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1.
Molecules ; 25(7)2020 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-32230753

RESUMEN

The present investigation is a comparison study of two nanocomposites: Nano-silica-coated oxyhydroxide aluminum (SiO2-AlOOH; SCB) and nano-silica-coated oxyhydroxide aluminum doped with polyaniline (SiO2-AlOOH-PANI; SBDP). The prepared nanocomposites were evaluated by monitoring the elimination of heavy metal Ni(II) ions from aquatic solutions. The synthesized nanocomposites were analyzed and described by applying scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR) techniques, as well as Zeta potential distribution. In this study, two adsorbents were applied to investigate their adsorptive capacity to eliminate Ni(II) ions from aqueous solution. The obtained results revealed that SBDP nanocomposite has a higher negative zeta potential value (-47.2 mV) compared with SCB nanocomposite (-39.4 mV). The optimum adsorption was performed at pH 8, with approximately 94% adsorption for SCB and 97% adsorption for SBDP nanocomposites. The kinetics adsorption of Ni ions onto SCB and SBDP nanocomposites was studied by applying the pseudo first-order, pseudo second-order, and Mories-Weber models. The data revealed that the adsorption of Ni ions onto SCB and SBDP nanocomposites followed the pseudo second-order kinetic model. The equilibrium adsorption data were analyzed using three models: Langmuir, Freundlich, and Dubinin-Radusekevisch-Kanager Isotherm. It was concluded that the Langmuir isotherm fits the experimental results well for the SCB and SBDP nanocomposites. Thermodynamic data revealed that the adsorption process using SCB nanocomposites is an endothermic and spontaneous reaction. Meanwhile, the Ni ion sorption on SBDP nanocomposites is exothermic and spontaneous reaction.


Asunto(s)
Aluminio/química , Compuestos de Anilina/química , Nanocompuestos/química , Polímeros/química , Purificación del Agua/métodos , Adsorción , Concentración de Iones de Hidrógeno , Iones/química , Cinética , Microscopía Electrónica de Rastreo , Nanocompuestos/ultraestructura , Níquel/análisis , Dióxido de Silicio/química , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Termodinámica , Agua/química , Contaminantes Químicos del Agua/química , Difracción de Rayos X
2.
Parasitol Res ; 106(2): 463-9, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19953271

RESUMEN

The gross pathological and histopathological changes associated with parasitic infection in the European eel (Anguilla anguilla Linnaeus, 1758) was investigated. A total of 65 eels collected from three sampling localities in Eastern Delta, Egypt were examined over the period of January-May 2008. The fish were subjected to standard procedures for parasitological and pathological examinations. Overall, 22 (33.8%) of the 65 fish examined were found to have parasitic infections. The eels harbored a total of six parasite species; among them, the nematode Anguillicoloides crassus was the most prevalent species (10.7%), followed by the Monogenea Pseudodactylogyrus anguillae (7.7%) and Dactylogyrus species (6.1%), the ciliate Trichodinella epizootica (4.6%), the Myxozoa Myxidium giardi (3.1%), and the cestode Proteocephalus macrocephalus (1.5%). Affected fish showed varying levels of tissue damage and pathological alterations including mild to severe degenerative, necrotic, and inflammatory changes in the affected organs.


Asunto(s)
Anguilla/parasitología , Parásitos/clasificación , Parásitos/aislamiento & purificación , Enfermedades Parasitarias en Animales/patología , Anguilla/anatomía & histología , Animales , Egipto , Histocitoquímica , Enfermedades Parasitarias en Animales/parasitología , Prevalencia
3.
Br J Biomed Sci ; 64(4): 168-74, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-18236739

RESUMEN

Human schistosomiasis is a chronic and debilitating parasitic disease caused by parasitic trematode worms (schistosomes). Praziquantel (PZQ) is the drug of choice as it is active against all Schistosoma species, can be administered easily, has high cure and egg reduction rates, with no or only mild side effects. Rapid re-infection following treatment and the concerns about PZQ resistance has led to the search for new drugs to treat schistosomiasis. Significant progress has been made with artemisinin derivatives (e.g., artemether [ART]) that are used for chemoprophylaxis. This present study aims to look at the effects of ART and PZQ on the antioxidant defence of immature (three-week-old) and mature (six-week-old) stages of S. mansoni. The possible development of time- or concentration-dependent changes in oxidative stress is assessed by incubation with different sublethal drug concentrations (50, 75, 100 ng/mL for both ART and PZQ) and different time periods (one and three hours). The results indicated a time- and concentration-dependent depletion of glutathione (GSH), which was greater in the immature worms after incubation with ART. On addition of ART to the incubation medium of mature and immature worms, elevation in lipid peroxidation (TBARS) level was observed, which was time- and concentration-dependent, and more prominent in the immature schistosomes. Addition of PZQ to the incubation medium containing the immature schistosomes did not have a significant effect on TBARS level, except after three hours' incubation with the highest concentration used; however, a significant rise was seen in the mature worms. The PZQ had no effect on the activities of superoxide dismutase (SOD), glutathione peroxidase (tGPx, sGPx and nGPx) and glutathione transferase (GST) in mature or immature worms. While ART induced SOD activity in mature worms, it induced tGPx, nGPx and GST activities in a time- and concentration-dependent manner in both mature and immature worms. Activation was more prominent in the immature schistosomes. The results of the present study indicate that the immature schistosomes are more prone to oxidative killing, which probably participates in the mechanism of antischistosomal action of ART against the immature stage of S. mansoni. The results suggest that the mechanism of schistosomicidal action of PZQ is probably not substantially dependent on oxidative stress or oxidative killing.


Asunto(s)
Antioxidantes/metabolismo , Artemisininas/farmacología , Praziquantel/farmacología , Schistosoma mansoni/efectos de los fármacos , Esquistosomiasis mansoni/tratamiento farmacológico , Esquistosomicidas/farmacología , Análisis de Varianza , Animales , Arteméter , Humanos , Estrés Oxidativo/efectos de los fármacos , Esquistosomiasis mansoni/metabolismo
4.
Meat Sci ; 71(4): 676-89, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22061213

RESUMEN

Over the past two decades, many human illness outbreaks were attributed to consumption of undercooked beef products containing Shiga toxin-producing Escherichia coli (STEC). The illnesses included mild or bloody diarrhea, hemorrhagic colitis, and the life-threatening hemolytic uremic syndrome (HUS). Tracing these outbreaks to O157 and an increasing number of non-O157 STEC strains suggests that beef safety concerns will continue to rise and may negatively affect the beef industry. To effectively address these concerns, it is critical to evaluate the role of beef in STEC infections. In this review, published reports on beef contamination were evaluated to assess prevalence rates and health risks of STEC isolates. Global testing of beef showed wide ranges of prevalence rates of O157 (from 0.01% to 54.2%) and non-O157 (from 1.7% to 62.5%) STEC. Of the 155 STEC serotypes found in beef, 31 and 25 are known to cause HUS and/or other illnesses, respectively.

5.
J Cancer Res Ther ; 11(1): 37-40, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25879333

RESUMEN

OBJECTIVES: To study the inhibitory effect of combining the gefitinib with cisplatin on tongue squamous cell carcinoma cells. MATERIALS AND METHODS: Two cell lines were used, tca8113 which is a cisplatin-sensitive cell line, and tca8113/CDDP which is a cisplatin-resistant cell line established in Jiamusi University Laboratories. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to calculate the IC 50 values of both drugs using both cell lines. Detection of Ras, Raf and ERK1/2 was done by using western blot technique after exposure to different concentrations of gefitinib and cisplatin. RESULTS: Tca8113/CDDP has shown more resistance to cisplatin than tca8113 and slightly more resistance to gefitinib than tca8113. Combination of the two drugs has shown to be more effective for both cell lines than when each alone even with lower concentrations. CONCLUSIONS: Combination of gefitinib and cisplatin is a better choice than using each drug alone.


Asunto(s)
Antineoplásicos/farmacología , Cisplatino/farmacología , Quinazolinas/farmacología , Carcinoma de Células Escamosas/tratamiento farmacológico , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Gefitinib , Humanos , Neoplasias de la Lengua/tratamiento farmacológico , Células Tumorales Cultivadas
6.
Toxicology ; 167(2): 101-34, 2001 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-11567776

RESUMEN

The worldwide contamination of foods and feeds with mycotoxins is a significant problem. Mycotoxins are secondary metabolites of molds that have adverse effects on humans, animals, and crops that result in illnesses and economic losses. Aflatoxins, ochratoxins, trichothecenes, zearelenone, fumonisins, tremorgenic toxins, and ergot alkaloids are the mycotoxins of greatest agro-economic importance. Some molds are capable of producing more than one mycotoxin and some mycotoxins are produced by more than one fungal species. Often more than one mycotoxin is found on a contaminated substrate. Factors influencing the presence of mycotoxins in foods or feeds include environmental conditions related to storage that can be controlled. Other extrinsic factors such as climate or intrinsic factors such as fungal strain specificity, strain variation, and instability of toxigenic properties are more difficult to control. Mycotoxins have various acute and chronic effects on humans and animals (especially monogastrics) depending on species and susceptibility of an animal within a species. Ruminants have, however, generally been more resistant to the adverse effects of mycotoxins. This is because the rumen microbiota is capable of degrading mycotoxins. The economic impact of mycotoxins include loss of human and animal life, increased health care and veterinary care costs, reduced livestock production, disposal of contaminated foods and feeds, and investment in research and applications to reduce severity of the mycotoxin problem. Although efforts have continued internationally to set guidelines to control mycotoxins, practical measures have not been adequately implemented.


Asunto(s)
Alimentación Animal/microbiología , Contaminación de Alimentos , Microbiología de Alimentos , Hongos , Micotoxinas/metabolismo , Micotoxinas/toxicidad , Animales , Humanos , Rumiantes/metabolismo , Rumiantes/microbiología
7.
Toxicology ; 159(3): 159-69, 2001 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-11223171

RESUMEN

Verotoxin-producing Escherichia coli (VTEC) produce one or two toxins known as VT1 and VT2. These toxins have been associated with several human illnesses. Dairy cattle harboring VTEC represent a potential health hazard because they enter the food chain as ground beef. The objective of this study was to assess the occurrence of VTEC in dairy heifers. A total of 91 fecal samples were rectally collected during four periods (spring, summer, fall, and winter of 1999) from 23 heifers. A random sample (n=530) of potential VTEC isolates were tested for verotoxicity and were screened by the polymerase chain reaction (PCR) for presence or absence of VT1 and/or VT2 genes. Thirteen isolates from two heifers (from the winter collection) were verotoxic and were confirmed as E. coli. VTEC were only detected during winter with an occurrence rate of 9.5%. Using PCR, five isolates had the VT1 gene while the remaining eight had the VT2 gene. The sequence and expression of VT1 and VT2 genes were confirmed. No E. coli O157:H7 was detected, but serotyping revealed that the five VT1-positive isolates were O26:NM (a non-motile strain of O26). The remaining eight isolates were untypeable. Identification of VTEC-positive cattle before slaughter is a critical step in any on-farm strategy to minimize the risk of beef contamination with such pathogens.


Asunto(s)
Enfermedades de los Bovinos/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157/aislamiento & purificación , Toxina Shiga I/biosíntesis , Toxina Shiga II/biosíntesis , Animales , Bovinos , Chlorocebus aethiops , Cartilla de ADN/química , ADN Bacteriano/análisis , Infecciones por Escherichia coli/diagnóstico , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/clasificación , Escherichia coli O157/genética , Escherichia coli O157/metabolismo , Heces/microbiología , Femenino , Nevada , Reacción en Cadena de la Polimerasa , Serotipificación , Toxina Shiga I/genética , Toxina Shiga II/genética , Células Vero/citología , Células Vero/efectos de los fármacos
8.
J Food Prot ; 64(10): 1613-6, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11601715

RESUMEN

Shiga toxin-producing Escherichia coli (STEC) produce toxins that have been associated with several human illnesses. E. coli O157:H7 is the most well-studied STEC and was first associated with consumption of improperly cooked ground beef in 1982. E. coli O157:H7 is not the only foodborne STEC because other STEC serotypes are also associated with human illnesses. The objective of this study was to assess prevalence of STEC in 23 yearling beef (Angus) heifers grazing an irrigated grass pasture in spring (April), summer (July), fall (October), and winter (December) of 1999. A total of 86 fecal samples were rectally collected and were subjected to microbiological testing for the presence of STEC. Nine E. coli isolates from five heifers (one in spring and fall and three in winter) were toxic to Vero cells. Of these isolates, four were E. coli O157:H7, two belonged to the serogroup O6, one O39:NM, one O113:H-, and the final isolate was untypable. The STEC prevalence rate in our herd ranged from 4% (spring) to 15% (winter). Based on detecting both O157:H7 and non-O157:H7 STEC in our heifers, it is clear that screening fecal samples should not be limited to E. coli O157:H7. Identification of STEC-positive cattle prior to slaughter should help in reducing the risk of beef contamination with such foodborne pathogens if pre- and/or postharvest control measures are applied to such animals.


Asunto(s)
Bovinos/microbiología , Escherichia coli O157/aislamiento & purificación , Toxinas Shiga/análisis , Animales , Toxinas Bacterianas , Técnicas de Tipificación Bacteriana , Escherichia coli O157/clasificación , Escherichia coli O157/metabolismo , Heces/microbiología , Femenino , Prevalencia , Estaciones del Año
9.
Vet Parasitol ; 14(1): 43-53, 1984 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-6538365

RESUMEN

The pathogenesis and clinical signs of Haemonchus longistipes infection were studied in four experimentally infected camels two of which were adults and the other two were young. In the former animals, an acute infection developed, characterized by mucoid diarrhoea, anorexia, anaemia, loss of body weight, oedema of the lower parts of the limbs, general malaise and death at 8-10 weeks post-infection. In the two younger camels, a less dramatic disease was encountered with less severe symptoms and no oedema, but also terminating fatally at 19-20 weeks post-infection. Parasitological, haematological and biochemical parameters were determined during the course of the infection and were mostly comparable with those usually encountered in haemonchosis of other animals.


Asunto(s)
Camelus/parasitología , Hemoncosis/veterinaria , Tricostrongiloidiasis/veterinaria , Animales , Proteínas Sanguíneas/análisis , Diarrea/veterinaria , Duodeno/parasitología , Recuento de Eritrocitos/veterinaria , Femenino , Hemoncosis/sangre , Hemoncosis/parasitología , Haemonchus/anatomía & histología , Recuento de Leucocitos/veterinaria , Masculino , Minerales/sangre , Recuento de Huevos de Parásitos/veterinaria , Estómago de Rumiantes/parasitología , Urea/sangre
10.
J Parasitol ; 69(5): 926-9, 1983 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-6672172

RESUMEN

Dogs fed raw camel meat containing two types of cysts shed unsporulated Hammondia heydorni oocysts and later sporulated Sarcocystis sporocysts in their feces, but were resistant to reinfection with the Hammondia cysts. Sporulated H. heydorni occysts did not induce an enteroepithelial cycle in dogs, but resulted in the formation of muscle cysts.


Asunto(s)
Camelus/parasitología , Coccidios/fisiología , Coccidiosis/parasitología , Carne , Animales , Gatos , Coccidiosis/transmisión , Perros , Heces/parasitología , Músculos/parasitología , Esporas/fisiología
11.
J Comp Pathol ; 95(3): 345-51, 1985 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-4031130

RESUMEN

Onchocerca raillieti was found to be prevalent in Sudanese donkeys. The parasite was reported from Central, Northern, Western and Eastern Sudan and was most predominant in the last locality. The pathological changes produced by adult worms in the ligamentum nuchae are mostly chronic and do not seem to cause any clinical manifestations. Likewise, the microfilariae, though found in high densities in the skin with a "spill over" into the eyes, produce no pathological changes in either the skin or eyes.


Asunto(s)
Oncocercosis/veterinaria , Perisodáctilos/parasitología , Animales , Femenino , Masculino , Oncocercosis/epidemiología , Oncocercosis/patología , Sudán
12.
J Comp Pathol ; 93(4): 619-28, 1983 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-6643762

RESUMEN

Goats are highly susceptible to Haemonchus longistipes and could therefore serve as an inexpensive model to study camel haemonchosis. The course of the disease in goats is similar to that in camels and to H. contortus infection in sheep and goats. Unlike the age-dependency of camel haemonchosis, however, the severity of H. longistipes infection in goats is dose-dependent and varies from mild to hyperacute.


Asunto(s)
Cabras/parasitología , Hemoncosis/veterinaria , Tricostrongiloidiasis/veterinaria , Animales , Proteínas Sanguíneas/análisis , Nitrógeno de la Urea Sanguínea , Femenino , Hemoncosis/sangre , Hemoncosis/parasitología , Hemoncosis/fisiopatología , Masculino
13.
J Comp Pathol ; 94(2): 169-74, 1984 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-6736305

RESUMEN

Camel haemonchosis is prevalent in the Sudan, especially during the rainy season, with a decrease in prevalence in the dry season possibly due to delayed maturation of the worms. The naturally occurring disease in Sudanese camels is characterized by emaciation, anaemia, oedema of the lower parts of the limbs, eosinophilia, hypoproteinaemia, hypoalbuminaemia, hyperglobulinaemia and eosinophilia, as well as elevated blood urea concentrations.


Asunto(s)
Camelus , Hemoncosis/veterinaria , Tricostrongiloidiasis/veterinaria , Enfermedades de los Animales/epidemiología , Enfermedades de los Animales/fisiopatología , Animales , Glucemia/análisis , Proteínas Sanguíneas/análisis , Femenino , Hemoncosis/sangre , Hemoncosis/epidemiología , Hemoncosis/fisiopatología , Masculino , Sudán , Urea/sangre
14.
J Comp Pathol ; 97(3): 293-7, 1987 May.
Artículo en Inglés | MEDLINE | ID: mdl-3611431

RESUMEN

Three-hundred and eighty five Saudi Arabian camels were surveyed for Eimeria infections and the pathology investigated. Eimeria dromedarii, E. rajasthani and E. cameli were detected, E. dromedarii being the most prevalent and E. cameli the least. Infections were more prevalent along the humid coastal areas than in the arid interior. All three parasites are pathogenic to young camel calves causing enteritis due to the destruction of intestinal mucosa by their giant schizonts. Older camels are oocyst-shedding carriers without clinical signs. Both schizogonic and sexual cycles of the three parasites occur in the jejunum and ileum of camels.


Asunto(s)
Camelus , Coccidiosis/veterinaria , Animales , Coccidiosis/parasitología , Coccidiosis/patología , Eimeria/crecimiento & desarrollo , Eimeria/aislamiento & purificación , Heces/parasitología , Femenino , Íleon/parasitología , Íleon/patología , Mucosa Intestinal/patología , Yeyuno/parasitología , Yeyuno/patología , Masculino , Arabia Saudita
15.
J Anim Sci ; 69(5): 2115-22, 1991 May.
Artículo en Inglés | MEDLINE | ID: mdl-2066322

RESUMEN

An in situ protein degradation trial and two growth trials were conducted to evaluate the use of fish meal (FM) as a protein supplement in feeder lamb diets. Finn cross and Hampshire lambs were given ad libitum access to corn diets, minerals, and water. In Growth Trial 1, four isonitrogenous (12.6% CP on a DM basis) and isocaloric (77% TDN) diets were supplemented with the following: a) 100% soybean meal (SBM); b) 70% SBM + 30% FM; c) 40% SBM + 60% FM; and d) 100% FM on a DM basis. Diets were fed to 144 lambs for 56 d in a randomized complete block (initial BW) design. In Growth Trial 2, four diets were fed to 80 lambs for 42 d in a completely randomized design with treatments arranged as a 2 x 2 factorial. Main effects in Growth Trial 2 were dietary CP level (13.3 or 14.9%) and source (SBM or SBM + FM). Alfalfa hay was used as the roughage part of each diet. In situ CP degradation (determined in cattle) of SBM, FM, and corn fed in both growth trials were 77.8, 52.3, and 56.8%, respectively. In neither growth trial was ADG affected (P greater than .05) by dietary CP source. Lambs gained faster (P less than .05) when the CP level was increased from 13.3 to 14.9% in Growth Trial 2. In both trials, protein efficiency ratio (grams of gain/grams of protein intake) and energy efficiency ratio (grams of gain/kilograms of TDN intake) were not different (P greater than .05) among diets. Because of the low ruminal degradation of corn protein, the relative value of SBM and FM in full-fed, high-corn diets was comparable.


Asunto(s)
Alimentación Animal , Proteínas en la Dieta/administración & dosificación , Productos Pesqueros , Alimentos Fortificados , Ovinos/crecimiento & desarrollo , Animales , Proteínas en la Dieta/metabolismo , Digestión , Ingestión de Alimentos , Femenino , Masculino , Distribución Aleatoria , Glycine max , Aumento de Peso , Zea mays
16.
J Anim Sci ; 69(5): 2147-56, 1991 May.
Artículo en Inglés | MEDLINE | ID: mdl-2066324

RESUMEN

Fish meal (FM) as a protein supplement in ruminant diets is presented to illustrate production responses to FM supplementation and to explain the possible factors that may affect the magnitude of these responses. Positive responses are consistently detected when FM is fed to nonruminants, but the responses when fed to ruminants have lacked consistency. Research indicates that ruminal protein degradation of FM is affected by processing factors including type and freshness of fish, addition of preservatives, stabilization of fat, type of dryer used, temperature and duration of heating, and the amount of fish solubles added back to the meal. Performance data published in the last two decades have been categorized into body weight gain and milk yield and composition. Fish meal was more effective in improving body weight gain in young than in finishing ruminants and in males than in females or castrated males. Daily gains and feed efficiencies were higher when FM supplemented medium- or poor-quality silages than when it was added to high-quality silages. No significant advantage was found for replacing protein sources that were highly ruminally degradable with FM in high-corn diets fed to growing ruminants. Milk yield and milk protein concentration were improved by FM supplementation of low-concentrate diets fed to cows in early lactation. However, milk fat percentage was negatively affected by FM supplementation. Reproduction data indicated that body gain and conception rates of high-producing cows were improved by supplementing their diets with FM during early lactation. Results suggest a significant advantage of FM supplementation to ruminant diets if the physiological status of the animal and the quality of the dietary ingredients are taken into account.


Asunto(s)
Alimentación Animal , Proteínas en la Dieta/metabolismo , Productos Pesqueros , Rumiantes/crecimiento & desarrollo , Animales , Lactancia , Leche/metabolismo , Rumiantes/fisiología , Aumento de Peso
17.
J Anim Sci ; 73(12): 3503-9, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8655422

RESUMEN

The objective of this study was to determine the effects of source of dietary CP and level of ruminally protected lysine and methionine (RPLM) on feedlot performance and carcass characteristics of Holstein steers during a growing-finishing trial (266 d). A total of 168 Holstein steers (182.7 +/- 27.5 kg) were used in a completely randomized design experiment (eight treatments; three pens of seven steers/treatment). Steers were given ad libitum access to high-concentrate diets (13% CP) containing 71% whole shelled corn, 10% corn silage, 4% condensed distillers solubles, and 15% protein supplements (DM basis). Treatments were arranged as a 2 x 4 factorial. The main factors were two sources of dietary CP and four levels of RPLM. The sources of dietary CP were soybean meal (SBM) or SBM and urea (SBM-U). Urea-N replaced 50% of SBM-N in the SBM-U diet. The levels of RPLM were 0, 5, 10, and 15 g per steer daily. No interactions (P > .10) between source of dietary CP and level of RPLM were observed for feedlot performance or carcass characteristics. Feedlot performance showed an advantage (P < .10) to feeding SMB during the first 84 d of the trial and an advantage to feeding SBM-U during the last 98 d of the trial. However, feedlot performance for the whole trial and carcass characteristics (except for fat thickness) were not affected (P > .10) by the source of dietary CP. Steers fed diets containing SBM-U had 12% less (P < .10) fat thickness than those fed diets containing SBM. Supplementation of diets with increasing levels of RPLM did not affect (P > .10) ADG or carcass characteristics. However, DMI and gain:feed showed cubic (P < .10) responses to increasing dietary level of RPLM. Supplementation of RPLM at the 10 g/d level improved gain:feed by 12% during the last 98 d of the trial, and this was a direct response to the cubic effects of RPLM on DMI. Results suggest a cost advantage for replacing 50% of SBM-N with that from urea in high-corn diets without negative effects on feedlot performance or carcass characteristics of growing-finishing Holstein steers with extended feeding periods (266 d). These types of diets seem to meet the amino acid requirements and are not limiting in lysine and methionine.


Asunto(s)
Alimentación Animal/normas , Composición Corporal/fisiología , Bovinos/fisiología , Proteínas en la Dieta/farmacología , Lisina/farmacología , Carne/normas , Metionina/farmacología , Alimentación Animal/análisis , Animales , Composición Corporal/efectos de los fármacos , Proteínas en la Dieta/administración & dosificación , Proteínas en la Dieta/análisis , Alimentos Fortificados , Lisina/administración & dosificación , Lisina/análisis , Masculino , Metionina/administración & dosificación , Metionina/análisis , Proteínas de Vegetales Comestibles/análisis , Proteínas de Vegetales Comestibles/farmacología , Proteínas de Soja , Urea/análisis , Urea/farmacología
18.
J Anim Sci ; 73(11): 3246-52, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8586580

RESUMEN

The objective was to compare the relative energy value of wet corn gluten feed (WCGF) to that of corn in a feedlot situation when diets were initially offered ad libitum (AL) or at restricted feed intake (RFI; 80% of AL). In a completely randomized block (pen location) design experiment, 144 beef heifers (204.1 +/- 18.2 kg) were used (six treatments; three pens of eight heifers/treatment). Treatments were levels of WCGF (on DM basis) in corn silage-based diets (AL; 25 or 50% WCGF) or high-moisture corn-based diets (RFI; 0, 25, 50, or 75% WCGF) during the growing phase (127 d). During finishing (84 d), all diets were offered AL and contained 5% corn silage by replacing corn silage with high-moisture corn in diets that were offered AL. Heifers that were initially at AL had similar (P > .1) feedlot performance (during growing and during the whole trial), digestibility of nutrients (OM, NDF, CP, and GE), and carcass characteristics. During finishing, however, these heifers had better (P = .06) ADG and gain:feed when 25% WCGF was fed. Heifers that were initially at RFI showed a linear decrease (P < .01) in ADG and gain:feed during growing with increasing dietary level of WCGF. However, increasing dietary level of WCGF resulted in a quadratic (P = .02) response in ADG and gain:feed during finishing and also in a quadratic (P = .07) response in ADG and a linear (P = .005) decrease in gain:feed during the whole trial. These quadratic responses indicated that the best performance was achieved at the 25 and 50% levels of WCGF. The decrease in cumulative gain:feed was only 3.5% at the 25 and 50% levels of WCGF but it was 11.4% at the 75% level. Increasing the level of WCGF in diets of heifers that were initially at restricted feed intake did not affect (P > .1) digestibility of nutrients but it improved some carcass characteristics linearly, decreasing fat thickness (P = .04), liver abscess (P = .02), and yield grade (P = .13). Results suggest that WCGF can substitute up to 25 or 50% of dietary DM without negative effects on feedlot performance, digestibility of nutrients, or carcass characteristics. In addition, restricting feeding during growing may be strategy that improves the utilization of WCGF at these levels.


Asunto(s)
Composición Corporal/fisiología , Bovinos/fisiología , Dieta/veterinaria , Digestión/fisiología , Ingestión de Alimentos/fisiología , Alimentación Animal/normas , Animales , Bovinos/crecimiento & desarrollo , Dieta/normas , Femenino , Glútenes/análisis , Glútenes/normas , Distribución Aleatoria , Zea mays/química , Zea mays/normas
19.
J Anim Sci ; 69(5): 2123-33, 1991 May.
Artículo en Inglés | MEDLINE | ID: mdl-2066323

RESUMEN

Four diets containing 15% CP were formulated to study the effects of dietary carbohydrate and protein sources on N metabolism and carbohydrate fermentation by ruminal bacteria. Diets were supplied to eight dual-flow continuous culture fermenters during three experimental periods in a randomized complete block design. Six replications were obtained for each diet. Treatments were arranged as a 2 X 2 factorial with two carbohydrate and two protein sources. Carbohydrate sources were corn and barley and protein sources were soybean meal (SBM) and fish meal (FM). Approximately 40% of the dietary CP was derived from SBM or FM and corn or barley provided 39% of dietary DM. All diets contained 15% grass hay, 20% wheat straw, and 10.1 to 15.3% solka floc (DM basis). Interactions (P less than .05) were observed between dietary carbohydrate and protein sources, resulting in a depression of VFA production (moles/day) and digestion (percentage) of ADF and cellulose when the corn-FM diet was fed. True OM digestion (percentage) was higher (P less than .05) for SBM than for FM diets and for corn than for barley diets. Although dietary CP degradation (percentage) was higher (P less than .05) for SBM than for FM diets, non-NH3 N in the effluent (grams/day) was not different among diets due to a greater (P less than .05) bacterial N flow for SBM than for FM diets. Despite the lower amino acid (AA) intake (P less than .05) for corn than for barley diets and also for FM than for SBM diets, flows (grams/day) of total AA, essential AA (EAA), and nonessential AA (NEAA) were similar (P greater than .05) among diets. However, greater (P less than .05) total AA, EAA, and NEAA flows (percentage of AA intake) were found for corn than for barley diets and for FM than for SBM diets. It is concluded, therefore, that ruminal escape protein derived from corn or FM has a significant effect on manipulating AA leaving the ruminal fermentation.


Asunto(s)
Bovinos/metabolismo , Carbohidratos de la Dieta/metabolismo , Proteínas en la Dieta/metabolismo , Nitrógeno/metabolismo , Rumen/metabolismo , Aminoácidos/análisis , Aminoácidos/metabolismo , Amoníaco/análisis , Alimentación Animal/análisis , Animales , Bacterias/metabolismo , Proteínas Bacterianas/biosíntesis , Ácidos Grasos Volátiles/análisis , Ácidos Grasos Volátiles/biosíntesis , Femenino , Fermentación , Productos Pesqueros , Hordeum , Rumen/microbiología , Glycine max , Zea mays
20.
J Anim Sci ; 69(5): 2134-46, 1991 May.
Artículo en Inglés | MEDLINE | ID: mdl-1648551

RESUMEN

Eight wether lambs fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 4 x 4 Latin square design to study the effects of carbohydrate and protein sources on ruminal protein metabolism and carbohydrate fermentation and intestinal amino acid (AA) absorption. Treatments were arranged as a 2 x 2 factorial. Carbohydrate sources were corn and barley; protein sources were soybean meal (SBM) and fish meal (FM). Diets contained 15.5% CP, of which 40% was supplied by SBM or FM. Corn or barley provided 39% of dietary DM that contained equal amounts of grass hay and wheat straw. Fish meal diets produced a lower (P less than .05) ruminal NH3 concentration and resulted in less CP degradation and bacterial protein flow to the duodenum than did SBM diets. Replacing SBM with FM increased (P less than .05) ruminal digestion of all fiber fractions. In addition, cellulose and hemicellulose digestibilities in the rumen tended to increase (P greater than .05) when barley replaced corn in the FM diets. Carbohydrate x protein interactions (P less than .05) were observed for OM digestion in the rumen and AA absorption in the small intestine (percentage of AA entering); these interactions were highest for the barley-FM diet. These results suggest that feeding FM with barley, which is high in both degradable carbohydrate and protein, might benefit ruminants more than feeding FM with corn, which is high in degradable carbohydrate but relatively low in degradable protein.


Asunto(s)
Carbohidratos de la Dieta/metabolismo , Proteínas en la Dieta/metabolismo , Mucosa Intestinal/metabolismo , Rumen/metabolismo , Ovinos/metabolismo , Aminoácidos/metabolismo , Amoníaco/análisis , Animales , Bacterias/metabolismo , Fibras de la Dieta/metabolismo , Digestión , Ácidos Grasos Volátiles/análisis , Fermentación , Productos Pesqueros , Hordeum , Concentración de Iones de Hidrógeno , Absorción Intestinal , Masculino , Nitrógeno/metabolismo , Rumen/microbiología , Glycine max , Zea mays
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