Rumen-protected choline supplementation in periparturient dairy goats: effects on liver and mammary gland

The current study investigated the effects of supplementing rumen-protected choline (RPC) on metabolic profile, selected liver constituents and transcript levels of selected enzymes, transcription factors and nuclear receptors involved in mammary lipid metabolism in dairy goats. Eight healthy lactating goats were studied: four received no choline supplementation (CTR group) and four received 4g RPC chloride/day (RPC group). The treatment was administered individually starting 4 weeks before expected kidding and continuing for 4 weeks after parturition. In the first month of lactation, milk yield and composition were measured weekly. On days 7, 14, 21 and 27 of lactation, blood samples were collected and analysed for glucose, beta-hydroxybutyrate, non-esterified fatty acids and cholesterol. On day 28 of lactation, samples of liver and mammary gland tissue were obtained. Liver tissue was analysed for total lipid and DNA content; mammary tissue was analysed for transcripts of lipoprotein lipase (LPL), fatty acid synthase (FAS), sterol regulatory binding proteins 1 and 2, peroxisome proliferator-activated receptor gamma and liver X receptor alpha. Milk yield was very similar in the two groups, but R PC goats had lower (P < 0.05) plasma beta-hydroxybutyrate. The total lipid content of liver was unaffected (P = 0.890), but the total lipid/DNA ratio was lower (both P < 0.05) in RPC than CTR animals. Choline had no effect on the expression of the mammary gland transcripts involved in lipid metabolism. The current plasma and liver data indicate that choline has a positive effect on liver lipid metabolism, whereas it appears to have little effect on transcript levels in mammary gland of various proteins involved in lipid metabolism. Nevertheless, the current results were obtained from a limited number of animals, and choline requirement and function in lactating dairy ruminants deserve further investigation.

Basfia succiniciproducens gen. nov., sp. nov., a new member of the family Pasteurellaceae isolated from bovine rumen

Gram-negative, coccoid, non-motile bacteria that are catalase-, urease- and indole-negative, facultatively anaerobic and oxidase-positive were isolated from the bovine rumen using an improved selective medium for members of the Pasteurellaceae. All strains produced significant amounts of succinic acid under anaerobic conditions with glucose as substrate. Phenotypic characterization and multilocus sequence analysis (MLSA) using 16S rRNA, rpoB, infB and recN genes were performed on seven independent isolates. All four genes showed high sequence similarity to their counterparts in the genome sequence of the patent strain MBEL55E, but less than 95 % 16S rRNA gene sequence similarity to any other species of the Pasteurellaceae. Genetically these strains form a very homogeneous group in individual as well as combined phylogenetic trees, clearly separated from other genera of the family from which they can also be separated based on phenotypic markers. Genome relatedness as deduced from the recN gene showed high interspecies similarities, but again low similarity to any of the established genera of the family. No toxicity towards bovine, human or fish cells was observed and no RTX toxin genes were detected in members of the new taxon. Based on phylogenetic clustering in the MLSA analysis, the low genetic similarity to other genera and the phenotypic distinction, we suggest to classify these bovine rumen isolates as Basfia succiniciproducens gen. nov., sp. nov. The type strain is JF4016(T) (=DSM 22022(T) =CCUG 57335(T)).

Effect of feeding cows genetically modified maize on the bacterial community in the bovine rumen

Rumen-cannulated cows (n = 4) were fed successively silage made from either conventional or genetically modified (GM) maize. Results revealed no effects of GM maize on the dynamics of six ruminal bacterial strains (investigated by real-time PCR) compared to the conventional maize silage.

[Rumenocentesis: a suitable technique for analysis of rumen juice pH in cattle?]

In the United States, rumenocentesis has been recommended especially for early diagnosis of subacute rumen acidosis (SARA). The objective of the current study was to evaluate health risks due to the technique ofrumenocentesis and to measure pH in ruminal juice using a commercial indicator paper (Pehanon) and a pH electrode (reference method). After 11 dairy cows underwent rumenocentesis, the clinical status of those animals was evaluated daily, and cows were slaughtered as well as pathologically--anatomically examined on day 7. During the observation period, the following pathological clinical signs were evident: forced inspiration (3 cows), transient episode of hyperthermia (2 cows), increased tension of the abdominal wall (8 cows) and positive foreign body tests (3 cows). One cow had to be culled on day 7 because of severe generalised septic peritonitis spreading from the site of rumenocentesis. At slaughter, hematoma formation in the area of the puncture site was found in 9 out of 10 cows. It was concluded that the severe complications encountered with this technique do not legitimate rumenocentesis as a routine procedure for collection of rumen juice samples in cows under Swiss conditions. The correlation between the pH reference method and the commercial indicator paper was the high (r = 0.926).