Effect of exogenous butyrate on the gastrointestinal tract of sheep. II. Hydrolytic activity in the rumen and structure and function of the small intestine.

The aim of this study was to determine the effect of exogenous butyrate on the activity of carbohydrate-digesting enzymes in the reticuloruminal digesta and structure and selected functions of the small intestine in sheep. Eighteen rams (30.8 ± 2.1 kg; 12 to 15 mo of age) were fed for 14 d a diet without (CTRL) or with sodium butyrate (BUT; 36 g/kg of offered DM). Butyrate concentration in the reticuloruminal fluid and proximal small intestinal digesta was greater for BUT compared with CTRL (P ≤ 0.05). Amylolytic activity was greater, whereas cellulolytic and xylanolytic activity in the reticuloruminal digesta was less for BUT compared with CTRL (P ≤ 0.04). Relative to BW, small intestinal tissue mass and small intestine length did not differ between treatments (P ≥ 0.15); however, absolute length of the small intestine was greater for BUT compared with CTRL (P = 0.04). In the duodenum, crypt depth tended (P = 0.10) to be greater, whereas in the ileum, crypt depth and muscularis thickness tended (P = 0.10) to be less for BUT compared with CTRL. Mitosis-to-apoptosis ratio in the proximal jejunum was greater for CTRL compared with BUT (P = 0.02). Expression of G-protein-coupled receptor 43 mRNA in the duodenal epithelium was greater for BUT compared with CTRL (P < 0.01). On the other hand, peptide transporter 1 mRNA expression in the distal sections of the small intestine, as well as activity of aminopeptidase A and dipeptidylpeptidase IV, were greater for CTRL (P ≤ 0.05). In summary, exogenous butyrate supplementation in feed affects hydrolytic activity in the rumen, and increased butyrate flow out of the reticulorumen affects both proximal and distal sections of the small intestine in sheep.

Effect of exogenous butyrate on the gastrointestinal tract of sheep. I. Structure and function of the rumen, omasum, and abomasum.

The aim of this study was to determine the effect of exogenous butyrate on the structure and selected functions of the stomach in sheep. Eighteen rams (30.8 ± 2.1 kg; 12 to 15 mo of age) were allocated to the study and fed a diet for 14 d without (CTRL) or with sodium butyrate (BUT; 36 g/kg of offered DM). Neither DMI nor initial BW differed between treatments (P ≥ 0.61), but final BW was greater for BUT compared with CTRL (P = 0.03). Butyrate concentration in the reticuloruminal fluid and abomasal digesta was greater for BUT compared with CTRL (P ≤ 0.01), but total short-chain fatty acids (SCFA) concentration, as well as concentration of other SCFA, did not differ between treatments (P ≥ 0.07). Relative to BW, reticuloruminal tissue mass tended (P = 0.09) to be greater and omasal digesta was less (P = 0.02) for BUT compared with CTRL. Dietary butyrate did not affect ruminal papillae length, width, and density nor did it affect ruminal epithelium thickness (P ≥ 0.12) in the ventral sac of the rumen. However, the DM of ruminal epithelium (mg/cm2) tended (P = 0.06) to be greater for BUT compared with CTRL. Omasal and abomasal epithelium thicknesses were greater (P ≤ 0.05) for BUT compared with CTRL. Mitosis-to-apoptosis ratio in the abomasal epithelium was less for BUT compared with CTRL (P = 0.04). Finally, the mRNA expression of peptide transporter 1 in the omasal epithelium was less (P = 0.02) and mRNA expression of monocarboxylate transporter 1 in the abomasal epithelium tended (P = 0.07) to be greater for BUT compared with CTRL. It can be concluded that exogenous butyrate supplementation affected not only the rumen but also omasum and abomasum in sheep.

The effects of iodised salt licks and teat dipping on the iodine content of cow's milk and blood plasma.

INTRODUCTION: Milk has been identified as the ideal carrier of iodine in the human diet. The iodine concentration in cow's milk depends on the iodine intake in the animal's daily rations. MATERIALS AND METHODS: The first experiment, which lasted for 90 days, investigated the effectiveness of salt licks containing 0 (control group), 150, and 300 mg I/kg (experimental groups) and the effect on the iodine content of cow's milk and blood plasma. The second experiment determined the effect of udder disinfection and iodine teat dipping with iodine disinfectant (experimental group) compared to chlorine dip (control group) on the iodine content of milk and blood plasma. Milk iodine and blood plasma concentrations were meas- ured using the Sandell-Kolthoff method modified by the Bobek and Kolczak procedure. RESULT: Salt licks containing 150 and 300 mg I/kg increased iodine intake by 7.5 and 15.0 mg I/day, respectively. Average iodine intake in the control group was 6.23 mg I/day, and 13.68 and 21.10 mg I/day in the experimental groups, respectively. There were no significant differences in the average cows' milk yield, which averaged 21.0 ± 1.1 kg/day. Average milk iodine content was 53.8 µg/1000 mL (control group), 65.0 and 84.7 µg/1000 mL (experimental groups). Average plasma iodine content tended to increase in the experimental groups, but the differences between the groups were not significant. In the second experiment iodine udder disinfection and teat dipping increased average milk iodine content from 44.0 ± 1.6 to 59.3 ± 2.3 µg/1000 mL. Average plasma iodine content increased only slightly, with a non- significant difference between the control and experimental groups. CONCLUSION: The iodine content of salt licks at 150 and 300 mg I/kg makes it possible to obtain from 65 to 85 µg I/1000 mL of cow's milk. Pre-milking udder hygiene and post-milking iodine teat dipping additionally increase the iodine content of milk by around 15 µg I/1000 mL milk, i.e. an increase of 35% in relation to cows from the control group.

Iodine concentration in Polish milk - variations due to season and region.

INTRODUCTION: Iodine concentration was studied in Polish consumer milk. MATERIAL AND METHODS: The milk originated from 13 provincial cities and 65 dairy cooperatives located in Poland. RESULTS: Milk iodine concentration in the winter season of 2007-2008 was 146.8 mg/L, with a standard deviation for the provinces of 27.9 mg/L and variation coefficient of 19.0% (n = 66 samples). Iodine concentration for provincial cities ranged from 76.3 to 192.0 mg/L. It was highest in the milk samples from the Lubelskie province (191.9 mg/L) and lowest in the milk samples from Podlasie (113.8 mg/L). In the summer season, milk iodine concentration averaged 100.4 mg/L, with a standard deviation of 38.9 ìg/L and variation coefficient of 38.8% (n = 27 samples). CONCLUSIONS: Iodine concentration for provincial cities ranged from 63.8 to 173.7 mg/L. Compared to the winter season, milk iodine concentration in the summer season was lower by an average of 25.2%, with a standard deviation of 4.3% (Kielce) to 52.2% (Wroclaw).