Two experiments were conducted with a total of 432 broiler chicks to investigate the influence of supplementing different amounts of boron to practical corn-soybean meal diets. The birds were housed in batteries and had free access to feed and water. In Experiment 1, 144 1-day-old broiler chicks were fed a basal diet supplemented with 0, 5, 40, 80, or 120 ppm boron for 21 days. Female body weight was not influenced by the dietary treatments. However, males supplemented with 5 ppm boron were heavier and their tibias resisted more load than the control birds. Overall feed conversion was not influenced by boron. In Experiment 2, 288 1-day-old broiler chicks were fed a basal diet supplemented with 0, 60, 120, 240, or 300 ppm boron for 22 days. Male and female body weights of the 300-ppm group were lower than those of the control birds. Percentage tibia ash was highest with 300 ppm boron. No significant differences were found in intestinal tract weight (grams of intestine per 100 g body weight) among treatments. Boron concentration in the breast muscle and liver increased as dietary concentration of boron increased. Data collected in these two experiments indicated that consumption of diets containing up to 240 ppm boron from hatch to 21 days of age was not detrimental to broiler performance. Data were not conclusive on the need for supplemental boron in broiler diets based on corn and soybean meal.
Exposure to DEET (N,N-diethyl-meta-toluamide) may have influenced the pattern of symptoms observed in soldiers with GWI (Gulf War Illness; Haley and Kurt, 1997). We examined how the addition of DEET (400mg/kg; 50% topical) to an exposure protocol of permethrin (2.6mg/kg; topical), chlorpyrifos (CP; 120mg/kg), and pyridostigmine bromide (PB;13mg/kg) altered the emergence and pattern of pain signs in an animal model of GWI pain (Nutter et al., 2015). Rats underwent behavioral testing before, during and after a 4week exposure: 1) hindlimb pressure withdrawal threshold; 2) ambulation (movement distance and rate); and 3) resting duration. Additional studies were conducted to assess the influence of acute DEET (10-100μM) on muscle and vascular nociceptor K7, K, Na1.8 and Na1.9. We report that a 50% concentration of DEET enhanced the development and persistence of pain-signs. Rats exposed to all 4 compounds exhibited ambulation deficits that appeared 5-12weeks post-exposure and persisted through weeks 21-24. Rats exposed to only three agents (CP or PB excluded), did not fully develop ambulation deficits. When PB was excluded, rats also developed rest duration pain signs, in addition to ambulation deficits. There was no evidence that physiological doses of DEET acutely modified nociceptor K7, K, Na1.8 or Na1.9 activities. Nevertheless, DEET augmented protocols decreased the conductance of K7 expressed in vascular nociceptors harvested from chronically exposed rats. We concluded that DEET enhanced the development and persistence of pain behaviors, but the anticholinesterases CP and PB played a determinant role.
Two experiments were conducted to study the effects on chick performance of a commercially available liquid methionine analog [2-hydroxy-4 (methylthio) butanoic acid; HMB] supplied through drinking water. Methionine activities of .025 and .05% were added to drinking water and compared with levels of .03, .06, or .09% included in a low-methionine basal diet from 0 to 21 days of age. Mortality was not significantly altered by any dietary treatment. Neither feed nor water intake was affected adversely by HMB inclusion in drinking water. Only male body weight in Experiment 1 did not respond to HMB feed supplementation. Equivalent levels of total sulfur amino acid intake among water treatments were associated with significantly heavier body weights than the control. In both experiments, body weight and feed efficiency of birds receiving .05% methionine activity as HMB in water were equal or superior to those of groups that received supplemented feed. The results indicate that, under the study conditions, HMB provided in drinking water can be effectively assimilated by broiler chicks, at least through 21 days of age.
Two experiments with White Leghorn hens (42 and 56 wk old, respectively) examined the effects of calcium supplementation through drinking water in the presence of adequate and inadequate dietary calcium. Each experiment was of 28 d duration with six replicate pens of five individually caged hens in each treatment. Treatments were a combination of either 2.25 or 3.5% dietary calcium coupled with tap water or water supplemented with .2% calcium from calcium lactate. In both studies, specific gravity of eggs was significantly improved when low dietary calcium was supplemented with .2% calcium in the drinking water. Egg production and egg weight were not influenced by waterborne calcium. Daily water intake was reduced by calcium lactate in all cases. Feed consumption was also depressed by waterborne calcium in both studies when 3.5% dietary calcium was given, and in Experiment 1 when 2.25% was fed. Waterborne calcium as calcium lactate was found to be effectively utilized for eggshell quality improvement when dietary sources were inadequate.
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