Ives Cláudio da Silva Bueno

In vitro evaluation, in vivo quantification, and microbial diversity studies of nutritional strategies for reducing enteric methane production.

The main objective of the present work was to study nutritive strategies for lessening the CH4 formation associated to ruminant tropical diets. In vitro gas production technique was used for evaluating the effect of tannin-rich plants, essential oils, and biodiesel co-products on CH4 formation in three individual studies and a small chamber system to measure CH4 released by sheep for in vivo studies was developed. Microbial rumen population diversity from in vitro assays was studied using qPCR. In vitro studies with tanniniferous plants, herbal plant essential oils derived from thyme, fennel, ginger, black seed, and Eucalyptus oil (EuO) added to the basal diet and cakes of oleaginous plants (cotton, palm, castor plant, turnip, and lupine), which were included in the basal diet to replace soybean meal, presented significant differences regarding fermentation gas production and CH4 formation. In vivo assays were performed according to the results of the in vitro assays. Mimosa caesalpineaefolia, when supplemented to a basal diet (Tifton-85 hay Cynodon sp, corn grain, soybean meal, cotton seed meal, and mineral mixture) fed to adult Santa Ines sheep reduced enteric CH4 emission but the supplementation of the basal diet with EuO did not affect (P > 0.05) methane released. Regarding the microbial studies of rumen population diversity using qPCR with DNA samples collected from the in vitro trials, the results showed shifts in microbial communities of the tannin-rich plants in relation to control plant. This research demonstrated that tannin-rich M. caesepineapholia, essential oil from eucalyptus, and biodiesel co-products either in vitro or in vivo assays showed potential to mitigate CH4 emission in ruminants. The microbial community study suggested that the reduction in CH4 production may be attributed to a decrease in fermentable substrate rather than to a direct effect on methanogenesis.

Effect of some essential oils on in vitro methane emission

The objectives of this study were to characterise four essential oils (EO) chemically and to evaluate their effect on ruminal fermentation and methane emission in vitro. The investigated EO were isolated from Achillea santolina, Artemisia judaica, Schinus terebinthifolius and Mentha microphylla, and supplemented at four levels (0, 25, 50 and 75 μl) to 75 ml of buffered rumen fluid plus 0.5 g of substrate. The main components of the EO were piperitone (49.1%) and camphor (34.5%) in A. judaica, 16-dimethyl 15-cyclooactdaiene (60.5%) in A. santolina, piperitone oxide (46.7%) and cis-piperitone oxide (28%) in M. microphylla, and γ-muurolene (45.3%) and α-thujene (16.0%) in S. terebinthifolius. The EO from A. santolina (at 25 and 50 μl), and all levels of A. judaica increased the gas production significantly, but S. terebinthifolius (at 50 and 75 μl), A. santolina (at 75 μl) and all levels of M. microphylla decreased the gas production significantly in comparison with the control. The highest levels of A. santolina and A. judaica, and all doses from M. microphylla EO inhibited the methane production along with a significant reduction in true degradation of dry matter and organic matter, protozoa count and NH3-N concentration. It is concluded that the evaluated EO have the potential to affect ruminal fermentation efficiency and the EO from M. microphylla could be a promising methane mitigating agent.

Effect of eucalyptus (Eucalyptus citriodora) fresh or residue leaves on methane emission in vitro

Rumen fermentation and methane emission for eucalyptus (Eucalyptus citriodora) fresh leaves (FL) or residue leaves (RL), after essential oil extraction from eucalyptus leaves in comparison with alfalfa (Medicago sativa) hay, were investigated in vitro. Eucalyptus FL and RL were obtained from the Distillery Trees Barras Company, Torrinha City, Sao Paulo, Brazil. The semi-automatic system of gas production was used to measure gas production, methane emission and rumen fermentation after 24 h incubation in vitro. The results showed that the crude protein (CP) contents were 76.4, 78.1 and 181.9 g kg−1 DM for eucalyptus FL, RL and alfalfa hay, respectively. The neutral-detergent fibre (NDF) and acid-detergent fibre (ADF) were significantly lower in eucalyptus FL and RL than alfalfa hay. The Eucalyptus fresh and residue leaves were rich in total phenols (TP) and total tannins (TT) but had negligible content of condensed tannins (CT). There was significant reduction in cumulative gas production about 54 and 51% with eucalyptus FL and RL, respectively, compared with alfalfa hay. The methane emission (mL/g DM) was reduced (P<0.05) by 53 and 57% with eucalyptus FL and RL, respectively, but the reduction was 21 and 16% when expressed on truly digested organic matter basis. There were a decline (P<0.05) in true dry and organic matter degradation in vitro in eucalyptus FL and RL compared with alfalfa hay substrate. The partitioning factor values were higher (P<0.05) in eucalyptus FL and RL than alfalfa hay. There was no significant difference observed between eucalyptus FL, RL and alfalfa hay in protozoa count. It is concluded that the eucalyptus leaves have potential effect to mitigate CH4 production in vitro, which may be attributed to a decrease in fermentable substrate rather than to a direct effect on methanogenesis.

Effects of chitosan on ruminal fermentation, nutrient digestibility, and milk yield and composition of dairy cows

Our objective was to evaluate the effects of providing increasing levels of chitosan on nutrient digestibility, ruminal fermentation, blood parameters, nitrogen utilisation, microbial protein synthesis, and milk yield and composition of lactating dairy cows. Eight rumen-fistulated Holstein cows [average days in lactation = 215 ± 60.9; and average bodyweight (BW) = 641 ± 41.1 kg] were assigned into a replicated 4 × 4 Latin square design, with 21-day evaluation periods. Cows were assigned to be provided with four levels of chitosan, placed into the rumen through the fistula, as follows: (1) Control: with no provision of chitosan; (2) 75 mg/kg BW; (3) 150 mg/kg BW; and (4) 225 mg/kg BW. Chitosan had no effect on dry matter intake (P > 0.73); however, chitosan increased (P = 0.05) crude protein digestibility. Propionate concentration was increased (P = 0.02), and butyrate, isobutyrate, isovalerate and acetate : propionate ratio were decreased (P ≤ 0.04) by chitosan. Chitosan had no effect (P > 0.25) on acetate, pH and NH3 ruminal concentration. Glucose, urea, and hepatic enzyme concentrations in the blood were similar (P > 0.30) among treatments. Nitrogen balance was not affected, but chitosan increased milk nitrogen (P = 0.02). Microbial protein synthesis was not affected by chitosan (P > 0.44). Chitosan increased (P = 0.02) milk yield, fat-corrected milk, protein and lactose production. Chitosan changes ruminal fermentation and improves milk yield of lactating dairy cows; therefore, we conclude that chitosan can be used as a rumen modulator instead of ionophores in diets for dairy cows.

Métodos de extração para determinação de progesterona em fezes de coelho (Oryctolagus cuniculus) através de radioimunoensaio

The purpose of this study was to find a practical procedure for the extraction of progesterone (P4) from feces and to determine if the P4 plasma profiles during pregnancy were reflected in the total fecal P4 of pregnant rabbits. The rabbit was used as model for the techniques. Plasma and feces were collected from 11 rabbits during a period of 42 days. Three different methods of P4 extraction were used. The total P4 was measured by solid-phase radioimmunoassay (RIA) with 125I-P4 as the tracer. Results suggested that it was possible to extract total P4 from rabbit feces with methanol and petroleum ether. Plasma and fecal P4 profiles were compared for both pregnant and ovariectomized rabbits. It was possible to differentiate total P4 extracted from day two through 28 after breeding (P<0.01).

Palatability of Horse Diets Containing Citrus Pulp (Citrus Sinensis) through the Preference Test

The aim of this study was to evaluate the acceptance of concentrates containing increasing levels of citrus pulp (7, 14, 21 and 28%) and the most preferred level of inclusion, observing the first action and the palatability using the preference test. Ten healthy mares, averaging 500 kg live weigh (LW), were housed in individual pens, where the four experimental concentrates were offered simultaneously, in a linear and continuous feeder for horses, for a period of 15 min. During this period, the first action (smelling or eating), the first choice (first concentrate effectively ingested) and the intake ratio (intake of each concentrate in relation to the total concentrate intake) were observed. Effect of inclusion on first action was observed (P<0.01), once 80% of animals fed promptly the concentrate and only 20% smelled it before the choice. The concentrate with 7% of citrus pulp presented the highest intake ratio (0.4425; P<0.01). For the first choice variable, there was no difference (P>0.05), however the concentrate with 7% was the most preferred (36.67%). Citrus pulp can be used as concentrate feed for horses. Therefore, low levels of inclusion in the concentrate, close to 7%, are recommended when the concentrate is based on corn, wheat bran, soybean meal, with no flavour agents like molasses.

Replacing wheat bran by corn gluten feed without steep water in complete dog food

Abstract Twenty-four adult Beagles were utilised to evaluate the partial replacement of wheat bran with corn gluten feed without steep water on digestibility and characteristics of faeces. The treatments were 0 (no substitution), 30, 60 or 90 g/kg of corn gluten without steep water. There was no effect (p > .05) on the digestibility coefficients (g/kg) of dry matter (0.771), organic matter (0.806), crude protein (0.813), ether extract (0.798), crude fibre (0.393), neutral detergent fibre (0.425), acid detergent fibre (0.286) and crude energy (0.812), whilst there was effect (p < .05) on the digestible and metabolisable energy. There were effects (p < .05) for dry matter and pH of faeces but no effect (p > .05) was found on the remaining faecal characteristics: excretion for 100 g of food (56.77 g), excretion (129.6 g/day and 49.0 g dry matter/day), score (3.90), dry matter excretion for 100 g of food (22.86 g), buffering capacity (BC) at pH 5 (57.81), ammonia nitrogen (1.46 g/kg of faecal dry matter) and water balance (333.25 mL/day), in vivo and in situ gas production (p > .05). Corn gluten feed without steep water can be utilised to replace up to 90 g/kg of wheat bran without causing negative effect on the digestibility and characteristics of faeces.

Biological availability and calcium requirements of growing equines receiving diets with different calcium levels

The objective of this work was to study the calcium metabolism in growing equines receiving diets with different calcium levels. Twelve male were used, with average age of twelve months and average alive weight of 221,0 kg. The treatments consisted of three diets, composed for increasing calcium levels (low = 0.15%-N15; standard = 0.45%-N45; high = 0.75%-N75), and standard phosphorus level (0.23%). Each animal was injected, through the right jugular vein, the volumes of a syringe, which corresponded to about 7.4 MBq of 45Ca (CaCl2). After the injection, blood samples (10 mL) were collected through left jugular vein at five minutes, 1, 2, 4, 6, 24, 48, 72, 96, 120 and 144 hours. The feces were daily collected in the morning, 24 hours after the application of the radionuclide until the seventh day, and an aliquot of 5% of the daily total excreted was collected and stored in freezer for posterior analysis. The same procedure of excrements was adopted for urine, when samples of 1% of the daily total volume had been collected. The experimental techniques used a completely randomized design with three treatments and four replications. No effects were observed on the plasma calcium, total calcium in urine and endogenous calcium in feces, with average values of 11,76; 5,54 and 20,86 mg/kgLW/day, respectively. No effects were observed for the biological calcium availability, with 81.67%, on average. Linear regressions between calcium levels in the diet and total calcium ingested, absorbed calcium, total calcium in feces and restrained calcium have been respectively verified, which were expressed according to the following equations: y=10.7+2.78x r2=1.0; y=12.41+2.24x r2=0.99; y=5.97+0.92x r2=0.93 and y=6.4+1.70x r2=0.94, with averages of 135.80; 113.21; 47.37 and 82.90 mg/kgLW/day, respectively.The objective of this work was to study the calcium metabolism in growing equines receiving diets with different calcium levels. Twelve male were used, with average age of twelve months and average alive weight of 221,0 kg. The treatments consisted of three diets, composed for increasing calcium levels (low = 0.15%-N15; standard = 0.45%-N45; high = 0.75%-N75), and standard phosphorus level (0.23%). Each animal was injected, through the right jugular vein, the volumes of a syringe, which corresponded to about 7.4 MBq of 45Ca (CaCl2). After the injection, blood samples (10 mL) were collected through left jugular vein at five minutes, 1, 2, 4, 6, 24, 48, 72, 96, 120 and 144 hours. The feces were daily collected in the morning, 24 hours after the application of the radionuclide until the seventh day, and an aliquot of 5% of the daily total excreted was collected and stored in freezer for posterior analysis. The same procedure of excrements was adopted for urine, when samples of 1% of the daily total volume had been collected. The experimental techniques used a completely randomized design with three treatments and four replications. No effects were observed on the plasma calcium, total calcium in urine and endogenous calcium in feces, with average values of 11,76; 5,54 and 20,86 mg/kgLW/day, respectively. No effects were observed for the biological calcium availability, with 81.67%, on average. Linear regressions between calcium levels in the diet and total calcium ingested, absorbed calcium, total calcium in feces and restrained calcium have been respectively verified, which were expressed according to the following equations: y=10.7+2.78x r2=1.0; y=12.41+2.24x r2=0.99; y=5.97+0.92x r2=0.93 and y=6.4+1.70x r2=0.94, with averages of 135.80; 113.21; 47.37 and 82.90 mg/kgLW/day, respectively.

Efeitos de diferentes níveis de cálcio dietético na cinética de cálcio e fósforo em eqüinos

This experiment was carried out to study calcium (Ca) and phosphorus (P) kinetics of growing horses fed diets with different Ca levels: 0.15%, 0.45, and 0.75%, using a deterministic and compartmental model. The information on metabolism and kinetic of Ca and P in tissues was obtained by the isotopic dilution technique. Dietary Ca levels influenced Ca true absorption, showing lower value (4.97 g Ca/day) for the Ca level of 0.15%. The changes of Ca between the blood and digestive tract were lower for 0,15% Ca. The flows between the blood and bone and blood and soft tissues did not show differences between treatments, but bone and tissue balance was lower for the level of 0.15%. Dietary Ca levels influenced on P in urine and values were higher for 0.15% (2.49 g P/anim.day). The mean true P absorption was of 83%, with no differences among treatments. Bone deposition of 9.69g P/anim.day was observed, showing that the amount of P fed was adequate in relation to the allowed amplitude for Ca:P ratio for the specie in the studied animal category. No differences between the P flows in the diverse compartments, for interference of the metabolism model. The ingestion of increasing levels of Ca affected the metabolism and the kinetic of this element, however Ca:P ratio is the predominant factor to determine the excretion, retention and absorption of Ca. The Ca deposition in bone is influenced by the amount ingested of this mineral. The P metabolism in growing horses was not affected by Ca levels. The amount of 13.4 g P/anim.day in the diet was sufficient to maintain P metabolism at normal standard levels.