Effect of Gamma Irradiation on Microbial Decontamination, Crude Nutrient Content, and Mineral Nutrient Composition of Laboratory Animal Diets.

Laboratory animal models are an important part of test design. Certain conditions such as microbial contamination in diets of these models could affect the results of experiments. One of the most important routes that predispose to contamination is generated through feeding of laboratory animals. This study aimed to show the effect of gamma irradiation in reducing bacteria concentrations, crude nutrient content, and concentrations of some minerals and trace elements in laboratory animal diets. Large-sized pellets with 10–15 mm diameter (commonly used for rats and hamsters) and small-sized pellets with 3–5 mm diameter (used for rabbits and guinea pigs) along with skimmed milk powder (SMP) as a food additive were exposed to gamma irradiation with different doses ranging from 3 to 30 kGy. The total microbial contamination and any possible changes in some mineral nutrient composition and the crude nutrient content were determined pre- and post-irradiation. Our data revealed that 25 kGy in pelleted diets and 18 kGy in SKM had superior effects in the reduction of bacterial contamination with little change in crude nutrient content and minerals and trace elements in nutrient requirements of laboratory animals. According to the results, gamma irradiation had minimal effects on crude nutrient content and the concentrations of some minerals and trace elements of laboratory animal diets, and it also eliminated bacterial and fungal contamination load. By using gamma irradiation, this method could yield a favorable outcome in controlling microbial contamination of animal diets.

Immunomodulatory effect of γ-irradiated Astragalus polysaccharides on immunosuppressed broilers.

In this study, we irradiated Astragalus polysaccharides (APS) using 25 kGy 60 Co γ ray to obtain γ-irradiated Astragalus polysaccharides (IAPS) and then investigated the effects of IAPS on growth performance and immune function of cyclophosphamide (CPM)-treated broilers. The physicochemical properties of APS and IAPS (molecular weight, water solubility, viscosity, morphological and structural properties) were evaluated. Then, 384 one-day-old Arbor Acres broiler chicks with similar initial weight were randomly assigned into 6 groups: the non-treated group (control), and CPM-treated groups were fed either a basal diet or the diets containing 900 mg/kg APS, or 900, 600, 300 mg/kg IAPS, respectively. On days 16, 18, and 20, all broilers except for the control group were intramuscularly injected with 0.5 ml CPM (40 mg/kg·BW). Broilers in the control group were intramuscularly injected with 0.5 ml sterilized saline (0.75%, wt/vol). This trial lasted for 21 days. The physicochemical treatment showed that γ irradiation could decrease the molecular weight and viscosity, and increase the water solubility of APS (p < 0.05), whereas the structural properties of APS was not affected. In the animal trial, 900 mg/kg APS or 900, 600 mg/kg IAPS relieved the decreased growth performance, thymus index, T lymphocytes proliferation, serum IgG concentration, NOS activity and the increased blood heterophil:lymphocyte ratio in CPM-treated broilers (p < 0.05). CPM-induced decreases in B lymphocytes proliferation and serum IgM concentration were only increased by IAPS at 900 mg/kg (p < 0.05). Overall, both APS and IAPS alleviated CPM-induced immunosuppression. Especially, IAPS possessed better immunomodulatory effect than APS, indicating that γ irradiation could be used as an effective method to enhance the immunomodulatory activity of APS.

Determine effect of pressure heating on carbohydrate related molecular structures in association with carbohydrate metabolic profiles of cool-climate chickpeas using Globar spectroscopy.

Grain has been heat-processed to alter rumen degradation characteristics and improve nutrient availabilities for ruminants. However, limited study was found on internal structure changes induced by processing on a molecular basis. The objectives of this study were to use advanced vibrational molecular spectroscopy to: (1) determine the processing induced carbohydrate (CHO) structure changes on a molecular basis, (2) investigate the effect of pressure heating on changes of CHO chemical profiles, CHO subfractions in cool-climate CDC Chickpea varieties, and (3) to reveal the association between carbohydrates related molecular spectra with carbohydrate metabolic profiles. The cool-climate CDC chickpea varieties with multisource were pressure heated in an autoclave at 120 °C for 60 min; and FTIR vibrational spectroscopy was used to detect the molecular spectra. Molecular spectroscopic results showed that compared to raw chickpea varieties, autoclave heating induced changes in both total CHO (region and baseline ca. 1186-946 cm-1) and structural CHO (STCHO, region and baseline ca. 1482-1186 cm-1), except for cellulosic compounds (CELC, region and baseline ca. 1374-1212 cm-1). The CHO chemical profile and rumen degradation results showed that autoclave heating decreased rumen degradable, undegradable and intestinal digestible sugar (CA4) content, but increased available fiber (CB3) content, without affecting available energy of chickpeas. The changes of CHO molecular spectra in chickpea varieties were strongly correlated with CHO chemical profiles, CHO subfractions, and CHO rumen degradation characteristics. Moreover, the regression analysis showed that STCHO peak 1 height could be used to predict sugar content, its rumen degradability and digestibility of chickpeas. Our results suggest that autoclave heating markedly changes sugar and fiber degradation characteristics. The carbohydrate molecular spectral profiles are associated with carbohydrate metabolic profiles in raw and pressure heated cool-climate chickpeas.

Assessment of the Content of Fluorescent Tracer in Granular Feed Mixture.

Background: This paper describes the use of fluorescence induced by UV radiation to evaluate the share of tracer in feed mixture. Methods: For the purpose of this study, three substances were used. They are as follows: Tinopal, Rhodamine B, and Uranine. Tracer in the form of maize or kardi was added to chicken feed before the mixing process. Grains used in the process were grinded in the mill sieve with a mesh size of 4 and 6 mm. The drawn samples of the mixture were illuminated with UV radiation to make grain tracer light, and then the photo was taken with a digital camera. The acquired images were analyzed with the use of a computer program running on the RGB color model, which was the way to obtain essential information about the percentage share of tracer. Results: It was observed that, in the case of kardi grains, the proposed method gives results significantly deviating from the verification method. Conclusions: Only the tests with the use of maize having an average particle diameter of 2.4 mm and tinted with the solution of Rhodamine B led to acceptable results (consensual with the predetermined verification level).

Ultraviolet irradiation of spray-dried porcine plasma does not affect the growth performance of nursery pigs when compared with nonirradiated bovine plasma.

Ultraviolet light irradiation of spray-dried porcine plasma (SDPP) decreases the risk of disease transmission, but it may decrease the activity of bioactive components in SDPP. Therefore, the objectives of this study were to determine growth performance, morbidity, and mortality responses of nursery pigs fed UV-irradiated SDPP (UV-SDPP) compared with nonirradiated spray-dried bovine plasma (SDBP). Pigs ( = 480; 6.09 ± 2.4 kg initial BW) were blocked by initial BW, and blocks were assigned to pens. the sex ratio was equalized within blocks and pens. Pens were randomly assigned to 1 of 5 dietary treatments (8 pigs/pen and 12 replicates/treatment) in a 3-phase feeding program (phase 1 = d 0 to 13, phase 2 = d 14 to 27, and phase 3 = d 28 to 55). Dietary treatments included a control diet without UV-SDPP or SDBP and diets containing 3% UV-SDPP, 3% SDBP, 6% UV-SDPP, or 6% SDBP during phase 1. Diets were formulated to meet or exceed nutrient requirements and contained the same concentrations of standardized ileal digestible Lys and Lys:ME ratio within phases. Pigs were provided ad libitum access to diets throughout the 55-d experiment. Dietary inclusion rates during phase 2 were reduced to 1.5% UV-SDPP, 1.5% SDBP, 3% UV-SDPP, and 3% SDBP, and all pigs were fed a common diet without UV-SDPP or SDBP during phase 3. Growth performance data were analyzed as a 2 × 2 factorial arrangement of treatments with a control within a completely randomized block design to evaluate the main effects of plasma processing (UV irradiated vs. nonirradiated) and dietary inclusion level, and block, room, and pen were random effects. In phase 1, there were no differences in G:F among treatments, but pigs fed 6% UV-SDPP and 6% SDBP had greater ( < 0.01) ADG (0.11 vs. 0.08 kg/d) and ADFI (0.17 vs. 0.15 kg/d) than pigs fed the control, 3% SDBP, and 3% UV-SDPP diets. After phase 1 (d13), feeding UV-SDPP or SDBP increased ( = 0.02) the BW of pigs. In phases 2 and 3 and the overall feeding period (d 0 to 55), there were no differences in ADG, ADFI, and G:F among dietary treatments. There was a linear decrease ( < 0.01) in mortality of nursery pigs as dietary inclusion rate of SDBP and UV-SDPP increased. In conclusion, feeding SDBP or UV-SDPP diets improved ADG and ADFI during the first 2 wk after weaning due to improved feed consumption, and UV irradiation appeared to have no detrimental effects on the feeding value of SDPP.

Effect of radiation on chemical composition and protein quality of cottonseed meal.

This study was conducted to compare the effects of electron beam (EB) and gamma ray (GR) irradiation treatments at doses of 10, 20 and 30 kGy on chemical composition, protein quality and protein digestibility of cottonseed meal (CSM). GR irradiation in all doses significantly decreased the crude fiber of samples compared to raw CSM. Free and total gossypol content of CSM was decreased significantly by utilizing both types of irradiation in a dose-dependent manner. Also, EB irradiation caused decrease in free and total gossypol content more than that of GR irradiation. GR irradiation at doses of 20 and 30 kGy, and EB irradiation at doses of 10, 20 and 30 kGy can significantly decrease protein solubility of CSM compared to that of a raw sample. GR irradiation at a dose of 30 kGy significantly increased apparent digestibility of protein compared to raw and EB irradiation of CSM at a dose of 10 kGy in Leghorn cockerels. Maximum increase in protein digestibility of CSM was observed in GR irradiation at a dose of 30 kGy. In conclusion, the present study showed that EB and GR irradiation reduced gossypol and crude fiber and increased protein digestibility of CSM but had no effect on protein quality of CSM.

Effectiveness of Protective Activities for Rehabilitation of the Forage Lands in Russia and Belarus Contaminated as a Result of the Chernobyl Accident.

Regularities of changes in the content of (137)Cs in green fodder during the remote period after the CNPP accident depending on application of agro-technical and agrochemical activities are analyzed. It is revealed that the use of mineral fertilizers reduces receipt of (137)Cs from the soil to forage and further to a food chain. It is also established that agrochemical activities are more effective than agro-technical ones.

Mycotoxin contamination of animal feedingstuff: detoxification by gamma-irradiation and reduction of aflatoxins and ochratoxin A concentrations.

Mycotoxins are fungal secondary metabolites identified in many agricultural products screened for toxigenic moulds. They have been reported to be carcinogenic, teratogenic, tremorogenic, haemorrhagic and dermatitic to a wide range of organisms. With the increasing stringent regulations for mycotoxins imposed by importing countries such as those of the European Union, many cereals that are not safe for human consumption are used in formulations intended for animal feed. Gamma-rays are reported in the scientific literature to destroy ochratoxin A and aflatoxin in food crops and feed. The present study provides preliminary data for establishing the effect of dose of gamma-irradiation, ranging from 0 to 15 kGy, on aflatoxins and ochratoxin A reduction in commercial animal feed. The mycotoxin levels were determined by means of immunoaffinity clean-up (IAC) and HPLC with fluorescence detection (HPLC-FLD). The maximum reductions found at 15 kGy were 23.9%, 18.2%, 11.0%, 21.1% and 13.6% for ochratoxin A, aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2, respectively. Results showed that the gamma-rays even at 15 kGy were not effective in the complete destruction of ochratoxin A and aflatoxins in the tested feed.

Using a non-invasive technique in nutrition: synchrotron radiation infrared microspectroscopy spectroscopic characterization of oil seeds treated with different processing conditions on molecular spectral factors influencing nutrient delivery.

Non-invasive techniques are a key to study nutrition and structure interaction. Fourier transform infrared microspectroscopy coupled with a synchrotron radiation source (SR-IMS) is a rapid, non-invasive, and non-destructive bioanalytical technique. To understand internal structure changes in relation to nutrient availability in oil seed processing is vital to find optimal processing conditions. The objective of this study was to use a synchrotron-based bioanalytical technique SR-IMS as a non-invasive and non-destructive tool to study the effects of heat-processing methods and oil seed canola type on modeled protein structure based on spectral data within intact tissue that were randomly selected and quantify the relationship between the modeled protein structure and protein nutrient supply to ruminants. The results showed that the moisture heat-related processing significantly changed (p<0.05) modeled protein structures compared to the raw canola (control) and those processing by dry heating. The moisture heating increased (p<0.05) spectral intensities of amide I, amide II, α-helices, and ß-sheets but decreased (p<0.05) the ratio of modeled α-helices to ß-sheet spectral intensity. There was no difference (p>0.05) in the protein spectral profile between the raw and dry-heated canola tissue and between yellow- and brown-type canola tissue. The results indicated that different heat processing methods have different impacts on the protein inherent structure. The protein intrinsic structure in canola seed tissue was more sensitive and more response to the moisture heating in comparison to the dry heating. These changes are expected to be related to the nutritive value. However, the current study is based on limited samples, and more large-scale studies are needed to confirm our findings.

[Application of deactivating properties of some sorbents in aquaculture feed production].

The possibility and effectiveness of application of selective sorbents for fish feed production in aquaculture in the area exposed to the radioactive pollution were studied. The investigations of the fish feed deactivating properties with additives of ferrocyn and potassium alginate, and magnesium on whitefish fry-fingerlings and yearlings were carried out. The study has shown that the ferrocyn performance is greater than 99% regardless of the fish age. 1% ferrocyn addition to feed allows increasing the acceptable concentration of feed compo- nents polluted by the above norm cesium radionuclide up to 20 times. The alginate additives in feed provide almost double decrease in the activity of fish tissues. The optimally effective alginate dose should exceed the calcium concentration in feed up to 4 times. It was found that utilization of the feedstock (fish meal, crops and legumes, oil meal and oil cake) polluted by radionuclides is possible in combined aquaculture feed pro- duction. The application of sorbents in feed will allow increasing the amount permissible for use of the feed components polluted above the norm; ensure the radiation safety of feed and, finally, the protection of aquatic biological resources from radioactive contamination. It is shown that the sorbent additive in feed is also jus- tified in case of fish farming in closed waters affected by radioactive pollution. Feeding by mixed fodder with the sorbent additives prevents fish from radionuclide intake from natural food sources.

The induction of a radiation-induced bystander effect in fish transcends taxonomic group and trophic level.

PURPOSE: To extend the investigations of bystander effect induction in fish of the same species as the irradiated fish, to bystander effect induction between fish species and between trophic levels. MATERIALS AND METHODS: To investigate interspecies bystander effect induction, zebrafish and medaka were irradiated with a 0.5 Gy X-ray dose and then swum with non-irradiated fish of the same and opposite species. To investigate trophic level bystander effect induction, California blackworms were irradiated with the same X-ray dose and then fed to non-irradiated rainbow trout. RESULTS: Reductions in clonogenic survival of the HPV-G (non-transformed human keratinocytes, immortalized with the human papilloma virus) reporter cell line, treated with tissue explant media, revealed that zebrafish and medaka induced a pro-apoptotic bystander effect in the other species and that, in trout, the normally anti-apoptotic effect caused by the consumption of non-irradiated blackworms was significantly reduced or lost if the blackworms had been irradiated. CONCLUSIONS: These results are the first to show that a radiation- induced bystander effect can transcend taxonomic group and trophic level in fish. This provides further evidence that bystander signals are widespread and conserved and may be transmitted through an ecosystem, as well as between individuals of the same species.

The effect of microwave treatment on animal fodder.

Preliminary research has suggested that in vitro dry matter disappearance (DMD) of some poor quality animal fodder materials can be improved by microwave treatment. Laboratory scale experiments revealed that dry matter percentage of Lucerne hay increased by 1.7% as microwave treatment time increased from 0 to 80 seconds. The in vitro DMD of lucerne hay increased by 14.9% during the same microwave treatment. In addition it was also demonstrated that microwave treatment significantly increased starch digestion of oats compared to the control samples. These experiments were followed up with a larger sample experiment in which 25 kg bags of Lucerne fodder were treated for 7.5, 15, 22.5 or 30 minutes in an experimental 6 kW microwave chamber. Dry matter percentage increased by 7.2% as microwave treatment time increased from 0 to 30 minutes. Microwave treatment significantly increased DMD during an in vitro digestion study; however there were no significant differences between the various microwave treatment times. The 15 minute treatment resulted in the greatest increase in dry matter disappearance (5.9%). The crude protein retained in the digestion residues increased by 19.2% as microwave treatment increased from 0 to 30 minutes. These laboratory studies were followed up with an animal response study in which a Merino sheep group being fed the microwave treated lucerne gained 8.1% of their initial body weight by the end of the trial compared to a 0.4% increase in body weight for the control group.

Management strategies for controlling endemic and seasonal mouse parvovirus infection in a barrier facility.

Despite improved diagnostic and rederivation capabilities, research facilities still struggle to manage parvovirus infections (e.g., mouse parvovirus (MPV) and minute virus of mice) in mouse colonies. Multi-faceted approaches are needed to prevent adventitious organisms such as MPV from breaching a barrier facility. In this article, the authors document recent changes to the Salk Institute's animal care program that were intended to help manage mouse parvovirus in the barrier facility. Specifically, the Institute started to use a new disinfectant and to give mice irradiated feed. The authors found an association between these modifications and a reduction in MPV incidence and prevalence in endemically infected colonies. These data suggest that using irradiated feed and appropriate disinfectants with contemporary management practices can be an effective plan for eradicating or controlling MPV infection in a research facility. The authors recommend further study of the environmental risk factors for parvovirus infection and of potential biological interactions associated with the use of irradiated feed.

Effects of irradiation of feed ingredients added to meal or pelleted diets on growth performance of weanling pigs.

Two experiments were conducted to evaluate the effects of irradiated ingredients in meal and pelleted diets on nursery pig performance. In Exp. 1, a total of 192 pigs (initial BW, 6.0 kg) were used in a 25-d experiment. Pigs were blocked by BW and randomly allotted in a 2 x 2 factorial arrangement of treatments with main effects of diet form (meal or pellet) and either irradiated (11.92 kGy) or nonirradiated spray-dried animal plasma (SDAP). Irradiated SDAP had less total bacterial amounts than nonirradiated SDAP, and pelleted diets also had less bacterial amounts than diets in meal form. However, the complete diets with and without irradiated SDAP had similar bacterial concentrations. There was a diet form x SDAP irradiation interaction (P < 0.05) for ADG from d 0 to 11 and d 0 to 25. Pigs fed irradiated SDAP in meal form had increased ADG compared with pigs fed the nonirradiated meal diet, with no change in ADG of pigs fed pelleted diets. In addition, from d 0 to 11, pigs fed irradiated SDAP or pelleted diets had greater G:F (P < 0.01) compared with pigs fed regular SDAP and meal diets, respectively. In Exp. 2, a total of 350 pigs (initial BW, 4.9 kg) were used in a 22-d experiment to determine the effects of feeding irradiated protein sources (SDAP, soybean meal, fish meal, or all 3) in meal and pellet diets on pig performance. Pigs were blocked by BW and randomly allotted to 1 of 10 treatments consisting of a single diet formulation fed in either meal or pellet form containing either no irradiated protein sources or irradiated SDAP, soybean meal, fish meal, or all 3 irradiated protein sources (10.20 kGy). Irradiated SDAP, soybean meal, and fish meal tended to have reduced total bacterial concentrations compared with nonirradiated plasma, and pelleted diets had reduced bacterial concentrations compared with diets in meal form. No irradiation x diet form interactions (P > 0.16) were observed. From d 0 to 11, pigs fed diets containing irradiated protein sources had greater (P < 0.03) G:F compared with pigs fed the control diets, with no difference in ADG or ADFI. From d 0 to 11, and overall (d 0 to 22), pigs fed pellet diets had greater G:F (P < 0.01) compared with pigs fed meal diets, with no difference in ADG and ADFI. These studies indicate that both irradiation and pelleting are manufacturing processes that can reduce bacteria concentrations in feed ingredients and diets. Irradiated SDAP, soybean meal, and fish meal improved G:F compared with control diets containing nonirradiated ingredients. Furthermore, pigs fed pelleted diets had increased G:F compared with pigs fed meal diets.

Ataxia and paralysis in cats in Australia associated with exposure to an imported gamma-irradiated commercial dry pet food.

Between June 2008 and March 2009, 87 cats in Australia developed symmetrical hindlimb ataxia, paraparesis, tetraparesis, paraplegia or tetraplegia in association with eating an imported, irradiated dry pet food. This communication reports the clinical signs and outcomes of those cats.

The experimental induction of leukoencephalomyelopathy in cats.

Leukoencephalomyelopathy of undetermined etiology has been described in specific pathogen-free cats. A study was established to assess if the long-term feeding of a gamma-irradiated diet could induce this disease. Cats fed exclusively on diet irradiated at 25.7-38.1 kGy ("typical" dose) and 38.1-53.6 kGy (high-end dose), respectively, developed typical lesions with attendant, progressively severe ataxia between study days 140 and 174. The onset of ataxia at day 140 and the number of animals affected at this time were similar in animals fed each ration. A maximum ataxia "score" was first reached by an animal on the high-end dose diet on day 167 and by 2 cats fed the "typical-end" dose diet 21 days later. Ataxic cats and 1 animal euthanized on day 93 prior to the onset of ataxia exhibited varying degrees of Wallerian degeneration in the spinal cord and brain, similar to the spontaneous disease. The elevated total antioxidant status of spinal cord segments and hepatic superoxide dismutase concentration of cats fed typical and high-end treated diets suggested free-radical involvement in the pathogenesis. The significantly elevated peroxide concentrations of the irradiated diets (1,040% and 6,440% of untreated values) may have resulted in increased oxidative insult, a factor possibly exacerbated by the treated diets' reduced vitamin A content. This study has reproduced leukoencephalomyelopathy in cats similar to spontaneous outbreaks by feeding a gamma-irradiated dry diet with elevated peroxide and reduced vitamin A concentrations.

Development of an analytical method based on microwave-assisted extraction and solid phase extraction cleanup for the determination of organochlorine pesticides in animal feed.

A method to determine 21 organochlorine pesticides in animal feed samples using microwave assisted extraction and solid phase extraction cleanup was optimised regarding its main parameters. After extraction with hexane-acetone (50:50), three different sorbents (alumina/ENVI-Florisil, ENVI-Carb and ENVI-Carb II/PSA) were assayed for the cleanup step. Analytes were eluted with hexane-ethyl acetate (80:20) and determined by gas chromatography and electron capture detection followed by gas chromatography-mass spectrometry. ENVI-Carb and ENVI-Carb II/PSA provided colourless eluates but fewer interferent compounds were found in ENVI-Carb II/PSA chromatograms, so this system was selected to carry out the purification of the extracts. The analytical recoveries obtained with this method were close to 100% in most cases with relative standard deviations lower than 10%. These percentages were similar to those obtained with the Soxhlet extraction procedure, which shows the method suitable for the determination of organochlorine pesticides in animal feed material. The method was also validated with the analysis of a certified reference material (CRM-115 BCR), and the results obtained were in good accordance with the certified values.

Transfer of Cl from herbage into tissues and milk products of dairy cattle and pigs.

Cl-36 is an important component of nuclear waste. The concentrations of stable chlorine (Cl) in pig and cow tissues were measured to provide information which can be used to parameterize models of (36)Cl transfer into agricultural animals. The concentration of stable Cl in cows' milk was 1.0 +/- 0.2 g L(-1), in cow muscle it was 0.7 +/- 0.2 g kg(-1) wet mass (wm) and in pig muscle 0.4 +/- 0.1 g kg(-1) wm. The concentration of stable Cl in cow and pig liver was 0.9 +/- 0.3 g kg(-1) wm, which was about two-fold higher than that in the kidney and lung. Due to homeostatic control, stable Cl concentrations in animal tissues are not related to the amount ingested daily in herbage at intake rates in the normal physiological range of up to 188 g day(-1) for cows and up to 40 g day(-1) for pigs. Therefore, the commonly used transfer coefficient is not suitable for use in quantifying the transfer of (36)Cl to milk and meat. Since the metabolism of stable Cl and (36)Cl in an animal's body is identical, the average equilibrium ratios of (36)Cl to stable Cl in the daily ration ((36)Cl (g kg(-1))/Cl (g kg(-1))) and animal tissues will be the same. We therefore conclude that the average equilibrium Cl isotopic ratio in the dietary daily intake should be used to predict the contamination of meat and milk with (36)Cl.

Efecto de altos niveles de hierro y molibdeno sobre la nutrición del cobre en vacas mestizas / High levels of dietary iron and molybdenum on copper nutrition in cross bred cows

Para estudiar el efecto de altos niveles de hierro (Fe) y molibdeno (Mo) sobre la nutrición del cobre (Cu), 20 vacas vacías, mestizas Bos taurus x Bos indicus, de 394 kg PV y de más de dos partos, fueron distribuidas según un diseño completamente aleatorizado en los siguientes tratamientos: (1) Testigo (T): 10 ppm Cu; (2) Mo: 10 ppm Cu y 20 ppm Mo; (3) Fe: 10 ppm Cu y 1000 ppm Fe; (4) MoFe: 10 ppm Cu y 1000 ppm Fe y 20 ppm Mo. Las vacas fueron alimentadas ad libitum con pasto de corte (Panicum maximun y Andropogun gayanus), 1,5 kg de alimento por animal día -1 (harina de maíz: 95 por ciento; urea: 5 por ciento) que contenía los minerales en las proporciones indicadas. Se tomaron muestras de suero sanguíneo para determinar Cu, Fe y la actividad de la ceruloplasmina. A través de biopsias, se tomaron muestras del tejido hepático cada 28 días, durante 192 días, para determinar la concentración de Cu, Fe y Mo. El consumo de pasto estuvo alrededor de 10 kg MS/animal día -1. El peso vivo no presentó diferencias entre tratamientos con valores de 385; 353; 396 y 382, kg para T, Mo, Fe, MoFe, respectivamente. La concentración de Cu sérico (µg ml-1) fue de 0,81; 0,67; 0,50 y 0,71, respectivamente para el mismo orden de los tratamientos, siendo Fe el más bajo (P<0,05). Para el Fe sérico, se observaron diferencias significativas entre los tratamientos (P<0,05), con valores de 1,49; 1,67; 2,08 y 1,93 µg ml -1, para el testigo, Mo, Fe y MoFe, respectivamente. Los valoresde Cp (absorbancia) fueron 0,093; 0,085; 0,084 y 0,087, para el testigo, Mo, Fe y MoFe, respectivamente, sin diferencias significativas entre tratamientos. Los niveles de Cu hepático fueron diferentes (P<0,01) entre tratamientos, con valores más altos (mg kgMS-1) para T (71,9) y más bajos para Mo (26,6), Fe (30,8) y MoFe (31,4). La concentración de Fe en el hígado registró valores (mg kgMS-1) de 559,0; 513,3; 559,8 y 797,3para T, Mo, Fe y MoFe, respectivamente, sin diferencias significativas...

To evaluate the effect of high levels of iron (Fe) and molybdenum (Mo) on copper (Cu) nutrition, 20 dry cross bred cows, Bos Taurus x Bos indicus, of 394 kg BW, with no less than two calving, were assigned to the following treatments: (1) Control (C); 10 ppm Cu(2); Mo 10 ppm + 20ppm Cu (Mo); (3) 10ppm Cu+ 1000 ppm Fe (Fe); and (4) 10 ppmCu+ 1000 ppm Fe+ 20 ppm Mo ( MoFe). Cows were fed chopped forage ad libitum (Panicum maximum and Andropogun gayanus) and 1.5 kg concentrate feed (corn meal, 95% and urea, 5%) containing minerals in the proportions as previously indicated. Serum samples were taken every 28 days for Cu, Fe and cerulopasmine (Cp) activity. Liver sample, via biopsy, at the same time intervals, were also taken to measure Cu, Fe and Mo concentrations. The experiment lasted 192 days. Body weights were not affected by treatments: 385; 353; 396 and 382 kg, respectively for T, Cu, Fe,and MoFe. Copper serum concentration values (µg ml-1) were 0.81, 0.67, 0.50 and 0.71, respectively for the same order, being Fe the lowest (P<0.05). Ceruloplasmine absorbancy values were not different among treatments. Liver copper concentration values were significantly different (P<0.05) among treatments, with higher value (mg KgMS-1) for T (71.9) and lower for Mo (26.6), Fe (30.8) and MoFe (31.4). Liver iron concentration (mg kgMS-1) values were not different among treatments, with values of 559.0, 513.3, 559.8, and 797.3 respectively for C, Mo, Fe and MoFe. Liver Mo take up (mg kgMS-1) was greater (P<0.01) for Mo treatment (19.9) and MoFe (15.8) in relation to T (1.7) and Fe (1.9). Results indicate that high levels of Mo and Fe decreased liver copper, below critical levels. However, the reduction of liver copper was no associated with clinical sign of copper efficiency. Probably lower levels of liver copper are required to show changes in ceruloplasmine and blood serum concentrations as well as other biochemical changes at tissue level...

Effects of electron beam irradiation on deoxynivalenol levels in distillers dried grain and solubles and in production intermediates.

Wheat contaminated with deoxynivalenol (DON), and distillers dried grain and solubles (DDGS) obtained after ethanol production from the contaminated wheat, were irradiated to doses ranging from 2.0 to 55.8 kGy using an electron accelerator. Samples of wet distillers grain, distillers solubles and stillage obtained during production of DDGS were also irradiated. All samples were analysed for Fusarium trichothecene mycotoxins by a method involving use of gas chromatography-mass spectrometry (GC-MS). The three production intermediates showed dose-dependent reductions in their DON contents ranging from 47.5 to 75.5% at the highest doses. Electron beam treatment produced a 17.6% reduction in the DON level of wheat at the highest dose used, but had no effect on DON in DDGS. These results indicate that electron beam treatment may provide a method for reducing DON levels in DDGS on an industrial scale.