Sodium selenite is used to prevent selenium deficiency known as nutritional muscular dystrophy or white muscle disease. In ruminants, selenium supplements are transformed partiality in insoluble form by ruminal microorganisms and its process decrease the selenium absorption in digestive gastrointestinal. However, the objective in this research was focused in encapsulated sodium selenite to be release into of a pH less than four, similarity to an intestinal environment. It was encapsulated by nanoprecipitation and emulsion–evaporation methods, within polymeric nanoparticles. The effect of these methods, polymer proportion (Eudragit RL and RS) and solvent (ethanol and acetone) on the physicochemical (drug entrapment, polidispersity index (PDI) and z potential) and morphological characteristics (particle morphology and particle size) were evaluated. Particle size from each nanoparticles, formulation ranged from 36.64 to 213.86 nm. Particle size, z potential and PDI increased (P ≤ 0.01) when nanoprecipitation and ethanol were used. No significant differences (P > 0.05) were observed when different polymeric proportions were used. Selenium entrapment was 26% when emulsion–evaporation method was used and 78% with nanoprecipitation. Nanoparticles produced by nanoprecipitation were spherical and had a great variation in particle size; on the other hand, nanoparticles produced by emulsion–evaporation were spherical as well as amorphous and presented a homogeneous nanopartcicle size distribution. The release of selenium from nanoparticles was higher in acid pH (less than 4), this condition may represent a better availability of the mineral in the small intestine.

The effects of exogenous fibrolytic enzymes (EFE; a mixture of two preparations from Trichoderma spp., with predominant xylanase and β-glucanase activities, respectively) on colonization and digestion of ground barley straw and alfalfa hay by Fibrobacter succinogenes S85 and Ruminococcus flavefaciens FD1 were studied in vitro. The two levels (28 and 280 μg/ml) of EFE tested and both bacteria were effective at digesting NDF of hay and straw. With both substrates, more NDF hydrolysis (p<0.01) was achieved with EFE alone at 280 than at 28 μg/ml. A synergistic effect (p<0.01) of F. succinogenes S85 and EFE on straw digestion was observed at 28 but not 280 μg/ml of EFE. Strain R. flavefaciens FD1 digested more (p<0.01) hay and straw with higher EFE than with lower or no EFE, but the effect was additive rather than synergistic. Included in the incubation medium, EFE showed potential to improve fibre digestion by cellulolytic ruminal bacteria. In a second batch culture experiment using mixed rumen microbes, DM disappearance (DMD), gas production and incorporation of 15N into particle-associated microbial N (15N-PAMN) were higher (p<0.001) with ammoniated (5% w/w; AS) than with native (S) ground barley straw. Application of EFE to the straws increased (p<0.001) DMD and gas production at 4 and 12 h, but not at 48 h of the incubation. EFE applied onto S increased (p<0.01) 15N-PAMN at 4 h only, but EFE on AS increased (p<0.001) 15N-PAMN at all time points. Prehydrolysis increased (p<0.01) DMD from both S and AS at 4 and 12 h, but reduced (p<0.01) 15N-PAMN in the early stage (4 h) of the incubation, as compared to non-prehydrolyzed samples. Application of EFE to barley straw increased rumen bacterial colonization of the substrate, but excessive hydrolytic action of EFE prior to incubation decreased it.

ABSTRACT:The objective was to evaluate the effect of different levels of selenium with two levels of grain corn in the diets on ruminal, postruminal, and total tract digestion of nutrients, ruminal fermentation characteristics, and selenium balance in lambs. A split-plot design was used in four periods with repeated Latin square using eight Suffolk × Dorset male lambs with four levels of selenium (sodium selenite, Na 2 SeO 3 ), without adding selenium, 0.3, 0.6, and 0.9 mg of selenium/kg dry matter (DM) with 70 and 50% of corn grain in the diet. The four selenium levels affected organic matter as follows: starch, neutral detergent fibre, nitrogen and selenium excretion; selenium ruminal digestion; organic matter, neutral detergent fibre, nitrogen and selenium postruminal digestion; and organic matter, neutral detergent fibre, nitrogen and selenium total tract digestion (P < 0.05). Starch and organic matter flow decreased with 0.6 and 0.9 mg of selenium with the 70% grain diet (P < 0.05). Selenium flow increased linearly with selenium levels (P < 0.01) with both levels of grain. Selenium supplementation increased linearly selenium concentration in ruminal fluid (P < 0.01), but did not affect other ruminal characteristics. Also, selenium absorption and retention was increased by selenium concentrations (P < 0.01). The apparent absorption of selenium increased (31%, P < 0.01) with the 70% grain diet. In conclusion, the high content of nonstructural carbohydrates improved the availability of selenium and 0.9 mg of selenium/kg DM improved the absorption and availability of selenium.

Three experiments were carried out to determine the optimum selenium-vitamin E injection level to maintain acceptable blood selenium (Se) status of does and kids, as well as to determine the relation of that status to mortality rates in kids. In experiment 1, 238 goats were assigned to one of three groups during the mating period: A1-control, A2-0.06mgSe+0.8IU vitE/kgBW and A3-0.125mgSe+1.7IU vitE/kgBW. No differences (P>.05) for fertility and prolificacy were observed among the groups. Blood Se concentration did not differ among Se-vit E groups and control group before injection, and both groups showed Se deficient condition. There was a trend (P<.05, 32%) to increase Se blood level 60 days post-treatment, but difference was not observed between A2 and control groups, while difference (P<.05; 103%) was observed between A1 and A2 groups vs high Se injection (A3 group). In experiment 2, 48 goats were divided into four groups: B1-control, B2-0.125mgSe+1.7IU vitE/kgBW, B3-0.25mgSe+3.4IU vitE/kgBW and B4-0.31mgSe+4.2IU vitE/kgBW. The B4 group reached the highest concentration at the third month after injection (0.11 ppm), then started to decline after 100 days, reaching a value slightly higher than B2 and B3 on the 135 th day of pregnancy. Results of B2 and B3 groups were slightly higher that those of B1 (P<0.05). In experiment 3, 194 kids (3 to 7 days postpartum) born from Se-deficient goats were used to compare the effectiveness of Se injection. They were divided into three groups: C1-control, C2-0.3mgSe+4.2IU vit E/kg BW and C3-0.6mgSe+8.4IU vit E/kg BW. C1 showed the highest percentage of mortality (60%) as compared to treated Se groups, that scored equal percentage of deaths (22% averaged). The concentration of Se in blood, on day 20 th after the onset of the treatment rapidly increased, according with level of Se injection. The 0.3mgSe/kgBW Se injection increased the blood Se concentration in pregnant goats and it was effective to prevent white muscle disease lesions, besides enhancing the survival of kids until weaning. 125mgSe+1,25mgSe+3,31mgSe+4,

Twenty hair (Pelibuey x Katadin x BlackBelly) and 20 wool (Rambouillet x Criollo) lambs were fattened in an intensive feeding system to reach 40kg body weight at ten months of age. The yield of lamb sides and back fat (51.9%, 2.5mm vs. 47.0%, 2.3mm) were greater in wool lambs. Meat pH was not different between phenotypes but meat temperature was higher during the first hours postmortem in wool lamb sides (27, 23, and 20, vs. 24, 20, and 17 o C). Protein content in meat from the neck (braquicephalic and esternocephalic muscles) and loin (Longissimus lumborum muscle) were higher in hair lambs (21.1 and 20.4 vs. 19.7 and 19.3 %), while moisture of the same muscles was higher in wool lambs (75.6 and 75.9 vs. 73.6 and 74.3%). Ash content was similar in both phenotypes, but palmitoleic acid was greater in hair lambs (2.9 and 2.7 vs. 2.7 and 2.5%). In fresh meat, pH, meat toughness, and water activity (Wa) of loin did not differ; but water holding capacity (WHC) was higher in hair lambs, and the same response was observed for cooked meat toughness from the neck, and in raw and cooked meat from loin. There were differences in the colour of meat from the neck, having values for L*, b* and tonalities greater in wool lambs, and a* greater for hair lambs. Sensorial parameters were similar in both phenotypes.Keywords: lamb meat, physicochemical characteristics, fatty acids, sensorial test (51,9%, 2,5mm vs. 47,0%, 2,3mm). Não houve diferenças entre os dois grupos de cordeiros para pH, mas a temperatura da carne foi mais alta durante as primeiras horas pós-morte, nas meias-carcaças dos cordeiros lanados (27, 23, 20 vs. 24, 20, 17°C). O conteúdo proteico da carne do pescoço (músculos braquicefálico e esternocefálico) e do lombo (músculo Longissimus lumborum) foi maior nos cordeiros deslanados (21,1 e 20,4 vs. 19,7 e 19,3%) enquanto o teor de umidade foi maior nas lanados (75,6 e 75,9 vs 73,6 e 74,3% RESUMO Vinte cordeiros deslanados (Pelibuey x Katadin x BlackBelly) e 20 cordeiros lanados (Rambouillet x Criollo) foram mantidos em um sistema intensivo de alimentação até atingirem 40kg, aos 10 meses de idade. O rendimento de carcaça e a espessura da gordura foram maiores nos cordeiros lanados

Ramirez-Bribiesca, J. E., Wang, Y., Jin, L., Canam, T., Town, J. R., Tsang, A., Dumonceaux, T. J. and McAllister, T. A. 2011. Chemical characterization and in vitro fermentation of Brassica straw treated with the aerobic fungus, Trametes versicolor . Can. J. Anim. Sci. 91: 695–702. Brassica napus straw (BNS) was either not treated or was treated with two strains of Trametes versicolor; 52J (wild type) or m4D (a cellobiose dehydrogenase-deficient mutant) with four treatments: (i) untreated control (C-BNS), (ii) 52J (B-52J), (iii) m4D (B-m4D) or (iv) m4D+glucose (B-m4Dg). Glucose was provided to encourage growth of the mutant strain. All treatments with T. versicolor decreased (P<0.05) neutral-detergent fibre and increased (P<0.05) protein and the concentration of lignin degradation products in straw. Ergosterol was highest (P<0.05) in straw treated with B-52J, suggesting it generated the most fungal biomass. Insoluble lignin was reduced (P<0.05) in straw treated with B-52J and B-m4D, but not with B-m4Dg. Mannose and xylose concentration were generally higher (P<0.05) in straw treated with fungi, whereas glucose and galactose were lower as compared with C-BNS. The four treatments above were subsequently assessed in rumen in vitro fermentations, along with BNS treated with 2 mL g−1of 5 N NaOH. Concentrations of total volatile fatty acids after 24 and 48h were lower (P<0.05) in incubations that contained BNS treated with T. versicolor as compared with C-BNSor NaOH-treated BNS. Compared with C-BNS, in vitrodry matter disappearance and gas production were increased (P<0.05) by NaOH, but not by treatment with either strain of T. versicolor. Although treatment with T. versicolor did release more lignin degradation products, it did not appear to provide more degradable carbohydrate to in vitro rumen microbial populations, even when a mutant strain with compromised carbohydrate metabolism was utilized. Production of secondary compounds by the aerobic fungi may inhibit rumen microbial fermentation.

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