Digestion and deposition of individual fatty acids in growing-finishing pigs fed diets containing either beef tallow or sunflower oil

The apparent digestibility and deposition in carcass of individual dietary fatty acids (FA) were determined in growing-finishing pigs fed diets containing either beef tallow or sunflower oil. The beef tallow was rich in saturated FA (SFA) and the sunflower oil had a high content of polyunsaturated FA (PUFA). A total of 39 barrows was used. The experimental diets contained 5% (w/w) of the variable fat source and were fed ad libitum . The dietary fat type had no effect (p > 0.05) on growth performance, even though the apparent digestibilities of crude fat and crude protein were higher (p < 0.05) in the animals fed sunflower oil. The pigs fed the sunflower oil diet showed higher apparent digestibilities (p < 0.05) of the sum of SFA, monounsaturated FA (MUFA) and PUFA, but had a lower digestibility (p < 0.05) of stearic acid. The intakes of individual digestible FA were derived feed intake data, FA contents of the diets and the digestibility of individual FA. For the entire feeding period of 13 weeks, the ratio of deposition in carcass to intake of digestible FA was increased (p < 0.05) for palmitic and stearic acid in the pigs fed sunflower oil, but the ratios for oleic acid and linoleic acid were decreased (p < 0.001). In the pigs fed sunflower oil instead of beef tallow, the deposition:intake ratio was raised for the SFA (p < 0.001), but diminished for the MUFA (p < 0.05). The calculated minimum de novo synthesis of SFA was increased (p < 0.05) and that of MUFA decreased (p < 0.05) in the pigs fed sunflower oil. It is concluded that the feeding of a diet with sunflower oil instead of beef tallow improved apparent digestibility of SFA, MUFA and PUFA, increased the deposition:digestible intake ratio for SFA, but lowered that for MUFA and PUFA.     

The Influence of Different Protein,Fat and Mineral Levels on the Digestibility of Fat and Fatty Acids Measured at the Terminal Ileum and in Faeces of Growing Pigs

Abstract

The influence of dietary protein, fat and mineral levels on crude fat and fatty acid digestibility was investigated in growing pigs. The experiment was a factorial design with two levels of protein (normal and high), two levels of dietary fat (3 and 15% of DM) and three levels of minerals (50, 100 and 150% of Danish Standard). Four litters, each of six female pigs, were used in the experiment.

Increasing the dietary protein content resulted in a moderate but significant increase in the ileal digestibility of fatty acids. The increase was most pronounced for the saturated fatty acids. Addition of animal fat to the basal diet caused a substantial increase in ileal digestibility of all fatty acids except stearic acid (18:0). A variation in the dietary mineral content of ±50% of the Danish Standard had no significant influence on ileal digestibility of crude fat and fatty acids. Apparently, microbial hydrogenation occurred in the hind-gut, but the increase in stearic acid (18:0) excretion could not be explained solely by biohydrogenation of unsaturated fatty acids. The interactions between dietary protein and fat on the increase of faecal 18:0 showed that the dietary composition had a very complex effect on the microbial activity in the hind-gut. Consequently, determination of fatty acid digestibility should be performed at the terminal ileum, whereas crude fat (Stoldt) digestibility can be carried out on faecal material.     

Studies on acid oils and fatty acids for chickens. II. Effect of free fatty acid content and degree of saturation of free fatty acids and neutral fat on fatty acid digestibility

1. Two experiments were designed to study the influence of free fatty acid content and degree of saturation of free fatty acids and neutral fat on digestibility of added fats and fatty acids. Sunflower oil and tallow were used as neutral fats, and palmitic, stearic, oleic and linoleic acids as free fatty acids. Fat inclusion was 80 g/kg and mixtures of each fat and each free fatty acid were prepared in the proportions 100:0, 70:30 and 40:60.

2. Experimental diets were evaluated for fat and fatty acid digestibilities with broiler chickens at 21 d of age. The metabolisable energy of fat was calculated from the product of digestibility and gross energy. Increasing concentrations of saturated free fatty acids decreased the ME of added fat, whereas unsaturated free fatty acids did not significantly affect the ME value of added fat.

3. Digestibilities of individual fatty acids were analysed by linear regression with rate of inclusion of free fatty acid in the fat blend: palmitic and stearic acids gave a negative slope, whereas oleic and linoleic acids gave a slope not statistically different from zero. Because slopes for saturated fatty acids did not differ between the sunflower oil and tallow treatments, synergism between unsaturated and saturated fatty acids was not detected.     

Determination of the alteration in fatty acid profiles, sensory characteristics and carcass traits of swine fed elevated levels of monounsaturated fats in the diet

The present study was designed to determine the effects of supplemental fat or oil rich in oleic acid on the fatty acid profiles (FAP) and physical and sensory traits of pork carcasses. Sixty barrows and gilts were equally distributed among five dietary treatments consisting of a control diet of corn and soybean meal and four similar test diets that contained 10% animal fat (45.3 oleic), safflower oil (72.1 oleic), sunflower oil (80.9 oleic) or canola oil (57.7 oleic). The pigs were slaughtered after being fed these diets for 90 d at about 100 kg live weight. Carcass traits, FAP and sensory properties were evaluated for each treatment. First-rib fat thickness, ham muscling score and longissimus muscle areas were not different (P less than .05), but last-rib fat thickness was increased (P less than .05) with the supplemental dietary fat or oils. No differences existed for marbling scores, lean color, firmness or texture scores between the controls and pigs supplemented with either animal fat or safflower oil. However, pigs supplemented with sunflower or canola oil had lower marbling scores, lean color, firmness and texture scores. Fat became softer and more oily (P less than .05) with the supplemental dietary safflower, sunflower and canola oils. Sensory evaluation (loin chops) showed no differences (P less than .05) in sustained juiciness, tenderness or flavor intensity evaluations among treatments. However, the pigs fed canola oil had lower (P less than .05) flavor quality scores or overall palatability evaluations. Chops from the pigs fed canola oil also had 46% more off-flavors than all other treatments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of forage and sunflower oil levels on ruminal biohydrogenation of fatty acids and conjugated linoleic acid formation in beef steers fed finishing diets

Six Hereford steers (295 kg) cannulated in the proximal duodenum were used to evaluate the effects of forage and sunflower oil level on ruminal biohydrogenation (BH) and conjugated linoleic acid (CLA) outflow. Steers were fed one of six treatment diets in a 3 x 2 factorial arrangement of treatments (grass hay level: 12, 24, or 36% of DM; and sunflower oil level: 2 or 4% of DM) in a 6 x 6 Latin square design. The remainder of the diet was made up of steam rolled corn and protein/mineral supplement. Duodenal samples were collected for 4 d following 10-d diet adaptation periods. Data were analyzed with animal, period, forage level, sunflower oil level, and two-way interaction between forage and sunflower oil level in the model. Dry matter intake showed a quadratic response (P < 0.04), with an increase in DMI as forage level increased from 12 to 24% followed by a decrease in DMI when 36% forage was fed. Flow of fatty acids at the duodenum was higher (P < 0.03) for 4 vs. 2% sunflower oil diets, and similar among forage levels. Apparent ruminal digestibility of NDF increased in a linear manner (P < 0.04) as dietary forage level increased. Ruminal BH of dietary unsaturated 18-C fatty acids, oleic acid, and linoleic acid increased linearly (P < 0.05) as dietary forage level increased. Linoleic acid BH tended (P < 0.07) to be greater for 4 than 2% sunflower oil level. Duodenal flow of pentadecyclic, stearic, linolenic, and arachidic acids increased linearly (P < 0.05) as dietary forage level increased from 12 to 36%. Duodenal flow of linoleic acid decreased in a linear manner (P < 0.03) with increasing dietary forage level. Flow of trans-10 octadecenoate decreased linearly (P < 0.03) as dietary forage level increased, whereas trans-11 vaccenic acid flow to the duodenum increased (P < 0.01) linearly with increased dietary forage. Dietary forage or sunflower oil levels did not alter the outflow of cis-9, trans-11 CLA. Flows of cis-11, trans-13, and cis-9, cis-11 CLA increased linearly (P < 0.05) with increased dietary forage. Flows of cis-11, cis-13, and trans-11, trans-13 CLA decreased linearly (P < 0.05) with increased dietary forage. Increasing dietary forage levels from 12 to 36% in beef cattle finishing diets increased BH of unsaturated 18-C fatty acid and outflow of trans-11 vaccenic acid to duodenum without altering cis-9, trans-11 CLA outflow.     

Sunflower oil supplementation alters meat quality but not performance of growing partridges (Alectoris chukar)

This study was conducted to evaluate the effects of sunflower oil supplementation (0%, 3%, 6% and 9%) to partridge chicks (Alectoris chukar) on growth performance, nutrient digestibility and carcass characteristics. Feed consumption and live weight gain were responsive to dietary sunflower oil inclusion during the starter period, but not during the grower period. Increasing sunflower oil level linearly increased crude protein and fat digestibilities. Except for abdominal fat, weights of inedible parts and edible organs remained unchanged by the diets. The treatments linearly decreased weight and efficiency of carcass and weights of wings and breast and did not alter weights of thighs and neck. Breast meat saturated fatty acids decreased linearly by 17.9% and unsaturated fatty acids increased linearly by 10.6%, as sunflower oil level increased in the diets. Monounsaturated fatty acids decreased linearly by 27.3%, whereas polyunsaturated fatty acids increased linearly by 51%. Overall, n‐3 (0.78% vs. 0.59%) and n‐6 (42.6% vs. 29.8%) were greater in breast meat in treatment groups than in control group. In conclusion, sunflower addition into diets has minimal effects on performance of growing partridges, but significantly alters meat fatty acid composition.     

The effect of animal fat and vegetable oil supplementation of feeds of different energy concentration upon the digestibility of nutrients and some blood parameters in rabbits

The effect of mixed animal fat and sunflower oil supplementation (5%) of a feed of medium (12.02 MJ DE/kg) and low (8.54 MJ DE/kg) energy concentration upon the digestibility of nutrients and on some blood parameters was investigated. The ether-extractable content of feed and faecal samples was determined by diethyl ether extraction (after Soxhlet) and the total (true) fat level was measured by the method of Stoldt (1952), viz. petroleum ether extraction of samples pretreated with 4 N HCl. In the majority of cases the voluntary feed intake decreased after the addition of animal fat or vegetable oil. Mixed animal fat supplementation significantly (by 5 and 11 units) improved the digestibility of the ether extract if added to either of the basal diets. The digestibility of crude fibre and N-free extract increased only in the case of the basal diet of low energy concentration (by 4 and 7 units, respectively). Sunflower oil addition produced changes of the same tendency (9, 9, 28 and 5 units). The digestibility of the crude protein was practically not altered by either supplementation. The total fat content of feed and faecal samples proved to be higher than that of the ether extract, on an average by 27 and 100%, respectively. Consequently, the digestibility coefficients of the total fat are by 10 units lower than those of the ether extract. The DE concentrations, calculated by means of the digestible ether extract or the total fat content, differed significantly only between the basal diets. The addition of mixed animal fat to either of the basal diets increased the blood concentration of total lipids (by 18 and 32%, respectively), while that of sunflower oil did not cause such an alteration. Neither fat nor oil supplementation had an effect on the cholesterol level of the blood plasma. Both the animal fat and the vegetable oil surplus modified the fatty acid composition of blood lipids. It was characteristic of each treatment that the proportion of polyunsaturated fatty acids increased.     

Comparison of regression and fat-free diet methods for estimating ileal and total tract endogenous losses and digestibility of fat and fatty acids in growing pigs

An experiment was conducted to 1) compare the regression and fat-free diet methods for estimating total or basal endogenous losses of fat (ELF) and fatty acids (ELFA) and true digestibility (TD) or standardized digestibility (SD) of fat and fatty acids in growing pigs and 2) compare these estimated values at the end of the ileum and over the entire intestinal tract. Ten barrows (initial body weight: 45.1 ± 2.8 kg) were surgically fitted with a T-cannula in the distal ileum and allotted to one of five experimental diets in a three-period Youden Square design. A fat-free diet was formulated using cornstarch, soy protein isolate, and sucrose. Four oil-added diets were formulated by adding four levels of soybean oil (2%, 4%, 6%, and 8%) to the fat-free basal diet at the expense of cornstarch. All diets contained 26% sugar beet pulp and 0.40% chromic oxide. Results indicated that there were no differences between true ileal digestibility (TID) of fat and true total tract digestibility (TTTD) of fat when pigs were fed soybean oil. The TID of C18:0 and total saturated fatty acids (TSFA) was greater than TTTD (P < 0.05). The total ELF at the end of the ileum were not different from that over the entire intestinal tract. In addition, total endogenous losses of C18:0 and TSFA were greater for the entire intestinal tract than at the end of the ileum, whereas total endogenous losses of C18:2 and total unsaturated fatty acids were just the opposite. Similar results were observed for basal ELF and ELFA. As the inclusion level of soybean oil increased, apparent digestibility (AD) of fat and fatty acids increased linearly (P < 0.05) except for apparent ileal digestibility of C18:0. However, SD of fat and fatty acids was not influenced by the inclusion level of soybean oil. Estimation of ELF and ELFA observed by the regression and fat-free diet methods did not differ when measured at the end of the ileal or total tract. There were no differences between the estimations of TD and SD of fat and fatty acids for soybean oil. Collectively, the estimation of TD or SD of fat can be measured over the entire intestinal tract, whereas the ileal analysis method should be used to determine the ELF, ELFA, and TD or SD of fatty acids. Correcting AD for basal ELF and ELFA can accurately estimate SD values of fat and fatty acids.     

Effect of fat sources and combinations on starter pig performance, nutrient digestibility and intestinal morphology

Three growth trials and one digestion trial were conducted to compare the effect of dietary fat sources and combinations on starter pig performance, nutrient digestibility and intestinal morphology. Growth trials 1 and 2, utilizing a total of 324 weanling pigs (21 +/- 3 d), were conducted to determine the influence of addition of soybean oil, coconut oil, choice white grease, 50% soybean oil: 50% coconut oil or 50% choice white grease: 50% coconut oil on starter pig performance. Diets were supplemented with 10% fat for the first 2 wk of the study and with 5% for the final 3 wk. The third growth trial, utilizing a total of 210 weanling pigs, was conducted to evaluate the effects of addition of soybean oil, coconut oil, 50% soybean oil: 50% coconut oil, 75% soybean oil: 25% coconut oil or 25% soybean oil: 75% coconut oil on starter pig performance and nutrient digestibility. Average daily gain and feed/gain were not changed during wk 0 to 2, but they were improved from 3 to 5 wk postweaning when fat was added to the diets. The combination of 50% soybean oil and 50% coconut oil resulted in higher ADG than the other fat combinations. A digestion trial utilizing 24 weanling pigs (21 +/- 3 d) was conducted to evaluate the effects of soybean oil, coconut oil, or combination of soybean oil and coconut oil on morphology of the small intestine and ileal and total tract apparent digestibilities of individual fatty acids, total fatty acids, N, DM and GE from d 5 to 8 postweaning. Pigs fed the combination of soybean oil and coconut oil tended to have increased (P less than .08) villus height compared with pigs fed soybean oil or coconut oil alone. Micrographs revealed intestinal morphology with long, round villi when this combination of oils was fed. These trials demonstrated that a combination of soybean oil and coconut oil improved (P less than .05) pig growth performance over coconut oil alone or with added choice white grease and tended to improve (P less than .12) ileal digestibility of medium-chain fatty acids (less than or equal to 14 C) compared to diets without added fat or containing soybean oil or coconut oil alone.     

测定不同果皮、胚乳、胚芽含量人工玉米建立生长猪玉米氨基酸消化率预测方程

本试验选用18头初始体重为(24.7±2.5)kg、安装简单T型回肠瘘管的三元杂交(杜洛克×长白×大白)去势公猪,采用直接法测定15种不同果皮、胚乳和胚芽比例的人工玉米表观和标准回肠末端氨基酸消化率,以此为依据建立生长猪对玉米氨基酸消化率的预测方程。试验采用3个6×6拉丁方设计,分为6期,15种日粮,以无氮日粮法测定内源氮损失,以三氧化二铬为指示剂。每个试验期为7 d,前5 d为预试期,后2 d为食糜收集期。结果表明:营养成分含量不同的玉米各种氨基酸消化率存在显著差异(P<0.05)。试验中15种人工玉米赖氨酸的表观消化率范围是59.56%~80.82%,标准消化率则为70.94%~91.87%。通过对人工玉米营养成分和消化率的测定,可建立赖氨酸、蛋氨酸标准回肠消化率的线性回归方程。     

Manipulation of the type of fat consumed by growing pigs affects plasma and mononuclear cell fatty acid compositions and lymphocyte and phagocyte functions

To investigate the immunological effect of feeding pigs different dietary lipids, 3-wk-old, weaned pigs were fed for 40 d on one of five diets, which differed only in the type of oil present (the oil contributed 5% by weight of the diet and the total fat content of the diets was 8% by weight). The oils used were soybean (control diet), high-oleic sunflower oil (HOSO), sunflower oil (SO), canola oil (CO), and fish oil (FO; rich in long-chain [n-3] polyunsaturared fatty acids). There were no significant differences in initial or final animal weights, weight gains, or health scores among the groups. There were no significant differences in the concentration of anti-Escherichia coli vaccine antibodies in the gut lumens of pigs fed the different diets. The fatty acid composition of the diet markedly affected the fatty acid composition of the plasma and of mononuclear cells (a mixture of lymphocytes, monocytes, and macrophages) prepared from the blood, lymph nodes, or thymus. The FO feeding resulted in a significant increase in the number of circulating granulocytes. The FO feeding significantly decreased the proportion of phagocytes engaged in uptake of E. coli and decreased the activity of those phagocytes that were active. The proliferation of lymphocytes in cultures of whole blood from pigs fed the HOSO, SO, or FO diets was less than in those from pigs fed the CO diet. Proliferation of lymph node lymphocytes from SO- or FO-fed pigs was less than that from control, CO-, or HOSO-fed pigs. The natural killer cell activity of blood lymphocytes from pigs fed the FO diet was significantly reduced compared with those from pigs fed the CO diet. The concentration of PGE2 in the medium of cultured blood, lymph node, or thymic mononuclear cells was lower if the cells came from pigs fed the FO diet. Thus, the type of oil included in the diet of growing pigs affects the numbers and functional activities of immune cells in different body compartments.     

Fatty acid composition,fat deposition,lipogenic gene expression and performance of broiler fed diet supplemented with different sources of oil

The present study assessed the effect of feeding palm oil (PO), sunflower oil (SO) and their combination on performance, fat deposition, fatty acid composition and lipogenic gene expression of broilers reared for 42 days. A total of 144 1‐day‐old broilers (Cobb500) were randomly allotted into four treatment diets with each having six replicates of six chicks in each replicate following a completely randomized design. Live weight gain and feed efficiency was significantly (P < 0.05) higher in birds fed with a combination of oil sources compared to controls. Birds fed with the combination of oil and SO alone had higher carcass yield and lower abdominal fat. Higher (P < 0.05) concentrations of unsaturated fatty acids (UFA) and lower concentrations of palmitic acid and saturated fatty acid (SFA) was found in birds fed SO alone and combinations of SO and PO. Furthermore, the outcomes showed that birds fed diet supplemented with SO and the combination of SO and PO down‐regulated gene expression of key hepatic lipogenic enzymes of fatty acids synthase (FAS), acetyl‐CoA carboxylase (ACC) and stearoyl‐CoA desaturase (SCD). These findings suggest that the diet containing the combination of 2% PO and 4% SO may reduce hepatic lipogenesis, as well as lower abdominal fat content of broilers.     

The fatty acid composition of muscle fat and subcutaneous adipose tissue of grazing heifers supplemented with plant oil-enriched concentrates

Our objective was to determine the effect of oil supplementation of pasture fed, beef cattle on the fatty acids, particularly CLA and PUFA, of muscle and s.c. adipose tissue. Forty-five Charolais crossbred heifers were blocked on BW and randomly assigned to 1 of 3 dietary regimens in a randomized complete block design (n = 15). The 3 treatments were: unsupplemented grazing (GO), restricted grazing plus a sunflower oil-enriched ration (SO), or restricted grazing plus a linseed oil-enriched ration (LO). Heifers were fed the experimental diets for approximately 158 d. Samples of LM muscle and s.c. adipose tissue were taken postmortem, the muscle fat was separated into neutral lipid and polar lipid (no separation was performed on the s.c. adipose tissue), and the fatty acid profile was determined by GLC. No effect of dietary treatment on carcass weight or total fatty acid concentration (mean 2,571 mg/100 g of muscle) in muscle fat was detected. Heifers offered SO had a greater (P < 0.001) proportion of CLA and C18:1trans-11 (1.90 and 9.35 vs. 1.35 and 6.89 g/100 g of fatty acids, respectively) in neutral lipid of muscle fat compared with those offered LO, which had a greater proportion of CLA and C18:1trans-11 than heifers offered GO (0.78 and 3.37 g/100 g of fatty acids, respectively). Similar effects were observed in the polar lipid and s.c. lipid. The PUFA:SFA ratio was greater in muscle fat and s.c. adipose tissue from supplemented heifers than in those offered GO (P < 0.001). Compared with LO, the PUFA:SFA ratio was greater (P < 0.05) in muscle fat of heifers offered SO, but there was no difference between SO and LO for this ratio in s.c. adipose tissue. The n-6:n-3 PUFA ratio was similar in muscle and s.c. adipose tissue for GO and LO, but it was greater (P < 0.05) for SO. It is concluded that supplementation of pasture-fed cattle with plant oil-enriched concentrates resulted in an increase in beef fat of some fatty acids considered to be of benefit to human health. Concentrates enriched with sunflower oil were more effective in increasing the CLA concentration, whereas linseed oil-enriched concentrates resulted in a more favorable n-6:n-3 PUFA ratio. The relevance to human health of the associated increase in C18:1trans-11 merits investigation.     

Effects of dietary non-digestible oligosaccharides on microbial characteristics of ileal chyme and faeces in weaner pigs.

Fructooligosaccharides (FOS) and transgalactooligosaccharides (TOS), which are non-digestible oligosaccharides (NDO), were included at 10 and 40 g/kg in an NDO--free control diet at the expense of purified cellulose. Each of the 5 diets was fed to 4 weaner pigs and microbial characteristics of their ileal chyme and faeces were assessed. The NDO-pigs had lower ileal pH than the control pigs. Dietary NDO did not affect the ileal volatile fatty acid concentration, though FOS-pigs had a higher concentration of lactic acid and relatively more iso-valeric acid and less acetic acid than TOS-pigs. The NDO-pigs had lower ileal aerobic bacterial counts than the control pigs, whilst the FOS-pigs had a larger ileal anaerobic bacterial counts than the TOS-pigs. The NDO-pigs had an higher faecal pH and their faecal volatile fatty acid pool contained relatively more iso-butyric acid and iso-valeric acid than the control pigs. The TOS-pigs tended to have higher faecal anaerobic bacterial counts and had a smaller concentration of faecal volatile fatty acid than the FOS-pigs. We concluded that whilst effects at the faecal level may have been partly due to a reduced intake of cellulose, dietary NDO can exert precaecal prebiotic effects in weaner pigs.     

Body composition and selected blood parameters in mice fed a combination of fibre and conjugated linoleic acid

Feeding mice conjugated linoleic acid (CLA) reduces body fat. Soluble fibre decreases apparent lipid digestibility. The objective of the present study was to examine whether a combination of dietary CLA and soluble fibre would further decrease the proportion of body fat than a diet with CLA alone. Therefore, we fed mice diets with CLA and different amounts of Nutrim, containing 10% soluble fibre. CLA was added to the control diet at the expense of high oleic acid sunflower oil (HOSF) component and Nutrim was added at the expense of an isoenergetic combination of starch, dextrose and cellulose. The diets were fed for 28 days. Weight gain after 28 days was less in CLA-fed animals than in HOSF-fed animals. Both CLA and Nutrim increased the body water content. CLA reduced total body fat and epidydymal fat but Nutrim did not. No interaction of CLA and fibre was detected. We, therefore, must conclude that under the present experimental conditions dietary CLA and fibre do not interact to reduce body fat deposition.     

Effect of supplementation of soy sauce oil and Ca salts of fatty acids on rumen fermentation,milk production and conjugated linoleic acid in milk of dairy cows

Eight cows were used to evaluate the effects of supplementation of soy sauce oil (SO) or Ca salts of fatty acids (FA) on rumen fermentation and milk production. The control diet (CO) consisted mainly of hay, corn silage and a concentrate. In the experimental diets, 400 g/day per cow of SO or FA (soybean oil and rapeseed oil) was supplemented to the CO diet. Experimental period for the three treatments was 14 days, and milk samples were taken during the last 2 days and rumen sample was taken on the last day. Dry matter intake was not affected by the treatments. The number of rumen protozoa at 0 h increased by SO and FA diets. Total volatile fatty acids at 2 h after feeding of SO diet was decreased compared to CO. The milk composition yield did not differ among treatments, although the percentages of fat and protein were decreased by SO and FA diets. The proportions of C8–C16 fatty acids in milk fat decreased, and those of C18 increased by SO and FA diets. The proportion of cis‐9, trans‐11 conjugated linoleic acid in milk fat by SO and FA diets increased by 120% and 135%, respectively. In spite of the slight suppression of rumen fermentation by SO diet, negative effects on feed intake and milk production were not detected.     

莱芜猪肌肉脂肪酸组成的发育性变化及其对肉质特性的影响

以40￣90kg6个体重阶段莱芜猪和新莱芜猪为试验对象(n=6),研究肌肉脂肪酸组成的发育性变化及其与肉质特性的关系。结果表明:①随着体重的增大,莱芜猪肌肉总脂含量显著(P<0.01)增加;饱和脂肪酸(SFA)总量的比例有下降的趋势,不饱和脂肪酸(UFA)总量有增加的趋势,但差异不显著;在UFA中,多不饱和脂肪酸(PUFA)总量及亚油酸的比例显著(P<0.01)下降,油酸比例显著(P<0.01)增加;②总体上,莱芜猪肌肉中的SFA+单不饱和脂肪酸总量、总脂、棕榈酸、棕榈烯酸的比例显著高于新莱芜猪,而PUFA总量、硬脂酸、亚油酸、花生烯酸的比例显著(P<0.01)低于新莱芜猪。各体重阶段2个品种间的脂肪酸组成也存在着较大的差异;③莱芜猪肌肉中的PUFA总量与总脂、水分、失水率、大理石纹评分相关显著;总脂与水分、大理石纹相关极显著(P<0.01);SFA、UFA总量与大理石纹呈显著(P<0.05)相关。     

Weekly digestibilities of diets supplemented with corn oil, lard or tallow by weanling swine

Two experiments were conducted to evaluate supplementation of diets with 8% corn oil, lard or tallow. In Exp. 1, 36 barrows weaned at 21 d of age were used to evaluate the effects of these three diets on digestibilities of fat and dry matter and subsequent N retentions from wk 1 to 4 postweaning. In Exp. 2, 147 weanling pigs in six replicates were used to evaluate weekly growth and feed performance measurements when fed these same diets for a 4-wk postweaning period. A large quantity of fat was absorbed (P less than .01) during wk 1 postweaning by pigs fed the corn oil diet, with the quantity absorbed similar for the three sources of fat from wk 2 to 4. Diets with corn oil had a higher apparent fat digestibility than diets supplemented with lard or tallow during each week postweaning (P less than .05). Apparent digestibility of fat increased (P less than .01) for each fat source each week postweaning but appeared to reach a plateau by wk 3 postweaning. Differences in apparent digestibility of fat between fat sources narrowed from wk 1 to wk 4, with digestibility of corn oil increasing from 79 to 89% and of animal fat sources increasing from 67 to 84%. Apparent digestibility of dry matter tended (P less than .10) to be highest when corn oil was provided during the initial 2-wk postweaning period. Although N retention was highest during wk 1 postweaning when the corn oil was fed, this response was attributed to the higher feed intakes of pigs fed this diet.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of emulsifiers and fat mixtures on the digestibility and sedimentation of fatty acids in calves

In a digestibility experiment with 4 X 4 calves the animals received 100 g mixture for calves, 50 g dried green fodder and either 656 g dried whole milk and 164 g dried skim milk (VM) or 656 g dried whole milk and 164 g added fat. The added fat consisted of a mixture of tallow and lard in a 1:1 ratio plus 10% emulgator ES 20 (FE) or 8% ES 20 and 2% soybean lecithin (FL) or 25% lard, 25% tallow, 40% rape/sunflower oil with 10% ES 20 (FO). The apparent digestibility of the fat amounted to 91% in group VM and in groups FE/FL/FO to 66/70/67% resp. The composition of fatty acids and the use of an unsuitable charge of dried skim milk are considered to be the causes of the low apparent digestibility. The apparent digestibility of the fatty acids decreased with their growing chain length. The higher digestibility of the unsaturated fatty acids is largely caused by changes due to bacterial activity in these fatty acids in the intestines and by the influence of metabolically changed faecal fat. The combination of the synthetic emulgator with lecithin did not improve fat digestion but diminished the total fat content in the blood.