Bilateral 'gut-tie' in a recently castrated steer

Small intestinal obstruction caused by 2 fibrous bands was found in a steer. Distended small intestine was palpable per rectum. Each band was located bilaterally between the caudal abdominal wall and the pelvic inlet. The compromised portion of intestine was considered nonviable and the animal was euthanized.     

Incarceration of Small Intestine Through Rents in the Gastrosplenic Ligament in the Horse

Incarceration of the small intestine through a rent in the gastrosplenic ligament was diagnosed in five horses. Three affected horses were mature males and two were mature females. Persistent moderate to severe abdominal pain, elevated heart rate, congested mucous membranes, serosanguineous peritoneal fluid, and distended small intestine on rectal examination were consistent findings.
Exploratory celiotomy or gross necropsy examination showed the incarcerated intestine to be distal jejunum or ileum. In all horses, the intestine had herniated cranially through the rent in the gastrosplenic ligament. The incarcerated intestine was situated lateral to the stomach and craniolateral to the spleen. Three horses underwent exploratory celiotomy, and the incarcerated small intestine was reduced by gentle traction and then resected. Two of these horses were alive more than 2 years postoperatively without recurrence of signs of abdominal pain, and one was euthanized because of dehiscence of the abdominal incision. Two horses were euthanized without surgical intervention, and necropsy examination revealed a recent rent in the gastrosplenic ligament. This condition should be considered in the differential diagnosis of causes of small intestinal strangulation and obstruction in the horse.     

Laparoscopic Abdominal Anatomy of Foals Positioned in Dorsal Recumbency

Eleven foals (nine cadavers and two anesthetized) positioned in dorsal recumbency were examined to describe normal abdominal anatomy viewed by laparoscopy. The foals ages ranged from 1 to 150 days. Insertion sites were selected for a Verres needle, laparoscope and instrument portals to avoid trauma to the umbilical structures. The abdominal cavity was insufflated to a pressure of 10 to 12 mm Hg using an automatic carbon dioxide insufflator. Laparoscopic examination allowed excellent observation of the umbilical structures, the bladder, the genital tract, the inguinal area, the liver and segments of the intestinal tract in all foals. However, the duodenum and ileum were not identified. An embryonic vestige of the yolk stalk (ductus pedunculi vitellini) was identified in six foals. In four foals, this appeared as a fibrous band extending from the umbilicus to the cranial abdominal cavity where it inserted on the small intestine. In two foals only the fibrous umbilical portion of the band was observed.     

Overwintering of Bovine Gastrointestinal Nematodes in Southwestern Ontario

Several steers, reared in isolation until approximately six months of age, were placed on a small isolated enclosed pasture from late spring to late fall of 1970, 1971 and 1972. The pasture was left vacant and unused during the winters and early springs. The pasture had been used in previous years by cattle, and in the late spring of 1970 was grazed by cattle know to be passing gastrointestinal nematode eggs in their feces. The steers were slaughtered periodically, and the prevalence of nematode species in the abomasum, small intestine, and large intestine, was determined from random samples of up to 100 adult male worms from each segment. The following nematodes were found in the steers in 1971 and 1972 and survived winters on pasture: Ostertagia ostertagi, O. lyrata, Cooperia oncophora, C. mcmasteri, Nematodirus helvetianus and Trichuris discolor. Two nematodes Cooperia punctata and Bunostomum phlebotomum known to be present on pasture in 1970, since they were recovered from the steers in that year, were not found in the steers in 1971 and 1972.     

Laparoscopic repair of a small intestinal mesenteric rent in a broodmare

OBJECTIVES : To describe standing laparoscopic repair of mesoduodenal rent inaccessible by ventral median celiotomy. STUDY DESIGN : Clinical case report. SAMPLE POPULATION : A 6-year-old Thoroughbred broodmare with a right displacement of the dorsal colon and small intestinal incarceration in a mesoduodenal rent. METHODS : Two days after correction of a right dorsal displacement of the ascending colon, small intestinal incarceration, and partial closure of mesoduodenal rent, standing left and right flank laparoscopy was used to explore the abdomen to identify the mesoduodenal defect. The mesenteric rent was repaired from right flank portals by approximation with hemostatic clips. RESULTS : Approximation of the mesoduodenal rent was achieved with laparoscopic clips. No further complications or signs of abdominal pain occurred over the following year. CONCLUSIONS : Mesenteric rents in the mesoduodenum can be repaired by laparoscopic techniques in the standing horse. CLINICAL RELEVANCE : Use of laparoscopic techniques in the standing horse should be considered for mesoduodenal rents that are not accessible form a ventral median celiotomy.     

Detection of immunological tolerance to bovine spumavirus (BSV) with evidence for salivary excretion and spread of BSV from the tolerant animal

A group of 17 Friesian-Holstein steers held in individual pens was examined for evidence of infection with bovine spumavirus (BSV). Serum was examined for specific antibody by 2 serological procedures, and circulatory leucocytes and throat swabs were examined for the presence of circulatory leucocyte-associated BSV (CLAB) and saliva-associated BSV (SAB). Initial tests showed that 7 of the 17 steers had specific antibody to BSV by both serological procedures, and a further steer developed such antibody during the first 3 months of holding the animals in single contiguous pens. All 8 of these specific antibody-positive steers were CLAB positive and SAB negative. Nine steers showed no specific antibody to BSV by either of the 2 serological procedures; 8 of these 9 steers showed no evidence of CLAB or SAB. The exception was one steer which was CLAB- and SAB-positive at each of 30 samplings taken over a period of 9 months observation, whilst remaining specific-antibody free. This steer was classed as immunologically tolerant of BSV, and epidemiological data suggested that lateral spread of infection had originated from this animal through the agency of saliva.     

地方猪种对纤维饲料利用的研究——Ⅱ.消化道形态与大肠内容物重量的变化

以三元杂种猪为对照,研究了东北民猪在3种NDF水平(0、10、20％)下消化道形态及后肠内容物鲜重的变化。试验从活重30千克开始,80千克结束时,每组在最后一次给食后的2、4、8、12或16小时随机屠宰2头。电击晕死后立即开膛取出内脏,分为胃、小肠、盲肠和结肠4段进行测量。结果表明猪对饲粮纤维含量的增加从胃肠道形态上发生明显的适应性变化,消化道长度、鲜重增加,尤其结肠长度增加明显,胃、小肠和结肠的鲜重显著地高于基础饲粮组。民猪胃重和结肠鲜重及长度的增加比对照杂种猪明显,消化道总鲜重及其占空体重的比例显著地高于对照杂种猪。随NDF水平的提高,大肠内容物鲜重明显增加,其中民猪更为突出,后肠是吸收水分的主要场所。     

Intestinal atresia and ectopia in a bovine fetus

A 2-year-old Red Holstein cow was presented with uterine torsion at 235 days of pregnancy. The fetus extracted by cesarean section had weak vital signs and marked abdominal distention. An edematous pouch that contained tubular structures with peristaltic activity was associated with the umbilical cord. Because of poor prognosis, both dam and fetus were euthanized. At necropsy, the fetus had severe distention of the forestomachs, abomasum, and proximal small intestine; absence of distal small intestine, cecum, and proximal colon; atresia of the 2 blind ends of the intestine; and atrophy of distal colon and rectum. The tubular structures associated with the umbilical cord were identified as the segments of intestine that were absent in the fetus. Intestinal atresia combined with ectopia may be caused by local ischemia during temporary herniation and rotation of the fetal gut into the extraembryonic coelom. The close connection between ectopic intestine and amniotic sheath of the umbilical cord in this case may have facilitated vascularization and allowed development and viability of the ectopic intestine.     

Association of serologic status for Neospora caninum and postweaning feed efficiency in beef steers.

OBJECTIVE: To determine the effects of serologic status for Neospora caninum on short-term weight gain, feed intake, and feed efficiency (feed intake/gain). DESIGN: Longitudinal observational study. ANIMALS: 34 weaned mixed-breed beef steers. PROCEDURE: Serologic status for N. caninum was determined for each steer on days 0 (weaning), 88, 116, 144, 172, and 200, using an agglutination test. Individual steer body weight was measured on days 0, 88, 116, 144, 172, 200, and 242 (slaughter). Daily feed intake was monitored from days 116 through 242. Serologic status was matched to animal performance for the period immediately following serum sample collection. A mixed mode, using repeated-measures with an unstructured covariance matrix, was used in the analysis. Breed, age, and pen effects were controlled for in the analysis. RESULTS: A reduction in average daily gain for the period following a positive serologic result was detected for the entire trial (6 measurements/steer). This may have been attributed to a significant impairment in feed efficiency rather than to an impairment in feed intake. Changes in serologic status in individual steers over time were common; additionally, the effects of serologic status on steer performance were also transitory. CONCLUSIONS AND CLINICAL RELEVANCE: Significant reductions in short-term weight gain and feed efficiency were associated with the presence of antibodies against N. caninum in postweaning beef steers.     

The effects of slaughter age on growth and carcass traits in an intensively managed crossbred beef herd

The purpose of this study was to determine and describe the effects of slaughter age (at constant weights) on pre- and post-weaning growth rate and carcass traits of unselected steer and heifer progeny from a crossbred beef herd. The data were obtained from 340 heifers and 377 steers weaned at 305 days of age and fed a high-energy post-weaning diet. Heifers and steers were slaughtered at individual unshrunk weights of 420 and 470 kg, respectively, and divided into slaughter age classes based on 25-day intervals. There were differences (P < 0.01) between slaughter age classes for all growth traits including 305-day (weaning) weight, post-weaning daily gain, days on feed, and weight/day. Mean 305-day weight of steers in the youngest slaughter age class (347.8 kg; 376–400 days of age) was 28% greater than the mean of steers in the oldest age class (272.2 kg;>501 days of age). The youngest steer class averaged 63% more for daily gain than the oldest steer class (1.462 vs. 0.894 kg); the corresponding value for heifers was 64%. Post-weaning time in the feedlot ranged from 84.7 days for the youngest steer to 215.6 for the oldest steer class. Calculations based on mean differences between age classes in 305-day weight, daily gain and days on feed indicated that variability in weaning weight and in daily gain were of similar importance in determining slaughter age. Marbling score was greater (P < 0.01) for older steer classes, but was not different in the heifer data. Fat thickness of the oldest steer class was 25% more than the youngest steer class (1.89 vs. 1.51 cm); the corresponding percent in heifers was 30%. With the exception of differences in untrimmed rib and chuck percents in steers (P < 0.05), and rib specific gravity in heifers (P < 0.05), carcass quantity traits were essentially unaffected by slaughter age class when marbling score and fat thickness were included as continuous independent variables. None of the organoleptic traits (tenderness, juiciness and flavour) were affected by slaughter age class.     

Site of magnesium and other macromineral absorption in steers fed high levels of potassium

Six Angus x Simmental steers, surgically equipped with abomasal and ileal cannulae, were used during three metabolism trials. Steers were blocked according to weight ad were allotted to three dietary K levels (.6, 2.4 and 4.8% dry basis) for each trial with the restriction that no animal would receive the same level during two successive trials. Each trial consisted of a 5-d transition, a 10-d preliminary period, a 7-d collection of feed, feces and urine and a 6-d sampling of feed, feces and abomasal and ileal fluid. Chromic oxide (.5%) was used as an indicator to measure flow through the digestive tract. Magnesium absorption decreased linearly (P less than .05) with increasing level of dietary K. The primary site of Mg absorption was the preintestinal region followed by a net secretion into the small intestine. Preintestinal Mg absorption was decreased 39% when 4.8% K was fed. Serum Mg was lower at high levels of dietary K. Potassium absorption increased linearly when expressed as g/d and curvilinearly when expressed as percentage of intake, with increasing levels of dietary K. When .6% K was fed, the primary site of K absorption was the small intestine, but with the high levels of K, the preintestinal region was also an important site of absorption. The effect of high K level on Mg absorption in steers was similar to that observed previously in sheep.     

Effect of nematode parasite infection on the performance of stocker cattle at high stocking rates on coastal bermudagrass pastures.

Studies were conducted during the summer of 2 successive years (1971 and 1972) to determine the effects of gastrointestinal nematode parasitism on performance failure of stocker beef steers grazed at high stocking rates on Coastal bermudagrass pastures. During each of the 2 years, 3 groups of steers were rotated at 7- to 10-day intervals on sets of three 1.63-ha pastures from mid-May to late October. (Each group was maintained on a given set of pastures.) In the 1971 program, from mid-May to early August (phase 1) each group consisted of 48 steers for a stocking rate of 29.6 steers/ha. From early August to late October (phase 2) the number of steers per group was reduced to 36 (stocking rate of 22.2 steers/ha) to improve the plane of nutrition. In the 1972 program, 2 groups were stocked at 48 steers per group (29.6 steers/ha) and a 3rd group was temporarily stocked with 58 steers (10 additional steers) to provide 2 animals each month for necropsy evaluation of worm burdens. With exception of the monthly removal of 2 steers from the 3rd group, the stocking rate in 1972 remained intact for the entire grazing season. In 1971, the 3 groups (groups 1, 2, and 3) were treated with thiabendazole (2 doses, 16 days between doses) before grazing. Parasite burdens and levels of pasture contamination were low initially and body weight gains were good during the 1st 3 months of grazing (phase 1). In the 2nd half (phase 2) of the grazing program, 1 group of steers given free-choice supplemental feed (1% of body weight/steer each day) and treated with anthelmintic (thiabendazole; 2 doses, 18 days between doses, during August) and another group, given supplemental feed only, had significantly better weight gains than did the 3rd group, not given supplemental feed nor treated with anthelmintic. There was no weight gain advantage derived from the reduced stocking rate in phase 2. Tracer calves, which were allowed to graze on pastures, developed an increased level of infection after August. Fecal egg counts in the principal steers and recovery of infective larvae from pasture paralleled the infection level in tracer calves. Necropsy evaluation of steers from groups 1, 2, and 3 at the end of the 1971 program indicated a similarity in total worm counts, but in the group not given supplemental feed nor treated with anthelmintic there was more generalized inflammation and a greater number of lesions in the abomasum (Ostertagia) and the caudal portion of the intestine (Oesophagostomum). Steers in the 3rd group also were in poorer condition. Initial worm burdens in the 3 steer groups (groups 4, 5, and 6) were low at the start of the 1972 program. One group was given freechoice supplemental feed (0.5% of body weight/steer each day) and treated with anthelmintics (thiabendazole in the 1st dose, levamisole in the 2nd dose, 12 days between doses, in May and August) and another group was given supplemental feed throughout the summer; the 3rd group was treated with anthelmintics (in May and August)...     

Evaluation of an inactivated Neospora caninum vaccine in beef feedlot steers

OBJECTIVE: To evaluate effects of vaccination of feedlot steers against bovine neosporosis on weight gain, feed intake and efficiency (feed intake per gain), and carcass characteristics. DESIGN: Longitudinal observational study. ANIMALS: 60 weaned Brangus steers seronegative for Neospora caninum. PROCEDURE: Steers were assigned to age-matched control and treatment groups. Steers in the treatment group received N. caninum vaccine on days 79 and 106, while control steers received 2 placebo injections. For each steer, serologic status for N. caninum was determined on days 0 (weaning), 51, 79, 106, 135, 163, 191, 219, and 247 by use of an ELISA; body weight was determined on the same days and at slaughter (day 259). Daily feed intake per steer was measured from days 79 to 259. RESULTS: Seroconversion occurred in 23 of 30 (76.7%) steers in the vaccinated group. Immediately after vaccination, average daily gain, average daily feed intake, and feed efficiency were significantly greater in the treatment group than in the control group, but these differences did not persist. No differences between groups were found in regard to live weight at slaughter, hot carcass weight, dressing percentage, or quality grade; however, steers in the vaccinated group had significantly lower yield grades than did control steers. CONCLUSIONS AND CLINICAL RELEVANCE: In feedlot steers, use of this vaccine against N. caninum was safe and did not affect overall feedlot performance or meat quality; effects on yield grade require further evaluation.     

Entrapment of the small colon through a mesocolic rent in a mare

A 6-year-old mare was presented for acute abdominal pain unresponsive to analgesics. Exploratory laparotomy revealed entrapment of the small colon through a 12 cm rent in the mesocolon. The incarcerated small colon was manually reduced and the rent in the mesocolon was sutured closed. The mare made excellent postoperative recovery and was discharged from the hospital 4 days later. The cause of the rent, which was chronic in appearance, is unknown.     

Studies on nitrogen and amino-acid absorption in the swine. Part 1. Passage of the chyme in the small intestine

Three female pigs of about 50 kg liveweight were provided with re-entrant canulas in the upper and lower sections of the small intestine and were catheterized to collect urine and blood (vena jugularis). After feeding once the experimental diet containing 15N-labelled, fat extracted dry curd as protein component, it was possible to determine, on two days, the chyme passed through the canulas and to separate aliquote portions thereof for analysis. The cellulose contained in the food was used as indicator for the passage rate of the chyme in the small intestine. The passage rates in the small intestine calculated from the amounts of cellulose and chyme were found to agree fairly well. The passage rates in the upper part of the small intestine were characterized by strongly marked, short-time peaks, right after feed intake, and by periods of relatively even chyme flow some eight hours after feeding. At the end of the small intestine almost constant chyme passage rates were observed over the whole experimental period.     

Impact of doramectin treatment at the time of feedlot entry on the productivity of yearling steers with natural nematode infections

OBJECTIVE: To measure the reduction in fecal nematode egg counts and productivity impact of treatment of yearling steers with doramectin at entry into the feedlot, compared with control steers treated only with fenthion. ANIMALS: 6,096 crossbred yearling steers with a mean (+/- SD) body weight of 377.0 (+/- 37) kg. PROCEDURE: Steers were implanted with zeranol and alternately separated to fill each of 24 pens. Groups of steers within 12 matched pairs of pens were randomly allocated to treatment with doramectin or no treatment with doramectin for internal nematodes. Fecal samples were collected from approximately every twentieth steer from each pen at day 0 and at reimplant (approx day 60). Each steer was weighed on day 0 and at reimplant and then mean body weights of steers per pen were determined at 120 to 140 days after trial initiation. RESULTS: Treatment steers had a significantly lower fecal egg count at reimplant than control steers. Treatment steers had a significantly greater mean daily gain during the study, significantly greater feed consumption, significantly lower feed-to-gain ratio, and significantly better quality carcass grades at slaughter. CONCLUSIONS AND CLINICAL RELEVANCE: Under the conditions of our trial, there was a significant fecal egg count reduction response to doramectin treatment, which resulted in significantly improved productivity. Results of economic analysis of return on investment indicated that even with low egg counts in heavy body weight cattle, nematode egg count reduction with doramectin significantly improved returns.     

Effects of maternal protein supplementation and inclusion of rumen‐protected fat in the finishing diet on nutrient digestibility and expression of intestinal genes in Nellore steers

The study aimed to evaluate nutrient digestibility and intestine gene expression in the progeny from cows supplemented during gestation and fed diets with or without rumen‐protected fat (RPF) in the feedlot. Forty‐eight Nellore steers, averaging 340 kg, were housed in individual pens and allotted in a completely randomized design using a 2 × 2 factorial arrangement (dams nutrition × RPF). Cows' supplementation started after 124 ± 21 days of gestation. The feedlot lasted 135 days and diets had the inclusion of zero or 6% of RPF. Digestibility was evaluated by total feces collection. Steers were slaughtered using the concussion technique and samples of pancreas and small intestine were collected immediately after the slaughter to analyze α‐amylase activity, and the expression of SLC5A1, CD36, and CCK and villi morphometry. Feeding RPF increased nutrients digestibility (p < 0.01). There was no effect of maternal nutrition on digestibility and α‐amylase activity in steers (p > 0.05). Duodenal expression of SLC5A1, CD36, and CCK increased in the progeny from restricted cows. In conclusion, protein restriction during mid to late gestation of dams has long‐term effects on small‐intestine length and on expression of membrane transporters genes in the duodenum of the progeny. However, maternal nutrition does not affect digestibility in the feedlot.     

An outbreak of sarcocystosis in a cattle herd.

In a cattle herd, 3 steers had anorexia and variable emaciation; 1 showed additional muscle stiffness, pyrexia, became recumbent and was killed in extremis. Gross changes in tissue specimens from this steer included grey-white foci in the skeletal muscle and a thickened, fibrous pleura. By histology interstitial pneumonia, myocarditis and necrotizing myositis were seen. There were wide-spread vascular lesions with endothelial damage, thrombosis and periarterial infiltrations. Sarcocystis-like schizonts were found in several organs, and different stages of thin-walled sarcocysts were seen in the myocardium. Examination of organs of 6 other steers in the same herd slaughtered 2 months later showed myocarditis, myositis, interstitial pneumonia and occasional vascular occlusions. There were a few schizonts in the spleen and lungs, and thin-walled sarcocysts were seen in the myocardium and skeletal muscle. It is concluded that development of vascular lesions probably represents an important step in the pathogenesis of sarcocystosis.     

Volvulus of the colon in a horse associated with a mesocolic-umbilical band

A 7-years-old Clydesdale mare was presented with severe abdominal distension and acute colic. Dilated large intestine was palpated per rectum and a ventral midline exploratory laparotomy was performed. A 180 degrees volvulus of the pelvic flexure was present, associated with an inelastic band of tissue connecting the mesocolon to the umbilicus. The band was ligated and transected, and the volvulus reduced. Postoperative complications included hyponatraemia, metabolic acidosis and laminitis. The possible aetiology of the mesocolic-umbilical band is discussed.     

Comparison of sampling techniques for measuring the antimicrobial susceptibility of enteric Escherichia coli recovered from feedlot cattle

OBJECTIVE: To evaluate the effectiveness of various sampling techniques for determining antimicrobial resistance patterns in Escherichia coli isolated from feces of feedlot cattle. SAMPLE POPULATION: Fecal samples obtained from 328 beef steers and 6 feedlot pens in which the cattle resided. PROCEDURE: Single fecal samples were collected from the rectum of each steer and from floors of pens in which the cattle resided. Fecal material from each single sample was combined into pools containing 5 and 10 samples. Five isolates of Escherichia coli from each single sample and each pooled sample were tested for susceptibility to 17 antimicrobials. RESULTS: Patterns of antimicrobial resistance for fecal samples obtained from the rectum of cattle did not differ from fecal samples obtained from pen floors. Resistance patterns from pooled samples differed from patterns observed for single fecal samples. Little pen-to-pen variation in resistance prevalence was observed. Clustering of resistance phenotypes within samples was detected. CONCLUSIONS AND CLINICAL RELEVANCE: Studies of antimicrobial resistance in feedlot cattle can rely on fecal samples obtained from pen floors, thus avoiding the cost and effort of obtaining fecal samples from the rectum of cattle. Pooled fecal samples yielded resistance patterns that were consistent with those of single fecal samples when the prevalence of resistance to an antimicrobial was > 2%. Pooling may be a practical altemative when investigating patterns of resistance that are not rare. Apparent clustering of resistance phenotypes within samples argues for examining fewer isolates per fecal sample and more fecal samples per pen.