Effect Of Dietary Fat Source Research Articles

Effect of dietary fat source on humoral immunity response of broiler chickens

Summary An experiment was conducted to study the effect of dietary fat source on immune responses of broiler chickens reared according to commercial practices. Immune measurements included weight and percentage of total body mass of the spleen, thymus and bursa of Fabricius, and responses to Sheep Red Blood Cell (SRBC) injection and vaccine titers for Newcastle Disease Virus (NDV), Infectious Bursal Disease Virus (IBDV) and Infectious Bronchitis Virus (IBV). In a completely randomised design, a total of 200 Ross 308 broiler chickens were assigned to four replicates (10 chicks) for each of five dietary treatments: 4% beef tallow; 4% canola oil; 4% sunflower oil, 2% beef tallow and 2% canola oil; and 2% beef tallow and 2% sunflower oil.

Effect of dietary fat source and bird’s sex on performance and peroxisome proliferator-activated receptor-γ gene expression in broiler chicks

The present study was conducted to investigate the effects of different sources and levels of dietary fat and bird’s sex on performance and gene expression of peroxisome proliferator-activated receptor-gamma (PPARγ), as an adipose differentiation and development regulatory key, in broiler chicks. One-week-old broiler chicks (840: 420 males and 420 females) were randomly allocated into a factorial arrangement of treatments including 3 different fat sources (soybean oil, yellow grease, and poultry fat), 3 different fat levels (0, 20, and 40 g/kg of diet), and 2 sex categories (male and female) based on a completely randomized design with 4 replicates of 15 birds each. In addition to performance parameters, abdominal fat tissue was collected from 6 wk-old chicks and total RNA was extracted by RNX reagent. A semi-quantitative reverse transcription PCR was performed to investigate the effects of dietary treatments on PPARγ gene expression. Results showed that dietary fat source had no effect on body weight gain (BWG); however, supplementation of 20 g/kg fat into the broiler diets improved feed conversion ratio (FCR). Male chicks had higher feed intake and BWG, as well as the better FCR values than female broilers. The highest expression of PPARγ gene was detected in the abdominal fat of birds fed on diets containing soybean oil and poultry fat, and females expressed PPARγ gene higher than males. Our findings indicated that different dietary fat sources and sex might affect the development of broiler abdominal fat by interfering in PPARγ gene expression.

Effects of Dietary Fat Source on Performance of Lactating Dairy Cows Fed a Pre-mixed Concentrate

Inclusion of a pre-blended concentrate (OneTrak®, Cargill Inc., Blair, NE) in the total mixed ration (TMR) for dairy cows can simplify the daily mixing of dietary ingredients. A cow’s response to fat supplementation can be affected by other dietary ingredients; however, little is known about production responses to dietary fat in diets with high concentrations of non-forage fiber. This study evaluated cow performance in response to fat sources when the ration contained a pre-blended concentrate composed largely of a non-forage fiber source. Six pens of mid-lactation cows were studied; the addition of saturated fat (Energy Booster 100) and rumenprotected unsaturated fat (Megalac) were compared to a control diet with no added fat. Milk yield tended to increase with both fat sources. Protein concentration decreased with fat supplementation but protein yield did not differ. Efficiency of conversion of feed to milk tended to increase for Megalac compared with Energy Booster. These responses to dietary fat are comparable to those for diets without OneTrak®, suggesting that no unusual dietary interactions with fat supplements are apparent with OneTrak® feeding programs.

Impact of dietary fat sources and feeding level on adipose tissue fatty acids composition and lipid metabolism related gene expression in finisher pigs

The present study investigated the effects of dietary fat sources and feeding level on performance, adipose tissue fatty acid profile and lipid metabolism related genes expression in finisher pigs. A total of 128 finisher pigs [average initial body weight (BW), 81.2±0.322kg] were allotted to 4 treatments on the basis of BW. There were 4 replicates in each treatment with 8 pigs per replicate. Pigs were fed diets containing 50.0g/kg linseed oil or animal fat, either ad libitum or restricted (15.0% less) in 2×2 factorial arrangement for 28d. Dietary fat source did not affect (P>0.05) average daily gain (ADG), average daily feed intake (ADFI) and gain to feed ratio (G:F). The ADG and ADFI of pigs fed ad libitum were greater (P<0.05) than that of restricted fed pigs. The G:F of restricted fed pigs was greater (P<0.05) than that of ad libitum fed pigs. Pigs fed 50.0g/kg linseed oil diet had greater (P<0.05) concentrations of adipose tissue polyunsaturated fatty acids (PUFA) like linoleic acid and α-linolenic acid than that of pigs fed 50.0g/kg animal fat diet. Saturated fatty acids (SFA) like palmitic acid (P<0.05), palmetoleic acid and steric acid (P<0.10) concentrations of adipose tissue were greater in pigs fed animal fat than pigs fed linseed oil. However, adipose tissue fatty acids concentrations were not affected (P>0.05) by feeding level. Adipose tissue expression of acetyl CoA carboxylase (ACC) and fatty acid synthase (FAS) were down-regulated, whereas expression of lipoprotein lipase (LPL) and hormone sensitive lipase (HSL) were up-regulated in finishing pigs fed restricted diets. However, fat sources of diet had no effects (P>0.05) on expression of ACC, FAS, LPL and HSL genes. Results obtained in the present study indicates that dietary inclusion of 50.0g/kg linseed oil have potential to improve the adipose tissue PUFA contents, and 15.0% feed restriction resulted into down-regulation of ACC and FAS and up-regulation of LPS and HSL expression in adipose tissue.

Influence of dietary fat source and feeding duration on pig growth performance, carcass composition, and fat quality (2014)

A total of 160 finishing pigs (PIC 327 × 1050; initially 100.5 lb) were used in an 84-d experiment to evaluate the effects of dietary fat source and feeding duration on growth performance, carcass characteristics, and fat quality. Dietary treatments included a corn-soybean meal control diet with no added fat or a 3 × 3 factorial with main effects of fat source (4% tallow, 4% soybean oil, or a blend of 2% tallow and 2% soybean oil) and feeding duration (d 0 to 42, 42 to 84, or 0 to 84). One pig was identified in each pen on d 0, and biopsy samples of the back, belly, and jowl fat were collected on d 0, 41, and 81. At the conclusion of the study, all pigs were harvested, carcass characteristics were measured, and back, belly, and jowl fat samples were collected. Overall (d 0 to 84), there were no differences between fat sources for growth and carcass characteristics; however, pigs fed diets with added fat from d 0 to 84 had improved (P < 0.036) F/G compared with pigs fed a control diet without added fat. Pigs fed added fat throughout the entire study also had improved (P < 0.042) ADG and F/G and heavier d-84 BW (P < 0.006) compared with pigs fed additional fat for only period 1 or 2. Adding fat for the entire study increased (P < 0.032) backfat and tended to reduce (P < 0.083) fat-free lean index compared with pigs fed the control diet without added fat. Added fat also increased (P < 0.05) iodine value (IV) compared with pigs fed the control diet. Increasing the feeding duration of soybean oil or a blend of soybean oil and tallow decreased monounsaturated and increased polyunsaturated fatty acids relative to feeding tallow (duration × fat source interaction, P < 0.05), with the greatest changes in C18:1 and C18:2, respectively. In conclusion, feeding added fat improved ADG and F/G; however, feeding soybean oil for increasing duration, either alone or in a blend with tallow, negatively affected the fatty acid composition and IV of finishing pigs.; Swine Day, Manhattan, KS, November 20, 2014

Effect of Dietary Fat Sources on the Fatty Acid Composition and Sensory Characteristics of Chicken Meat

The research was carried out in two experiments on Ross 308 male hybrid chickens. Chickens were divided into five groups (five dietary treatments differing in source and concentration of plant oil and fish oil). Feeding chickens with diets of determined composition from 22nd to 42nd day of fattening resulted in altered fatty acid profile in white meat and dark meat, and in significantly lowered n-6/n-3 polyunsaturated fatty acids (PUFA) ratio in white meat. Increase of n-3 PUFA concentration in diets resulted in statistically significant (P = 0.001) increase of n-3 PUFA, as well as in decrease (P = 0.02) of n-6 PUFA in white and dark chicken meat in the 1st experiment. The 2nd experiment resulted in statistically significant increase of n-3 PUFA concentration in white and dark chicken meat (P 0.05). In order to produce chicken meat as functional product, it is possible to reach balance between high n-3 PUFA concentration and satisfactory sensory traits characteristics of chicken meat.

Effects of Dietary Fat Types on Growth Performance, Pork Quality, and Gene Expression in Growing-finishing Pigs.

This study was performed to determine the effects of dietary fat sources, i.e., beef tallow, soybean oil, olive oil and coconut oil (each 3% in feed), on the growth performance, meat quality and gene expression in growing-finishing pigs. A total of 72 crossbred pigs (Landrace×Large White×Duroc) were used at 71±1 kg body weight (about 130 d of age) in 24 pens (320×150 cm) in a confined pig house (three pigs per pen) with six replicate pens per treatment. The growing diet was given for periods of 14±3 d and the finishing diet was given for periods of 28±3 d. The fat type had no significant effect either on growth performance or on chemical composition or on meat quality in growing-finishing pigs. Dietary fat type affected fatty acid composition, with higher levels of unsaturated fatty acids (UFAs) and monounsaturated fatty acids (MUFAs) in the olive oil group. Microarray analysis in the Longissimus dorsi identified 6 genes, related to insulin signaling pathway, that were differentially expressed among the different feed groups. Real time-PCR was conducted on the six genes in the longissimus dorsi muscle (LM). In particular, the genes encoding the protein kinase, cAMP-dependent, regulatory, type II, alpha (PRKAR2A) and the catalytic subunit of protein phosphatase 1, beta isoform (PPP1CB) showed the highest expression level in the olive oil group (respectively, p<0.05, p<0.001). The results of this study indicate that the type of dietary fat affects fatty acid composition and insulin signaling-related gene expression in the LM of pigs.

Effect of dietary fat source on fatty acid profile and lipid oxidation of eggs

This study investigated the effects of supplementary dietary lipid sources on the fatty acid profile and lipid oxidation of eggs. Five isoenergetic (12.6 MJ AME/kg DM) and isonitrogenous (170 g CP/kg DM) diets were formulated, using a control diet (50 : 50 blend of fish- and linseed oil), fish oil, sunflower oil, high oleic acid (HO) sunflower oil and tallow at a 30 g/kg inclusion level. Two hundred individually caged HyLine Silver-Brown hens (20 weeks of age) were randomly allocated to the five dietary treatments (n = 40 hens/treatment). Birds received the experimental diets from 20 weeks of age. At 30 weeks of age, 12 eggs per treatment were randomly selected for analyses of egg yolk fatty acid methyl esters (FAME), thiobarbituric acid reactive substances (TBARS) and peroxide values (PV). Dietary lipid sources affected FAME, TBARS and PV of egg yolk significantly. The fish oil treatment resulted in the highest TBARS (0.27 mg malonaldehyde/kg yolk) and PV (3.96 milli-equivalent peroxide/kg fat) whereas the HO sunflower oil resulted in the lowest TBARS (0.13 mg malonaldehyde/kg yolk) and PV (2.77 milli-equivalent peroxide/kg fat). Fish oil also resulted in the lowest n-6 to n-3 ratio (1.16 to 1), while sunflower oil resulted in the highest ratio (24.6 to 1). Results indicate that the fatty acid profile of eggs could be altered by means of dietary intervention. However, an improvement of omega-3 type fatty acids of eggs will result in a higher susceptibility to lipid oxidation and possibly a shorter shelf-life of stored eggs.Keywords: Fish oil, high oleic sunflower oil, linseed oil, percentage yolk fat, peroxide value, tallow

Effects of choice white grease and soybean oil on growth performance, carcass characteristics, and carcass fat quality of growing-finishing pigs

A total of 144 barrows and gilts (initial BW = 44 kg) were used in an 82-d experiment to evaluate the effects of dietary fat source and duration of feeding fat on growth performance, carcass characteristics, and carcass fat quality. Dietary treatments were a corn-soybean meal control diet with no added fat and a 2 × 4 factorial arrangement of treatments with 5% choice white grease (CWG) or soybean oil (SBO) fed from d 0 to 26, 54, 68, or 82. At the conclusion of the study (d 82), pigs were slaughtered, carcass characteristics were measured, and backfat and jowl fat samples were collected. Fatty acid analysis was performed, and iodine value (IV) was calculated for all backfat and jowl fat samples. Pigs fed SBO tended to have increased (P = 0.07) ADG compared with pigs fed CWG. For pigs fed SBO, increasing feeding duration increased (quadratic, P < 0.01) ADG and G:F. For pigs fed CWG, increasing feeding duration improved (quadratic, P < 0.01) G:F. For pigs fed SBO or CWG, increasing feeding duration increased carcass yield (quadratic, P < 0.04) and HCW (quadratic, P < 0.02). Dietary fat source and feeding duration did not affect backfat depth, loin depth, or lean percentage. As expected, barrows had greater ADG and ADFI (P < 0.01) and poorer G:F (P = 0.03) than gilts. Barrows also had greater last-rib (P = 0.04) and 10th-rib backfat (P < 0.01) and reduced loin depth and lean percentage (P < 0.01) compared with gilts. Increasing feeding duration of CWG or SBO increased (P < 0.10) C18:2n-6, PUFA, PUFA:SFA ratio, and IV in jowl fat and backfat. Pigs fed SBO had greater (P < 0.01) C18:2n-6, PUFA, PUFA:SFA ratio, and IV but decreased (P < 0.01) C18:1 cis-9, C16:0, SFA, and MUFA concentrations compared with pigs fed CWG in jowl fat and backfat. Barrows had decreased (P = 0.03) IV in jowl fat and backfat compared with gilts. In summary, adding SBO or CWG increased the amount of unsaturated fat deposited. Increasing feeding duration of dietary fat increases the amount of unsaturated fatty acids, which leads to softer carcass fat.

Effect of dietary fat sources on fatty acid deposition and lipid metabolism in broiler chickens

The hypothesis tested was that dietary vegetable fats rich in saturated fatty acids, when compared with a vegetable oil rich in linoleic acid, increase fat deposition in broiler chickens and affect synthesis or oxidation, or both, of individual fatty acids. Diets with native sunflower oil (SO), a 50:50 mix of hydrogenated and native SO, palm oil, and randomized palm oil were fed to broiler chickens. Intake of digestible fat and fatty acids, whole body fatty acid deposition, hepatic fatty acid profile, and hepatic enzyme activities involved in fatty acid oxidation and synthesis were measured. The fat deposition:digestible fat intake ratio was significantly lower for the SO group in comparison with the groups fed the vegetable fats rich in saturated fatty acids. The difference between digestible intake and deposition of C18:2, reflecting its maximum disappearance rate, was highest for the SO group and lowest for the palm oil- and randomized palm oil-fed birds. The calculated minimal rate of de novo synthesis of monounsaturated fatty acids (MUFA), calculated as deposition minus digestible intake, was more than 50% lower for the SO group than for the other 3 dietary groups. Based on the fatty acid profiles in the liver, it would appear that increasing contents of C18:2 decrease the desaturation of saturated fatty acids into MUFA. It is concluded that a diet rich in C18:2 in comparison with different kinds of vegetable saturated fatty acids decreases the deposition of fat, especially of MUFA. It appears to be caused by a higher β-oxidation and a reduced de novo synthesis of MUFA, but this conclusion is not fully supported by the measured activities of enzymes involved in fatty acid synthesis and oxidation.

Dietary fat type and level affect thyroid hormone plasma concentrations in rats

(Received 10 June 2008; revised version 26 March 2009; accepted 24 June 2009)ABSTRACT The objective of the study was to examine the effect of dietary fat source and level on plasma thyroid hormone concentrations. For three weeks, male Wistar rats (n=54) were fed diets containing fats differing in fatty acid (FA) composition: sunflower oil predominantly containing polyunsaturated n-6 FA, group S; rich in monounsaturated FA rape seed oil, group R; and saturated FA palm oil, group P; at three levels (w/w): 5% LF, 10% MF, and 20% HF. Total thyroxine levels were higher in group P than R on the LF and MF diets. The free thyroxine concentration in rats on the LF diet was higher in group R than in S and P; on the MF diet, higher in group R and P than S; and on the HF diet, higher in group P than S. Triiodothyronine levels were influenced by fat composition only in rats fed the HF diet, being lower in group S than P. The results of this study suggest that diets differing with respect to fat type and level might have opposite effects on thyroid hormone values.KEY WORDS: thyroid, thyroxine, triiodothyronine, reverse-triiodothyronine, nutrition, fatty acids, rats

Fat content, fatty acid profile and off-flavours in goats milk—Effects of feed concentrates with different fat sources during the grazing season

A specific rancid and tart off-flavour, probably due to lipolysis of the milk fat, is common in Norwegian goat milk during some seasons. We compared the effects of dietary fat sources on goat milk fat composition and flavour. The experiment was conducted from June to October with 30 animals from the Norwegian Dairy Goat breed. In summer a semi-natural mountain pasture provided roughage, while the animals grazed on a lowland cultivated pasture in the autumn. The goats were fed silage according to appetite indoors for the final 5 weeks of the experiment. The animals were divided into two groups fed different types of concentrate: concentrate A containing sunflower oil (40 g/kg) (mainly C18:1/C18:2) and concentrate B containing 60 g/kg of saturated long chain fatty acids (LCFA) (mainly C16:0/C18:0). Individual milk samples for sensory and chemical analysis were collected in connection with the yield measurements seven times during the experiment (in lactation weeks 10, 14, 16, 17, 19, 22 and 25). The intensity of rancid and tart flavour increased during the mountain grazing period. Milk from goats fed concentrate B (saturated LCFA) showed the lowest ( P<0.05) frequency of rancid taste. No differences ( P>0.05) in the fat, protein and lactose content in the milk were observed between the two groups. Feeding saturated LCFA resulted in less ( P<0.05) ‘goat fatty acids’ (C6:0–C10:0) content and higher ( P<0.05) content of C16 and C18 fatty acids in the milk. It is concluded that supplements with saturated LCFA altered the fatty acid composition in the milk, thereby reducing the frequency of rancid flavours. It appears that the positive effect of supplementation with saturated LCFA was due to a direct effect on the fatty acid composition in the milk. Depression of the ‘goat fatty acids’ C6–C10 could have minimized flavour defects, and a higher content of C16:0 in the milk could have improved the stability of the milk fat globule membrane and thereby decreased the level of lipolysis and off-flavour.

Interaction of dietary high-oleic-acid sunflower hulls and different fat sources in broiler chickens

The effect of dietary fat sources (high-oleic-acid sunflower seeds, HOASS; palm oil, PO; and high-oleic-acid sunflower oil, HOASO) and high-oleic-acid sunflower hulls (HOAS hulls; 40 g/kg of diet) on performance, digestive organ size, fat digestibility, and fatty acid profile in abdominal fat and blood serum parameters was evaluated in chickens (from 1 to 21 d of age). Bird performance and digestive organ size were not affected by either dietary fat source or sunflower hull supplementation. Fat digestibility in birds fed diets enriched (HOASS and HOASO) in monounsaturated fatty acids (MUFA) was increased compared with those fed the PO diet. The addition of sunflower hulls did not modify fat digestibility. The fatty acids pattern of abdominal fat reflected the dietary fat profile. The greatest concentrations of C16:0 and C18:0 were found in birds fed PO diets. The C18:1n-9 content was increased in birds that received HOASS and HOASO diets compared with those fed PO diets. The greatest content of C18:2n-6 was observed in birds fed HOASS diets. The ratio of polyunsaturated fatty acid (PUFA) to MUFA was significantly increased in birds fed PO diets compared with those fed HOASS or HOASO diets. The addition of sunflower hulls to the diets resulted in a decrease of C18:2n-6 and PUFA concentrations and PUFA:MUFA ratio in abdominal fat. Dietary fat sources and sunflower hulls modify blood triglycerides and serum lipoproteins. A decrease in triglyceride concentrations was observed in birds fed HOASS diets compared with those fed PO and HOASO diets. The greatest concentrations of serum high density, very low density (VLDL), and low density lipoproteins were found in birds receiving HOASO, PO, and HOASS diets, respectively. The addition of sunflower hulls to the diets caused an increase of serum triglycerides and VLDL concentrations. The MUFA-enriched diets had lower triglyceride and VLDL concentrations than did diets rich in saturated fatty acids. However, the sunflower hull addition had the opposite effect.

Interactive effects of dietary fat source and slaughter weight in growing-finishing swine: III. Carcass and fatty acid compositions1

Crossbred pigs (n=288) were used to test the interactive effects of dietary fat source and slaughter weight on dissected carcass composition and fatty acid composition of composite carcass samples. Pigs were blocked by initial BW, and within each of 9 blocks, pens (8 pigs/pen) were randomly assigned to either control corn-soybean meal grower and finisher diets (Ctrl) or diets formulated with 5% beef tallow (BT), poultry fat (PF), or soybean oil (SBO). Immediately after treatment allotment, as well as at mean block BW of 45.5, 68.1, 90.9, and 113.6 kg, 1 pig was randomly selected from each pen and slaughtered, and primal cuts from right carcass sides were dissected into muscle, fat, bone, and skin components. Muscle and fat tissues were then ground, and random composite samples were collected from each carcass for fatty acid composition analysis. Fat source did not alter pork primal cut yields (P >or= 0.294), nor were the percentages of carcass muscle (P=0.213), fat (P=0.502), and bone (P=0.551) affected by dietary fat source. Conversely, percentages of the whole shoulder and ham decreased linearly (P<0.001), and the percentages of loin and belly increased (P<0.001) linearly with increasing slaughter weight. Moreover, linear decreases (P<0.001) in carcass muscle, bone, and skin, as well as a linear increase (P<0.05) in carcass fat, were observed as slaughter weight increased from 28.1 to 113.6 kg. Composite samples from pigs fed the BT or Ctrl diets had greater (P<0.05) proportions of SFA, particularly oleic and stearic acids, than those from pigs fed the PF and SBO diets when slaughtered at 45.5, 68.1, and 90.9 kg (fat source x slaughter weight, P<0.001). Percentages of MUFA (including palmitoleic, oleic, and cis-vaccenic acids) decreased (P<0.05), and percentages of all PUFA, especially linoleic and linolenic acids, and iodine values increased (P<0.05) in samples from SBO-fed pigs as slaughter weight increased from 28.1 to 113.6 kg (fat source x slaughter weight, P<0.001). Dietary fat source did not affect carcass composition; however, including 5% SBO in swine diets increased the polyunsaturation of pork, which could lead to economic ramifications associated with soft pork and pork fat.

Interactive effects of dietary fat source and slaughter weight in growing-finishing swine: II. Fatty acid composition of subcutaneous fat1

Crossbred pigs (n=288) were used to test the interactive effects of dietary fat source and slaughter weight on the fatty acid composition of subcutaneous fat. Pigs were blocked by initial BW (28.1 kg), and, within blocks, pens (8 pigs/pen) were randomly assigned to either grower and finisher diets devoid of added fat (Ctrl) or diets formulated with 5% beef tallow (BT), poultry fat (PF), or soybean oil (SBO). Immediately after treatment allotment, as well as at mean block BW of 45.5, 68.1, 90.9, and 113.6 kg, 1 pig was randomly selected from each pen, slaughtered, and, within 1 h postmortem, samples of backfat were removed from each carcass between the 4th and 8th thoracic vertebra and separated into the inner, middle, and outer layers for fatty acid composition analysis. During the first 17.4 kg of BW gain, percentages of all SFA increased by more than 4% in subcutaneous fat of pigs fed the Ctrl and BT diets, but decreased by 4.4 and 7.7% in pigs fed the PF and SBO diets, respectively (fat source x slaughter weight, P<0.001). Proportions of all MUFA in subcutaneous fat from BT-fed pigs increased by 6.1% during the first 17.4 kg of BW gain, but MUFA percentages in SBO-fed pigs decreased by 9.1% between 28.1 and 45.5 kg (fat source x slaughter weight, P<0.001). Conversely, percentages of all PUFA from SBO-fed pigs increased by 39.9%, whereas PUFA concentrations in BT-fed pigs decreased by 12.6% as slaughter weight increased from 28.1 to 45.5 kg (fat source x slaughter weight, P<0.001). Resultant iodine values (IV) of subcutaneous fat from SBO-fed pigs increased (P<0.05) from 73.5 to 85.2 within the first 17.4 kg of BW gain, and remained elevated above those of their contemporaries fed the Ctrl, BT, or PF diets at each subsequent slaughter weight (fat source x slaughter weight, P<0.001). The inner backfat layer had the greatest (P<0.05) proportions of all SFA and the least (P<0.05) proportions of all PUFA, whereas the outer layer had the least (P<0.05) percentages of all SFA but the greatest (P<0.05) percentages of all MUFA. Even though the middle and outer subcutaneous fat layers had similar (P>0.05) PUFA percentages, the greatest (P<0.05) and least (P<0.05) IV were in the outer and middle layers, respectively. As expected, the fat source included in swine diets was responsible for the fatty acid compositional changes in subcutaneous fat, yet the results of this study indicate that feeding 5% SBO dramatically increased the polyunsaturation of subcutaneous fat within the first 17.4 kg of BW gain, with backfat IV exceeding 80 thereafter.

Interactive effects of dietary fat source and slaughter weight in growing-finishing swine: I. Growth performance and longissimus muscle fatty acid composition1

Crossbred pigs (n=288) were used to test the interactive effects of dietary fat source and slaughter weight on live performance, carcass traits, and fatty acid composition of the LM. Pigs were blocked by initial BW, and, within each of 9 blocks, pens (8 pigs/pen) were randomly assigned to either control corn-soybean meal grower and finisher diets devoid of added fat (Ctrl) or diets formulated with 5% beef tallow (BT), poultry fat (PF), or soybean oil (SBO). Immediately after treatment allotment, as well as at mean block BW of 45.5, 68.1, 90.9, and 113.6 kg, 1 pig was randomly selected from each pen, slaughtered, and allowed to chill for 48 h at 1 degrees C. Backfat was measured on the right sides, and a sample of the LM was removed for fatty acid composition analysis. Regardless of source, inclusion of fat in swine diets did not (P >or= 0.349) affect ADG, ADFI, or G:F. Furthermore, carcasses from pigs fed diets formulated with 5% fat had greater (P=0.013) average backfat depths than those from pigs fed the Ctrl diet. Body weight, carcass weight, and backfat depths increased (P<0.001) as slaughter weight increased from 28.1 to 113.6 kg. The proportion of SFA in the LM increased (P<0.001) with increasing slaughter weight from 28.1 to 68.1 kg, but SFA percentages were similar between 68.1 and 113.6 kg, and pigs fed the Ctrl diet had greater (P=0.032) proportions of SFA than pigs fed the SBO and PF diets. Moreover, the proportion of all MUFA increased (P<0.001) by 9.4 percentage units from 28.1 to 113.6 kg; however, only pigs fed the SBO diet had reduced (P=0.004) MUFA percentages than those fed the Ctrl, BT, and PF diets. Even though the proportion of PUFA in the LM decreased with increasing slaughter weight, pigs fed SBO had greater PUFA percentages, a greater PUFA-to-SFA ratio, and greater iodine values than pigs fed all other dietary treatments when slaughtered at BW of 45.5 kg or greater (fat source x slaughter weight, P < 0.001). Results of this study indicate that fat source had little to no impact on live pig performance, but feeding a polyunsaturated fat source altered the fatty acid profile of the LM within the first 17.4 kg of BW gain; more specifically, including 5% SBO in swine diets could lead to economical ramifications associated with soft pork or fat.

Tissue fatty acid composition of pigs fed different fat sources

Dietary fat influences the physico-chemical properties of meat, and fatty acid (FA) composition may have implications on human health. The objectives of the experiment were to study tissue FA partitioning and the effect of dietary fat source on tissue FA composition. Seventy crossbred gilts (61.8 ± 5.2 kg BW average) were fed one of seven treatments: a diet containing a very low level of fat (no fat (NF)) and six fat-supplemented diets (10%: tallow (T), high-oleic sunflower oil (HOSF), sunflower oil (SFO), linseed oil (LO), fat blend (FB: 55% tallow, 35% SFO, 10% LO) and fish oil blend (FO: 40% fish oil, 60% LO). Differential tissue FA depositions were observed, with flare fat being the most saturated, followed by intermuscular, and subcutaneous being the least saturated. Monounsaturated fatty acid (MUFA) deposition showed an opposite tissue pattern. Subcutaneous fat showed the highest MUFAs, intermuscular fat showed intermediate values and flare fat showed the lowest MUFAs. Intramuscular polyunsaturated fatty acid (PUFA) content was less susceptible to dietary treatment modifications compared with other depots. Significant tissue FA modifications were observed due to dietary treatments, mainly in diets rich in PUFA. The saturated fatty acids (SFA) were high in NF-fed and low in HOSF-fed animals, MUFA were high in HOSF-fed and low in SFO-, LO- and FO-fed animals, while PUFA were high in SFO- and LO-fed and low in HOSF-, T- and NF-fed animals. Pigs fed LO and FB showed detectable levels of EPA, which depended on the linolenic content of the diet. The only effective way to increase tissue DHA contents was to add DHA in the diet through FO feeding. Araquidonic acid was high in SFO diets and low in LO and FB diets, and also high in intramuscular fat compared with other tissues. EPA and DHA were also high in intramuscular fat compared with other fat depots. The deposition of oleic and linoleic acids depended on the composition of dietary fat, as their deposition varied between diets, even at similar levels of intake of each FA. The NF diet resulted in the greatest proportion of SFAs (palmitic and stearic) of all treatments tested. SFAs were less susceptible to modification than MUFA in response to the different PUFA levels supplemented in the diet. T resulted in less fat deposition in some of the fat depots and more in others, suggesting that T could partition fat differently among fat depots.

Effects of dietary fat source on physical, chemical and sensorial quality of calves’ meat

Effects of dietary fat source on physical, chemical and sensorial quality of calves’ meat

Effects of choice white grease or soybean oil on growth performance and carcass characteristics of grow-finish pigs (2007)

A total of 144 barrows and gilts (PIC) with an initial BW of 97 lb were used to evaluate the effects of dietary fat source and duration of feeding on growth performance and carcass fat quality. Dietary treatments included a corn-soybean meal control diet with no added fat or a 2 × 4 factorial arrangement with 5% choice white grease (CWG) or soybean oil and with-drawal of the fat 0, 14, 28, or 56 days before market (82 days). At the end of each feeding duration, pigs were switched to the control diet. At the end of the study (d 82), jowl fat and backfat samples were collected. Lengthening the duration of feeding soybean oil increased (quadratic, P<0.01) ADG and improved F/G. Increasing the feeding duration of CWG had no effect on ADG, but improved (quadratic, P<0.01) F/G. Increasing the feeding duration of CWG or soybean oil increased (quadratic, P<0.02) dressing percentage with the improvement being greater (P<0.06) for pigs fed CWG compared to pigs fed soybean oil. Gilts had increased (P<0.01) iodine value (IV; more unsaturated fat) compared to barrows. Increasing feeding duration of either soybean oil or CWG increased (quadratic, P<0.01) IV compared to pigs fed the control diet. In summary, adding fat to the diet improved pig growth performance but increased jowl fat and backfat IV. Feeding fat during any stage influenced jowl IV at market with duration of feeding having the greatest response with soybean oil.; Swine Day, 2007, Kansas State University, Manhattan, KS, 2007

Effects of Various Fat Sources, α-Tocopheryl Acetate, and Ascorbic Acid Supplements on Fatty Acid Composition and α-Tocopherol Content in Raw and Vacuum-Packed, Cooked Dark Chicken Meat

A factorial design was used to study the effects of dietary fat sources (beef tallow, fresh and oxidized sunflower oils, and linseed oil), α-tocopheryl acetate (0 and 225 mg/kg), and ascorbic acid (0 and 110 mg/kg) supplementation on fatty acid composition, as well as on fat and α-tocopherol content in vacuum-packed raw and cooked meat stored at −20°C. Raw meat fatty acid composition was affected by dietary fat sources and tocopheryl acetate supplementation. After cooking, meat composition was only affected by dietary fat sources. Birds fed linseed oil yielded meat rich in n-3 fatty acids, especially linolenic acid, which provides about 20% of the adequate intake for this fatty acid. Birds fed sunflower or oxidized sunflower oil produced meat rich in n-6 fatty acids, whereas those fed beef tallow resulted in meat rich in saturated and monounsaturated fatty acids. Raw and cooked dark chicken meat α-tocopherol content was only affected by tocopherol supplementation. Supplementation with α-tocopheryl acetate led to α-tocopherol–enriched meat, which provides about 25% of the recommended dietary allowance. Moreover, this content in vacuum-packed samples was not modified even after 7 mo of storage at − 20°C.