Ethoxylated rapeseed oil derivatives as novel adjuvants for herbicides

Ethoxylates of rapeseed oil and of methylated rapeseed oil were synthesized and tested as adjuvants for 2,4-D and phenmedipham. Provided they had less than 6 units of ethylene oxide (EO), 1.0 to 10 g litre(-1) ethoxylates in water induced droplet spreading on barley leaves. In an acetone-based medium all derivatives strongly promoted the foliar uptake of 2,4-D, with no clear influence of the ethoxylation degree. In the same medium there was a negative influence of ethoxylate chain length on the foliar uptake of phenmedipham. In a water-based medium, phenmedipham applied with rapeseed oil emulsified with ethoxylated (20 EO) rapeseed oil displayed uptake rates close to a commercial preparation. The same was true for phenmedipham applied with ethoxylated (2 EO) methylated rapeseed oil. In bioassays, phenmedipham prepared with methylated rapeseed oil emulsified with ethoxylated (20 EO) rapeseed oil was as efficacious on barley as a commercial formulation. The same was true for phenmedipham prepared with ethoxylated (2 EO) methylated rapeseed oil. However, neither rapeseed oil nor methylated rapeseed oil emulsified with ethoxylated (2 EO) methylated rapeseed oil conferred good efficacy to phenmedipham. Hence, ethoxylated rapeseed oil derivatives are promising adjuvants or formulants for herbicides.     

Feeding value of an enzymatically digested protein for early-weaned pigs

Weanling pigs were used in a series of studies to determine the feeding value of an enzymatically digested protein product developed from a blend of swine and poultry abattoir by-products. The initial study used 156 pigs weaned at approximately 22 d of age to compare the product with menhaden fish meal in Phase II diets. The product supported equal growth rate, and there was no preference for diet exhibited based on inclusion level of the enzymatically digested protein product. The second study used 100 pigs weaned at approximately 21 d of age to compare the product with spray-dried animal blood cells in Phase II diets. The product supported a growth rate equal to that with the blood cells, and the combination of products enhanced growth rate (P<.05). The third study used 265 pigs to compare the product with spray-dried porcine plasma in a slope ratio growth assay. Results demonstrated a relative feeding value of 91% for the product over a 4-wk feeding period. The fourth study used 290 pigs to compare the product with spray-dried porcine plasma in Phase II diets; results demonstrated comparable growth performance. The final study used 180 pigs to compare the product with spray-dried porcine plasma in Phase I diets; results demonstrated comparable growth performance. These data indicate that the enzymatically digested abattoir by-product is a high-quality protein source for weanling pigs.     

The effect of long-acting injectable selenium formulations on blood and liver selenium concentrations and liveweights of red deer (Cervus elaphus)

AIM: To evaluate the efficacy of a new long acting injectable selenium ( Se ) formulation to increase the Se status and prevent Se deficiency in red deer. METHODS: Groups of weaned red deer (four stags and six hinds/group) grazing pastures containing <30 mg Se/kg DM were injected subcutaneously with either 0.5, 1.0 or 2.0 mg Se/kg as a new formulation of BaSeO4 (Deposel Multidose), 1.0mgSe/kg of a current formulation (Deposel), or not treated. Blood Se concentrations and liveweight were measured nine times at intervals over 377 and 270 days, respectively. RESULTS: Both formulations of Se elevated blood Se concentrations from 105 nmol/l pre-injection for at least 377 days with peak levels of 1894, 1395 and 818 nmol/l for high, medium and low doses of Deposel Multidose, respectively, at 73141 days, and 1508 nmol/l at 73-141 days for the medium dose of Deposel, which persisted at similar levels for the duration of the study. Deposel Multidose produced fewer and less severe subcutaneous tissue reactions than Deposel. Pastures contained 10 to 30 mg Se/kg DM. There was no significant difference in growth rate between treated and control deer. There was a significant (p<0. 01) linear relationship (y = 1.25x + 71.6, R2=0.86) between blood (x) and liver (y) Se concentrations in the range of 120 - 2100 nmol/l for blood concentrations, and 200 - 3000 nmol/kg for liver concentrations. CONCLUSION: Injections of BaSeO4 in both formulations studied were effective in increasing the Se status of deer but the new formulation produced fewer and less-severe tissue reactions. Young growing red deer appear less sensitive to Se deficiency as measured by weight gain, than sheep and cattle, suggesting that reference ranges for those species are not appropriate for deer. There was a linear correlation between blood and liver selenium concentrations.     

Isolation of oral spirochetes from dogs and cats and provisional identification using polymerase chain reaction (PCR) analysis specific for human plaque Treponema spp

Identification of plaque spirochetes from dogs is rare and no studies to date report cultivation of canine or feline plaque spirochetes. Plaque samples obtained from canine and feline patients were cultured in broth media. Spirochetes cultured were subjected to microscopic evaluation and were cloned on a solid medium. The clones were provisionally identified using species-specific PCR for treponema isolated from human plaque. Canine spirochete clones included Treponema denticola, T. socranskii ssp., T. vincentii, T. maltophilum, T. medium, and T. pectinovorum. Feline clones included T. maltophilum and T. socranskii. Non-amplified clones may represent novel treponemes. Future studies will be aimed at comparison of the spirochetes present in dogs and cats with or without periodontal disease.     

Efficacy and safety of selamectin against fleas and heartworms in dogs and cats presented as veterinary patients in North America

A series of randomized, controlled, masked field studies was conducted to assess the efficacy and safety of selamectin in the treatment of flea infestations on dogs and cats, and in the prevention of heartworm infection in dogs. In addition, observations were made on the beneficial effect of selamectin treatment on dogs and cats showing signs of flea allergy dermatitis (FAD). In all studies selamectin was applied topically, once per month, in unit doses providing a minimum dosage of 6mgkg(-1). Dogs and cats with naturally occurring flea infestations, some of which also had signs associated with FAD, were assigned randomly to receive three months of topical treatment with selamectin (220 dogs, 189 cats) or a positive-control product (dogs: fenthion, n=81; cats: pyrethrins, n=66). Selamectin was administered on days 0, 30, and 60. Day 0 was defined as the day that the animal first received treatment. Flea burdens were assessed by flea comb counts and clinical evaluations of FAD were performed before treatment, and on days 14, 30, 60, and 90. On days 30, 60, and 90, mean flea counts in selamectin-treated dogs were reduced by 92.1, 99.0, and 99.8%, and mean flea counts in fenthion-treated dogs were reduced by 81.5, 86.8, and 86.1%, respectively, compared with day 0 counts. Also, on days 30, 60, and 90, mean flea counts in selamectin-treated cats were reduced by 92.5, 98.3, and 99.3%, and mean flea counts in pyrethrin-treated cats were reduced by 66.4, 73.9, and 81.3%, respectively, compared with day 0 counts. Selamectin also was beneficial in alleviating signs in dogs and cats diagnosed clinically with FAD. A total of 397 dogs free of adult heartworm infection from four heartworm-endemic areas of the USA were allocated randomly to six months of treatment with selamectin (n=298) or ivermectin (n=99). Selamectin achieved a heartworm prevention rate of 100%, with all dogs testing negative for microfilariae and adult heartworm antigen on days 180 and 300. Selamectin was administered to a total of 673 dogs and 347 cats having an age range of 6 weeks to 19 years (3954 doses). The animals included 19 purebred or crossbred Collies (Bearded, Border, and unspecified). There were no serious adverse events. Results of these studies indicated that selamectin was highly effective in the control of flea infestations in dogs and cats without the need for simultaneous treatment of the environment or of in-contact animals and also was beneficial in alleviating signs associated with FAD. Selamectin also was 100% effective in preventing the development of canine heartworms and was safe for topical use in dogs and cats.     

Prevention of experimentally induced heartworm (Dirofilaria immitis) infections in dogs and cats with a single topical application of selamectin

In a series of six controlled studies (four in dogs, two in cats), heartworm-free dogs and cats were inoculated with Dirofilaria immitis larvae (L(3)) prior to topical treatment with the novel avermectin selamectin or a negative control containing inert formulation ingredients (vehicle). Selamectin and negative-control treatments were administered topically to the skin at the base of the neck in front of the scapulae. In dogs, selamectin was applied topically at dosages of 3 or 6mgkg(-1) at 30 days post-inoculation (PI), or of 3 or 6mgkg(-1) at 45 days PI, or of 6mgkg(-1) at 60 days PI. Cats were treated topically with unit doses providing a minimum dosage of 6mgkg(-1) selamectin at 30 days PI. Of the animals that were treated 30 days PI, some dogs were bathed with water or shampoo between 2 and 96h after treatment, and some cats were bathed with shampoo at 24h after treatment. Between 140 and 199 days PI, the animals were euthanized and examined for adult D. immitis. Adult heartworms developed in all control dogs (geometric mean count, 18.7 worms) and in 88% of control cats (geometric mean count, 2.1 worms). Selamectin was 100% effective in preventing heartworm development in dogs when administered as a single topical dose of 3 or 6mgkg(-1) at 30 days after infection, 3 or 6mgkg(-1) at 45 days after infection, or 6mgkg(-1) at 60 days after infection. Selamectin was 100% effective against heartworm infections in cats when administered as a single topical unit dose of 6mgkg(-1). Bathing with water or shampoo between 2 and 96h after treatment did not reduce the efficacy of selamectin as a heartworm prophylactic in dogs. Likewise, bathing with shampoo at 24h after treatment did not reduce the efficacy of selamectin in cats. These studies demonstrated that, at the recommended dosage and treatment interval, a single topical administration of selamectin was 100% effective in preventing the development of D. immitis in dogs and cats.     

Efficacy and safety of selamectin against Sarcoptes scabiei on dogs and Otodectes cynotis on dogs and cats presented as veterinary patients

A series of randomized, controlled and masked field studies was conducted in veterinary patients to evaluate the efficacy of selamectin, a novel avermectin, in the treatment of naturally occurring Sarcoptes scabiei infestations on dogs and Otodectes cynotis infestations on dogs and cats. A total of 342 dogs and 237 cats participated in these studies, which were conducted at 40 veterinary practices in the USA and Europe. Animals were randomly assigned to treatment with selamectin or a positive-control product (existing approved products). Selamectin was administered as a unit dose providing a minimum of 6mgkg(-1) (range: 6-12mgkg(-1)) in a topical preparation applied to the skin in a single spot on day 0 (O. cynotis in cats, n=144), or on days 0 and 30 (O. cynotis and S. scabiei in dogs, n=83 and n=122, respectively). The presence of parasites was assessed before treatment and at 30 days (for all studies) and 60 days (for O. cynotis and S. scabiei dog studies) after first treatment. The animals were also evaluated clinically at each assessment period. Based on skin scrapings, the efficacy of selamectin against S. scabiei infestations on dogs was >95% by day 30, and 100% by day 60. Against O. cynotis, selamectin eliminated mites in 94-100% of cats by day 30, and in 90% of dogs by day 60. The positive-control products achieved similar results. Thus, selamectin was safe and effective against ear mites in dogs and cats and sarcoptic mange in dogs when used in field (veterinary patient) studies in dogs and cats of a wide variety of ages and breeds.     

Efficacy and safety of selamectin against gastrointestinal nematodes in cats presented as veterinary patients

A series of randomized, controlled, masked, field (veterinary patient) studies were conducted in the USA and Europe to evaluate the efficacy of selamectin, a novel macrocyclic lactone of the avermectin subclass, in the treatment of naturally acquired gastrointestinal nematode infections in cats. After confirmation of ascarid and/or hookworm infection, 298 cats of various ages and breeds were randomly assigned to treatment with selamectin (n=202) or an existing commercially approved positive-control product (n=96). Unit doses of selamectin (providing a minimum dosage of 6mgkg(-1)) were administered topically to the skin in a single spot at monthly intervals. Quantitative fecal examinations were performed on days 0 (before treatment), 30, and 60. In the selamectin-treated cats, fecal ascarid egg counts were reduced by 99.6 to 100% on day 30, and by 99.9 to 100% on day 60. Fecal hookworm egg counts were reduced by 98.3% on day 30, and by 100% on day 60 in the selamectin-treated cats. The positive-control products achieved reductions in egg counts of 96.5 to 100% (ascarids) and 98.9 to 99.9% (hookworms). These studies have shown that monthly topical administration of selamectin is safe and highly effective in the treatment of naturally acquired ascarid and hookworm infections in cats.     

Inheritance of Carboxin Resistance in a European Field Isolate of Ustilago nuda

ABSTRACT Two carboxin-resistant field isolates of Ustilago nuda from Europe were crossed with a carboxin-sensitive field isolate from North America. Meiotic tetrads isolated from germinating F(1) teliospores of one of the hybrids were tested for carboxin resistance and mating type. Carboxin resistance was shown to be controlled by a single gene (CBX1R), because a 1:1 segregation of carboxin resistance was observed in all 27 tetrads. Tetrad analysis indicated that the loci for carboxin resistance (Cbx1) and mating type (MAT1) segregate independently but may be located on the same chromosome. Tetrad analysis was not possible with the F(1) hybrid of he other field isolate, and its resistance cannot yet be attributed to CBX1R. Carboxin resistance was qualitatively dominant to sensitivity in vitro, as demonstrated by triad analysis of germinating F(1) teliospores. Quantitative in planta infection percents supported the conclusion that CBX1R is dominant, although incompletely, in the F(1) hybrid of one of the field isolates. Also, fewer than expected carboxin-sensitive F(2) individuals were observed in planta. However, inoculations of host plants with U. nuda have resulted in similar, unexpected variation in the past.