Acidose ruminal subaguda em ovinos Santa Inês: estudo clínico, laboratorial e avaliação da laminite por termografia infravermelha e radiologia digital

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Milho, amido ou caroço de algodão associados à glicerina bruta em dietas para ovinos

Pós-graduação em Zootecnia - FCAV

Acidose láctica ruminal aguda induzida experimentalmente em ovinos: estudo clínico e laboratorial

Pós-graduação em Medicina Veterinária - FCAV

Degradabilidade da matéria seca e da proteína bruta de grãos secos e de silagens de grãos úmidos de híbridos de milho (Zea mays), submetidos a diferentes processamentos

The objective of this work was to evaluate the effect of processing two corn hybrids conserved, dry and humid grains, the dry matter (DM) and crude protein (CP) degradability in situ. The particle size was determined and difference was verified in MGD (Medium Geometric Diameter) of processed ingredients. Three sheep were used with rumen canulated, in a completely randomized design, using a factorial outline 2 x 2 x 3, being two corn hybrid, two conservation methods and three processing forms (whole, coarsely and finely ground), with five times of incubation (3, 6, 12, 24 and 48 hours). The fraction A in SDC (silage of dent corn) of DM was superior to GDC (grain of dent corn) in all of the particles size. The ensiling process increased the DM solubility, reducing the fraction B in comparison to dry grain. The values regarding the fractions DP and DE the 5% per hour of the protein, were larger for SDC and GDC, it presents a decreasing when the incubation time advances. The fermentation rate was superior for SDC and GDC. The ensiling process has positive effect in the decreasing of DM and CP in comparison to GDC.

Attenuation of ruminal methanogenesis

Ruminal methanogens reduce carbon dioxide to methane (CH 4 ), thereby preventing hydrogen use by bacteria for VFA synthesis resulting in a 2 to 12% loss in feed gross energy. Methane is a greenhouse gas that contributes to global warming. The objectives of this work were to determine: (1) the extent to which ruminal cultures acquire resistance to a nitrofuranyl derivative of para-aminobenzoate (NFP) and an extract from the plant Yucca shidigera (Yucca); (2) the effect of distillers dried grains plus solubles (DDGS) on ruminal CH4 production; (3) the effect of brome hay-based diets, corn-based diets, and in vivo 2-bromoethansulfonate treatment on ruminal methane (CH4 ) production; and (4) the effect of the above treatments on the methanogen population. Ruminal cultures treated with NFP for 90 d maintained a diminished capacity to generate CH4 , but cultures became resistant to the inhibitory effects of Yucca treatment within 10 d. Both treatments decreased (P < 0.01) the relative abundance of total Archaea and the order Methanomicrobiales, but Yucca treatment increased (P < 0.01) the relative abundance of the order Methanobacteriales. The replacement of brome hay and corn with DDGS in lamb diets decreased (P < 0.01) and increased (P < 0.05), respectively, the amount of CH4 produced per unit of digested DM. The substitution of DDGS for brome hay increased (P < 0.01) the relative abundance of the order Methanomicrobiales. The replacement of brome hay with corn decreased (P < 0.05) the amount of CH4 produced per unit of digested DM, and also decreased (P < 0.05) the relative abundance of both Archaea and the order Methanomicrobiales. However, the abundance of the order Methanobacteriales increased (P < 0.05) as corn replaced brome hay. Intraruminal administration of 2-bromoethansulfonate decreased (P < 0.05) CH4 emissions, and decreased (P < 0.05) the relative abundance of Archaea and Methanobacteriales. In conclusion, NFP may be efficacious for chronically inhibiting ruminal methanogenesis, and the replacement of dietary forage with DDGS attenuates CH4 emissions from ruminant animals. Changes in domain- and order-specific ribosomal DNA indicators of methanogens are not consistently correlated with changes in CH4 production.

Intake, nutrient apparent digestibility and ruminal constituents of sheep fed diets with canola, sunflower or castor oils

The objective in this experiment was to determine the effects of feeding diets with canola, sunflower or castor oils on intake, nutrient apparent digestibility and ruminal constituents of crossbred Dorper x Santa Ines sheep. Four rumen-cannulated animals of 90.2 +/- 11.4 kg average body weight were assigned to a 4 x 4 latin square. Animals remained individually in cages for the metabolism assay and were fed diets containing roughage at 500 g/kg and concentrate based on ground corn and soybean meal also at 500 g/kg. No oil was added to the control diet, whereas the others had canola, sunflower or castor oils at 30 g/kg (DM basis). There was no difference for the intake of DM and nutrients, except for ether extract, which was greater when animals received oil. The digestibility coefficients of dry matter, organic matter, crude protein, non-fiber carbohydrates and neutral detergent fiber were not changed; however, the addition of oil increased the ether extract digestibility. The values of total digestible nutrients (TDN, g/kg of DM), digestible energy (DE, Mcal/kg of DM), TDN intake and DE intake also did not change with the addition of lipids. Concerning the ruminal constituents, the addition of vegetable oils reduced the concentrations of acetate, butyrate and total short-chain fatty acids. Adding canola, sunflower or castor oils at 30 g/kg in diets with 500 g roughage/kg and 500 g concentrate/kg does not impair the intake or digestibility of nutrients in sheep, although it reduces the concentration of short-chain fatty acids in the rumen.

Comparative in vitro evaluation of forage legumes (prosopis, acacia, atriplex, and leucaena) on ruminal fermentation and methanogenesis

Two experiments in vitro were conducted to evaluate four Egyptian forage legume browses, i.e., leaves of prosopis (Prosopis juliflora), acacia (Acacia saligna), atriplex (A triplex halimus), and leucaena (Leucaena leucocephala), in comparison with Tifton (Cynodon sp.) grass hay for their gas production, methanogenic potential, and ruminal fermentation using a semi-automatic system for gas production (first experiment) and for ruminal and post ruminal protein degradability (second experiment). Acacia and leucaena showed pronounced methane inhibition compared with Tifton, while prosopis and leucaena decreased the acetate:propionate ratio (P<0.01). Acacia and leucaena presented a lower (P<0.01) ruminal NH3-N concentration associated with the decreasing (P<0.01) ruminal protein degradability. Leucaena, however, showed higher (P<0.01) intestinal protein digestibility than acacia. This study suggests that the potential methanogenic properties of leguminous browses may be related not only to tannin content, but also to other factors.

Chemical characterization and in vitro biological activity of four tropical legumes, Styzolobium aterrimum L., Styzolobium deeringianum, Leucaena leucocephala, and Mimosa caesalpiniaefolia, as compared with a tropical grass, Cynodon spp. for the use in ruminant diets

Leucaena leucocephala (LEU) and three under-utilized tanniferous legumes, Styzolobium aterrimum L. (STA), Styzolobium deeringianum (STD), and Mimosa caesalpiniaefolia Benth (MIC) were chemically characterized and the biological activity of tannins was evaluated using in vitro simulated ruminal fermentation through tannin-binding polyethylene glycol (PEG) and compared with a non-tanniferous tropical grass hay, Cynodon spp. (CYN). The Hohenheim gas test was used and gas production (GP) was recorded at 4, 8, 12, 24, 32, 48, 56, 72, 80, and 96 h incubation with and without PEG. Kinetic parameters were estimated by an exponential model. STA, STD, and LEU contained higher (P < 0.05) crude protein than MIC, which had greater neutral detergent fibre and acid detergent fibre. Total phenols, total tannins, and condensed tannins (CT) were consistently the highest in MIC. Gas production was the lowest from MIC (P < 0.05) and the highest in LEU and STA. MIC + PEG largely reduced (P < 0.05) the lag phase and the fractional rate of fermentation and increased potential GP. Kinetic parameters of STA + PEG and LEU + PEG were not affected. LEU + PEG produced greater gas increment (P < 0.05) than STD + PEG, although both legumes had the same CT. All legumes except MIC were more extensively degraded than CYN. However, fermentation of the legumes was differently affected by the presence and proportions of CT, indigestible fibre or both.

Comparison of indigestible markers from in situ and in vivo incubation to predict apparent digestibility in hay- and corn-fed horses

Four castrated crossbred horses were used in a randomized block design to study the use of indigestible internal markers iNDF and iADF obtained in situ (from bovines) or in vivo (from equines). Treatments consisted of determining digestibility by the direct method comprising total feces collection (TC) and by the indirect method comprising internal markers iNDF and iADF obtained by in situ incubation in bovine rumen or in vivo by the mobile nylon bag (MNB) technique with horses. iNDF-IV and iADF-IV resulted in better marker recovery rate (RR) (91.50%), similar to TC. The in situ technique resulted in lower RR values for the two indigestible markers, averaging 86.50% (p < 0.05). Estimates of the nutrient coefficient of digestibility (CD) were adequately predicted by iADF-IV, for horses fed on hay exclusively, with rates 46.41, 48.16, 47.92 and 45.51% for dry matter (DM), organic matter (OM), FDN and gross energy, respectively. Results show that MNB may be used to obtain iADF in horses fed on coast-cross hay exclusively, whereas NDFi and ADFi were selected for horses fed on mixed diets to predict the coefficient of nutrient digestibility.

Effects of flavomycin on ruminal fermentation, In situ degradability and In vivo digestibility in bovine fed sugarcane diets

Problem statement: The aim of the present study was to characterize and differentiate the effects of addition of flavomycin or monensin on ruminal fermentation and degradability as well as on total digestibility in bovine. Approach: Twelve non-pregnant and non-lactating cows (736 kg of BW) were randomly assigned to three treatments: control, flavomycin (20 mg animal-1 day-1) and monensin (300 mg animal-1 day-1). The trial lasted 21 days. The last 10 days were used for external marker administration (15 g of chromic oxide animal-1 day-1). The last 5 days of the trial were used for feces collection and evaluation of corn grain, soybean meal or sugarcane ruminal degradability and the 21st day was used for ruminal fluid sampling. Results: Monensin increased 27.2%, on average, propionate molar proportion at 0, 4, 6, 8, 10 and 12 h after feeding, compared to control and flavomycin groups. When compared to control, flavomycin reduced the degradation rate of soybean meal CP in 31.0%, decreasing the effective degradability when passage rates of 5 and 8% h-1 were used. Dry matter intake, pH, total Short Chain Fatty Acids (tSCFA) or ammoniacal Nitrogen (NH3-N) concentration were not influenced by the addition of either antibiotics. Effective degradability of sugarcane NDF was not influenced by the use of either antibiotic; neither were the TDN nor the digestibility of DM, CP, EE, NFE, ADF, NDF, GE or starch of the diet. Conclusion/Recommendations: In the present study, it was possible to show the beneficial effects of monensin but not of flavomycin, on rumen fermentation

Bottle effects, toxicity and cell viability during incubation experiments to asses community respiration

Máster en Oceanografía

Ruminal drinkers: endocrine and metabolic status and effects of suckling from a nipple instead of drinking from a bucket

In ruminal drinkers (RD) ingested milk is transported into the rumen and not into the abomasum. Because this is followed by changes in digestibility and absorption, we have tested whether this is associated with postprandial metabolic and endocrine changes. Unweaned, bucket-fed calves (one RD, two controls) were studied on seven farms. On d 1, after metabolic and endocrine 12-h profiles were studied, RD and one control calf were fed for 10 d by nipple, whereas the other control calf was fed by bucket. On d 11, metabolic and endocrine 12-h profiles were again studied. On d 1, mean plasma concentrations of glucose, triglycerides, urea, insulin, insulin-like growth factor-1 (IGF-1), 3,5,3'-triiodothyronine (T3), thyroxine (T4) and leptin were significantly different between RD and controls, whereas mean concentrations of non-esterified fatty acids (NEFA), total protein, albumin, and glucagon did not differ significantly among groups. In RD concentrations of glucose, NEFA, insulin, growth hormone, IGF-1, and T4 were higher, and of urea were lower on d 11 than on d 1. Glucose and insulin concentrations increased postprandially in healthy calves on d 1, but barely in RD and remained lower than in controls, and there was no rise of NEFA and triglyceride concentrations on d 1 after the initial postprandial decrease in RD, in contrast to controls. But on d 11 postprandial responses of these four traits were similar in RD and controls and urea and T4 concentrations on d 11 became normalized. However, glucose and T3 concentrations in RD on d 11 were still lower than in one or both control groups. In conclusion, various metabolic and endocrine traits in RD differed from healthy controls. Drinking by floating nipple instead of drinking from bucket for 10 d normalized several metabolic and endocrine traits in RD.