Structural changes in the small intestine of female turkeys receiving a probiotic preparation are dose and region dependent.

Gut microbiota have been shown to play a critical role in the maintenance of host health. Probiotics, which regulate gut microbiota balance, could serve as an effective alternative to antibiotic growth promoters. Since changes in the gastrointestinal tract, caused by a variety of different strains, groups and amounts of microorganisms, may be reflected in its histological structure, the aim of the present study was to examine the effects of rising doses of a mixed probiotic preparation on the structure and development of the small intestine of female turkeys. Eighty, three-day-old, healthy, female turkeys (Big-6 breed) were used in the current (16-week) study. The turkeys were randomly allocated to four weight-matched (59.70 ± 0.83 g) groups (n = 20), according to probiotic treatment dose (0, 107 cfu•g-1, 108 cfu•g-1 or 109 cfu•g-1, in 500 g•1000 kg-1) (cfu - a colony-forming unit). Three, non-genetically modified strains of probiotic cultures obtained from poultry, four bacterial and one yeast culture, were used. Histomorphometric analysis of the structure of the small intestinal wall of the duodenum and jejunum was performed. All probiotic doses used in the current study exerted a beneficial effect on the histological structure of the small intestine; however, the observed effect was dose and region dependent. Significant increases in villi height, crypt depth, villi and crypt width, mucosa thickness, epithelial height, enterocyte number, absorption surface and intestinal ganglia geometric indices were observed, specifically in the duodenum of birds receiving an intermediate dose of probiotic (108 cfu•g-1). The probiotic doses used in the current study differed significantly in their effect on the small intestine (P < 0.01), with the intermediate dose (108 cfu•g-1) significantly improving 58% of the parameters assessed, compared to the control. The duodenum was more susceptible to the favourable effects of the probiotic than the jejunum (56% v. 31% improvement in the parameters assessed) (P < 0.01). The weakest favourable effect was observed in the group that received the highest dose of probiotic.

The effect of feeding system and sex on the performance and selected gastrointestinal features of fattening pigs.

The aim of the study was to evaluate the efficiency of two feeding systems for fattening pigs (wet and dry), taking into account their sex, on performance, nutrient digestibility, and some histological and microbiological parameters of the gut. The study was conducted on 450 fattening pigs, divided into 6 groups (n = 75) and housed in pens with 15 pigs per pen. The first three groups, divided according to sex, i.e. gilts, barrows and boars subjected to immunocastration (B-I), received complete dry feed, while the next three, divided in the same manner according to sex, were fed a fermented liquid diet. The nutritional value of the feeds, calculated on a dry weight basis, was similar for the two feeding systems in both stages of the fattening period. The best weight gains were observed in the group B-I pigs which received the liquid diet, and the poorest in the gilts fed the dry feeds. The best feed conversion ratio (FCR) was observed in the boars treated with Improvac®, especially those receiving the liquid diet. The feeding system significantly influenced the digestibility of nutrients, with higher apparent digestibility coefficients for crude protein, fat and fibre noted in the animals fed in the wet system. The liquid feeding system caused an increase in crypt depth in the colon in all groups of pigs, as well as an increase in the width of the muscular layer. A significant decrease in the total bacterial count was observed in the calcium, especially in the animals fed in the wet system.

Review: Exogenous butyrate: implications for the functional development of ruminal epithelium and calf performance.

The importance of the use of exogenous butyrate in calves' diets is due to its role as a factor stimulating the functional development of ruminal epithelium and improving calf performance during the transition from preruminant to ruminant status. Our review will first present results related to effects of the administration of butyrate in calves' diets on the development of ruminal epithelium toward a more effective absorption and metabolism of fermentation products from the rumen. The introduction of sodium butyrate at a level of about 0.3% of diet dry matter is accompanied by an increase to 35% in butyrate concentration in the rumen of 33-day-old calves. Mutual reliance between an enhanced ruminal concentration of butyrate and the activities of transcription factors, genes and proteins involved in cell proliferation, ketogenesis and the maintenance of cell pH homeostasis in the ruminal epithelial cells has been clearly confirmed in many experiments. Second, the review presents results related to the effects of the introduction of butyrate salts in the diet on calf performance. Of 11 studies a positive effect was found in six; five of these were obtained from the calves that started receiving butyrate supplement at a level of about 0.3% diet dry matter from the age of 3 to 5 days. Results indicate that when a supplement is given to calves soon after birth the functional development of ruminal epithelium in cooperation with the endocrine and digestion systems is transferred into improving the efficiency of rearing. There have been no studies on the effects of greater amounts of butyrate salts in milk replacer; butyrate constitutes about 1.2% of the whole cow's milk dry matter. In older calves, when butyrate administration is provided as a component of a starter concentrate at the increasing inclusion rate from 0.3% to 3.0%, the practical effect in calf performance relates to the risk of depression of rumen pH below 5.5 and accompanying disruption of the organization of the ruminal epithelial tissue. The higher risk is noted in calves received starter with substantial content of a rapidly degradable starch. At present, the insufficient number of positive results confirming the beneficial effect of butyrate supplements in terms of an improvement in performance does not allow their recommendation for use in the practical feeding of calves.

Performance, pork quality and fatty acid composition of entire males, surgically castrated or immunocastrated males, and female pigs reared under organic system.

This study was carried out on the farm specializing in organic pig production on 80 fatteners of the Polish native Pulawska breed, allocated into 4 groups (20 pigs each): EM--entire (uncastrated) males, IM--immunocastrates--males vaccinated with Improvac, CM--surgically castrated males and G--gilts. The highest average daily gains were achieved by the IM group, slightly lower by EM, whereas the lowest by CM and G groups. Content of polyunsaturated fatty acids (PUFA) in intramuscular fat and backfat (10.19% and 10.68%, respectively) of IM was lower (P < 0.05) than in fat of EM (11.4% and 13.20%, respectively), but higher (P < 0.05) in comparison to CM (8.43% and 8.71%, respectively). Vaccination of boars against GnRH has not decreased quality traits of organically produced pork. Furthermore, comparing to meat from surgically castrated males, it resulted in better qualities (lower fat content in carcass, higher PUFA level in fat, better physicochemical meat properties).