Abomasal ulceration and abomaso-pleural fistula in an 11-month-old beefmaster bull.
(25/204)
An 11-month-old, beefmaster bull presented with anorexia and signs of respiratory disease. Physical examination, thoracic ultrasonography and radiography, and pleural fluid analysis indicated pericarditis and septic neutrophilic pleuropneumonia. Postmortem findings were abomasal adherence to the diaphragm, a fibrotic fistulous tract connecting the abomasum and pleural cavity, granulomatous abomasitis, granulomatous pericarditis, and fibrinonecrotic pleuritis. (+info)
A comparison of duodenal osmolality and energy content as controlling factors of gastric emptying in the calf.
(26/204)
1. The relative importance of energy content and osmolality of the duodenal chyme in the feed-back control of gastric emptying was investigated in the milk-fed calf fitted with gastric (abomasal) and duodenal re-entrant cannulae. 2. Duodenal infusion of isosmolal solutions, containing glucose, fructose or galactose, with a range of combustible energy content (0--1.46 MJ/l.) resulted in the same high rate of emptying of test meals from the stomach (abomasum). Abomasal emptying was, therefore, not affected by the energy content of the duodenal infusate. 3. Gastric secretion of acid and pepsinogen, and the volume of gastric secretions produced were also unaffected by the energy content of isosomolal duodenal infusates. 4. The results of the study show that the combustible energy content of the intestinal chyme is not a direct determinant of gastric function and that total osmolality of the lumenal contents is the only parameter influencing duodenal receptors under the conditions of our experiments. (+info)
Cholinergic and noncholinergic innervation of the smooth muscle layers in the bovine abomasum.
(27/204)
The intrinsic innervation of muscle layers in the mammalian gastrointestinal tract has been mainly studied in nonruminants. The aim of this study was to identify intrinsic motor neurones in the bovine abomasum that innervate the circular and longitudinal muscles. Circular (CMN) and longitudinal muscle motor neurones (LMN) were selectively labeled by application of the retrograde tracer 1,1'-didodecyl-3,3,3',3'-tetramethyl indocarbocyanine perchlorate (DiI) onto the muscle layers. The transmitter phenotype was determined by immunohistochemical detection of choline acetyltransferase (ChAT), nitric oxide synthase (NOS), and neurone-specific enolase (NSE). On average, the myenteric ganglia contained 61 +/- 19 NSE-positive cell bodies, of which 89% were ChAT-positive and 10% were NOS-positive. Only 0.7% of NSE-positive neurones (41 of 5,777) contained both ChAT and NOS. Application of DiI onto the circular and longitudinal muscles revealed on average 60 +/- 27 (n = 4) and 68 +/- 36 (n = 4), respectively, labeled cell bodies in the myenteric plexus. For the circular and longitudinal muscles the proportions of ascending to descending neurones were 76 : 24% and 54 : 46%, respectively. While most ascending CMN were ChAT-positive (96%), 51% of the descending CMN were ChAT-negative. All ascending and 95% of descending LMN were ChAT-positive. It was concluded that cholinergic excitatory innervation is predominant in both muscle layers of the abomasum. Whereas the circular muscle receives cholinergic excitatory and nitrergic inhibitory innervation, the longitudinal muscle is only innervated by cholinergic pathways. This innervation pattern is different from that in gastric muscle layers in monogastric animals. (+info)
Influence of abomasal infusion of glucose or partially hydrolyzed starch on pancreatic exocrine secretion in beef steers.
(28/204)
Five crossbred steers (348 +/- 12 kg) fitted with a pancreatic pouch draining the main pancreatic duct and duodenal re-entrant and abomasal infusion cannulas were used in a 5 x 5 Latin square design to determine the influence of postruminal carbohydrate source and level on pancreatic exocrine secretion in beef steers. Abomasal infusion treatments (250 mL infused/h) were water (control), 20 g/h glucose, 40 g/h glucose, 20 g/h starch hydrolysate (SH), and 40 g/h SH. Infusion periods were 8 d with 3 to 4 d of rest between periods. Pancreatic juice was collected for 6 h on d 8 of each collection period. Every 30 min a 10% subsample was composited and frozen and the remainder was infused into the duodenum via the reentrant cannula. Abomasal infusion of glucose or SH increased (P < 0.10) total secretion of pancreatic juice and decreased (P < 0.10) secretion of alpha-amylase activity. Abomasal carbohydrate infusion did not influence total secretion of protein, trypsin activity, or chymotrypsin activity. This experiment indicates that increasing postruminal glucose or SH decreases pancreatic alpha-amylase secretion. (+info)
Relevance of apolipoproteins in the development of fatty liver and fatty liver-related peripartum diseases in dairy cows.
(29/204)
Most metabolic diseases in dairy cows occur during the peripartum period and are suggested to be derived from fatty liver initially developed during the nonlactating stage. Fatty liver is induced by hepatic uptake of nonesterified fatty acids that are released in excess by adipose tissues attributable to negative energy balance. The fatty accumulation leads to impairment of lipoprotein metabolism in the liver, and the impairment in turn influences other metabolic pathways in extrahepatic tissues such as the steroid hormone production by the corpus luteum. Detailed understanding of the impaired lipoprotein metabolism is crucial for elucidation of the mechanistic bases of the development of fatty liver and fatty liver-related peripartum diseases. This review summarizes results on evaluation of lipoprotein lipid and protein concentrations and enzyme activity in cows with fatty liver and those with ketosis, left displacement of the abomasum, milk fever, downer syndrome and retained placenta. Obtained data strongly suggest that decreases in serum concentrations of apolipoprotein B-100, apolipoprotein A-I and apolipoprotein C-III, a reduction in activity of lecithin:cholesterol acyltransferase and induction of haptoglobin and serum amyloid A are intimately related to the development of fatty liver and fatty liver-related diseases. Moreover, determination of the apolipoprotein concentrations and enzyme activity during the peripartum period is useful for early diagnoses of these diseases. (+info)
Effect of diet on Shiga toxin-producing Escherichia coli (STEC) growth and survival in rumen and abomasum fluids.
(30/204)
The gastrointestinal tract of ruminants is the main reservoir for Shiga toxin-producing Escherichia coli (STEC) strains, potentially pathogenic for humans. We used for the first timerumen fluid in which no exogenous carbon source or other supplement was added to compare acid resistance and growth of STEC in physiological physico-chemical conditions. We showed that acidic conditions resulting from the combination of high volatile fatty acid concentration and moderately acidic pH did not alter the survival of STEC, and that human non-O157:H7 STEC isolates were able to persist in the rumen contents in spite of acid stress, low oxygen availability and nutrient deprivation, in the same manner as bovine STEC isolates do. Furthermore, our results support the hypothesis that a grain-rich diet may induce mechanisms of STEC acid resistance in the rumen that allow STEC survival in the abomasum. (+info)
Methionine as a methyl group donor in growing cattle.
(31/204)
Holstein steers were used in two 5 x 5 Latin square experiments to evaluate the sparing of methionine by alternative sources of methyl groups (betaine and choline). Steers were housed in metabolism crates and limit-fed a soybean hull-based diet high in rumen degradable protein. To increase energy supply, ruminal infusions of volatile fatty acids and abomasal infusions of glucose were provided. An amino acid mixture, limiting in methionine, was infused abomasally to ensure that nonsulfur amino acids did not limit protein synthesis. Treatments for Exp. 1 were abomasal infusion of 1) water, 2) 2 g/d L-methionine, 3) 1.7 g/d L-cysteine, 4) 1.6 g/d betaine, and 5) 1.7 g/d L-cysteine + 1.6 g/d betaine. Treatments for Exp. 2 were abomasal infusion of 1) water, 2) 2 g/d L-methionine, 3) 8 g/d betaine, 4) 16 g/d betaine, and 5) 8 g/d choline. In both experiments, nitrogen retention increased in response to methionine (P < 0.05), demonstrating a deficiency of sulfur amino acids. Responses to cysteine, betaine, and choline were all small and not significant. The lack of response to cysteine indicates that the response to methionine was not due to transsulfuration to cysteine or that cysteine supply did not alter the flux of methionine through transsulfuration. The lack of response to betaine suggests that the steers' needs for methyl groups were met by the dietary conditions or that betaine was relatively inefficient in increasing the remethylation of homocysteine to methionine and, thereby, reducing the synthesis of cysteine from homocysteine. Under our experimental conditions, responses to methionine were likely due to a correction of a deficiency of methionine per se rather than of methyl group donors. (+info)
Effects of ruminal and postruminal infusion of starch hydrolysate or glucose on the microbial ecology of the gastrointestinal tract in growing steers.
(32/204)
Forty crossbred steers were used to determine the effects of carbohydrate supply site on the indigenous bacteria of the gastrointestinal tract. Steers were fitted with ruminal and abomasal infusion catheters and assigned randomly to one of eight groups in a complete randomized block design. The experimental period was 36 d. Treatments included: 1) a pelleted basal diet fed at 0.163 Mcal ME x (kg BW(0.75)) x 1 x d(-1) (LE); 2) the basal diet fed at 0.215 Mcal ME x (kg BW(0.75)) (-1) x d(-1) (HE); 3) the basal diet fed at 0.163 Mcal ME x (kg BW(0.75))(-1) x d(-1) with ruminal infusion of starch hydrolysate (SH) (RSH); 4) the basal diet fed at 0.163 Mcal ME x (kg BW(0.75))(-1) x d(-1) with abomasal infusion of SH (ASH); and 5) the basal diet fed at 0.163 Mcal ME x (kg BW(0.75))(-1) x d(-1) with abomasal infusion of glucose (AG). The total volume ofinfusate (5 kg x site(-1) x d(-1)) was equalized across treatments and infusion sites by infusion of water. Glucose and SH were infused at rates of 14.35 and 12.64 g x (kg BW(0.75)) x d(-1), respectively. Ruminal, cecal, and fecal samples were obtained on d 36. Ruminal pH was low (5.79) in LE steers and unaffected (P > 0.10) by increased energy intake or carbohydrate infusion. Cecal and fecal pH were 6.93 and 7.00, respectively, for LE steers. Increasing energy intake (P < 0.10) and the rate of carbohydrate infusion (P < 0.01) significantly decreased cecal and fecal pH compared with LE. Ruminal counts of anaerobic bacteria in LE steers were 8.99 log10 cells/g and abomasal carbohydrate infusion had no affect (P > 0.10) on these numbers. However, ASH and AG steers had approximately 1.5 log10 cells/g more (P < 0.01) cecal and fecal anaerobic populations. Ruminal, cecal, and fecal aerobic bacterial counts were 40, 22, and 23%, respectively, lower than anaerobic counts. Generally, aerobic counts responded similarly to the anaerobic counts. Less than 1% of the anaerobic bacteria enumerated in the rumen, cecum, and feces were coliforms, and 97% of the coliforms were Escherichia coli. Carbohydrate infusions resulted in only numerical increases in fecal coliform and E. coli concentrations (P > 0.10). Fecal E. coli were highly acid sensitive in all steers, with less than 1% surviving a 1-h exposure to low pH (2.0). This suggests that cecal or fecal pH is not a good indicator of acid resistance, and it supports the concept that there are other factors that may induce acid resistance. (+info)