Effects of a diet supplemented with caprylic and/or capric acid on piglet performance, apparent digestibility of nutrients, intestinal microflora and small intestine (ileum) structure were investigated. The experiment was performed on 252 piglets (24 litters) allocated to 4 experimental groups (6 litters each). The animals were fed with a standard feed mixture (control) or the same mixture supplemented with 2 g of caprylic or capric acid (groups C 8 and C 10 , respectively) per 1 kg of feed. Group C 8 +C 10 received 1 g of caprylic and 1 g of capric acid. Apparent digestibility was estimated using Cr 2 O 3 as an indicator, while microbiological analyses were performed using standard agar plates. The short-chain fatty acid (SCFA) content of the ileum and caecum digesta was analysed using Varian 340 analyzer. The piglets receiving caprylic or capric acids grew significantly (P<0.01) faster than the control ones (average daily gains during the whole experiment, i.e. between days 1 and 84 of age, were: 288, 269, 278 and 234 g, respectively). The best feed utilization (1.3 kg per kg) was found in animals receiving caprylic acid. The acids also lowered piglet mortality, while significantly increased protein digestibility (P<0.01) and, to a lesser degree (P<0.05), also fibre digestibility. There was no significant difference in acidity of the digesta between control and experimental groups. Capric acid increased the amount of aerobic bacteria as compared to the control group, but the amount of Escherichia coli remained unchanged. The population of Clostridium perfringens was reduced by both caprylic and capric acids (P<0.01). Acids had no effect on SCFA content of the ileum but lowered the acetic acid content of the caecum digesta. Capric acid had the strongest effect on villi, which were significantly higher (306 μm) than in the control group (233 μm). Differences 557 HANCZAKOWSKA E. ET AL.in crypt depth were smaller but the crypts were also the deepest in piglets receiving capric acid. The results suggest that caprylic and capric acids added to the feed improve piglet performance, probably due to positive changes in the mucosal epithelium structure of the ileum.

The effect of supplementing piglet diets with acidifiers containing the short-chain fatty acids -SCFA (propionic C 3 and formic) together with medium-chain fatty acids -MCFA (caprylic C 8 and capric C 10 ) on performance, nutrient apparent digestibility, intestinal microflora and small intestine structure was investigated. The study was performed on 326 piglets allocated to 5 experimental groups. They were fed a standard diet (Group I -control) or a standard diet supplemented with 0.5% propionic and formic acids (Group II -PF). Group III (PF + C 8 ), group IV (PF + C 10 ) and group V (PF + C 8 + C 10 ) received the same mixture as group II with a supplement of 0.2% of caprylic and/or capric acids, respectively. Apparent digestibility of nutrients and microbiological analyses were performed. The structure of jejunum mucosa was also examined. Piglets receiving capric acid (groups IV and V) had the highest body weight gains. Piglets receiving MCFA digested protein and fiber better (P≤0.05) than piglets receiving SCFA as acidifier. There was no difference in intestinal microflora except for Clostridium perfringens, the population of which was reduced by SCFA (group II). Villi of the mucosal epithelium were the highest (P ≤ 0.05) in piglets receiving SCFA with capric acid (group IV). Under the conditions of this study a mixture of SCFA (propionic and formic) with capric acid significantly improves performance of piglets.

From a body weight of 60 to 112 kg, forty-two pigs were fed a standard diet that was either not supplemented (control) or supplemented with a dried water extract of nettle (NE) at a rate of 500 (group LN) or 1000 mg/kg (group HN). Protein deposition was greater in LN than in HN or control pigs. The higher level of NE resulted in decreased body weight gains and increased loin eye area. NE induced changes in the fatty acid profile of meat, but in the blood, it failed to affect the total cholesterol (TC) concentration , while decreasing the HDL level and TC/HDL ratio.