Evaluation of the clinical and allergen specific serum immunoglobulin E responses to oral challenge with cornstarch,corn, soy and a soy hydrolysate diet in dogs with spontaneous food allergy

Fourteen dogs with known clinical hypersensitivity to soy and corn were maintained on a limited antigen duck and rice diet until cutaneous manifestations of pruritus were minimal (78 days). Sequential oral challenges with cornstarch, corn and soy were then performed. Subsequently, the dogs were fed a diet containing hydrolysed soy protein and cornstarch. Throughout the study period the dogs were examined for cutaneous manifestations of pruritus and, additionally, serum was collected for measurement of allergen-specific and total immunoglobulin (Ig)E concentrations. Intradermal testing with food antigens was performed prior to entry into the study and after 83 days. A statistically significant clinical improvement was measured between days 0 and 83. Significant pruritus was induced after oral challenge with cornstarch, corn and soy (P = 0.04, 0.002, 0.01, respectively) but not with the hydrolysed diet (P = 0.5). The positive predictive value of the skin test for soy and corn allergy was reduced after feeding a soy and corn free diet. Although increases in soy and corn-specific serum IgE concentrations were measured in individual dogs post challenge they were not statistically significant and could not be used to predict clinical hypersensitivity.     

Forage and breed effects on behavior and temperament of pregnant beef heifers

Background： Integration of behavioral observations with traditional selection schemes may lead to enhanced animal well-being and more profitable forage-based cattle production systems.Brahman-influenced（BR;n = 64） and Gelbvieh × Angus（GA;n = 64） heifers consumed either toxic endophyte-infected tall fescue（E＋） or one of two nontoxic endophyte-infected tall fescue（NT） cultivars during two yr.Heifers were weighed at midpoint and termination of grazing.Grazing behavior（grazing,resting in the shade,lying,or standing without grazing） was recorded（n = 13 visual observations per yr in June and July） for each pasture.During yr 2,exit velocity（EV） and serum prolactin（PRL） were determined.Results： Grazing behavior was influenced（P 0.05） by an interaction between fescue cultivar and breed type.Gelbvieh × Angus heifers assigned to E＋ pastures had the lowest percentage of animals grazing and the largest percentage of animals resting in the shade.Brahman-influenced heifers had faster EV（P 0.001） than GA heifers（0.52 vs.0.74 ± 0.04 s/m,respectively）.Body weight（BW） was affected（P 0.01） by an interaction of tall fescue cultivar and d,and an interaction of tall fescue cultivar and breed type.Heifers grazing NT pastures were heavier（P 0.01） than heifers grazing E＋ pastures at midpoint and termination.Gelbvieh × Angus heifers grazing NT pastures were heavier（P 0.01） than GA and BR heifers grazing E＋ and BR heifers grazing NT pastures.An interaction of forage cultivar and breed type occurred on serum PRL（P 0.01）.Conclusion： Collectively fescue cultivar,EV,and concentrations of serum PRL were associated with grazing behavior.Heifers grazing NT pastures were observed to be grazing more than heifers assigned to E＋ pastures,regardless of breed type,which may have contributed to changes in BW and average daily gain（ADG） in heifers.Integration of behavioral observations along with traditional selection schemes may lead to enhanced animal well-being and more profitable forage-based cattle production systems.