Site of nutrient digestion by dairy cows fed corn of different particle sizes or steam-rolled.

Five primiparous Holstein cows were cannulated in the rumen, duodenum, and ileum and were fed diets containing 50% alfalfa silage and 36.6% coarse-, medium-, or fine-ground corn (CGC, MGC, and FGC, respectively, with mean particle sizes of 4.8, 2.6, or 1.2 mm), steam-rolled corn (SRC; density of 0.53 kg/L), or a 50:50 mix of CGC and SRC (SC) to evaluate how corn processing affects site of digestibility of nonstructural carbohydrates (NSC) and neutral detergent fiber (NDF). Decreasing the particle size of corn quadratically affected true ruminal digestibility of NSC (49.8, 46.5, and 87.0%, respectively). Because of compensatory digestion postruminally, a smaller increase (from 91.3 to 98.0%) in total tract digestibility of NSC was noted as particle size decreased. A small but significant linear shift in NDF digestion from the rumen to the large intestine was detected as corn particle size decreased. The addition of SRC to CGC linearly increased true NSC digestibility in the rumen about 20 percentage units but had much smaller effects on total tract digestibility. Despite the large impact of corn processing on NSC digestibility in the rumen, flow of bacterial N to the rumen was not affected by treatment. Reducing the particle size of corn decreased the apparent escape of corn protein, but steam-rolling had no effect. Corn should be finely ground to maximize total tract OM digestibility or steam-processed to densities less than 0.53 kg/L for maximal starch digestibility. However, fine-grinding or steam-processing of corn may have only a modest impact on total tract OM digestibility.

Synovial fluid analysis in cattle: a review of 130 cases.

OBJECTIVE: To compare synovial fluid characteristics of cattle with infectious and noninfectious arthritis. STUDY DESIGN: Retrospective cohort study. ANIMAL OR SAMPLE POPULATION: 130 cattle. METHODS: Synovial fluid was analyzed for total nucleated cell count (NCC), absolute number and percentages of polymorphonuclear (PMN) and mononuclear cells, total protein (TP) concentration, and specific gravity. Cattle were categorized as having infectious or noninfectious arthritis based on physical and lameness examinations, joint radiographs, and microbial culture results. Kruskal-Wallis 1-way analysis of variance was used to compare synovial fluid analysis data from different categories. Selection of cut-off values for the calculation of likelihood ratios, sensitivity, specificity, and positive and negative predictive values was based on examination of the distribution of the data using histograms. RESULTS: Cattle with infectious arthritis had significantly higher numbers of total NNC, PMN cells, TP concentration, and specific gravity (P = .0001) and a significantly higher percentage of PMN cells compared with cattle with noninfectious arthritis (P = .0001). The percentage of mononuclear cells was significantly higher in cattle with noninfectious arthritis (P = .0001). CONCLUSIONS: Synovial fluid analysis is useful for differentiation of infectious and noninfectious causes of joint disease in cattle. CLINICAL RELEVANCE: Cattle with a synovial fluid total NCC > 25,000 cells/microL, a PMN cell count > 20,000 cells/microL or more than 80% PMN cells, and TP > 4.5 g/dL should be considered to have infectious arthritis.

Effects of replacing forage fiber or nonfiber carbohydrates with dried brewers grains.

Four primiparous Holstein cows in late lactation were used in a 4 x 5 Youden square design. Each cow was fitted with ruminal, duodenal, and ileal cannulas. Treatments were a control diet with a high concentration of forage, a control diet with a low concentration of forage, and three diets in which dried brewers grains replaced a portion of the forage, concentrate, or both. Cows were fed and milked twice daily in 14-d periods. Chromic oxide and Yb (soaked in acid) were used as markers for digesta flow and rate of passage, respectively. No significant differences in ruminal pH or rates of passage caused by treatment were detected. Although brewers grains had slower digestion rates of neutral detergent fiber (NDF) in situ and faster passage rates than did alfalfa, brewers grains had minor effects on site of NDF digestion. Intake of dry matter was depressed by the higher NDF concentrations in diets in which brewers grains replaced concentrate, but a long-term feeding study is needed to verify this conclusion. Although brewers grains did not appear to be very effective at stimulating milk fat percentage, dry matter intake was maintained when brewers grains replaced forage, and it appears that brewers grains can successfully replace a portion of the forage NDF in the diets of lactating cows.

Multifocal polyostotic aneurysmal bone cysts in a llama.

A 3.3-year-old 125-kg castrated male llama was evaluated because of acute non-weight-bearing lameness on the left hind limb. Physical examination revealed crepitus in the midportion of the femur. On radiographs, a comminuted middiaphyseal fracture was seen. There was also a region of bone lysis with cortical thinning and expansion in the distal metaphysis and epiphysis of the left femur. Multiple small circular lesions were observed in the proximal metaphysis of the left femur, and the proximal portion of the left tibia appeared irregular. The owner elected to pursue treatment, and the fracture was repaired with 2 compression plates. Multiple bone biopsy specimens were obtained and submitted for bacterial culture and histologic examination. Cultures yielded neither bacteria nor fungi. Histologic examination revealed fibrous connective tissue, normal appearing cortical bone, and an absence of medullary structures. The llama was maintained in a hind-limb sling for 14 days after surgery, at which time follow-up radiography revealed a comminuted fracture of the proximal portion of the femur. The llama was euthanatized, and multifocal polyostotic aneurysmal bone cysts were found in the proximal and distal metaphyses of the left femur and tibia. Cysts were lined by fibroblasts or endothelial-like cells.

Intussusception in cattle: 336 cases (1964-1993).

OBJECTIVE: To evaluate risk factors and to describe clinical and laboratory findings, surgical management, and postoperative outcome for cattle with intussusception. DESIGN: Hospital-based, case-control epidemiologic study and retrospective case series. SAMPLE POPULATION: Medical records of cattle admitted to 17 veterinary medical teaching hospitals in North America. PROCEDURE: Epidemiologic analysis of demographic data and detailed analysis of medical records for selected cattle. RESULTS: 336 cattle with intussusception were identified, 281 had small intestinal, 7 had ileocolic, 12 had cecocolic, and 36 had colocolic intussusceptions. Sex and season were not significantly associated with cattle developing intussusception, whereas calves < 2 months old were at greater risk of developing small intestinal intussusception than older cattle. Analysis of medical records of 57 cattle with intussusception revealed that these cattle were mildly hyponatremic, hypochloremic, hypocalcemic, azotemic, and hyperglycemic. Right flank laparotomy with a cow in a standing position, followed by intestinal resection and end-to-end anastomosis was the most common means of surgical correction. Overall survival rate (20/57; 35%) and postoperative survival rate (20/46; 43%) for cattle with intussusception were much lower than previously reported. CLINICAL IMPLICATIONS: Although rare in cattle, intussusception was most common in calves < 2 months old. Survival rate for cattle treated for intussusception was low (< 50%).

Fatty acid digestion in lactating dairy cows fed fats varying in degree of saturation and different fiber sources.

Six cannulated cows were assigned to six treatments in a 6 x 6 Latin square design to evaluate the effects of fat saturation and amount and source of effective fiber on fatty acid metabolism. Cows were fed a control diet with no added fat or diets with 5% added fat from saturated tallow, tallow, or animal-vegetable fat; the diets with animal-vegetable fat had three percentages of effective fiber: 40% forage, 40% forage plus 20% soyhulls, or 60% forage. Cows fed diets supplemented with fat tended to have more disappearance of total fatty acids in the rumen than did those fed the control diet. Disappearance of fatty acids from the rumen, especially C16 and C18, was higher for cows fed the low fiber diet. The apparent digestibility of fatty acids in the small intestine was higher for cows fed the control diet than for those fed supplemental fat. Apparent digestibility also was reduced as fat saturation increased, primarily because of saturated tallow. Digestibility of C18:1 in saturated tallow was reduced, apparently in association with other saturated fatty acids. Fiber source had no effects on apparent intestinal digestibility of fatty acids. Concentrations of C18:0 and C18:1 in milk fat increased as the degree of fat saturation decreased, reflecting higher unsaturated C18 intake and ruminal biohydrogenation of polyunsaturated C18 fatty acids.

Fractures and luxations of the pelvis and proximal femur.

Although lameness caused by fractures and luxations of the pelvis and proximal femur are rare, they are serious and often end an animal's productive life unless properly diagnosed and promptly treated. Diagnosis of these injuries is difficult without special radiographic equipment; however, careful physical examination will often lead to a tentative diagnosis. Coxofemoral luxations and slipped capital epiphysis are two of these life-threatening injuries. This article discusses their diagnosis and possible options for treatment, which can lead to a useful, productive life. The diagnosis of other pelvic injuries is discussed, although these injuries are often not as amenable to treatment.

Teat and udder surgery.

Teat and udder surgery is certainly one of the major areas of soft tissue surgery. In recent years, there have been great advances in what can be accomplished with teat and udder surgery. This article reviews teat and udder surgery from the simplest technique to the most complex. Diagnosis and prognosis are covered, as well as the actual surgical techniques.

Dehorning the adult goat.

Although goats are ideally disbudded as infants, occasionally they are not. Goats grow horns much more rapidly than most owners realize and use these horns on other goats and, occasionally, people. Dehorning adult goats is not as easy as dehorning cattle. The techniques for tranquilizing, anesthetizing, and dehorning adult goats is described and aftercare is discussed.

Female reproductive surgery.

Although cesarean section is covered in a separate article, this article on miscellaneous female reproductive surgery will hopefully help to get and keep the cow pregnant. Procedure such as rectovaginal lacerations, vaginal tumors, prolapsed cervical rings, and vaginal prolapse repair are covered. In addition to procedures that will help with pregnancy, ovariectomy and hysterectomy are also covered.

How to develop a proactive formulary system.

To develop a quality formulary system, a proactive approach is necessary. This approach incorporates a prospective product and concurrent product analyses. A prospective product analysis, in turn, involves a review of current formulary agents, those likely to enter the marketplace shortly, and the formation of an expert review panel. This panel's tasks are to examine therapeutic, economic, and humanistic aspects of therapy and to set initial parameters for appropriate and cost-effective use of accepted products. Keys to a successful formulary system are to continuously monitor drug use and compliance with criteria and to work collaboratively with all institutional professionals in the development, implementation, and monitoring of the system.

Effects of fat saturation and source of fiber on site of nutrient digestion and milk production by lactating dairy cows.

Six primiparous cannulated cows were assigned to six treatments in a 6 x 6 Latin square design to evaluate the effects of degree of fat saturation and amount and source of effective fiber on site of nutrient digestion and milk production. Cows were fed for ad libitum intake a control diet with no added fat or diets with 5% added fat from saturated tallow, tallow, or animal-vegetable fat; the diets with animal-vegetable fat had 40% forage, 40% forage plus 20% soyhulls, or 60% forage. Ruminal acetate:propionate was higher when soyhulls replaced forage NDF because of the higher digestibility of soyhulls in the rumen and total tract. Ruminal digestion of NDF was decreased as unsaturation of fat increased. True and apparent efficiencies of bacterial protein synthesis were increased as fat unsaturation increased, probably because of reduced recycling of microbial N in the rumen. The digestibility of fatty acids in the small intestine was higher in cows fed no fat than in those fed fat and was reduced as fat unsaturation decreased, primarily because of the saturated tallow. Dry matter intake was decreased 14% by increased fat unsaturation. All fat supplements depressed milk protein percentage. Production of 4% FCM tended to decrease linearly as unsaturation of fat increased. In diets with 5% added fat, a degree of saturation between saturated tallow and tallow (iodine values of 18 and 62) appears to be optimum for fatty acid digestibility and DMI.

Digestion in the rumen and total tract of forage-based diets with starch or dextrose supplements fed to Holstein heifers.

Three diets were fed to six cannulated heifers in a replicated 3 x 3 Latin square design. Diets were a high forage control, a high forage diet with dextrose (5.6% of DM), and a medium concentrate (39.7% of DM) diet. Diets contained 13.3% CP and 1% NaHCO3 and were fed as a TMR twice daily. Mean ruminal pH (6.47), glucose concentration (.55 mM), and reducing sugar concentration (.64 mM) in heifers were similar across diets. Rate of orchardgrass NDF digestion in situ was faster for heifers fed the dextrose than for those fed the medium concentrate diet, but both were similar to that for heifers fed the control diet. Heifers fed the medium concentrate and dextrose diets had faster ruminal particulate fractional passage rates than those fed the control diet. True ruminal and apparent total tract digestion of OM and NDF were similar among diets, but ruminal NDF digestion tended to be higher with the control than with the medium concentrate diet. Total NAN and bacterial N flow to the duodenum and efficiency of bacterial protein synthesis in the rumen were greater with the medium concentrate diet than with the control and dextrose diets. The results were consistent with others that demonstrated that factors related to nonstructural carbohydrates in the diet other than just low ruminal pH affect ruminal fiber digestion; however, these results were not as strong as those of our previous in vitro work.

Small-intestinal volvulus in cattle: 35 cases (1967-1992).

Medical records of 35 cattle with small-intestinal volvulus were reviewed. Surgical correction was performed on 32 cattle, and 17 of these cattle were discharged from the hospital. Mean duration of clinical signs for survivors was not significantly different from that for nonsurvivors, and the most commonly recorded clinical signs were abdominal pain, anorexia, lethargy, abdominal distention, and dehydration. Physical examination of cattle with intestinal volvulus revealed tachycardia, tachypnea, and normothermia. Rectal examination findings included distended small intestine, scant feces or mucus, and tight bands coursing dorsoventrally in the middle portion of the abdomen. Clinicopathologic testing revealed azotemia, hypocalcemia, hyperglycemia, and leukocytosis with a left shift. Nonsurvivors had significantly lower mean preoperative venous blood pH and mean base excess and higher mean serum potassium concentration than did survivors. A diagnosis of volvulus of the entire small intestine was made during surgery in 25 cattle, whereas volvulus of the distal jejunum and ileum was diagnosed during surgery in 7 cattle. Survival rate following surgical correction of volvulus of the entire small intestine (44%) was not significantly different from survival rate following surgical correction of volvulus of the distal jejunum and ileum (86%). However, survival rate for dairy cattle (63%) was significantly higher than survival rate for beef cattle (22%). To determine potential risk factors for the development of small-intestinal volvulus, epidemiologic data from cattle admitted to veterinary teaching hospitals throughout North America were collected by searching records entered into the Veterinary Medical Data Base.(ABSTRACT TRUNCATED AT 250 WORDS)

Femoral and tibial fractures in a newborn calf after transplacental infection with bovine viral diarrhoea virus.

A one-week-old Brown Swiss calf had fractures of the metaphyseal regions of the left femur and right tibia, and a generalised, severe derangement of osteogenesis. Alternating zones of sclerosis and radiolucency in the metaphysis of all the long bones was visible radiographically. A histopathological examination revealed a segmental disruption of trabecular modelling, with subsequent fracture. Immunohistochemistry using a monoclonal antibody for bovine viral diarrhoea (BVD) virus revealed abundant viral antigen in the pituitary gland, hypothalamus and thyroid gland. Intestinal tissue was positive on fluorescent antibody testing for the virus. The lesions indicate that transplacental infection with BVD virus can result in severe skeletal abnormalities and fractures.

Abomasal luminal pressure in cattle with abomasal volvulus or left displaced abomasum.

The abomasal luminal pressure was determined during surgery in 54 dairy cows with abomasal volvulus (AV) and another 50 dairy cows with left displaced abomasum. The luminal pressure was high in all cattle with AV and 49 (98%) cattle with left displaced abomasum. Luminal pressure was significantly higher in cattle with AV (median, 11.7 mm of Hg; range, 4.1 to 32.4 mm of Hg) than cattle with left displaced abomasum (median, 8.7 mm of Hg; range, 3.5 to 20.7 mm of Hg). Among cattle with AV, abomasal luminal pressure was significantly higher in cattle that died or were sold for slaughter following surgery (median, 20.6 mm of Hg; n = 8) than in cattle that were retained in the herd (median, 11.0 mm of Hg; n = 46). The luminal pressure was weakly correlated with the preoperative serum alkaline phosphatase activity but not correlated with duration of inappetence before surgery. Calculation of likelihood ratios and construction of a response operating characteristic curve for cattle with AV indicated that a cut-off value of 16 mm of Hg for luminal pressure optimized the distribution of cattle into productive and nonproductive groups. The sensitivity, specificity, positive predictive value, and negative predictive value of a luminal pressure < 16 mm of Hg in predicting a productive outcome were 0.83, 0.75, 0.95, and 0.43, respectively.

Risk factors for abomasal volvulus and left abomasal displacement in cattle.

A hospital-based case-control study was conducted to evaluate and compare risk factors for abomasal volvulus (AV) and left displaced abomasum (LDA) in cattle. Medical record abstracts were derived from 17 North American veterinary schools by the Veterinary Medical Data Program for all cattle admitted between Jan 1, 1977 and Dec 31, 1986, and for those with a diagnosis of AV or LDA. From a total of 108,956 individual cattle records, 1,036 cases of AV and 7,695 cases of LDA were identified, with a ratio of LDA to AV cases of 7.4 to 1. In-hospital mortality was 23.5% for AV and 5.6% for LDA. Age, breed, gender, and season each had significant (P less than 0.05) effects on risk for AV and LDA. Risk for AV and LDA increased with increasing age, with greater risk in cattle aged 4 to 7 years. Dairy cattle were at higher risk of developing AV (adjusted odds ratio, 36.4) and LDA (adjusted odds ratio, 95.2) than were beef cattle. The odds of AV in Brown Swiss cattle were significantly (P less than 0.0001) lower, and the odds of LDA in Guernsey cattle were significantly (P less than 0.0001) higher than those in Holstein cattle. Female cattle were also at higher risk of developing AV (adjusted odds ratio, 3.3) and LDA (adjusted odds ratio, 29.1) than were male cattle. The odds of AV and LDA varied considerably throughout the year, with the lowest number of cases observed in autumn. Seasonal development of AV differed significantly (P less than 0.0001) from that of LDA, with the odds of AV and LDA being highest in January and March, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)