Repletion of blood selenium concentrations in weaned beef calves

Eighty-three weaned beef calves severely deficient (less than 20 micrograms/L) in blood selenium (Se) were allotted by sex, weight and breed to one of six regimens of Se supplementation for 108 days to examine the efficacy of various Se supplementation programs and to monitor the repletion rate of blood Se concentrations. Cattle in treatment 1 received an IM injection of sodium selenite and an ad libitum feeding of 20 mg Se/kg salt-mineral mixture. Salt-mineral mixtures (treatments 2, 3, 4 and 5) were formulated to contain 20, 40, 80 and 160 mg Se/kg supplement, respectively, and were offered free-choice. Treatment 2 served as the selenium-treated control because 20 mg Se/kg supplement was the maximum permissible by FDA in commercial salt-mineral preparations at the time of this study. Cattle in treatment 6 received a salt-mineral supplement which contained no Se but dried brewers grain (434 micrograms Se/kg) was incorporated in the ration as an organic source of Se and fed at a rate of 1.1 kg/head/day. There was a within group time/treatment interaction (P less than 0.01) among all treatments as blood Se concentrations significantly increased over time. Final mean whole blood Se concentrations for treatments 1-6 were 87.8, 60.6, 95.1, 123.1, 154.2 and 91.4 micrograms/L, respectively. Treatments 1, 3, 4, 5 and 6 effectively increased and maintained whole blood Se concentrations at adequate levels (greater than 70 micrograms/L) by day 84. Treatment 2 (control) increased blood Se during the 108-day study, but blood Se concentrations never exceeded marginal levels (50-70 micrograms/L). Cattle consumed less salt-mineral supplement as the concentration of Na selenite increased from 20 to 160 mg Se/kg supplement.     

Influence of sodium diethyldithiocarbamate (Imuthiol) on lymphocyte function and growth in weanling pigs

Mitogen-stimulated lymphocyte proliferation, delayed-type hypersensitivity (DTH) reactions, interleukin-2 (IL-2) production, and growth performance were evaluated in 3-week-old pigs treated with imuthiol. Lymphocyte proliferative responses to Con A and PWM were reduced (P < 0.05) in pigs treated with imuthiol at 25 mg/kg; PHA proliferative responses were not influenced by imuthiol treatment. Imuthiol at 2.5 mg/kg and 25 mg/kg lowered IL-2 production when compared to saline-treated controls. Delayed-type hypersensitivity responses to PHA were higher in 25 mg/kg imuthiol-treated pigs; however, 2.5 mg/kg imuthiol-treated pigs had lower DHT reactions. Imuthiol at 2.5 mg/kg and 25 mg/kg reduced (P < 0.05) average daily feed intake. These data suggest that in vivo imuthiol treatment in pigs lowers lymphocyte proliferative responses, IL-2 production, and growth performance.     

Effect of chemotherapy on semen characteristics of Balami rams infected with Anaplasma ovis

Six intact Balami rams were experimentally infected with Anaplasma ovis. Another six were infected one month after splenectomy and six others served as controls. Clinical manifestations of the disease, first observed between 5 to 7 days post-infection, were more severe and prolonged in the splenectomised-infected than in the intact-infected group. There was progressive deterioration in semen quality, which was also significantly more severe and prolonged in the splenectomised than in the intact-infected rams. Following treatment with long-acting terramycine, clinical recovery occurred earlier in the intact-infected (1–4 weeks) than in the splenectomised-infected group (5–7 weeks). A similar pattern was observed in post-treatment improvement in the spermiogram. However, although the infected animals recovered clinically by 1–7 weeks post-treatment, restoration of the reproductive potential did not occur for 20 to 25 weeks. It appears that stress factors may aggravate the deliterious effects of anaplasmosis.     

Gastrointestinal food allergy and its role in large domestic animals

The significance of food allergy as a primary cause for gastrointestinal disturbances in domestic animals, especially calves and piglets, is discussed. The immunological backgrounds and pathogenesis are described in some detail. The clinical and pathological manifestations in animals are related to those in man. Diagnostic possibilities, therapy and prevention, as far as known in animals, are mentioned and, based on human experiences, further extensions are proposed.     

Electron microscopy of equine respiratory viruses in organ cultures of equine fetal respiratory tract epithelium

Organ cultures of equine fetal tracheal and nasal turbinate epithelium were inoculated with equine influenza virus-A1 (EIV-A1), equine herpesvirus-1 (EHV-1), or equine rhinovirus-1 (ERV-1). Infected organ cultures were processed for scanning and transmission electron microscopy at various intervals and were compared with noninfected controls. Organ cultures inoculated with ERV-1 appeared normal with the exception of rare island-like lesions in infected nasal turbinate. Virus particles were not seen in thin sections of organ cultures infected with ERV-1. The EHV-1 caused extensive loss of the epithelial layer in tracheal and nasal turbinate organ cultures. The classic stages of herpesvirus morphogenesis were seen in thin sections of organ cultures infected with EHV-1. The EIV-A1 caused a scattered loss of cilia that was only apparent in infected tracheal organ cultures. Cilia were also seen bound in bundles. In thin sections, EIV-A1 particles were seen budding from the bases of microvilli.     

Rapid diagnosis of Aujeszky's disease in pigs by immunofluorescence

Direct immunofluorescence on impression smears of brain and pharynx was compared with virus isolation in cell culture for the diagnosis of Aujeszky's disease in experimentally and naturally infected pigs. Pharyngeal impression smears were more sensitive than virus isolation in two pigs killed 10 and 12 days after experimental infection. Both methods were of similar sensitivity in the detection of virus from field cases of disease. Smears of brain and pharynx were more sensitive than virus isolation for tissue which had been stored at room temperature (approximately 20 degrees C) for up to 48 hours. Some reduction in the amounts of virus recovered from tissues and the intensity of fluorescent staining occurred in these samples.     

Thirteen cases of botulism in horses fed big bale silage

An outbreak of pharyngeal and limb paresis involving four horses and nine ponies in the south east of England is described. Nine of the animals died or were destroyed on humane grounds. The clinical features suggested a diagnosis of botulism and mouse innoculation tests confirmed the presence of type B toxin in the serum of one case. All animals were fed big bale silage. It is describe how, in plastic wrapped silage manufacture, conditions of fermentation may be inadequate to prevent the growth of Clostridium botulism. Examination of a sample of silage fed to the affected horses suggested that this was probably the source of the toxin.     

Direct and maternal genetic differences between lines of mice selected for body weight and litter size: traits of dams

Genetic differences in performance of dams were estimated by linear contrasts using means of two selected lines of mice and reciprocal F1's, F2's and backcrosses. The lines were selected for increased 6-wk body weight (W) or increased litter size (L). Genetic differences estimated were direct average (gD), direct heterosis (hD), maternal average (gM), progeny average (gP), and progeny heterosis (hP). For dam weight and feed consumption from 12 to 21 d postpartum (pp), gD was the largest genetic difference and favored line W. For litter size, litter weight at birth, litter efficiency (litter weight gain/dam feed consumption) from birth to 12 d pp and within litter mortality from 1 to 21 d pp, gD favored L and, except for hD in litter efficiency, was the most important genetic difference for these traits. Direct heterosis was the only significant difference for litter weight at 21 d pp, litter efficiency from 12 to 21 d pp and within litter mortality at parturition. The gM were larger in W than in L for dam weight and feed consumption, and for litter size and weight at birth, but they were usually of smaller magnitude than gD. The gP were significant only in litter traits measured before 12 d pp and favored W. For no trait measured was hP of consequence. Line differences in dam and litter weight accounted for genetic differences in dam feed consumption. Genetic differences in litter size at birth were not due to line differences in dam weight. The lower mortality within litters nursed by crossbred dams was responsible for hD on litter weight and litter efficiency. Within but not among lines, higher mortality rates were associated with larger litters.     

Survey of quality defects in market beef and dairy cows and bulls sold through livestock auction markets in the Western United States: I. Incidence rates

A survey was conducted to quantify incidence of Beef Quality Assurance (BQA)-related defects in market beef and dairy cows and bulls selling at auction during 2 seasons in 2008. Twenty-three BQA-related traits were evaluated by 9 trained personnel during sales at 10 livestock auction markets in Idaho (n = 5; beef and dairy), California, (n = 4; dairy only), and Utah (n = 1; beef and dairy). Overall, 18,949 unique lots (8,213 beef cows, 1,036 beef bulls, 9,177 dairy cows, and 523 dairy bulls,) consisting of 23,479 animals (9,299 beef cows, 1,091 beef bulls, 12,429 dairy cows, and 660 dairy bulls) were evaluated during 125 sales (64 spring, 61 fall) for dairy and 79 sales (40 spring, 39 fall) for beef. The majority of market beef cows and bulls (60.9 and 71.3%, respectively) were predominantly black-hided, and the Holstein hide pattern was observed in 95.4 and 93.6% of market dairy cows and bulls, respectively. Market cattle weighed 548 ± 103.6 kg (beef cows), 751 ± 176.1 kg (beef bulls), 658 ± 129.7 kg (dairy cows), and 731 ± 150.8 kg (dairy bulls). Most beef cows (79.6%) weighed 455 to 726 kg, and most beef bulls (73.8%) weighed 545 to 954 kg, respectively. Among market beef cattle, 16.0% of cows and 14.5% of bulls weighed less than 455 and 545 kg, respectively, and 63.7% of dairy cows and 81.5% of dairy bulls weighed 545 to 817 kg or 545 to 954 kg, respectively. However, 19.5% of dairy cows and 13.1% of dairy bulls weighed less than 545 kg. Mean BCS for beef cattle (9-point scale) was 4.7 ± 1.2 (cows) and 5.3 ± 0.9 (bulls), and for dairy cattle (5-point scale) was 2.6 ± 0.8 (cows) and 2.9 ± 0.6 (bulls). Some 16.5% of beef cows and 4.1% of beef bulls had a BCS of 1 to 3, whereas 34.8% of dairy cows and 10.4% of dairy bulls had a BCS of 2 or less. Emaciation (beef BCS = 1, dairy BCS = 1.0) or near-emaciation (beef BCS = 2, dairy BCS = 1.5) was observed in 13.3% of dairy cows and 3.9% of beef cows. Among beef cattle, 15.1% of cows and 15.4% of bulls were considered lame. In contrast, 44.7% of dairy cows and 26.1% of dairy bulls were lame. Ocular neoplasia (cancer eye) was observed in only 0.6% of beef cows, 0.3% of beef bulls, 0.3% of dairy cows, and 0.0% of dairy bulls. However, among animals with ocular neoplasia, it was cancerous in 34.4% of beef bulls, 48.0% of dairy cows, and 73.3% of beef cows. In conclusion, numerous quality defects are present in market beef and dairy cattle selling at auction in the Western United States, which could influence their value at auction.