Production of Lambs After the Transfer of Fresh and Cryopreserved in vitro Produced Embryos from Prepubertal Lamb Oocytes and Unsorted and Sex-sorted Frozen-thawed Spermatozoa

Cumulus-oocyte complexes from hormone-stimulated 3-4-week-old (n=43) and 6-7-week-old (n=12) prepubertal lambs were matured in vitro and incubated with unsorted, or X- or Y-spermatozoa separated with a high-speed cell sorter (SX MoFlo)frozen-thawed. Presumptive zygotes were then cultured to the blastocyst stage, and transferred to recipients fresh or after cryopreservation (frozen). Oocyte cleavage was higher (p <0.05) with unsorted (515/926, 55.6%) than X- or Y-spermatozoa (261/672, 38.8% and 229/651, 35.2%, respectively) and blastocyst formation (% zygotes) by Day 9 of in vitro culture was lower (p <0.05) for X- (102/261, 39.1%) than unsorted spermatozoa (249/515, 48.3%), but did not differ between Y-spermatozoa (103/229, 45.0%) and unsorted spermatozoa, or between X- and Y-spermatozoa (p >0.05). For fresh embryos, survival to term was 50.0% (3/6) for unsorted, 0.0% (0/6) for X- and 16.7% (1/6) for Y-spermatozoa-derived embryos (p >0.05), and for frozen embryos was 4.0% (2/50) for unsorted, 9.1% (2/22) for X- and 2.9% (1/34) Y-spermatozoa-derived embryos (p >0.05). Of the two lambs born from X-spermatozoa-derived embryos, one was female (50%), and from the two Y-spermatozoa-derived lambs, both were male (100%), demonstrating that lambs can be produced after the transfer of fresh and cryopreserved IVP embryos derived from prepubertal lamb oocytes and frozen-thawed sex-sorted sperm.     

Growth performance of nursery pigs fed diets containing increasing levels of corn distiller's dried grains with solubles originating from a modern Midwestern ethanol plant

Two experiments were conducted to determine the effects of including distiller's dried grains with solubles in nursery diets on growth performance, and to establish maximum inclusion rates for corn distiller's dried grains with solubles originating from modern, "new-generation" ethanol plants (built since 1990). Ninety-six crossbred pigs (BW = 6.18 +/- 0.14 kg) were blocked by gender and ancestry, and pigs within each block were randomly assigned to one of six dietary treatments (four pigs/pen, four pens/dietary treatment) in each of two growth performance experiments. Dietary treatments provided 0, 5, 10, 15, 20, or 25% distiller's dried grains with solubles during Phases 2 and 3 of a three-phase nursery feeding program for early-weaned pigs. Pigs in Exp. 1 were slightly older (19.0 vs. 16.9 d of age) and heavier (7.10 vs. 5.26 kg) at the beginning of the experiment compared to pigs in Exp. 2. All pigs in both experiments were provided a commercial pelleted Phase 1 diet for the first 4 d after weaning and were then switched to their respective experimental Phase 2 diets, which were fed for 14 d, followed by their respective Phase 3 experimental diets, which were fed for a subsequent 21-d feeding period. Experimental diets were formulated to contain equivalent apparent ileal digestible lysine (1.35 and 1.15%), apparent ileal digestible methionine + cystine (0.80 and 0.65%), ME (3,340 and 3,390 kcal/kg), calcium (0.95 and 0.80%), and total phosphorus (0.80 and 0.70%) within Phases 2 and 3, respectively. Overall growth rate, ending body weight, and feed conversion were similar among pigs regardless of dietary distiller's dried grains with solubles level for both experiments. In Exp. 1, feed intake was not affected by dietary treatment (P > 0.10). In Exp. 2, however, increasing the level of distiller's dried grains with solubles linearly decreased feed intake (P < 0.02) during Phase 2 and tended to decrease voluntary feed intake (P < 0.09) over the length of the experiment. These results suggest that the corn distiller's dried grains with solubles used in this study can be included in Phase 3 diets for nursery pigs at dietary levels of up to 25% without negatively affecting growth performance after a 2-wk acclimation period. Including high levels of corn distiller's dried grains with solubles in diets for pigs weighing less than 7 kg in BW, however, may negatively influence feed intake and growth.     

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.     

Intravenous lipid emulsion for treating permethrin toxicosis in a cat

A 2-year-old cat was presented with acute onset seizures, tremors, and hypersalivation. Permethrin toxicity was diagnosed based on a history of recent flea treatment. Measures were taken to minimize further absorption of permethrin, and methocarbamol and intravenous lipid emulsion were used to control tremors. The cat recovered and was discharged within 42 h.     

Seroprevalence of feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) in shelter cats on the island of Newfoundland,Canada

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses found within domestic and wild cat populations. These viruses cause severe illnesses that eventually lead to death. Housing cats communally for long periods of time makes shelters at high risk for virus transmission among cats. We tested 548 cats from 5 different sites across the island of Newfoundland for FIV and FeLV. The overall seroprevalence was 2.2% and 6.2% for FIV and FeLV, respectively. Two sites had significantly higher seroprevalence of FeLV infection than the other 3 sites. Analysis of sequences from the FeLV env gene (envelope gene) from 6 positive cats showed that 4 fell within the FeLV subtype-A, while 2 sequences were most closely related to FeLV subtype-B and endogenous feline leukemia virus (en FeLV). Varying seroprevalence and the variation in sequences at different sites demonstrate that some shelters are at greater risk of FeLV infections and recombination can occur at sites of high seroprevalence.     

Heinz body hemolytic anemia associated with high plasma zinc concentration in a dog

Acute zinc toxicosis from the ingestion of pennies was diagnosed in a dog with Heinz body hemolytic anemia (PCV = 14%), leukocytosis (51,000 cells/ml) with a left shift (3,060 band neutrophils; 37,740 segmented neutrophils) and monocytosis (4,080 cells/ml), azotemia (BUN = 60 mg/dl), bilirubinemia (total bilirubin = 5.3 mg/dl), hypokalemia (3.0 mEq/L), high serum alkaline phosphatase activity (691 U/L), high total plasma solids (8.1 g/dl), hemoglobinuria, and proteinuria. Despite aggressive medical treatment, renal failure ensued, and the dog died of cardiac arrest. The clinical signs, clinical course, and laboratory findings in this dog were similar to what has been reported in other cases of acute zinc toxicosis in dogs, with the exception of a history of generalized seizures and the findings of Heinz bodies. Although a causative relationship between plasma zinc values and Heinz body formation cannot be proven, their association suggests that oxidative damage to erythrocyte hemoglobin and cell membrane proteins may be involved in the pathogenesis of zinc-induced hemolysis.