We aimed to evaluate the effects of chitosan and microbial inoculant addition to sugarcane silage fermentation, gas and effluent losses, chemical composition, in situ dry matter (DM), neutral detergent fibre (NDF) degradation and aerobic stability. A completely randomized design with four treatments (n = 40) was performed. It was arranged in a 2 × 2 factorial scheme with chitosan [0 and 6 g/kg of sugarcane DM—1.66 g/kg of natural matter (NM)] and microbial inoculant (0 and 8 mg/kg on NM). Each g of inoculant contained 3.9 × 1010 UFC/g of Pediococcus acidilactici and 3.75 × 1010 UFC/g of Propionibacterium acidicipropionici. The addition of microbial inoculant increased lactic acid concentration in silos treated with chitosan. Furthermore, chitosan increased pH and tended to increase acetic acid of silage. In contrast, the inoculant decreased pH and acetic acid, besides increasing ethanol concentration. As chitosan addition increased DM recovery, inoculant addition decreased it. Chitosan decreased NDF and acid detergent fibre (ADF) level and increased DM degradation, while inoculant decreased DM content, DM and NDF degradation. In addition, chitosan improved the aerobic stability only in non‐inoculated silos. Thus, chitosan has a positive effect on silage fermentation, reducing fermentative losses, and improving silage chemical composition and degradation. Conversely, the addition of microbial inoculant negatively affected silage DM recovery, chemical composition, and its association with chitosan decreased the aerobic stability when compared to the exclusive use of chitosan.

This study aimed to evaluate the effects of increasing levels of chitosan (CHI) on sugarcane fermentation profile and losses, chemical composition, and in situ degradation. Treatments were: 0, 1, 2, 4, and 8 g of CHI/kg of dry matter (DM). Twenty experimental silos (PVC tubing with diameter 28 cm and height 25 cm) were used. Sand (2 kg) was placed at the bottom of each silo to evaluate effluent losses, and silos were weighed 60 d after ensiling to calculate gas losses. Samples were collected from the center of the silo mass to evaluate silage chemical composition, in situ degradation, fermentation profile, and mold and yeast count. Data were analyzed as a completely randomized design, and the treatment effect was decomposed using polynomial regression. Chitosan linearly increased acetic acid and NH3-N concentration, while yeast and mold count, and ethanol concentration decreased. Intermediary levels of CHI (from 4.47 to 6.34 g/kg DM) showed the lower values of effluent, gas, and total losses. There was a quadratic effect of CHI on the content of non-fiber carbohydrates, neutral and acid detergent, and in situ DM degradation. The lowest fiber content was observed with levels between 7.01 and 7.47 g/kg DM, whereas the highest non-fiber carbohydrate content and in situ DM degradation were found with 6.30 and 7.17 g/kg DM of CHI, respectively. Chitosan linearly increased acetic acid and NH3-N concentration, whereas it linearly reduced ethanol concentration and count of yeast and mold. Thus, intermediary levels of CHI, between 4.47 and 7.47 g/kg of DM, decrease fermentation losses and improve the nutritional value of sugarcane silage.

The current study aims to evaluate the effects of increasing levels of xylanase enzyme (XYL) on sugarcane silage fermentation, fermentative losses, chemical composition, dry matter (DM), neutral detergent fibre (NDF) degradation and aerobic stability. A completely randomized design trial was performed with five treatments and 50 experimental silos. Treatments were: 0, 100, 200, 300 and 400 mg of XYL per kg of DM. XYL contained 10 000 U/g. There was a quadratic effect of XYL on silage pH and acetic acid concentration: lower pH and higher acetic acid concentrations were found at intermediary levels of the enzyme. XYL decreased lactic acid concentration linearly. Furthermore, the enzyme had a quadratic effect on effluent and total losses, with higher losses at intermediary XYL levels. There was a quadratic effect of XYL on organic matter (OM), non-fibre carbohydrates (NFC) and crude protein (CP) content. In addition, a quadratic effect of XYL was observed on NDF content and degradation. Intermediary levels of XYL showed higher concentration of OM and NFC. The addition of XYL had no effect on silage temperature and pH after aerobic exposure. Thus, intermediate levels of XYL increased acetic acid and decreased silage pH. Besides positive effects on silage composition, intermediary XYL levels decreased NDF degradation.

Resumo: Embora ruminantes aproveitem fibras dos alimentos, a degradação varia de acordo com a composição físico-química. Enzimas fibrolíticas tem sido utilizadas para aumentar a degradação ruminal de fibras, podendo otimizar o aproveitamento dos nutrientes. O objetivo deste estudo foi avaliar o efeito da enzima fibrolítica xilanase e de um blend enzimático contendo xilanase, celulase e glucanase, em alimentos volumosos: feno de alfafa (Medicago sativa), capim-Braquiária (Urochloa ruziziensis syn Brachiaria ruziziensis) cana-de-açúcar (Saccharum officinarum), capim-Mombaça (Megathyrsus maximus syn Panicum maximum cv. Mombaça) e silagem de milho (Zea mays). O delineamento experimental foi inteiramente casualizado com 5 repetições (vacas), para cada tratamento. Os tratamentos consistiram em uma pré-incubação por 12 horas em tampão de McDougall: 1) sem a adição de enzimas (CT); 2) com a adição de 200 mg/kg de matéria seca (MS) de amostra (XI); e com a adição de 200 mg kg -1 de MS de amostra (BL). Após a aplicação dos tratamentos, as amostras dos alimentos foram incubadas no rúmen das vacas, por 96 horas. O capim-Mombaça apresentou maiores degradações da MS e FDN que as demais forrageiras avaliadas. A xilanase tendeu a aumentar a degradação da fibra em detergente ácido (FDA) em relação ao controle. O blend enzimático aumentou a degradabilidade da MS e FDN, em relação ao CT e tendeu a aumentar a degradação da MS e da FDN em relação à XI. A adição do blend enzimático aumenta a degradação da MS e FDN, sendo uma estratégia enzimática recomendada na dieta de ruminantes.Palavras-chave: digestão ruminal, fibra em detergente neutro, incubação , xilanase Abstract: Although ruminants could utilize fiber of feeds, the degradation varies according to it physicochemical composition. Fibrolitic enzymes have been used to increase ruminal degradation of fibers, and can optimize the use of nutrients. The objective of this study was to evaluate the effect of the xylanase fibrolytic enzyme and an enzymatic blend containing xylanase, cellulase and glucanase in roughage: alfalfa hay (Medicago sativa), Brachiaria grass (Urochloa ruziziensis syn Brachiaria ruziziensis) sugarcane (Saccharum officinarum), Mombasa grass (Megathyrsus maximus syn Panicum maximum cv. Mombasa) and corn silage (Zea mays). The experimental design was completely randomized with 5 replicates (cows), for each treatment. Treatments consisted of a pre-incubation for 12 hours in McDougall's buffer: 1) without the addition of enzymes (CT); 2) with the addition of 200 mg xilanase per kg dry matter (DM) of sample (XI); and with the addition of 200 mg of enzymatic blend per kg sample MS (BL). After application of the treatments, the feed samples were incubated in the rumen of cows for 96 hours. Mombasa grass presented higher DM and NDF degradations than the other evaluated forages. The xylanase tended to increase the degradation of the acid detergent fiber (ADF) in relation to the control. The enzymatic blend increased degradation of DM and NDF in relation to the CT and tende...

Os efeitos de diferentes taxas de semeadura e altura de corte na produção e composição bromatológica do milheto foram avaliados em dois experimentos executados em delineamento em blocos casualizados. No primeiro experimento, foram utilizadas 32 parcelas (1,2 x 1,2 m) e avaliadas as taxas de semeadura de 24, 35, 50 e 60 kg/ha. Três cortes foram realizados para avaliar a altura das plantas, a produção de massa fresca e seca, os teores de matéria seca (MS), fibra em detergente neutro (FDN), proteína bruta (PB) e lignina, assim como a digestibilidade in situ da matéria seca e FDN. No segundo experimento, 20 parcelas (1,2 x 3,0 m) foram usadas para avaliar o efeito das alturas de corte de 20, 30, 40 e 50 cm, sobre as variáveis previamente citadas. De acordo com o aumento da taxa de semeadura, houve aumento linear da altura das plantas e da produção de massa seca e fresca e tendência de redução linear da digestibilidade in situ da matéria seca, sem afetar a composição da forragem. A altura de corte não afetou a concentração de proteína bruta, mas aumentou linearmente a altura das plantas, a produção de massa seca e o teor de matéria seca e tendeu a reduzir a digestibilidade in situ da FDN e a concentração de lignina. Assim, o emprego de maiores taxas de semeadura (60 kg/ha) e de altura de corte (50 cm) aumentam a produção de forragem, enquanto que menores alturas de corte aumentam a qualidade da forragem.

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This study aimed to evaluate the effects of chitosan and homolactic microbial inoculant on fermentative losses, chemical composition, fermentative profile, and aerobic stability of whole-plant soybean silage (WPSS). Additionally, it was evaluated nutrients intake and digestibility of sheep fed increasing levels of WPSS. Thirty experimental silos were randomly allocated to one of the following treatments: 1) CON: control, WPSS without additives; 2) LPPA: WPSS with Lactobacillus plantarum and Pediococcus acidilactici; and 3) CHI: chitosan, WPSS with 5 g/kg of chitosan. Ten male sheep were used to evaluate increasing dietary levels of WPSS: 0, 200, 400, 600, and 800 g/kg of diet dry matter (DM). Additives increased silage lactic acid bacteria and decreased the count of mold and yeast, gas, and total losses. Silages treated with additives had lower pH, NH3-N, and ethanol concentrations and higher lactic and propionic acids relative to CON. LPPA-treated silos showed higher organic matter and non-fiber carbohydrates content than CHI-ones. Additives increased the aerobic stability of WPSS. The addition of WPSS in sheep diets linearly increased nutrients intake and digestibility. Chitosan and LPPA improve WPSS fermentation, aerobic stability, and nutritional value. The WPSS in substitution to Cynodon hay increases sheep feed intake and nutrients digestibility.

This study aimed to evaluate recombinant bovine somatotropin (rbST) supply on feed intake, performance, serum metabolites, and blood cells count of transition cows. Thirty pregnant Holstein cows (607 ± 28.6 kg of body weight) were randomly allocated to one of the following treatments: 1) Control (CON), without rbST supply; and 2) rbST: 250 mg of slow release rbST (Lactotropin, Elanco Animal Health, USA) supplied every 14 d from 28 d of the expected calving date until 28 d of lactation. rbST group had increased dry matter intake during the post partum period and higher body condition score in both pre-and post-partum periods compared to CON. rbST treatment increased milk yield and milk fat content. Although no effects were observed on serum metabolites before parturition, rbST increased post-partum serum concentrations of glucose, cholesterol, and ionized calcium, and decreased serum concentration of triacyglyceride. rbST had minor effects on complete blood cell count, which included reduced neutrophil counts. In conclusion, this study supports that rbST supply during transition period improves performance of dairy cows that is partially related to improvements in metabolism.