Effect of hot-fat trimming on factors associated with the subprimal yield of beef carcasses.

Thirty-two crossbred cattle (steers = 17; heifers = 15) exhibiting an ultrasound fat thickness at the 12 to 13th rib region of at least 10 mm were selected from a slaughter shift at a commercial packing plant. After splitting, alternating sides of each carcass were trimmed of 1) subcutaneous fat in excess of 6.4 mm; 2) all kidney, pelvic, and heart fat; and 3) all cod or udder fat and fat in the flank region. Both sides of each carcass were fabricated into subprimals (final trim level of 6.4 mm) according to normal industry procedures. Effect of hot-fat trimming, yield grade (3, 4, and 5), and gender on hot-fat trim, fabrication fat trim, major subprimal, and total subprimal yield of untrimmed and trimmed carcasses were determined. Higher numerical yield grade (YG) corresponded with higher (P less than .05) percentages of hot-fat trim. Hot-fat trimming increased (P less than .05) the difference in fabrication fat trim between steers and heifers and between YG 3 and YG 5. Steers and heifers differed (P less than .05) in percentage of major subprimals and total subprimals when processed conventionally, whereas hot-fat trimming eliminated this difference (P less than .05). Untrimmed YG 3 carcasses had 3.1 and 5.0% higher major subprimal yield (P less than .05) than untrimmed YG 4 and YG 5 carcasses, respectively, whereas hot-fat trimming reduced this difference to 2.5% for YG 4 and to 3.7% for YG 5.(ABSTRACT TRUNCATED AT 250 WORDS)     

Infectious diseases of New-World camelids (NWC)

Although there are notable infectious conditions that are capable of producing clinical disease in the NWC, overall, these species are quite healthy. Of the bacterial diseases, enterotoxemia caused by Clostridium perfringens types C and D would be deemed the most significant in North America, while type A also would be regarded as important in South America. Other important bacterial infections of potential concern are tuberculosis, Johne's disease, anthrax, malignant edema, actinomycosis, tetanus, and the South American condition referred to as alpaca fever, which, to date, has not been observed in North America. Fungal infections include classical ringworm, principally caused by Trichophyton spp., and the cases of coccidioidomycosis that are associated with the arid desert lands of the southwestern United States. Most notable of naturally occurring viral infections in the NWC would be rabies, ecthyma, and a recently described blindness neuropathy that has been associated with the equine herpesvirus I. NWC can be infected experimentally with agents causing hoof-and-mouth disease and vesicular stomatitis, but naturally occurring cases do not seem to occur. Serological evidence of exposure to many viral agents, including blue tongue, parainfluenza 3, bovine respiratory syncytial virus, bovine herpesvirus I, bovine viral diarrhea, influenza A, and rotavirus, has been demonstrated; however, no clinical disease associated with these agents, as yet, is apparent.     

Genetic analyses of resistance of the wheat differential cultivars Carstens V and Spaldings Prolific to two races of Puccinia striiformis

Genetic analysis of resistance of wheat seedlings to two races of Puccinia striiformis was conducted on F₁, F₂ and F₃ generations from crosses Carstens V (CV) × Lee, Spaldings Prolific (SPA) × Lee and CV × SPA. F₂ generations from crosses of CV and SPA with Strubes Dickkopf (SD) were also studied. The plants were classified into six resistance classes and analysed by factorial correspondence analysis and nonhierarchical classification. The two P. striiformis isolates tested were a French isolate of race 43E138 and a Lebanese isolate of race 2E16, selected for the differences in their virulence spectra for the common differential cultivars Strubes Dickkopf and Nord Desprez. Resistance of CV and SPA was recessive and dominant to races 43E138 and 2E16, respectively. CV possessed three or four resistance genes, one of them being expressed with both races. Two genes of CV had a cumulative effect for resistance to 43E138 and two or three gave dominant resistance to 2E16. SPA had three resistance genes, all of which gave resistance to 2E16 and two of which also gave resistance to 43E138. SPA had one gene in common with CV for resistance to both races. Furthermore, the gene for resistance to race 2E16 in CV and SPA was allelic with a gene in SD, and was probably Yr25 .     

Use of spectral radiance for correcting nitrogen deficiencies and estimating soil test variability in an established bermudagrass pasture

The use of variable rate technology has become increasingly popular for applying plant nutrient elements. The most widely used method for determining variable fertilizer rates is presently based on soil testing and yield mapping. Three field studies (Bumeyville 1995, Burneyville 1996, and Ardmore 1996) were initiated in established Midland bermudagrass [Cynodon dacrylon (L) Pers.] pastures to determine the relationship between spectral radiance at specific wavelengths with forage nitrogen (N) removal and biomass, and to determine field variability of soil test parameters. Variable N (applied to 1.5 × 2.4 m subplots within 2.4 × 45.7 m main plots), fixed N and check treatments were evaluated at each location. Spectral radiance readings were taken in the red (671±6 nm), green (570±6 nm), and near infrared (NIR) (780±6 nm) wavelengths. The normalized difference vegetation index (NDVI) was calculated as NIR‐red/NIR+red. Variable N rates were applied based on NDVI. The highest fixed variable N rate was set at 224, 336, and 672 kg N ha^‐1 for Burneyville, 1995, 1996, and Ardmore, 1996, respectively. At Bumeyville, soil samples were collected in all variable rate plots (1.5 × 2.4 m) and analyzed for various soil test characteristics. NDVI, red, green, and NIR spectral radiance readings were correlated with bermudagrass forage N removal and yield. Correlation of forage yield and N removal with red, NIR, and NDVI were best with maximum forage production, however, when forage production levels were low correlation decreased dramatically for the red wavelength compared with NIR and NDVI. Forage yield and forage N removal in variable rate treatments increased when compared to the check while being equal to the half‐fixed and fixed rates where higher N rates were applied. Also, variability about the mean in variable rate plots was significantly lower than half‐fixed and fixed rates which supports adjusting N rates based on indirect NDVI measurements. Variable N rate plots reduced fertilizer inputs by 60% and produced the same yield as fixed rate plots, while fixed and half‐fixed rates did not increase N content in the forage over that of the variable rate treatment. Soil sample data collected from small consecutive plots (<4 m²) was extremely variable indicating that intense sampling would be needed if variable fertilizer application were to be based on soil test results.     

Cimetidine for treatment of melanomas in three horses

Cimetidine, an H2 histamine antagonist, was used in the clinical management of progressive, multifocal melanomatosis in 3 adult gray horses. Prior to treatment, the tumors had increased rapidly in size and number in 2 horses (duration of 6 and 27 months, respectively) and slowly in the third horse (duration of 48 months). All 3 horses were treated with cimetidine (2.5 mg/kg of body weight, PO, q 8 h) for 2 months to 1 year. During treatment, the number and size of the melanomas decreased substantially (50 to 90%). The progression of the disease was halted in 2 horses and controlled in the third horse, which is still being treated with cimetidine (1.6 mg/kg, PO, q 24 h). The horses in which treatment was terminated have not been treated for 31 and 41 months, respectively, during which time the melanomas have not increased in number or size.     

Evaluation of Likelihood of Co-Occurrence of Erwinia amylovora with Mature Fruit of Winter Pear

ABSTRACT Phytosanitary concerns about fire blight prohibit export of U.S.-grown pears to some countries without this disease. To examine these concerns, we evaluated the potential for co-occurrence of Erwinia amylovora with mature, symptomless winter pear fruit by inoculation experiments and by survey of commercial orchards. Immature pear and apple fruit were inoculated in orchards with E. amylovora strain 153N as resuspended lyophilized cells or as ooze from diseased tissues. Regardless of inoculum source, population size of Ea153N on fruit declined by an order of magnitude every 3 to 4 days during the first 2 weeks after inoculation; at 56 days after inoculation, Ea153N was not detected, except on 1 of 450 fruit with 4 colony forming units (CFU). After inoculation of flowers, calyx-end survival of Ea153N on pear and apple fruit declined from high populations at petal fall to a few cells at harvest, with no detection of the pathogen after a 7-week cold storage. Migration of Ea153N into symptomless pear fruit from diseased branches was evaluated by enrichment assay and nested polymerase chain reaction of internal fruit core tissues; these assays failed to detect the pathogen in healthy fruit from diseased trees. At harvest, E. amylovora could not be detected on 5,599 of 5,600 fruit of d'Anjou pear sampled from commercial orchards in major production areas of the Pacific Northwest; one fruit yielded 32 CFU of the pathogen. Postharvest, mature pear fruit contaminated with Ea153N and subsequently wounded required a dose of >10,000 cells at the wound site to allow for persistence of the pathogen through a 7-week-cold storage. We conclude that epiphytic E. amylovora shows similar survival characteristics on both pear and apple fruit, this pathogen is not an endophyte within mature symptomless pear fruit, its presence is exceptionally rare on commercially produced fruit, and that epiphytic survival of E. amylovora through a postharvest chilling period is unlikely given the unrealistically high population size required for persistence.     

Llama reproduction

The reproductive anatomy, physiology, and breeding behavior of the llama is unique enough to make familiarity with it imperative. Female puberty averages 12 months, while many males are not reproductively functional until after 3 years. Proper management of a breeding pair or herd is necessary to maintain maximum reproductive performance. Proof of pregnancy is suggested by rejection of the male and may/should be confirmed by progesterone assay, rectal palpation, or ultrasound techniques. The postpartum female is notable for breeding back rapidly, with high pregnancy rates resulting. Both male and female factors enter into llama infertility, with each gender having significant incidence of reproductive anatomical abnormalities. Management as well as acquired infertility problems (heat factors, trauma, infection, neoplasia, and hormonal imbalances) contribute to the bulk of infertility cases investigated. Techniques used to diagnose infertility in llamas are quite comparable to the equine species; however, female body size and semen analysis in the male present significant challenges. The approach to therapy has been quite empirical to date, owing to lack of consistent problems and numbers to afford conclusive trials. Alterations of pregnancy include resorption, abortions, and stillbirths. Resorption between 30 to 60 days of gestation is reported regularly. Abortions caused by stress occur regularly. Infection abortions caused by leptospirosis, toxoplasmosis, and chlamydiosis are to be expected. Ponderosa pine-related abortions are suspected. In summary, I find use for a broad background in large animal theriogenology to apply to llama infertility. There no doubt are additional diagnostic techniques and therapeutic regimens that have application, and it is up to us all to keep good records and share the information.     

Disseminated mast cell tumor infiltrating the sphenoid bone and causing blindness in a dog

Mast cell tumors are found in most organs and tissues with variable biologic behavior in dogs. This case illustrates the clinical and magnetic resonance imaging (MRI) findings in a dog with disseminated mast cell tumor infiltrating the sphenoid bones. A 6‐year‐old male neutered Greyhound presented with a 3‐day history of acute onset of blindness. General physical examination was normal. Neurological examination revealed mildly disorientated mental status, absent menace response in both eyes, bilaterally decreased vestibulo–oculocephalic reflexes and absent direct and consensual pupillary light reflex in both eyes. An electroretinogram indicated normal retinal function in both eyes. A lesion involving the middle and rostral cranial fossa was suspected. Hematology and serum biochemistry were normal except decreased urea (1.2 mmol/L). MRI of the head revealed heterogeneous signal intensity of the sphenoid bones on T2‐weighted images and loss of their normal internal architecture. Cerebrospinal fluid analysis was normal. Abdominal ultrasound revealed hepatosplenomegaly and mesenteric lymphadenopathy. Fine needle aspirates were taken from the jejunal lymph nodes and the spleen. Results were consistent with disseminated mast cell tumor. The owner declined any treatment and the dog was euthanatized. Postmortem examination confirmed disseminated mast cell tumor affecting multiple organs, including the sphenoid bones. To our knowledge, this is the first case describing MRI features of disseminated mast cell tumor affecting the sphenoid bones and causing acute onset of blindness in a dog.