and protein content, but different fat and energy content (2 and 38 g fat, 320 and 640 kcal, respectively). Paracetamol was mixed into the meals and gastric emptying was estimated by the paracetamol absorption method. All subjects were normoglycaemic and given 7 IU insulin aspart at commencement of ingestion. Postprandial blood samples were taken during 4 h. The areas under the curves for plasma glucose and serum paracetamol concentrations were larger after the low-fat than after the high-fat meal during the first 2 h (P = 0.047 and P = 0.041, respectively). The difference between meals in time-to-peak in glucose and paracetamol concentrations did not reach statistical significance (high-fat vs. low-fat meal: 210 min (120-240) vs. 120 min (50-240), P = 0.080 and 120 min (75-180) vs. 60 min (60-120), P = 0.051, respectively). Changes in glucose concentrations correlated with simultaneous changes in paracetamol concentrations (P < 0.001). For the first time, we have shown that the initial glycaemic response is reduced after a meal with higher compared with a meal with lower fat content in adolescents with T1DM given a rapid-acting insulin analogue preprandially. The type and dose of preprandial insulin may need adjustment to the fat content of the meal to reach postprandial normoglycaemia.

Effects of supplemental fat on growth performance and quality of beef from steers fed corn finishing diets1

To measure the effects of dietary fat on feedlot performance and carcass characteristics, and on beef appearance, moisture binding, shelf life, palatability, and fatty acid content, 126 crossbred beef steers (321.1 +/- 0.57 kg of BW) were allotted to a randomized complete block (3) design with a 3 x 2 + 1 factorial arrangement of dietary treatments. The main effects were level of yellow grease (0, 3, or 6%) and alfalfa hay (3.5 or 7%) in corn-based diets containing 15% potato by-product (PB). The added treatment was 6% tallow and 7% alfalfa in a barley-based diet containing 15% PB. Dry matter intake and ADG were not affected by diet; however, G:F and diet NE content increased linearly (P < 0.10) with yellow grease. Kidney, pelvic, and heart fat (2.0 to 2.3 +/- 0.07) and yield grade (2.8 to 3.1 +/- 0.09) increased linearly (P < or = 0.05) with yellow grease. Steers fed corn plus 6% yellow grease had lower (P < 0.05) beef firmness and beef texture scores but greater (P < 0.01) fat color score than those fed barley plus 6% tallow. Moisture retention of beef was not affected by dietary treatment, except purge score during retail storage, which was decreased linearly (P < 0.01) from 2.1 to 1.6 +/- 0.06 by level of yellow grease. Steaks from steers fed barley plus 6% tallow had greater (P < 0.05) shear force than those from steers fed corn plus 6% yellow grease, and beef flavor increased linearly (P < 0.05) from 6.2 to 6.7 +/- 0.11 as the level of yellow grease increased. Level of yellow grease linearly increased (P < 0.01) transvaccenic acid (TVA) by 61% and CLA content of beef by 48%. Beef from steers fed corn plus yellow grease had lower (P < 0.05) palmitoleic and oleic acids and greater (P < 0.05) linoleic, TVA, and CLA than beef from steers fed the barley-tallow diet. Feeding yellow grease increased diet energy content, which increased carcass fatness, and altered beef fatty acid content, which increased beef flavor without affecting moisture retention, shelf life, or cooking properties of the beef. Additionally, beef from steers fed corn plus 6% yellow grease was more tender and had more polyunsaturated fatty acid content and CLA than beef from steers fed barley plus 6% tallow.

Growth and development of offspring following supplementation of sow diets with oil during mid to late gestation

This study aimed to determine the consequences of altering the fatty acid profile of sow diets during mid-to-late gestation; oils of different fatty acid composition were chosen as energy supplements to provide diets with different fatty acid profiles. Forty-eight multiparous sows were used to evaluate the effects of fat supplementation from day 60 of gestation until parturition. Sows were allocated to either 3 kg/day of commercial sow pellets (control; C) or an experimental diet consisting of 3 kg/day of commercial sow pellets supplemented with 10% extra energy in the form of excess pellets (E), palm oil (P), olive oil (O), sunflower oil (S) or fish oil (F). From days 0 to 60 of gestation, all sows were given 3 kg/day of sow pellets as for the C group. The E diet resulted in the heaviest piglets at birth whereas the offspring of O and S sows were the lightest at birth. The offspring of S sows remained lighter throughout the pre-weaning period, and were also the leanest by 14 days of age. In contrast, pigs born to S sows possessed more fat by the time they reached commercial end point (≈140 days of age). In conclusion, altering the fatty acid profile of the sow diet during the second half of gestation has long-term consequences for the development of their offspring.

Effect of feeding different sources of fat during gestation and lactation on reproduction of beef cows and calf performance

Experiment 1: Over a 2-yr period, a total of 231 Angus crossbred cows were assigned randomly to one of three gestation diets to evaluate the effects of fat sources on birth weight, weaning weight and average daily gain of calves, calf condition at birth, calf mortality, body weight of cows, gestation length, calving percentage, and the percentages of retained placenta and dystocia. Isonitrogenous and isoenergetic supplements were based on whole flaxseed (FLA), calcium salts of palm oil (Megalac®, MEG) or no fat (CON). All cows were fed grass silage (90% of ad libitum intake) until 1 mo before calving. Cows were then fed grass silage for ad libitum intake until they were put on pasture. Cows were offered 600 g of supplement per head per day starting 43 d before the first calving for a period averaging 78 d. Diet had no effect on body weight (BW) of cows at calving. Birth weights of calves were similar among treatments. However, calf mortality percentage at birth was almost four times higher (P = 0.03) for cows fed CON compared with those fed FLA and MEG. More than 90% of cows rejected placenta within 12 h of calving and treatment had no effect. Cows fed FLA and CON tended (P ≤ 0.10) to have higher cumulative pregnancy rates (92.9 and 91.9%, respectively) than those fed MEG (76.7%). Experiment 2: From 2000 Jan. 19 to 2000 Sep. 05, 41 heifers received 600 g per head per day of one of the three supplements used in exp. 1 to determine the effect of fat supplementation during pregnancy and breeding. Diet had no effect on calf birth weight, but contrasts indicated that heifers fed MEG tended (P = 0.09) to have a lower pregnancy rate than those fed CON. These data suggest that cows and heifers fed grass silage and/or on pasture would not be deficient in omega 3 fatty acids, thus would not benefit from a supplement rich in omega 3 fatty acids such as flaxseed. However, fat supplementation contributed to lower calf mortality at birth in cows, but not in heifers. Key words: Beef, flaxseed, reproduction, fatty acids

Effect of fat supplementation on nitrogen utilisation of lambs and nitrogen emission from their manure

The effects of various fats on nitrogen digestion and metabolism of lambs and their manure were investigated in six isoenergetic diets ( n = 6) with similar contents of absorbable protein. Treatments were either a control diet or diets containing 25 g/kg of additional ether extract from rumen-protected fat, coconut oil, rapeseed, sunflower seed or linseed. Fat supplementation resulted in trends for higher apparent nitrogen digestibilities (significant with coconut oil; P < 0.05, post hoc test) and body nitrogen retention ( P < 0.1). Urinary nitrogen losses and their proportion of manure nitrogen did not differ significantly among groups as was also true for C / N ratio, dry matter, nitrogen and ammonia nitrogen contents of the manure. In the first week of manure storage, most fat supplements tended to decrease gaseous nitrogen emission as assessed by respiration chamber and mass balance measurements. These differences tended to be mitigated after 7 weeks of manure storage. Only the coconut-oil treatment still resulted in numerically lower nitrogen emissions. In conclusion, addition of fat source in the diet, in addition to increasing dietary energy and suppressing methanogenesis, can under certain circumstances decrease gaseous nitrogen emission from the manure.

Effects of Supplemental Fat on Performance of Laying Hens

2 Abstract: 360 Hy-line W36 hens were fed the diets with four different levels of fat (0, 1.5, 3.0 and 4.5%) to determine different levels of supplemental fat on performance of laying hens from 35 to 44 week of age. Hy- line W-36 hens at 35 week of age were randomly assigned into 4 dietary treatments (6 replicates of 15 birds per treatment). As fat level increased, feed intake linearly decreased from 99.1 to 93.5, resulting a 5.7 % decrease in feed intake. As fat level increased, feed conversion linearly decreased. Increasing fat had no effects on egg production, egg weight, egg mass, egg specific gravity, and body weight of laying hens. Increasing fat improved nutrient (protein, amino acids, calcium, and phosphorus) utilization. It may be a good choice to supplement high level of fat to improve protein (amino acids) utilization and to decrease cost of production especially when fat price is cheap and prices of protein source ingredients are expensive.

232 EFFECT OF DIETARY FAT SUPPLEMENTATION ON OOCYTE AND EMBRYO QUALITY AND ON EARLY EMBRYONIC DEVELOPMENT OF SHEEP

The objective was to evaluate the effect of fat supplementation on oocyte quality and in vitro embryonic development (48 h). A total of 18 ewes, with a body condition score of 2.5 to 3 points out of 5, having had three to four lamb births, and at three to four months post-lamb birth, were distributed between an experimental oil group (OG; n = 9) that received corn oil (4% of the MS/diet) and a control group (CG; n = 9) that didn't receive oil. The two groups were maintained in confinement for 21 days (the duration of the experiment) and fed first with a concentrate diet followed by forage. The animals had access to minerals and water ad libitum. The diets were similar in energy (10.3 ± 0.05 MJ/s/d) and protein (141.75 ± 5.7 gPC/s/d) for both groups. The estrous cycle was synchronized (14 days) with intravaginal sponges (40 mg of fluorogestone acetate), inserted 7 days after the beginning of the diets. The end of the diet coincided with the retirement of the sponges. One day before sponge retirement, 75 mg prostaglandin F2α per sheep was administered, followed by ovarian stimulation with 1000 IU of pregnant mare serum gonadotropin (PMSG). Follicular diameter was determined by ventral laparotomy with the aid of a micrometer. Follicles were classified as small (2 to 2.9 mm), medium (3 to 4.9 mm), and large (&gt;5 mm); oocytes were collected in TCM-199 medium. Oocytes were classified as excellent, good, fair, or low quality and transferred to Petri dishes in drops (50 mL) of TCM-199. Oocytes were matured and fertilized in vitro and cultured for 48 h. Oocyte quality as well as maturation, fertilization, and cleavage rates were compared by ANOVA. Ewes from the OG group presented a statistically higher proportion of oocytes with excellent quality (42%; P &lt; 0.05) than GT ewes (26%). The proportion of good quality and fair quality oocytes was similar among groups (P &gt; 0.05). A higher proportion of oocytes of low quality was found in the control group than in the OG group (40% vs. 18%); however, there was no significant difference (P &gt; 0.05). Higher rates of maturation, fertilization, and early development were found in the OG compared with the CG (81.8, 60.6, and 36.4 vs. 68.6, 42.9, and 17.1, respectively); however, the differences were not significant (P &gt; 0.05). In conclusion, the addition of 4% corn oil in the diet improved the quality of the oocytes; however, it had no significant effect on early embryonic development.

Effects of supplemental fat on growth performance and quality of beef from steers fed barley-potato product finishing diets: II. Fatty acid composition of muscle and subcutaneous fat1

One hundred sixty-eight crossbred steers (317.1 +/- 1.0 kg) were used to evaluate the effects of supplemental fat in finishing diets on the fatty acid composition, including the 9,11 isomer of conjugated linoleic acid, of beef. Steers were allotted within three weight blocks to a randomized complete block design with a 3 x 2 + 1 factorial arrangement of dietary treatments. Main effects were level of yellow restaurant grease (RG; 0, 3, and 6%), and level of alfalfa hay (AH; 3.5 and 7%) with an added treatment containing 6% tallow (T) and 7% AH in barley-based diets containing 15% potato by-product and 7% supplement (all dietary levels are on a DM basis) fed for an average of 165 d. Fatty acids of the LM and s.c. fat from four randomly selected steers per pen were quantified using GC after methylation with sodium methoxide. Dietary treatment did not (P > 0.10) affect total fatty acid (FA) content of the LM (143 +/- 5.2 mg/g) or fat (958 +/- 7.9 mg/g). Myristic acid increased linearly (P < 0.01) with increasing RG from 3.1 to 3.7 +/- 0.1 g/100 g of FA in muscle. Stearic acid increased linearly (P < 0.05) as RG increased in the diet, from 11.4 to 12.9 +/- 0.4 g/100 g of FA in LM and from 9.9 to 12.2 +/- 0.3 g/100 g of FA in fat. Compared with T, steers fed 6% RG had more (P < 0.05) oleic acid in LM (42.7 vs. 40.3 +/- 0.5 g/100g FA) and in fat (43.0 vs. 40.9 +/- 0.5 g/100g FA). The cis-9, trans-11 conjugated linoleic acid (CLA) increased quadratically (P < 0.01) with increasing dietary RG in LM from 0.45 to 0.64 to 0.62 +/- 0.03 g/100 g of FA and increased in fat from 0.61 to 0.84 to 0.83 +/- 0.04 g/100 g of FA. Moreover, cis-9, trans-11 CLA was higher (P < 0.05) in fat from steers fed RG compared with T (0.81 vs. 0.69 +/- 0.04 g/100 g of FA), and tended to be higher (P = 0.07) in muscle (0.62 vs. 0.54 +/- 0.03 g/100 g of FA. Feeding yellow restaurant grease increased content of cis-9, trans-11 CLA in beef without an increase total FA content.

Effects of supplemental fat on growth performance and quality of beef from steers fed barley-potato product finishing diets: I. Feedlot performance, carcass traits, appearance, water binding, retail storage, and palatability attributes1

To measure the effects of dietary fat on feedlot performance, carcass characteristics, and beef appearance, moisture binding, shelf life, and palatability, 168 crossbred beef steers (317 +/- 1.0 kg) were allotted randomly, within weight blocks, to a randomized complete block design with a 3 x2 + 1 factorial arrangement of dietary treatments. Main effects were level of yellow restaurant grease (RG; 0, 3, or 6%) and level of alfalfa hay (AH; 3.5 or 7%), with the added treatment of 6% tallow and 7% AH in barley-based diets containing 15% potato by-product and 7% supplement fed for 165 d (all dietary levels on a DM basis). Dietary treatment did not (P >0.10) affect DMI, LM area, beef brightness, or beef texture. Level of RG linearly increased (P <0.05) ADG from 1.48 to 1.60 kg/d, diet NE(m) from 2.4 to 2.6 Mcal/kg, diet NE(g) from 1.7 to 1.9 Mcal/kg, and internal fat from 2.1 to 2.4%. Level of RG linearly increased (P <0.05) G:F from 0.184 to 0.202, but decreased (P <0.05) beef firmness score from 3.0 to 2.8 and fat luster score from 3.1 to 2.8. Level of AH did not (P >0.10) affect any of the measurements; however, AH interacted with level of RG on fat thickness and yield grade (linear; P <0.05), as well as marbling score and percentage of carcasses grading USDA Choice (quadratic; P <0.05). Fat thickness and yield grade increased with increasing RG level in 3.5%, but not in 7%, AH diets. In steers fed 3.5% RG, marbling scores and percentage of carcasses grading Choice were greatest when fed with 3.5% AH, and least when fed 7% AH. Steers fed tallow had lower marbling scores (P = 0.01) and percentage of carcasses grading Choice (P = 0.066) than those fed RG. Retail storage attributes, including visual and instrumental color, decreased during storage (P <0.01), but were not (P >0.10) affected by diet. Trained sensory panel scores for initial tenderness increased quadratically (P = 0.07) as dietary RG increased, but diet did not (P >0.10) affect drip loss, cooking loss, or trained sensory panel scores for sustained tenderness, initial and sustained juiciness, and beef flavor. Therefore, RG increased diet energy, improved performance, and increased carcass fatness; however, dietary fat and AH did not affect most measurements of water retention, color stability, or palatability of beef.

지방의 공급형태와 Ca 및 Mg의 첨가가 In Vitro 발효 및 비육후기 한우의 성장성적에 미치는 영향

This study was aimed at investigating the effect of fat supplementation with divalent ions such as MgO and on 1) in vitro ruminal fermentation characteristics and insoluble fatty acid formation, and on 2) animal performance in finishing Hanwoo bulls. In in vitro trial, five different types of diets based on supplementation sources of fat and divalent ions, i.e. T=basal diet+4% tallow, T-Ca=T+0.5% , T-Mg=TA+0.5% MgO, T-MgCa = T +0.5% +0.5% MgO, T-caS =4% Ca salt tallow, were tested. Higher pH values were observed at 6 hr incubation(P to tallow or Ca soap tallow during incubation(P + MgO, T-CaS = control + Ca soap tallow (EE 5.30%). After feeding each diet for 80 days, average daily weight gain showed 0.89, 1.02, 1.17kg in diets 1, 2 and 3, respectively. The highest feed efficiency was observed(0.12) in diet 2 group, followed by diet 3 (0.10) and 1 groups(0.08; P

Effects of fat supplementation in early lactation dairy cows

Effects of fat supplementation in early lactation dairy cows

Response of lactating cows to three supplemental fat sources as affected by forage in the diet and stage of lactation: a meta-analysis of literature

Research on fat supplementation has demonstrated that the production response of dairy cows to supplemental fats is highly variable, both among and within fat sources. Differential responses to dietary fats that have been observed when feeding the same type of fat to cows fed different basal diets suggests fat by diet interactions occur. A summary of the available literature on the effects of fat supplementation on dry matter intake (DMI), milk yield and composition and nutrient digestion in dairy cattle since 1980 was performed. Fat sources examined were tallow, calcium salts of palm fatty acids (CaS), and selected hydrolyzed tallow fatty acids (SHTFA). Responses of lactating dairy cows to increased levels of added fat were evaluated as affected by fat source and the main forage in the basal diet. Effect of stage of lactation on the response to fat supplementation was also examined. Decreased DMI and modest milk yield increases occurred for the fat sources evaluated. Different responses to supplemental fats were observed depending on the main forage in the basal diet. Feeding tallow with diets high in corn silage decreased DMI and milk fat yield, with no effect on milk production. However, a moderate positive milk production response was observed when tallow was fed with alfalfa-based diets or diets with corn silage and alfalfa in similar proportions. Supplemental SHTFA resulted in moderate positive milk fat percentage and yield response, regardless of the main forage in the basal diet. A significant positive milk yield response was observed when CaS was fed with diets high in corn silage, but not with alfalfa-based diets or diets with alfalfa and corn silage in similar proportions. An interaction between stage of lactation and amount of supplemental fat was observed, with supplemental fat increasing milk production of early lactation cows but not that of mid lactation cows, where milk fat depression occurred. Interactions between fat type and characteristics of the basal diets must be identified in order to predict the production responses of dairy cows to supplemental dietary fats.

Performance, body nitrogen conversion and nitrogen emission from manure of dairy cows fed diets supplemented with different plant extracts

1. Effect of fat supplementation on nitrogen utilisation of lambs and nitrogen emission from their manure A. Machmüller, D.A. Ossowski, M. Kreuzer Livestock Science CrossRef

Conjugated Linoleic Acid and Vaccenic Acid in Rumen, Plasma, and Milk of Cows Fed Fish Oil and Fats Differing in Saturation of 18 Carbon Fatty Acids

The objective of this study was to examine the effect of feeding fish oil (FO) along with fat sources that varied in saturation of 18 carbon fatty acids (high stearic, high oleic, high linoleic, or high linolenic acids) on rumen, plasma, and milk fatty acid profiles. Four primiparous Holstein cows at 85 d in milk (± 40) were assigned to 4×4 Latin squares with 4-wk periods. Treatment diets were 1) 1% FO plus 2% commercial fat high in stearic acid (HS); 2) 1% FO plus 2% fat from high oleic acid sunflower seeds (HO); 3) 1% FO plus 2% fat from high linoleic acid sunflower seeds (HLO); and 4) 1% FO plus 2% fat from flax seeds (high linolenic; HLN). Diets were formulated to contain 18% crude protein and were composed of 50% (dry basis) concentrate mix, 25% corn silage, 12.5% alfalfa silage, and 12.5% alfalfa hay. Milk production, milk protein percentages and yields, and dry matter intake were similar across diets. Milk fat concentrations and yields were least for HO and HLO diets. The proportion of milk cis-9, trans-11 conjugated linoleic acid (CLA; 0.71, 0.99, 1.71, and 1.12 g/100g fatty acids, respectively), and vaccenic acid (TVA; 1.85, 2.60, 4.14, and 2.16 g/100g fatty acids, respectively) were greatest with the HLO diet. The proportions of ruminal cis-9, trans-11 CLA (0.09, 0.16, 0.18, and 0.16 g/100g fatty acids, respectively) were similar for the HO, HLO, and HLN diets and all were higher than for the HS diet. The proportions of TVA (2.85, 4.36, 8.69, and 4.64 g/100g fatty acids, respectively) increased with the HO, HLO, and HLN diets compared with the HS diets, and the increase was greatest with the HLO diet. The effects of fat supplements on ruminal TVA concentrations were also reflected in plasma triglycerides, (2.75, 4.64, 8.77, and 5.42 g/100g fatty acids, respectively); however, there were no differences in the proportion of cis-9, trans-11 CLA (0.06, 0.07, 0.06, and 0.07 g/100g fatty acids, respectively). This study further supports the significant role for mammary delta-9 desaturase in milk cis-9, trans-11 CLA production.