ABSTRACT This research was conducted to investigate the effect of live and inactive sugarcane yeast on beef cattle voluntary intake, apparent digestibility of nutrients, ruminal pH, volatile fatty acids (VFA) concentrations, and ruminal ammonia. Five rumen-cannulated Nellore heifers were distributed in a 5×5 Latin square design, with five experimental periods of 15 days, with seven days for adaptation to the additives and the remaining days for data records and sampling. Total mixed ration (TMR) was composed by corn silage (20%) and concentrate (80%) based on corn and soybean meal. Five treatments were evaluated: without additive use (negative control; NC); chemical buffer addition – 0.71% in concentrate DM of sodium bicarbonate and 0.18% of magnesium oxide (positive control, PC); 10 g/day live yeast (LY); 15 g/day of inactive yeast (IY15); and 30 g/day of inactive yeast (IY30). Sugarcane yeasts were directly infused in rumen immediately after morning and afternoon feed supply. Feed additives did not affect voluntary intake, nutrient digestibility, and sorting behavior of animals. However, heifers from all treatments presented preferential intake of fibrous fraction of diet, especially those from NC and IY15. Nitrogen balance, VFA concentrations, and blood parameters were not influenced as well. Sodium bicarbonate and magnesium oxide led to greater ruminal pH than yeast, and IY15 presented greater pH than IY30. Ruminal ammonia was increased by the use of additives. Active and inactive yeasts are not recommended as feed additives for bovines fed diets with 80% of concentrate since it allows animals to select fibrous particles from TMR, and no representative gain in ruminal parameters and digestibilities are guaranteed.

O presente trabalho foi conduzido com o objetivo de relatar surtos de fotossensibilização causados por Froelichia humboldtiana em equídeos no Estado do Rio Grande do Norte, Brasil. Foram examinados animais de três propriedades rurais, além de asininos abandonados nas estradas. Procedeu-se a coleta de amostras de sangue periférico de cinco jumentos e dois equinos para análise das atividades das enzimas hepáticas e concentrações de bilirrubina total, direta e indireta. Das áreas de pele com lesões de dois jumentos e de um equino foram realizadas biópsias. Constatou-se que 50 asininos, 18 equinos e duas mulas foram acometidos. Dos asininos acometidos, 45 eram jumentos criados soltos em margens de estradas. Relatou-se a morte de 30 jumentos em decorrência de miíases e debilidade. Os animais tinham histórico de apresentarem lesões de fotodermatite aproximadamente um mês após pastarem em áreas invadidas por F. humboldtiana e recuperavam-se das lesões 10 a 30 dias após serem retirados dessas áreas. Porém, o quadro de prurido e automutilação retornava em uma ou duas semanas quando os equídeos eram reintroduzidos nessas áreas. Ao exame clínico de asininos jovens e adultos, foram observadas feridas extensas, ulceradas, que drenavam exsudato seroso abundante. Todas essas feridas decorriam de traumas causados por automutilação secundária ao intenso prurido. Além disso, muitas das feridas apresentavam miíase. Os equinos e as mulas apresentavam lesões de fotodermatite somente nas áreas de pele despigmentadas, não sendo observadas lesões oculares. A avaliação histopatológica de biópsias de pele revelou inflamação perivascular na derme superficial. Na epiderme havia extensas úlceras, recobertas por fibrina associada a infiltrado neutrofílico e numerosos agregados bacterianos basofílicos superficiais. As atividades séricas de AST, GGT e as concentrações de bilirrubina no soro estavam dentro dos valores de referência. O diagnóstico de fotossensibilização primária associada à ingestão de F. humboldtiana foi baseado na epidemiologia, sinais clínicos, bioquímica sérica, biópsia de pele e reocorrência das lesões após os animais serem reintroduzidos no pasto invadido pela planta. Conclui-se que a F. humboldtiana é uma importante causa de fotossensibilização primária em equídeos no semiárido brasileiro, resultando em quadro de debilidade e morte de grande número de animais, principalmente asininos que não recebem tratamento adequado.

The study was conducted in order to report outbreaks of photosensitization caused by Froelichia humboldtiana in equidae in the state of Rio Grande do Norte, Brazil. Animals from three farms and donkeys found abandoned in roads were examined. Peripheral blood samples were collected from five donkeys and two horses for analysis of serum activities of liver enzymes and concentrations of total, direct and indirect bilirubin. Skin biopsies were collected from two donkeys and a horse for histopatological exams. Fifty donkeys, 18 horses and two mules were affected. Of the affected donkeys, 45 were raised on roadsides and 30 died due to myiasis and weakness. The animals had a history of presenting skin lesions of photodermatitis about one month after being grazing in areas invaded by F. humboldtiana and recovered 10-30 days after being removed from these areas. If the animals were reintroduced in the paddocks with F. humboldtiana, pruritus and self-mutilation returned in a week or two. Young and adults donkeys showed extensive ulcerated wounds, that drained abundant serous exudate. All these wounds resulted from trauma caused by secondary self-mutilation to intense itching. In addition, many wounds had myiasis. The horses and mules had lesions of photodermatitis only in the areas of depigmented skin, no ocular lesions were observed. Histopathology of skin biopsies revealed perivascular inflammation in the superficial dermis. The epidermis had extensive ulcers, covered by fibrin associated with neutrophilic infiltrate and numerous basophilic bacterial aggregates. The serum activities of AST, GGT and serum concentrations of bilirubin were within normal ranges. The diagnosis of primary photosensitization associated with ingestion of F. humboldtiana was based on the epidemiology, clinical signs, serum biochemistry, skin lesions, and the recurrence of lesions after the reintroduction of the animals into the pasture invaded by the plant. F. humboldtiana is an important cause of primary photosensitization in equidae in the Brazilian semiarid region, resulting in weakness and death of large numbers of animals, mainly donkeys that don’t receive proper treatment.

The objective of the experiment was to classify 20 protein co-products and by-products of the biodiesel industry with potential to use in ruminant feeding. The meals evaluated were: cottonseed, canudo-de-pito, crambe, sunflower, castor-oil seeds detoxified with calcium, non-detoxified castor-oil seeds and soybean; and the cakes were: cottonseed, peanut, babassu, crambe, palm oil, sunflower, licuri, macauba seeds, non-detoxified castor-oil seeds, turnip and jatropha. The samples were quantified to determine dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber corrected for ash and protein (NDFap), non-fiber carbohydrates (NFC), acid detergent fiber corrected for ash and protein (ADFap), lignin, cutin and starch levels. The CP profile was characterized in fractions A, B1, B2, B3 and C. The in vitro dry matter digestibility (IVDMD), in vitro neutral detergent fiber digestibility (IVNDFD), rumen degradable and undegradable protein, intestinal digestibility, indigestible neutral detergent fiber and undegradable neutral detergent insoluble protein were evaluated. The OM, CP, EE, NDFap, NFC, ADFap, lignin, cutin and starch contents varied from 81.95 to 95.41%, 18.92 to 57.75%, 0.56 to 18.40%, 10.13 to 62.30%, 3.89 to 27.88%, 6.15 to 36.86%, 1.19 to 5.04%, 0 to 17.87% and 0.68 to 14.50%, respectively. The values of fractions A, B1, B2, B3 and C ranged from 5.40 to 43.31%, 0.08 to 37.63%, 16.75 to 79.39%, 1.86 to 59.15% and 0.60 to 11.47%, respectively. Concentrations of IVDMD, IVNDFD, rumen-degradable and undegradable protein, intestinal digestibility, indigestible NDF and undegradable neutral detergent insoluble protein ranged from 31.00 to 95.92%, 55.04 to 97.74%, 41.06 to 97.61%, 2.39 to 58.94, 9.27 to 94.26%, 1.05 to 40.80% and 0.29 to 2.92%, respectively. Some of these products can replace soybean meal, specially the Macauba seeds cake, cottonseed meal and peanut and turnip cakes based on digestive characteristics.