RESUMEN
A series of 6 floor pen trials was conducted to determine the effects of a quillaja and yucca combination product on the performance and carcass traits of growing broiler chickens vaccinated for coccidiosis at the hatchery. In each of the trials graded levels (0, 250, and 500 ppm) of a quillaja and yucca combination (QY) were fed to Ross 708 broilers for the duration of each 42 d test. Trials were arranged in completely randomized block designs involving a minimum of 11 blocks per trial. At the start of each trial, pens contained 55 broilers. In order to provide each bird with an enteric disease challenge, 5 kg commercial broiler litter containing 104 CFU Clostridium perfringens per gram was placed in each pen. In addition, the sporulated oocysts of Eimeria acervulina and E. maxima were added to each pen at the outset of each test. At d 21 of the trials, coccidial lesion scores, mortality and performance were determined; final performance and total mortality were assessed at 42 d. At the completion of each test, 10 birds of average body weight per pen were selected for carcass evaluations; whole and chilled carcass yield were determined, and pre- and post-chill breast measurements were made. A combined analysis of the results of the 6 trials (75 replications per treatment) was used to determine treatment effects and each variable was assessed by linear regression analysis. Results indicated that QY significantly reduced mortality and coccidial lesions scores at d 21 (P < 0.05). Performance was significantly improved by both levels of QY at 21 and 42 d, and significant linear effects were observed for these variables (P < 0.05). All carcass characteristics were significantly improved by QY administration and significant linear responses were observed for each carcass variable (P < 0.05). These results indicate that by reducing intestinal disease challenge, QY provided linear improvements in performance. In addition, QY positively affected carcass parameters as each variable responded linearly to QY feeding (P < 0.05).
Asunto(s)
Coccidiosis , Eimeria , Enfermedades de las Aves de Corral , Yucca , Alimentación Animal/análisis , Animales , Pollos , Coccidiosis/prevención & control , Coccidiosis/veterinaria , Dieta , Estiércol , Enfermedades de las Aves de Corral/prevención & control , QuillajaRESUMEN
A series of studies was conducted to determine the effects of a quillaja and yucca (saponin) combination (QY) product on postvaccination oocyst production, development of coccidial immunity, and final bird performance of broilers administered live coccidiosis vaccines. In all, 3 groups of tests were carried out. Study 1 evaluated the effects of QY (0 and 250 ppm) on oocyst per gram of feces (OPG) following vaccination at day-of-age; OPG were measured from 5 to 12 d postvaccination. Study 2 determined the effects of QY (250 ppm) in the presence of 3 commercial coccidiosis vaccines in floor pens. OPG were measured weekly for birds receiving each vaccine and for each corresponding vaccine group fed QY. To determine whether QY influenced the development of coccidial immunity induced by the 3 vaccines, 5 birds were removed from each pen at 28 d and challenged with pathogenic levels of Eimeria spp. At 6 d post challenge, lesion scores were used to evaluate the effects of QY on immune protection provided by each vaccine. In addition, comparisons of final bird performance were made between birds given each vaccine and their corresponding vaccinates fed QY. Study 3 comprised a meta-analysis of 15 floor pen trials in which 21- and 42-d body weight, feed conversions, and total mortality were compared between coccidiosis-vaccinated broilers and similarly vaccinated broilers fed QY (250 ppm). Results of these experiments indicated that feeding QY to vaccinated broilers did not significantly affect OPG from days 5 through 12 postvaccination (P > 0.05). For each vaccine tested in study 2, OPG values were the highest at 14 and 21 d postvaccination. QY significantly reduced OPG at 14 d postvaccination for 2 of the vaccines tested, and produced a similar effect in 1 vaccine at 21 d postvaccination. The remaining vaccine was not affected by QY in the postvaccination OPG results. Despite these changes in OPG, significant differences in lesion scores following the Eimeria challenge were not observed for any vaccinated groups receiving QY. Irrespective of the vaccine, both interim and final feed conversion values were significantly improved when QY was fed (P < 0.01). Similarly, results of a 15-trial meta-analysis indicated that QY-fed vaccinated broilers had higher body weights, improved feed conversions, and lower mortality than their vaccinated controls. Results show that while QY may induce changes in OPG following vaccination, coccidia-vaccinated broilers fed QY develop immunity equivalent to that of controls and show significant improvements in performance and mortality.
Asunto(s)
Coccidiosis , Enfermedades de las Aves de Corral , Vacunas Antiprotozoos , Saponinas , Yucca , Alimentación Animal/análisis , Animales , Pollos , Coccidiosis/prevención & control , Coccidiosis/veterinaria , Enfermedades de las Aves de Corral/prevención & control , QuillajaRESUMEN
The DE values of corn grain for pigs will differ among corn sources. More accurate prediction of DE may improve diet formulation and reduce diet cost. Corn grain sources ( = 83) were assayed with growing swine (20 kg) in DE experiments with total collection of feces, with 3-wk-old broiler chick in nitrogen-corrected apparent ME (AME) trials and with cecectomized adult roosters in nitrogen-corrected true ME (TME) studies. Additional AME data for the corn grain source set was generated based on an existing near-infrared transmittance prediction model (near-infrared transmittance-predicted AME [NIT-AME]). Corn source nutrient composition was determined by wet chemistry methods. These data were then used to 1) test the accuracy of predicting swine DE of individual corn sources based on available literature equations and nutrient composition and 2) develop models for predicting DE of sources from nutrient composition and the cross-species information gathered above (AME, NIT-AME, and TME). The overall measured DE, AME, NIT-AME, and TME values were 4,105 ± 11, 4,006 ± 10, 4,004 ± 10, and 4,086 ± 12 kcal/kg DM, respectively. Prediction models were developed using 80% of the corn grain sources; the remaining 20% was reserved for validation of the developed prediction equation. Literature equations based on nutrient composition proved imprecise for predicting corn DE; the root mean square error of prediction ranged from 105 to 331 kcal/kg, an equivalent of 2.6 to 8.8% error. Yet among the corn composition traits, 4-variable models developed in the current study provided adequate prediction of DE (model ranging from 0.76 to 0.79 and root mean square error [RMSE] of 50 kcal/kg). When prediction equations were tested using the validation set, these models had a 1 to 1.2% error of prediction. Simple linear equations from AME, NIT-AME, or TME provided an accurate prediction of DE for individual sources ( ranged from 0.65 to 0.73 and RMSE ranged from 50 to 61 kcal/kg). Percentage error of prediction based on the validation data set was greater (1.4%) for the TME model than for the NIT-AME or AME models (1 and 1.2%, respectively), indicating that swine DE values could be accurately predicted by using AME or NIT-AME. In conclusion, regression equations developed from broiler measurements or from analyzed nutrient composition proved adequate to reliably predict the DE of commercially available corn hybrids for growing pigs.
Asunto(s)
Alimentación Animal/análisis , Pollos/metabolismo , Metabolismo Energético/fisiología , Porcinos/crecimiento & desarrollo , Porcinos/metabolismo , Zea mays/metabolismo , Fenómenos Fisiológicos Nutricionales de los Animales/fisiología , Animales , Dieta/veterinaria , Digestión/fisiología , Heces/química , Modelos Lineales , Masculino , Modelos Estadísticos , Nitrógeno/análisis , Análisis de Regresión , Reproducibilidad de los Resultados , Zea mays/químicaRESUMEN
Genetically modified (GM) canola (Brassica napus L.) line containing event DP-Ø73496-4 (hereafter referred to as 73496 canola) was produced by the insertion of the glyphosate acetyltransferase (gat4621) gene derived from Bacillus licheniformis. Expression of the GAT4621 protein present in 73496 canola plants confers in planta tolerance to the herbicidal active ingredient glyphosate. The objective of this study was to compare the nutritional performance of broiler chickens fed canola meal from 73496 canola seed with that of broiler chickens fed non-GM canola meal in a 42-d feeding trial. Diets were prepared using meal processed from seed from unsprayed 73496 plants or from plants sprayed with an in-field application of glyphosate herbicide [73496(S)]. For comparison, additional diets were produced with canola meal obtained from the non-GM near-isogenic control or non-GM commercial reference DuPont Pioneer brand varieties 42H72, 42H73, 46A65, and 44A89. Diets were fed to Ross 708 broilers (n = 120/group, 50% male and 50% female) in 3 phases: starter and grower phases containing 10 or 20% canola meal, respectively, and a finisher phase with a common corn-soybean meal diet without any canola meal. No statistically significant differences were observed in growth performance measures or organ and carcass yields between broilers consuming diets produced with canola meal from unsprayed or sprayed 73496 seed and those consuming diets produced with canola meal from control seed. Additionally, all performance, organ, and carcass measures from control, 73496, and 73496(S) canola treatment groups were within tolerance intervals constructed using data from the reference canola groups. It was concluded from these results that meal processed from 73496 canola seed (unsprayed plants or plants sprayed with glyphosate) was nutritionally equivalent to meal processed from non-GM near-isogenic control canola seed.
Asunto(s)
Alimentación Animal/análisis , Brassica napus/química , Pollos/fisiología , Dieta/veterinaria , Plantas Modificadas Genéticamente/química , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Bacillus/genética , Composición Corporal , Brassica napus/genética , Pollos/crecimiento & desarrollo , Relación Dosis-Respuesta a Droga , Femenino , Masculino , Plantas Modificadas Genéticamente/genética , Distribución AleatoriaRESUMEN
The performance of broilers fed diets containing maize grain from event DP-Ø9814Ø-6 (98140; gat4621 and zm-hra genes) and processed fractions (meal, hulls, and oil) from soybeans containing event DP-356Ø43-5 (356043; gat4601 and gm-hra genes) was evaluated in a 42-d feeding study. Diets were produced with nontransgenic maize grain and soybean fractions from controls with comparable genetic backgrounds to 98140 and 356043 (control), 98140 maize and 356043 soybean (98140 + 356043), or 3 commercially available nontransgenic maize and soybean combinations. Ross 708 broilers (n = 120/group; 50% male, 50% female) were fed diets in 3 phases: starter (d 0 to 21), grower (d 22 to 35), and finisher (d 36 to 42). Starter diets contained (on average) 63% maize and 28% soybean meal, grower diets 66% maize and 26% soybean meal, and finisher diets 72% maize and 21% soybean meal; soybean hulls and oils were held constant at 1.0 and 0.5%, respectively, across all diets in all phases. Weight gain, feed intake, and mortality-adjusted feed efficiency were calculated for d 0 to 42. Standard organ and carcass yield data were collected on d 42. Data were analyzed using a mixed model ANOVA with differences between control and 98140 + 356043 group means considered significant at P < 0.05. Reference group data were used only to estimate experimental variability and to generate tolerance intervals. No significant differences were observed in weight gain, mortality, mortality-adjusted feed efficiency, organ yields, or carcass yields between broilers consuming diets produced with 98140 + 356043 and those consuming diets produced with control maize and soybean fractions. All values of response variables evaluated in the control and 98140 + 356043 groups fell within calculated tolerance intervals. Based on these results, it was concluded that the combination of genetically modified 98140 maize and 356043 soybean fractions was nutritionally equivalent to nontransgenic maize and soybean controls with comparable genetic backgrounds.
Asunto(s)
Alimentación Animal/análisis , Glycine max/genética , Zea mays/genética , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Composición Corporal , Pollos , Dieta/veterinaria , Femenino , Masculino , Valor Nutritivo , Plantas Modificadas GenéticamenteRESUMEN
The objective of this study was to compare the nutritional performance of laying hens fed maize grain from event DP-Ø9814Ø-6 (98140; gat4621 and zm-hra genes) and processed soybean meal from soybeans containing event DP-356Ø43-5 (356043; gat4601 and gm-hra genes), individually or in combination, with the performance of hens fed diets containing nontransgenic maize and soybean meal. Healthy pullets (n = 216) placed in cages (3 hens/cage) were randomly assigned to 9 dietary treatments (8 cages/treatment): nontransgenic controls 1, 2, and 3 (comparable genetic background controls for 98140, 356043, and 98140 + 356043, respectively); reference 1, reference 2, and reference 3 (commercially available nontransgenic maize-soybean meal sources); and 98140 (test 1), 356043 (test 2), and 98140 + 356043 (test 3). The experiment was divided into three 4-wk phases (24 to 28 wk, 28 to 32 wk, and 32 to 36 wk of age), during which time hens were fed mash diets. Performance (BW, feed intake, and egg production) and egg quality data were collected. Data were analyzed using a mixed model ANOVA; differences between the control and respective test group means were considered significant at P < 0.05. Data generated from the reference groups were used only in the estimation of experimental variability and in generating the tolerance interval. Body weight and BW gain, egg production, and production efficiency for hens fed the test diets were similar to the respective values for hens fed the corresponding control diets. Haugh unit measures and egg component weights were similar between the respective test and control groups, and no differences were observed in quality grades or crack measures. All observed values of the control and test groups were within the calculated tolerance intervals. This research indicates that the performance and egg quality of hens fed diets containing 98140 maize grain, 356043 soybean meal, or a combination of the 2 was comparable with that of hens fed diets formulated with nontransgenic maize grain or soybean meal control diets with comparable genetic backgrounds.
Asunto(s)
Alimentación Animal/análisis , Pollos/fisiología , Dieta/veterinaria , Glycine max/genética , Valor Nutritivo , Zea mays/genética , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Huevos/normas , Femenino , Plantas Modificadas GenéticamenteRESUMEN
DP-3Ø5423-1 (305423) is a genetically modified soybean that was produced by biolistic insertion of the gm-fad2-1 gene fragment and gm-hra genes into the germline of soybean seeds. Expression of gm-fad2-1 results in greater concentrations of oleic acid (18:1) by suppressing expression of the endogenous FAD2-1 gene, which encodes an n-6 fatty acid desaturase enzyme that catalyzes desaturation of 18:1 to linoleic acid (18:2). The GM-HRA protein expressed by the gm-hra gene is a modified version of the soybean acetolactate synthase enzyme that is used as a selectable marker during transformation. A 42-d feeding trial was conducted with broiler chickens to compare the nutritional performance of 305423 soybeans with nontransgenic soybeans. Diets were prepared using processed fractions (meal, hulls, and oil) from 305423 soybean plants. For comparison, additional diets were produced with soybean fractions obtained from a nontransgenic near-isoline (control) and nontransgenic commercial Pioneer brand varieties (93B86, 93B15, and 93M40). Diets were fed to Ross x Cobb broilers (n = 120/group, 50% male and 50% female) in 3 phases. Starter, grower, and finisher diets contained 26.5, 23, and 21.5% soybean meal, respectively. Soybean hulls and oil were added at 1.0 and 0.5%, respectively, across all diets in each phase. No statistically significant differences were observed in growth performance (BW, mortality, feed efficiency), organ yield (liver and kidney), or carcass yield (breast, thigh, leg, wing, and abdominal fat) variables between broilers consuming diets prepared with isolated fractions from 305423 or near-isoline control soybean. Additionally, all performance and carcass variables from control and 305423 soybean treatment groups fell within tolerance intervals constructed for each response variable using data from broilers fed diets prepared with reference soybean fractions. Based on the results from this study, it was concluded that 305423 soybeans were nutritionally equivalent to non-transgenic control soybeans with a comparable genetic background.
Asunto(s)
Alimentación Animal/análisis , Pollos/crecimiento & desarrollo , Dieta/veterinaria , Glycine max , Aceite de Soja/farmacología , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Composición Corporal , Peso Corporal , Femenino , Riñón/anatomía & histología , Hígado/anatomía & histología , Masculino , Mutagénesis Insercional , Ácido Oléico/metabolismo , Tamaño de los Órganos , Plantas Modificadas Genéticamente , Glycine max/genética , Glycine max/metabolismoRESUMEN
A genetically modified maize (Zea mays L.) line that contains the Optimum GAT trait (event DP-Ø9814Ø-6; 98140) was produced by integration of the gat4621 and zm-hra genes. The expressed GAT4621 and ZM-HRA proteins confer tolerance to the herbicidal active ingredient glyphosate and acetolactate synthase-inhibiting herbicides, respectively. The objective of this study was to compare the nutritional performance of 98140 maize grain to nontransgenic maize grain in a 42-d feeding trial in broiler chickens. Diets were prepared using grain from untreated 98140 plants and from plants treated with an in-field application of herbicides (98140 + Spray). For comparison, additional diets were produced with maize grain obtained from the nontransgenic near-isogenic control (control) and nontransgenic commercial reference Pioneer brand hybrids 33J56, 33P66, and 33R77. Diets were fed to Ross x Cobb broilers (n = 120/group, 50% male and 50% female) in 3 phases: starter, grower, and finisher containing 58.5, 64, and 71.5% maize grain, respectively. No statistically significant differences were observed in mortality, growth performance variables, or carcass and organ yields between broilers consuming diets produced with maize grains from unsprayed or sprayed 98140 and those consuming diets produced with near-isogenic control maize grain. Additionally, all performance and carcass variables from control, 98140, and 98140 + Spray test maize treatment groups were within tolerance intervals constructed using data from reference maize groups. Based on these results, it was concluded that 98140 maize grain (unsprayed or sprayed with a herbicide mixture) was nutritionally equivalent to nontransgenic control maize with comparable genetic background.
Asunto(s)
Alimentación Animal , Pollos/crecimiento & desarrollo , Dieta/veterinaria , Zea mays , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Peso Corporal , Femenino , Riñón/anatomía & histología , Hígado/anatomía & histología , Masculino , Tamaño de los Órganos , Plantas Modificadas Genéticamente , Zea mays/genética , Zea mays/metabolismoRESUMEN
Event DP-356Ø43-5 (356043; Optimum GAT) is a genetically modified soybean (Glycine max) that was produced by insertion of the gat4601 and gm-hra genes. The expression products of these genes are the glyphosate acetyltransferase 4601 and acetolactate synthase proteins, respectively. Expression of the glyphosate acetyltransferase 4601 protein confers tolerance in planta to the herbicidal active ingredient glyphosate, whereas expression of the acetolactate synthase protein confers tolerance to sulfonylurea and imidazolinone herbicides. The objective of this study was to compare the nutritional equivalence of 356043 soybeans to nontransgenic soybeans in a 42-d feeding trial in broiler chickens. Diets were prepared using processed fractions (meal, hulls, and oil) from untreated 356043 soybean plants or from soybean plants treated with a mixture of glyphosate, chlorimuron, and thifensulfuron (356043 + Gly/SU). For comparison, additional diets were produced with soybean fractions obtained from a nontransgenic near-isoline (control; 091) and nontransgenic commercial Pioneer varieties (93B86, 93B15, and 93M40). Diets were fed to Ross x Cobb broilers (n = 120/group, 50% male and 50% female) in 3 phases. Starter diets contained 30% soybean meal, grower diets 26% soybean meal, and finisher diets 21.5% soybean meal. Soybean hulls and oil were added at 1.0 and 0.5%, respectively, across all diets in each phase. No statistically significant differences were observed in mortality, growth performance variables, or carcass and organ yields between broilers consuming diets produced with 356043 or 356043 + Gly/SU soybean fractions and those consuming diets produced with near-isoline control soybean fractions. Additionally, all performance and carcass variables from control, 356043, and 356043 + Gly/SU soybean treatment groups fell within the tolerance intervals constructed using data from reference soybean groups. Based on the results from this study, it was concluded that 356043 soybean was nutritionally equivalent to nontransgenic control soybean with a comparable genetic background.
Asunto(s)
Alimentación Animal , Pollos , Dieta , Glycine max , Aceite de Soja , Animales , Femenino , Masculino , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Composición Corporal , Pollos/crecimiento & desarrollo , Dieta/veterinaria , Plantas Modificadas Genéticamente , Estándares de Referencia , Glycine max/genética , Aumento de PesoRESUMEN
The effect of graphite addition on the mechanism of hydrogen uptake by titanium during mechanochemical activation in hydrogen flow was studied using kinetic, structural, microscopic, and spectroscopic techniques. As was found, already a small graphite admixture of about 0.5 wt % changed the kinetics of mechanically induced H2 sorption and significantly stimulated Ti-H2 interaction. Two new types of occupation sites available for hydrogen were observed, which are characterized by low H2 desorption temperatures: about 650 and 750 K instead of 1000 K.
RESUMEN
Soybean meal (SBM) contains heat-resistant mannans. Domesticated turkeys are sensitive to mannans because of the high inclusion rate of SBM in their diets, causing increased chyme viscosity, wet droppings, and reduced feed conversion. Three experiments of similar design were conducted to determine the effect of mannan-endo-1,4-f'-mannosidase supplementation of corn-SBM diets on market turkeys. Experiment 1 was conducted at North Carolina State University using Nicholas hens raised from 1 to 98 d of age. Experiments 2 and 3 were conducted at PARC Institute Inc. using Large White turkey toms raised from 1 to 126 d of age. In each experiment, birds were randomly assigned to litter floor pens. Each pen was assigned to one of four experimental treatments in 2 x 2 factorial arrangement of two basal diets containing 44% CP and 48% CP SBM (SBM-44 and SBM-48, respectively) with or without 100 million units (MU) Hemicell/tonne (1 MU = 106 enzyme activity U). Birds fed SBM-44 had lower final BW (14.9 vs. 14.56 kg 18 wk BW / tom; 7.66 vs. 7.46 kg 14 wk BW/hen, P < 0.05) and higher final cumulative feed/gain than those fed the SBM-48. Hemicell supplementation generally improved performance of all birds, with a greater response in birds fed SBM-44. Hemicell improved BW and feed/gain by 1% (P = 0.779) and 3% (P = 0.377) in hens and 2.5% (P = 0.0016) and 4% (P = 0.0001) in toms, respectively. The results of these experiments indicate that some of the adverse effects of antinutritional factors of SBM of on turkey growth performance can be alleviated by dietary mannan-endo-1,4-beta-mannosidase supplementation.
Asunto(s)
Alimentación Animal , Peso Corporal/efectos de los fármacos , Proteínas en la Dieta , Glycine max , Manosidasas/farmacología , Pavos/crecimiento & desarrollo , Animales , Suplementos Dietéticos , Ingestión de Energía , Conducta AlimentariaRESUMEN
During the period from January to June, combined-sex broiler chickens were inoculated with coccidia via drinking water at 14 d of age. In a completely randomized design (eight replicate pens; 88 chicks per pen) using built-up litter, experimental diets contained monensin plus 0.20% dietary sodium bicarbonate (SBC), which provided 0.054% sodium and 0.144% bicarbonate. Treatment with SBC significantly improved coccidial lesion score, 45-d body weight, and feed efficiency compared with monensin alone. In a 2 x 5 factorial trial using built-up litter pens (eight replicate pens; 88 chicks per pen) vs. each ionophore alone, 0.20% dietary SBC with monensin significantly improved body weight, uniformity, and feed efficiency; 0.20% SBC with halifuginone, lasalocid, monensin, or salinomycin significantly reduced mortality; and 0.20% SBC with lasalocid, monensin, or salinomycin significantly increased breast meat yield. In a 2x4 factorial trial (12 replicate pens; 88 chicks per pen) on built-up litter, corn-soy and corn-soy-meat diets (higher potassium, lower chloride) with monensin were evaluated using 0.054% sodium from SBC, NaCl, or sodium sulfate decahydrate (SSD). With both diet types, SBC (0.20%) or NaCl (0.139% extra) significantly improved weight uniformity, feed efficiency, mortality, and breast meat yield; however, the SSD results were closer to controls. In a 21-d battery brooder test using similar diets and design (2x4 factorial; 4 replicate pens; 10 chicks per pen), SBC and NaCl significantly reduced coccidial lesion scores; SSD produced a significant, but weaker effect. Extra NaCl significantly increased water intake (approximately 37%), water excretion (approximately 27%), and litter moisture (approximately 22%) with both diet types. The SSD did not affect water intake.
Asunto(s)
Alimentación Animal , Pollos/fisiología , Coccidiosis/veterinaria , Coccidiostáticos/farmacología , Animales , Coccidiosis/prevención & control , Dieta , Femenino , Masculino , Productos de la Carne , Bicarbonato de Sodio/farmacología , Cloruro de Sodio/farmacología , Glycine max , Sulfatos/farmacología , Zea maysRESUMEN
A target animal safety study investigated the effects of providing 25-hydroxyvitamin D3 (25-OH-D3) in laying hen feed at levels ranging from 0.5 to 10 times the level commonly used for vitamin D3 supplementation in the poultry industry. Following a 28-day preconditioning period, 5 groups of laying hens were fed commercial diets containing 68.9 micrograms of vitamin D3/kg feed (control) or 41.25 (0.5x), 82.5 (1x), 412.5 (5x), or 825 (10x) micrograms of 25-OH-D3/kg feed. The study compared the effects of the control level of vitamin D3 and the various test levels of 25-OH-D3 on health, performance, hematology, and 25-OH-D3 tissue concentrations in laying hens from 0 to 112 d of treatment and on health, performance, gross pathology and histopathology from 113 to 224 d of treatment. Gross pathologic and histopathologic examination of selected tissues after 224 d revealed no lesions attributable to vitamin D toxicity at any level of test material. Concentrations of 25-OH-D3 in edible tissues at 112 d were similar for birds in the control and 1x groups. On the basis of all variables monitored, including body weight gain and feed conversion, the 10x level of 25-OH-D3 produced clear toxicity (but no mortality), the 5x level caused limited threshold toxicity, and the 1x level induced no toxicity. These results indicate that 25-OH-D3 is safe for use in laying hen feed as a source of vitamin D3 at 82.5 micrograms/kg feed (1x), with a margin of safety of approximately 5x between the proposed 1x level and the 5x level (412.5 micrograms/kg feed) that constitutes threshold toxicity in layers.
Asunto(s)
Alimentación Animal/efectos adversos , Calcifediol/efectos adversos , Pollos/metabolismo , Colecalciferol/análisis , Animales , Recuento de Células Sanguíneas/efectos de los fármacos , Recuento de Células Sanguíneas/veterinaria , Peso Corporal/efectos de los fármacos , Calcifediol/metabolismo , Relación Dosis-Respuesta a Droga , Ingestión de Alimentos/efectos de los fármacos , FemeninoRESUMEN
A target animal safety study investigated the effects of providing 25-hydroxyvitamin D3 (25-OH-D3) as a replacement for vitamin D3 in pelleted turkey feeds. Five groups of turkeys were fed diets containing vitamin D3 at 68.9 micrograms/kg feed (control) or 25-OH-D3 at concentrations of 49.5 (0.5x), 99 (1x), 495 (5x) or 990 (10x) micrograms 25-OH-D3/kg feed. The effects of 25-OH-D3 or vitamin D3 on performance, health, hematology, gross pathology and tissue concentrations of 25-OH-D3 in female and male turkeys were compared at 112 days of feeding. There was no significant difference from control in pen body weight in any of the groups. When feed conversion was calculated without taking into account body weights of birds that died during the study, there was no significant difference from control in any of the groups. When feed conversion was corrected for mortality, the only significant effect was that females at the 5x level (495 micrograms 25-OH-D3/kg feed) had improved feed conversion. Significantly increased mortality occurred during the study in the 10x (990 micrograms 25-OH-D3/kg feed) male group only. No histomorphologic tissue alterations attributable to dietary administration of 25-OH-D3 were observed in tissues examined at any dietary level of 25-OH-D3. 25-OH-D3 did not adversely affect animal health at the proposed use level of 99 micrograms/kg feed when replacing vitamin D3 in turkey rations. The proposed use level also provides at least a 5-fold margin of safety.
Asunto(s)
Alimentación Animal , Calcifediol/administración & dosificación , Pavos/metabolismo , Crianza de Animales Domésticos , Animales , Peso Corporal , Calcifediol/farmacocinética , Colecalciferol/administración & dosificación , Colecalciferol/fisiología , Femenino , MasculinoRESUMEN
Two predictions concerning the perceived severity of crimes can be derived from evolutionary theory. The first, arising from the theory of inclusive fitness, is that crimes in general should be viewed as more serious to the degree that the victim is genetically related to the perpetrator. The second, arising from the deleterious effects of inbreeding depression, is that heterosexual sexual coercion should be perceived as more serious the closer the genetic relationship of victim and perpetrator, particularly when the victim is a female of fertile age. Two hundred and thirty university students estimated the magnitude of the severity of brief crime descriptions in three separate studies. In the first two, the biological kinship of victim and perpetrator was varied, and in the third, the hypothetical genetic relatedness of the subject and the fictitious victim was varied. All three studies found the linear relationships between biological kinship and perceived crime severity predicted by theory.
RESUMEN
Although large deletions comprise 65% of the mutations that underlie most cases of Duchenne and Becker muscular dystrophies, the DNA sequence characteristics of the deletions and the molecular processes leading to their formation are largely unknown. Intron 7 of the human dystrophin gene is unusually large (110 kb) and a substantial number of deletions have been identified with endpoints within this intron. The distribution of 28 deletion endpoints was mapped to local sequence elements by PCR. The break points were distributed among unique sequence, LINE-1, Alu, MIR, MER and microsatellite sequences with frequencies expected from the frequency of those sequences in the intron. Thus, deletions in this intron are not associated primarily with any one of those sequences in the intron. Nine deletion junctions were amplified and sequenced. Eight were deletions between DNA sequences with minimal homology (0-4 bp) and are therefore unlikely to be products of homologous recombination. In the ninth case, a complex rearrangement was found to be consistent with unequal recombinational exchange between two Alu sequences coupled with a duplication. We have hypothesized that a paucity of matrix attachment regions in this very large intron expanded by the insertion of many mobile elements might provoke a chromatin structure that stimulates deletions (McNaughton et al., 1997, Genomics 40, 294-304). The data presented here are consistent with that idea and demonstrate that the deletion sequences are not usually produced by homologous DNA misalignments.
Asunto(s)
Distrofina/genética , Eliminación de Gen , Intrones , Distrofias Musculares/genética , Secuencia de Bases , Rotura Cromosómica , Clonación Molecular , Análisis por Conglomerados , Células Eucariotas , Humanos , Modelos Genéticos , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Recombinación Genética , Análisis de Secuencia de ADNRESUMEN
At 7 d postinoculation (DPI) with a mixed culture of avian Eimeria species, 21-d-old chicks maintained in batteries and floor pens on a diet containing 0.15% (3 lb/ton) betaine plus 66 ppm (60 g/ton) salinomycin were significantly heavier and had significantly lower feed conversion ratios and mortality than chicks fed diets containing 0.15% betaine or 66 ppm salinomycin alone, or the control diet. At 31 DPI, when the chicks were 45 d old, the differences between the diet groups were not as great as at 7 DPI. In vitro, except at high concentrations, betaine was nontoxic to sporozoites of Eimeria tenella or Eimeria acervulina and had little effect on their invasion and development in cultured cells. In vivo, invasion by E. tenella and E. acervulina sporozoites was significantly reduced in all chicks fed diets containing betaine or salinomycin compared with that in control chicks. There was a significant interaction between betaine and salinomycin that impacted on invasion by both species. Overall development of E. tenella did not appear to be adversely affected by addition of betaine to diets containing salinomycin. Conversely, development of E. acervulina was reduced in chicks fed diets containing 0.075% (1.5 lb/ton) betaine plus 66 ppm salinomycin as compared with that in chicks fed salinomycin alone.
Asunto(s)
Betaína/farmacología , Pollos/crecimiento & desarrollo , Pollos/parasitología , Coccidiosis/veterinaria , Eimeria tenella/fisiología , Eimeria/fisiología , Lipotrópicos/farmacología , Enfermedades de las Aves de Corral/epidemiología , Animales , Células Cultivadas , Coccidiosis/tratamiento farmacológico , Coccidiosis/fisiopatología , Coccidiostáticos/farmacología , Coccidiostáticos/uso terapéutico , Interacciones Farmacológicas , Eimeria/efectos de los fármacos , Eimeria tenella/efectos de los fármacos , Técnicas In Vitro , Incidencia , Intestinos/efectos de los fármacos , Intestinos/parasitología , Intestinos/patología , Riñón/efectos de los fármacos , Riñón/parasitología , Riñón/patología , Masculino , Enfermedades de las Aves de Corral/tratamiento farmacológico , Enfermedades de las Aves de Corral/fisiopatología , Piranos/farmacología , Piranos/uso terapéutico , Distribución AleatoriaRESUMEN
The sequence of a 112-kb region of the human dystrophin (DMD/BMD) gene encompassing the deletion prone intron 7 (110 kb) and the much shorter intron 8 (1.1 kb) has been determined. Recognizable insertion sequences account for approximately 40% of intron 7. LINE-1 and THE-1/LTR sequences occur in intron 7 with significantly higher frequency than would be expected statistically while Alu sequences are underrepresented. Intron 7 also contains numerous mammalian-wide interspersed repeats, a diverse range of medium reiteration repeats of unknown origin, and a sequence derived from a mariner transposon. By contrast, the shorter intron 8 contains no detectable insertion sequences. Dating of the LI and Alu sequences suggests that intron 7 has approximately doubled in size within the past 130 million years, and comparison with the corresponding intron from the pufferfish (Fugu rubripes) suggests that the intron has expanded some 44-fold over a period of 400 million years. The possible contribution of the insertion elements to the instability of intron 7 is discussed.
Asunto(s)
Distrofina/genética , Evolución Molecular , Intrones/genética , Composición de Base , Genes/genética , Humanos , Datos de Secuencia Molecular , Secuencias Repetitivas de Ácidos Nucleicos/genética , Análisis de Secuencia de ADN , Eliminación de Secuencia/genéticaRESUMEN
There are several portable peak flow meters available. These instruments vary in construction and performance. Guidelines are recommended for minimum performance and testing of portable peak flow meters, with the aim of establishing a procedure for standardizing all peak flow meters. Future studies to clarify the usefulness of mechanical test apparatus and clinical trials of peak flow meters are also recommended.