The effect of olive leaves supplementation on the feed digestibility, growth performances of pigs and quality of pork meat

The influence of olive leaves supplementation on feed digestibility, growth performance of pigs and pork meat quality was investigated. Pigs fed diets with olive leaves at 5% (OL5) and 10% (OL10) levels had lower daily weight gain (DG) and daily feed intake (DFI) than pigs fed a conventional diet (OL0) but differences were not observed between groups fed with the different quantities of leaves. Additionally, pigs fed diets with leaves had the worst feed:gain ratio and showed a decrease in overall backfat. Chops from pigs fed the leaf diets had lower peroxide (PV) and conjugated diene (CD) contents than chops from pigs fed conventional diets. Moreover, chops from pigs fed with the higher quantity of leaves also showed a lower drip loss. After a storage period of 8 days at 4 °C, meat obtained from both OL5 and OL10 animals also differed (P < 0.05) in PV and %CD values from those fed a conventional diet. Since the fatty acid composition of the longissimus muscles was not different, differences in oxidative stability could only be explained by the significantly higher α-tocopherol concentration in intramuscular fat and backfat in pigs fed with olive leaf diets.     

Characterization of antimicrobial-resistant phenotypes and genotypes among Salmonella enterica recovered from pigs on farms, from transport trucks, and from pigs after slaughter

The main objectives of this study were to determine antimicrobial resistance patterns among Salmonella serotypes and to evaluate the role of transport trucks in dissemination of antimicrobial-resistant strains of Salmonella. Salmonella from groups of nursery and finishing pigs on farms, from trucks, and from pigs after slaughter were compared using serotyping, patterns of antimicrobial resistance, and pulsed-field gel electrophoresis patterns. The five farms included in the study yielded 858 isolates representing 27 Salmonella serovars. The most common resistance observed (80% of all isolates) was to tetracycline; resistance to ampicillin (42%), chloramphenicol (31%), amoxicillin/clavulanic acid (30%), and piperacillin (31%) also were common. We found a correlation between serovar and antimicrobial resistance. High correlation was found between Salmonella Typhimurium var. Copenhagen and chloramphenicol resistance (Spearman rank correlation, rho = 0.7). Multidrug resistance was observed primarily in Salmonella Typhimurium var. Copenhagen (94%) and Salmonella Typhimurium (93%) and was much less common in the other common serovars, including Salmonella Derby (7%) and Salmonella Heidelberg (8%). Of the 225 isolates exhibiting the most common pentaresistance pattern in this study, amoxicillin/clavulanic acid-ampicillin-chloramphenicol-piperacillin-tetracycline, 220 (98%) were Salmonella Typhimurium var. Copenhagen, and 86% of the isolates of this serovar had this pattern. Isolates from the trucks were similar, based on pulsed-field gel electrophoresis patterns, to those from the cecum and mesenteric lymph nodes of pigs on two of the farms, suggesting the probable infection of pigs during transport. Class I integrons were also common among various serovars.     

Effect of a high linoleic acid diet on lipogenic enzyme activities and on the composition of the lipid fraction of fat and lean tissues in the pig

The aim of this study was to examine the influence of a high linoleic acid diet on lipogenic enzyme activities in pig tissues and on the dietetic quality of these tissues (subcutaneous adipose tissue, Semimembranosus and Diaphragma muscles). Pigs were fed diet M containing 4% of maize oil or diet T containing 4% of tallow from 40 to 100 kg live weight. We did not observe any differences in growth or slaughter performances that could be attributed to diet. Lipogenic enzyme activities were higher in the adipose tissue of pigs fed diet M. However, diet had no effect on lipogenesis in the muscles. The lipid, linoleic acid, and cholesterol contents were higher in the adipose tissue of pigs fed diet M whereas the oleic acid concentration of the adipose tissue was lower. No significant increase in the lipid content of either muscle was however observed in pigs fed diet M. The linoleic acid and cholesterol contents were higher in both muscles of pigs fed diet M than in muscles of pigs fed diet T.     

Diet supplementation with thyme oil and its main component thymol failed to favorably alter rumen fermentation,improve nutrient utilization,or enhance milk production in dairy cows

Phenolic compounds and essential oils with high content of phenolic compounds have been reported to exert antimicrobial activities in vitro. The objective of this study was to determine the effects of dairy cow diet supplementation with thyme oil and its main component thymol on intake and total-tract apparent digestibility of nutrients, rumen fermentation characteristics, ruminal protozoa, nitrogen excretion, and milk production. For this aim, we used 8 multiparous, ruminally cannulated Holstein cows in a replicated 4 × 4 Latin square design (28 d periods), balanced for residual effects. Cows were fed 1 of the 4 following experimental treatments: total mixed ration (TMR) with no additive (control); TMR + monensin [24 mg/kg of dry matter (DM)]; TMR + thyme oil (50 mg/kg of DM); and TMR + thymol (50 mg/kg of DM). Compared with the control diet, feeding thyme oil or thymol had no effect on DM intake, nutrient total-tract apparent digestibility, total N excretion, ruminal pH, ammonia concentration, total volatile fatty acid (VFA) concentration, or acetate:propionate ratio. Ruminal protozoa density was not modified by thyme oil, but decreased with thymol supplementation. Supplementation with thyme oil or thymol did not affect milk production, milk composition, or efficiency of milk production. Neither thyme oil nor thymol affected efficiency of dietary N use for milk N secretion (N intake/milk N). Supplementation with monensin tended to decrease DM intake (–1.2 kg/d) and milk fat yield. Total-tract apparent digestibility of nutrients did not differ between cows fed monensin and cows fed the control diet. Total VFA concentration was not changed by monensin supplementation compared with control, but adding monensin shifted the VFA profile toward more propionate and less acetate, resulting in a decrease of acetate:propionate ratio. Protozoa density and ammonia concentration were lower in the ruminal content of cows fed monensin compared with that of cows fed the control diet. Total N excretion was not affected by monensin supplementation. Likewise, efficiency of use of dietary N for milk N secretion was unchanged in cows fed monensin. The results of this study contrasted with the claimed in vitro antimicrobial activity of thyme oil and thymol: we observed no positive effects on rumen metabolism (i.e., N and VFA) or milk performance in dairy cows. Under the conditions of this study, including thyme oil or thymol at 50 mg/kg of DM had no benefits for rumen fermentation, nutrient utilization and milk performance in dairy cows.     

Acceptability and nitrogen utilisation of Tower and Erglu rapeseed meals by the growing pig.

Acceptability and nitrogen utilisation studies were made with diets containing barley and either extracted soy bean meal (SBM) or one of the two low glucosinolate extracted rapeseed meals Tower (TRSM) and Erglu (ERSM). In acceptability studies SBM, TRSM and ERSM were substituted isometrically at 20% in diets which were offered ad libitum for 8 weeks to pigs of 23 kg initial liveweight. There were four groups of four castrate male pigs, and four groups of four gilt pigs, per group, per diet. For the first 2 weeks intake per unit metabolic weight (W^0.75) was greatest, but thereafter was least, for the SBM diet. In metabolism studies three diets were computed and fed so that 54.5 % of the daily intake of 170 g of crude protein was derived from SBM, TRSM or ERSM. Twelve caged castrate male pigs of 25 kg liveweight were fed on each diet. Apparent digestibility of crude protein was higher for the SBM diet compared with the TRSM (P<0.05) and ERSM (P>0.05) diets. Nitrogen retention decreased significantly from the SBM to the ERSM to the TRSM diets. In an individual feeding growth experiment, using 12 castrate male and 12 gilt pigs per diet, isonitrogenous diets based on SBM, TRSM and ERSM were fed, on a liveweight related basis, between 23 and 67 kg liveweight. The SBM fed pigs grew significantly faster and required significantly less crude protein per unit of gain than those fed TRSM and ERSM, between which there were no significant differences.     

Effects of feeding elevated concentrations of monounsaturated fatty acids and vitamin E to swine on characteristics of dry cured hams

Thirty Large White×Great York gilts were fed six experimental diets containing three levels of poly and monounsaturated fatty acids. Within each dietary fat treatment, one group was fed a basal level of vitamin E (20 mg α-tocopheryl acetate/kg diet) and the other group received a supplemented level (200 mg α-tocopheryl acetate/kg diet). Concentration of α-tocopherol was significantly higher in hams from pigs fed supplemented dietary levels of vitamin E (P<0.0001), but no significant effect of dietary fat was observed. Dietary vitamin E supplementation reduced the concentration of thiobarbituric acid reactive substances after 9 days storage of sliced samples (P<0.0001), while dietary fat source showed no significant effect. Significantly lower oxidation was observed in ham homogenates from pigs fed higher concentrations of monounsaturated fatty acids after 120 min of incubation under pro-oxidant conditions (P=0.013). No effect of dietary treatment was observed in ham volatile aldehyde profile. No significant effect of dietary vitamin E was observed on surface redness during storage, but a significant effect was observed for luminosity after 7 days of storage (P=0.033). Hams from pigs fed diets enriched in monounsaturated fatty acid showed higher ‘a’ values (P=0.040) in stored sliced samples. Sensory evaluation revealed a significant effect of dietary vitamin E on redness of ham slices (P<0.001). Dietary supplementation with vitamin E also produced a significantly higher odour and flavour intensity (P=0.006 and P=0.01 respectively). Dry cured ham samples from pigs fed higher amounts of monounsaturated fatty acids showed a significantly higher consistency fat than those from pigs fed polyunsaturated fatty acids.     

Functional Characteristics, Fatty Acid Composition, and Palatability of Bacon from Pigs Fed Canola

Thirty-six pigs were fed diets containing 20% intact canola (IC), 20% ground canola (GC) or 0% canola (C). Processing yields and proximate composition of bacon were not affected by diet. Bacon from pigs fed GC had less saturated fatty acids and more monounsaturated fatty acids than bacon from pigs fed the IC or C diets. Bacon from pigs fed the C diet had less polyunsaturated fatty acids than bacon from pigs fed the IC or GC diets. Palatability of bacon from C, IC or GC treatments after 0 or 4 weeks storage was not different. After 8 weeks of storage, panelists tended to prefer control bacon over bacon from pigs fed the GC diet. Bacon from pigs fed the GC diet had higher 2-thiobarbituric acid values than bacon from pigs fed the IC or C diets.     

Influence of dietary fat and α-tocopherol supplementation on lipid oxidation in pork

Sixty-four pigs, approximately 3 weeks old, were fed diets containing 3% beef tallow or 3% soya oil with either a basal (10-50 mg/kg diet) or supplemented (200 mg/kg diet) level of α-tocopheral acetate. In pigs fed the soya oil diet the neutral and polar lipid fractions of muscle tissue and the total lipid fraction of adipose tissue had significantly (P < 0·05) higher C18:2/C18:1 ratios when compared to pigs fed the tallow diet. Muscle from pigs fed the soya oil diet was significantly more susceptible (P < 0·05) to lipid oxidation than muscle from pigs fed the tallow diet. In pigs receiving the α-tocopherol supplemented diet, α-tocopherol levels were approximately 3·3, 2·8 and 2-times higher in plasma, muscle and adipose tissue, respectively, when compared to pigs fed the basal level of α-tocopherol acetate. α-Tocopherol supplementation significantly increased (P < 0·05) the oxidative stability of muscle from pigs fed both the tallow and soya oil diets.     

Influence of finishing diet on fatty acid profiles of intramuscular lipids, triglycerides and phospholipids in muscles of the Iberian pig

Thirty Iberian × Duroc pigs allotted in groups of ten animals were fed in three traditional different management systems ('Montanera' (MO), fed on acorns; 'Recebo' (RE), fed on acorns and a commercial diet; and 'Cebo' (CE), fed on a commercial diet). Masseter muscle was obtained to evaluate the influence of management system on fatty acid (FA) composition of lean. The FA composition of the intramuscular total lipids, triglyceride (TG) and phospholipid (PL) fractions was evaluated. Muscle from MO pigs had greater quantities of monounsaturated fatty acids (MUFA) in the total lipids, triglyceride and phospholipid fractions than the other feedings. The percentage of saturated fatty acids (SFA) of i.m. total lipids and TGs increased (P < .05) with duration of feeding on RE and CE, from 35.13-35.10% in MO pigs to 37.47-37.84% in RE pigs and 39.98-41.11% in CE pigs. PLs from RE and CE pigs contained more C(18:2) and C(20:4) and less C(18:1) than MO pigs.     

Diet-induced changes in alginate- and laminaran-fermenting bacterial levels in the caecal contents of rats

Brown algae contain soluble polysaccharides, such as alginic acid, fucoidan and laminaran. To assess the induction of dietary fiber-fermenting bacteria in the intestine, rats were fed diet containing no dietary fiber (control) or 2% w/w of the polysaccharides for 2 weeks. The levels of dietary fiber-fermenting bacteria in caecal contents were determined using decimal dilution culture containing 1% w/v of the fibers. Caecal microbiota in the rats was analyzed using polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). In the culture method, 4–9 log viable cells/g caecal content of alginate-fermenting bacteria was detected in rats fed alginate, while this was not detected in rats fed the control diet. Although laminaran-fermenting bacteria were detected in control rats (4–9 log viable cells/g), the level observed in rats fed laminaran was 8 or 9 log viable cells/g. On the other hand, fucoidan-fermenting bacteria were not detected in rats fed fucoidan. DGGE analysis showed laminaran administration increased the diversity of bacterial bands. Clostridium spp. and Parabacteroides distasonis were detected as typical species in rats fed alginate and laminaran. The results indicate that the intake of soluble fermentable fibers in edible brown algae can alter the intestinal microbiota and its fermentation capacity.     

Rice protein concentrate partially replaces dried whey in the diet for early‐weaned piglets and improves their growth performance

BACKGROUND: Recently, rice protein concentrate (RPC), a much cheaper source of dietary protein, has become commercially available for use in the feed industry. Importantly, dietary supplementation with RPC can increase feed intake by early‐weaned pigs. The objective of this study was to determine whether RPC can replace milk protein in the diet for early‐weaned pigs. RESULTS: Neither average daily gain (ADG), average daily feed intake (ADFI), nor the feed/gain ratio differed among the treatment groups in weeks 1 and 2. In week 3, the addition of 5 or 10% RPC to diets increased (P < 0.05) ADFI and ADG of pigs compared to those in the control group fed a 60% dried whey diet. During the entire 21‐day trial, ADFI and ADG were greater (P < 0.05) in pigs fed the 5 and 10% RCP diets than in pigs fed the 60% dried whey and 15% RCP diets. There were no differences in the serum concentrations of growth hormone on days 14 and 21, serum concentrations of insulin growth factor‐I (IGF‐I) on day 14, or IGF‐I gene expression in liver and skeletal muscle on days 14 and 21 among the dietary treatments. Serum concentrations of IGF‐I in pigs fed the 5, 10 and 15% RPC diets were greater than those in pigs fed the 60% dried whey diet. CONCLUSION: Findings indicate that up to 10% RPC can be used to replace dried whey in the diet for 7‐ to 21‐day‐old weaned piglets and can improve their growth performance. Copyright © 2008 Society of Chemical Industry     

Effect of duration of feeding under free-range conditions on production results and carcass and fat quality in Iberian pigs

This experiment was undertaken to provide information on the effect of feeding system applied during the finishing period (100-150kg) on the quality of Iberian pig meat. Four feeding systems were applied: pigs fed under free-range conditions with acorns and grass fully available during 111 days (FR(111)), pigs fed concentrate diet in confinement during 28 days and free-range with acorns and grass fully available during 83 days (CDC(28)+FR(83)), pigs fed concentrate diet in confinement during 65 days and free-range with acorns and grass fully available during 46 days (CDC(65)+FR(46)) and pigs fed concentrate diet in confinement with a feed average daily amount of 3.1kg during 111 days (CDC(111)). The CDC(111) pigs had more muscular carcasses characteristics than the remaining groups of pigs. However, the higher concentration of C18:1 n-9 in subcutaneous backfat was found in FR(111) pigs. In the neutral lipids from intramuscular fat of Longissimus dorsi only the C18:2 n-6 and C18:3 n-3 proportions were affected by feeding system, and the n-6/n-3 ratio observed was lower in FR(111) and CDC(28)+FR(83) pigs than in CDC(111) pigs. In the neutral lipids from hepatic fat the proportion of n-6 fatty acids was lower in FR(111) pigs than in CDC(65)+FR(46) and CDC(111) pigs.     

Physical activity-induced alterations on tissue lipid composition and lipid metabolism in fattening pigs

In a first experiment one group of pigs was maintained in free-range conditions according to the traditional way in a Mediterranean forest (exercised-1) and another group was housed individually and received acorns (sedentary-1). In a second experiment two groups of pigs were fed a mixed diet for the whole experimental period. One of these groups was housed individually in 8 m² pens (sedentary-2). The other group was housed in a corridor and forced to walk daily (exercised-2).The subcutaneous fat and neutral lipids of muscle from the exercised pigs fed acorns had higher C18:1n-9, MUFA, C18:1/C18:0, MUFA/SAT and lower C16:0 and SAT when compared with the fat from the pigs fed acorns in confinement. Those exercised animals fed the mixed diet had also lower C16:0 and SAT in subcutaneous fat and lower SAT and higher C18:2, C18:3, PUFA and MUFA/SAT in neutral lipids when compared with the sedentary pigs, which may indicate that delta-9-desaturase activity was higher in exercised than in sedentary pigs. Exercised pigs had higher acid and neutral esterases and lower neutral lipase activity than sedentary pigs. No differences in the α-tocopherol concentration and TBARS values of meat samples among the pigs that received a mixed diet either exercised or sedentary were observed. The moderate exercise reduced the postprandrial concentrations of triglycerides in plasma, but did not reduce other plasma levels.     

Oxidative and lipolytic changes during ripening of Iberian hams as affected by feeding regime: extensive feeding and alpha-tocopheryl acetate supplementation

The effect of pig feeding in an extensive system based on acorn and pasture or in confinement with a control diet containing 5 mg α-tocopheryl acetate kg(-1) of feed and a 100 mg α-tocopheryl acetate kg(-1) enriched diet on evolution of lipid changes throughout ripening of dry-cured hams was investigated. Feeding regime significantly affected TBA-RS, peroxide value and hexanal content of Biceps femoris and Semimembranosus muscles. Muscles from pigs fed supplemented diet with α-tocopherol or fed extensively on acorn and grass showed significant lower (p<0.05) TBA-RS and peroxide value than ham muscles from pigs fed the basal diet at 210 days of processing. Both feedings reduced significantly (p<0.05) hexanal content at day 210 and day 700. Muscle slices from pigs fed on acorn showed significant higher scores (p<0.05) in aroma and flavour intensity, cured flavour and numerically lower rancid scores than those from control diet hams. ?     

Prediction of the feeding background of Iberian pigs using the fatty acid profile of subcutaneous, muscle and hepatic fat

Thirty Iberian pigs weighing 95 kg were randomly distributed into three groups of 10 animals each and fattened in three traditional management systems ['montanera' (MO), fed extensively on acorns, 'cebo' (CE) fed on a commercial diet and 'recebo' (RE), fed on acorns and a commercial diet]. Fatty acids from the Masseter muscle, lard and liver were analysed. In the lard, fatty acid profiles from MO and RE pigs presented minor differences; however, in the liver, RE pigs showed differences to MO pigs in most of the fatty acids studied. This suggests that the muscle and especially the liver fatty acid profile reflects the feeding regime during the last phase of feeding, while the lard reflects longer term differences.     

INCLUDING CHESTNUTS AND SUGAR BEET PULP IN DIETS FOR PIGS: THE EFFECTS ON THE QUALITY OF PORK MEAT AND THE SENSORY PROPERTIES OF DRY-CURED SAUSAGE (CHORIZO GALLEGO)

This research was aimed at evaluating how the inclusion of dried chestnuts and dried sugar beet pulp in diets for pigs affected the quality of pork meat and the sensory properties of dry-cured sausage ( chorizo gallego ). The meat from pigs that received a diet with chestnuts and sugar beet pulp (CBP) showed lower thiobarbituric acid values and higher water-holding capacity than meat from pigs fed a conventional diet (C). Significant differences were also observed between both batches in color parameters and fatty acid composition of the meat. In the sensory analysis of chorizo, the sausages manufactured with meat from pigs fed the CBP diet were significantly better rated than those with meat from pigs fed a C diet in appearance, odor, flavor, texture and overall score.

PRACTICAL APPLICATIONS

The inclusion of dried chestnuts and dried sugar beet pulp in diets for pigs during the fattening period allowed us to recover some of the ingredients more traditionally used in the feeding of pigs. This inclusion modifies some parameters of the resulting pork meat quality; (it decreases lipid oxidation and increases water-holding capacity and polyunsaturated fatty acid content) and also improves the sensory properties of any dry-cured product made with this pork meat.     

Salmonella in food animals and humans in northern Thailand

A study was conducted to describe the epidemiology of Salmonella spp. in chickens, pigs, dairy cows, farm workers with and without livestock contact, and children with diarrhea. Samples were collected in the Chiangmai and Lampoon provinces of northern Thailand during 2000-2003. A total of 2141 samples were processed. The prevalences of Salmonella in chickens at the farm, slaughterhouse and chicken meat at the market were 4%, 9% and 57%, respectively. In pigs, the prevalence at the farm, slaughterhouse and pork at the market were 6%, 28% and 29%, respectively. The prevalence of Salmonella in dairy cows was 3%. Salmonella was isolated from 36% of farm workers with livestock contact and 33% of those with no livestock contact, and from 7% of diarrheal children at the hospital. The longitudinal study of Salmonella in pigs showed that the incidences of Salmonella isolation at the farm, slaughterhouse, and market were 7%, 50% and 20%, respectively. The most frequently isolated serotypes of Salmonella were Weltevreden in chickens and humans, and Rissen in pigs. Serotypes varied between farm, slaughterhouse and market for isolates from chickens and pigs. Antimicrobial resistance was present in isolates from all types of animals and humans in the study, with widespread resistance to tetracycline and nalidixic acid. The proportions of resistant organisms among Salmonella from diarrheal children were high, and higher proportions of multi-drug resistant organisms were observed among Salmonella isolates from farm workers with livestock contact than among isolates from workers with no livestock contact.     

乳酸菌发酵饲料对生长猪生产性能的影响

研究了乳酸菌发酵饲料对规模化猪场生长猪生产性能和健康的影响。对照组直接饲喂基础日粮,1组饲喂"基础日粮+20%乳酸菌发酵饲料(风干)",2组饲喂"基础日粮+30%乳酸菌发酵饲料(风干)",3组饲喂"基础日粮+50%乳酸菌发酵饲料(风干)"。结果表明:1、2和3组平均日增重比对照组分别提高了9.67%、11.47%和13.68%,3组与对照组相比差异极显著,1、2组与对照组相比差异显著;1、2和3组头平均日采食量比对照组分别提高了3.47%、4.16%和4.88%,3组与对照组相比差异极显著,1、2组与对照组相比差异显著。1、2和3组料肉比比对照组分别下降了5.16%、6.35%和7.54%,发病率比对照组分别降低了38.46%、46.15%和69.23%;1、2和3组比对照组多盈利22.7%、26.8%和31.6%。     

半乳甘露寡糖替代抗生素对猪常乳中激素水平的影响

将24头长×大二元母猪随机分为4组,每组6头,以研究同一玉米-豆粕型基础日粮中按20mg/kg添加吉它霉素、20mg/kg维吉尼亚霉素和质量分数0.10%半乳甘露寡糖,对它们在泌乳高峰期分泌的常乳中激素水平的影响。结果表明:与对照组相比,维吉尼亚霉素和半乳甘露寡糖可以显著提高乳中生长激素的水平;吉它霉素也有提高的趋势,但未达显著水平;与对照组和两个抗生素组相比,半乳甘露寡糖可以显著提高乳中肿瘤坏死因子的水平;与吉它霉素组相比,半乳甘露寡糖可以显著提高乳中皮质醇的含量,其它3组两两间无显著差异。半乳甘露寡糖可以通过改变乳中某些生物活性因子的浓度而间接地起到促进吮乳仔猪健康生长的作用。     

Extra‐virgin and refined olive oils decrease plasma triglyceride,moderately affect lipoprotein oxidation susceptibility and increase bone density in growing pigs

The objective of this study was to determine the health benefits of extra‐virgin and refined olive oils, which are high in mono‐unsaturated fatty acids (MUFAs) and polyphenolic compounds using the pig as a model. Thirty‐two cross‐bred pigs were individually penned, allocated to one of four dietary treatments and fed ad libitum for 28 days. Two of the experimental diets consisted of a basal diet containing 12% tallow and either 7% sunflower oil (TSO) or 7% extra‐virgin olive oil (TEVO) on a w/w basis. The remaining diets contained 19% extra‐virgin olive oil (EVO) or 19% of refined olive oil (RO). On days 7, 14 and 28 fasted and 3‐h post‐prandial blood samples were taken. Body composition was measured at the beginning and end of the study using dual energy X‐ray absorptiometry. Daily gain, feed intake and lean and fat deposition were not significantly different between the treatments. However, the daily increase in bone mineral density was higher in pigs fed diets containing olive oil (1.23 vs 2.54, 6.28, 5.20 mg cm^?2 per day for TSO, TEVO, EVO and RO, respectively, P = 0.050). Both fasting and non‐fasting plasma triglycerides were lower (P = 0.003) in pigs fed MUFA‐rich diets, while the cholesterol profile was not significantly different between the treatments. The results from in vitro copper‐induced lipid peroxidation, expressed in terms of conjugated dienes, showed that low density lipoprotein (LDL) particles in postprandial serum from pigs fed olive oil were moderately more resistant to oxidative modification. In conclusion, these data demonstrate that both extra‐virgin and refined olive oils attenuate postprandial hypertriglyceridaemia, moderately affect oxidation susceptibility and increase bone mineral density in growing pigs. Copyright © 2006 Society of Chemical Industry