Natural Matter Basis Research Articles

Perfil fermentativo, valor nutricional e estabilidade aeróbia de silagens mistas de capim-elefante e cunhã

Abstract The aim was to evaluate the effect of butterfly pea inclusion on the fermentation dynamics, nutritional quality and aerobic stability of mixed elephant grass silages. Butterfly pea levels (0, 20, 40, 60 and 80% on a natural matter basis) were added to elephant grass silages. A completely randomized design was adopted, with 5 treatments and 3 replications, totaling 15 experimental silos, which were opened after 30 days of fermentation. The inclusion of butterfly pea in elephant grass silages resulted in a quadratic effect for permeability, density, maximum pH, final pH, time to reach maximum temperature and aerobic stability (P<0.05). Butterfly pea inclusion levels increased dry matter recovery, pH, dry matter, organic matter, ether extract, crude protein and total digestible nutrients (P<0.001) and reduced gas and effluent losses, mineral matter, neutral detergent fiber, acid detergent fiber, hemicellulose, cellulose, lignin and total carbohydrates (P<0.001). Inclusions of 40, 60 and 80% of butterfly pea provided temperature increases at 10, 20, 30 and 40 hours. The inclusion of butterfly pea with levels of up to 80% reduces fermentation losses, allows for a nutritional increase and increase in aerobic stability of silages.

Ensiling Sorghum with Urea, Aerobic Exposure and Effects on Intake, Digestibility, Ingestive Behaviour and Blood Parameters of Feedlot Lambs.

This study was carried out to evaluate the effect of ensiling sorghum silage with urea and amending the aerobic exposure nutrients intake and apparent digestibility, ingestive behaviour and blood serum metabolites of feedlot lambs. Forty uncastrated crossbred Dorper × Santa Inês lambs, aged 150 ± 15 days and with an initial body weight of 21.73 ± 2.40 kg, were used. Animals were assigned in a 2 × 3 factorial arrangement. Thus, six silage diets were produced with various urea addition levels (UA: 0 and 5 g/kg on a natural matter basis) and periods of aerobic exposure of silages (PAE: 0, 24 and 48 h). An effect was observed for nutrient intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre corrected for ash and protein (NDFap) and total digestive nutrients TDN (g/day) and for the total apparent digestibility of DM, OM and CP. There was an interaction effect between urea levels and aerobic exposure for ether extract (EE) and NDFap intakes (g/kg) and nonfibrous carbohydrate (NFC) digestibility (g/kg) (p = 0.012). The addition of 5 g/kg of urea to sorghum ensilage improved the digestibility parameters without changing dry matter intake and ingestive behaviour. The addition or not of urea does not change the blood parameters of the animals.

Microbial inoculant and cottonseed cake as additives for millet silage at different fermentation times

ABSTRACT The purpose of the present study was to evaluate the effect of the addition of microbial inoculant and cottonseed cake on the fermentation profile, microbial population, aerobic stability, organic acids, chemical composition and losses of millet silages. The experimental design was completely randomised, in a 4 × 2 factorial arrangement, with the following treatments: (1) Control (millet); (2) Millet + 10% cottonseed cake (on a natural matter basis); (3) Millet + Weissella cibaria – heterofermentative lactic acid bacteria; (4) Millet + cottonseed cake and Weissella cibaria (blend); and two opening times (30 and 90 days after ensiling) with four replications, totalling 32 experimental units. Silages containing cottonseed cake had greater (P = .008) dry matter recovery. There was effect (P < .001) of the opening time on the counts of lactic acid bacteria, mould and yeast, and under aerobic stability, which were higher in silages opened at 90 days. The addition of cottonseed cake resulted in an increase in the nutritional quality of the silage, compared to control silages and silages inoculated with Weissella cibaria. The addition of cottonseed cake in millet silage proved to be efficient in reducing silage losses, improving the fermentation profile and nutritional value.

Elephant grass cv. BRS capiaçu silage with inclusion of different proportions of silk cotton

The objective was to evaluate the qualitative and nutritional aspects of elephant grass cv. BRS capiaçu silage with increasing proportions of silk cotton. A completely randomized design was used with five (0, 15, 30, 45, and 60% on natural matter basis) different inclusion proportions of silk cotton to elephant grass silage and four repetitions. Silages were prepared in PVC minisilos and remained ensiled for 42 days. The inclusion of silk cotton resulted in a linear reduction in dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose, and indigestible neutral detergent fiber (iNDF) contents at 0.06, 0.30, 0.23, 0.20, and 0.09 percentage points for each 1% inclusion, respectively. There was an increasing linear effect of crude protein (CP) and total digestible nutrients (TDN), with an increase of 39.32 and 20.89% from the lowest to the highest inclusion of silk cotton to elephant grass cv. BRS capiaçu silage. Values of pH, gas losses (GL), effluent losses (EL), dry matter recovery (DMR), hemicellulose, and lignin were not influenced by the evaluated inclusion levels, showing estimated averages of 3.87, 1, 42%, 11.55kg t-1 natural matter, 97.36%, 19.30%, and 7.20%, respectively. An increasing linear effect was found for fraction a, c, effective degradability (ED) (2% and 5%) dry matter, with an increment of 0.05, 0.0005, and 0.11 percent points, respectively. There was a quadratic effect for fraction b, potential degradability (PD), ED (2%), with minimum points of 23.72%, 50.52%, (at 45% inclusion level) 39.69%, (at 15% inclusion level) respectively. The indigestible fraction (IF) had a quadratic effect with a maximum of 49.48% at the 45% inclusion level. The colonization time (CT) linearly reduced by 0.09 percentage points for each 1% inclusion evaluated. According to the parameters evaluated, the inclusion of up to 60% silk cotton improved nutritional aspects and nutritional value of elephant grass cv. BRS capiaçu silage.

Effects of organic acids in total mixed ration and feeding frequency on productive performance of dairy cows

This study aimed to evaluate the effects of organic acid (OA; Mold-Zap, Alltech, Nicholasville, KY) inclusion in the total mixed ration (TMR) and feeding frequency of TMR for lactating dairy cows on intake, total-tract apparent digestibility, sorting index, feeding behavior, ruminal fermentation, milk yield and composition, nitrogen balance, and serum metabolites. Twenty-four lactating Holstein cows, 4 with rumen cannulas, with (mean ± standard error) 247 ± 22.2 d in milk, 672 ± 14.6 kg of body weight, and 31.1 ± 1.09 kg of milk yield at the beginning of the experiment were used. The cows were distributed in a balanced and contemporary 4 × 4 Latin square experimental design and randomly assigned in a 2 × 2 factorial arrangement to evaluate OA [0 (OA-) or 0.5 (OA+) L of Mold-Zap/tonne of TMR on a natural matter basis] and feeding frequency of TMR offered once a day (1×) or twice a day (2×). Each experimental period lasted 21 d, with 14 d for acclimation and 7 d for data collection. The treatments were tested for TMR, in which its temperature was recorded every 2 h through a 24-h period in each experimental period. Organic acid-treated TMR showed a lower temperature during the 24-h period compared with nontreated TMR. The OA and feeding frequency had no effect on intake and total-tract apparent digestibility of dry matter and nutrients, aside from a tendency to increase neutral detergent fiber digestibility in cows fed 2×. Also, cows fed 1× tended to select more particles between 19 and 8 mm and refused particles smaller than 4 mm, whereas cows fed OA tended to select more particles smaller than 4 mm. Cows fed OA had greater milk yield and milk protein and lactose yields, but tended to have higher 3.5% fat-corrected milk yield. Neither treatment influenced ruminal and serum variables nor milk fat yield and milk production efficiency. Cows fed OA spent less time idling and tended to have lower rumination time, and tended to have higher time spent drinking water and eating, whereas animals fed 1× spent more time drinking water. Under the conditions of this experiment, we conclude that it was possible to reduce the feeding frequency of TMR, without negative effects on dairy cow performance. However, the use of OA resulted in higher milk yield and mitigated TMR temperature rise regardless of feeding frequency. The effect of external factors such as collective stimulation of intake and stage of lactation on feeding frequency effect must be surveyed in further research.

PSXII-17 Trace minerals source influences the performance of Nellore cattle in the growing phase during the transition between dry to rainy season in Brazil

Abstract The relative bioavailability of trace minerals may vary between the sources and impact the animal performance. The study was carried out to evaluate the effect of TM source (Cu and Zn) on the liver concentration and performance of Nellore cattle supplemented in the growing phase during the transition between dry to rainy season. A hundred and twenty Nellore young bulls (BW = 349.72 ± 24 kg; 24 months), blocked by BW, were assigned randomly to twelve paddocks (six paddocks/treatment and 10 animals/paddock). Animals grazing Urochloa brizantha cv. Marandu and supplemented at 5 g/kg BW with soybean meal, corn and mineral mix (250 g/kg of CP and 650 g/kg de NDT, natural matter basis). Supplements consisted of 40 mg Cu and 148 mg Zn/kg DM from either inorganic TM (ITM) or hydroxy TM (HTM) Intellibond® sources. Liver samples were collected at the beginning and end of the study (three animals per paddock). Animals were weighed at each period (30 days) during three periods. Period was used as a REPEATED measurement for BW and values of initial BW as independent covariates for all variables. Paddock was considered experimental unit. Data were analyzed by ANOVA using PROC MIXED, SAS 9.4. The animals supplemented with HTM had higher (+0.037 kg/day) general ADG (day 0 to 90; P = 0.012), with 0.469 and 0.506 kg/day to ITM and HTM, respectively. Final BW (day 90) from animals fed HTM was 5.13 kg higher than ITM (391.97 vs. 397.11 kg BW; P = 0.030). No differences were found in the liver concentrations of Cu and Zn between ITM or HTM (P ≥ 0.288). Cu and Zn from HTM improve the performance of animals supplemented in pasture compared to ITM sources.

Dry matter concentration and corn silage density: Effects on forage quality

Considering the hypothesis that density and dry matter (DM) concentration may be used as indicators of silage nutritional quality, the aim of the present study was to determine density and maturation stage (i.e. DM concentration) of corn silages under farm conditions in Brazil, establishing relationships between density and physical and chemical characteristics. In a completely randomized design, 20 bunkers of corn silage, each from a different farm, were used for data collection. Using a coring machine, 5 samples of silage were extracted from an exposed face of each silo and samples were analyzed for density of compaction, plus concentrations of DM, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), total digestible nutrients (TDN), total carbohydrate (TC), non-fiber carbohydrate (NFC) and starch (STA), as well as electrical conductivity. There was significant variation in many of the parameters measured with the greatest variation in density on a natural matter basis. Negative correlations were observed between percentages of DM, NDF and ADF in the silage and silage density on a natural matter basis (P&lt;0.05). On the other hand, DM% was positively correlated with concentrations of STA, TDN and TC (P&lt;0.05). Density on a DM basis showed positive correlation with STA but was negatively correlated with NDF and ADF (P&lt;0.05) indicating that the more fibrous material is harder to compact. A technology transfer program seems warranted to inform Brazilian farmers of these findings and the importance of harvesting forage at a stage of growth when quality would be better to increase the probability of achieving adequate compaction of the ensiled material and hence better quality of material at feeding out.

Efeitos do capim mombaça (panicum maximum cv. mombaça) e melaço em pó na silagem de leucena (leucaena leucocephala)

The objective of this study was to evaluate the bromatologic quality of Leuchena ( Leucaena leucocephala ) silage increasing levels of powder sugarcane molasses. In addition, it was produced Leuchena silage, but with the addition of increasing levels of powder sugarcane molasses (0, 2, 4, and 6% on natural matter basis). In total, four treatments with four repetitions were evaluated using experimental cylindrical-PVC silos arranged in a completely randomized design. After 30 days, silos were opened and evaluated pH, dry matter (DM), mineral matter (MM), neutral detergent fiber (NDF), acid detergent fiber (ADF), and hemicelulose. The use of powder molasses as an additive in the ensiling of leucena presented desirable effects in the ensiled mass, promoting some improvements in the quality of the same. The results show that as the inclusion of molasses powder in silage increases, a reduction in the levels of FDA, NDF and pH occurs. Up to 4% of molasses powder in Leucena silage is indicated for best results of MM (%) and MS (%).

Intake, performance and nutrient digestibility of sheep fed sugarcane treated and ensiled with calcium oxide or urea

The objective of this study was to evaluate intake, performance and nutrient digestibility of sheep supplemented with sugarcane ensiled with four levels of calcium oxide (0.0, 0.8, 1.6 and 2.4%) and urea (1.5%), on a natural matter basis. Twenty castrated Santa Ines lambs with 24.09 kg average weight were housed in individual 1.5 m² pens, distributed in a completely randomized design. The diet supplied had a roughage:concentrate ratio of 70:30 and the experimental period lasted 77 days, of which 14 days were used for adaptation to the diet and three 21-day periods for data collection. No differences were observed for the average daily intake of dry matter, ether extract, neutral detergent fiber, neutral detergent fiber corrected for ash and protein, total carbohydrates, hemicellulose and total digestible nutrients. The treatment with urea showed differences for the intake (kg/day) of crude protein, acid detergent fiber and non-fibrous carbohydrates. There was no effect of diets on the digestibility of dry matter, ether extract, neutral detergent fiber, acid detergent fiber or total digestible nutrients, but there was a quadratic effect for total carbohydrates and increasing linear effect for non-fibrous carbohydrates. The calcium intake increased as the levels of calcium oxide in the sugarcane were elevated. The calcium:phosphorus ratio in the silage of calcium oxide was different from the silage with urea and control. No effect was observed for the performance characteristics of sheep. Sugarcane silages with calcium oxide levels of up to 2.4% or with urea do not improve the intake or weight gain of sheep.

Performance evaluation, feces production and digestibility of nutrients in pigs from different genetic groups

The objective of this experiment was to evaluate the performance, feces production and digestibility of the main ingredients in feed of different pig genotypes. Forty eight pigs (24 barrows and 24 gilts) averaging 50.81 ± 4.63 kg until 81.14 ± 6.55 kg of body weight and 93.63 ± 6.08 days of age were used. Four treatments represented by four lineages were used: 1- commercial pig breeding line, selected for growth and lean meat production; 2- commercial pig breeding line, selected for prolificacy; 3- crossbred animals (Landrace x Large White); 4- non selected genetic line. Two animals were housed per pen and they received isonutrient and isoenergetic and feed and water ad libitum. The experimental design was completely randomized in a 4x2 factorial arrangement (genetic lines, genders). A greater average daily gain was observed to hybrid animals selected for lean meat production compared to animals selected to prolificacy and a greater feed conversion was observed for the hybrid animals for lean meat (P<0.05). Total feces production (natural matter basis) had a lower level (P<0.05) for the hybrid animals for lean meat production compared to the hybrid group for prolificacy and non-selected genetic group. The animals without selection showed lower digestibility indexes for natural matter (P<0.05) and the nonselected genetic group and crossbred animals (Large White x Landrace) showed the lowest digestibility index for phosphorous. Pigs select for growth and lean meat production are more efficient in converting food into meat and have less fecal production. According the gender, the females are more efficient to the performance parameters.

Avaliação do desempenho, da produção de fezes e da digestibilidade de nutrientes em suínos de diferentes grupos genéticos

The objective of this experiment was to evaluate the performance, feces production and digestibility of the main ingredients in feed of different pig genotypes. Forty eight pigs (24 barrows and 24 gilts) averaging 50.81 ± 4.63 kg until 81.14 ± 6.55 kg of body weight and 93.63 ± 6.08 days of age were used. Four treatments represented by four lineages were used: 1- commercial pig breeding line, selected for growth and lean meat production; 2- commercial pig breeding line, selected for prolificacy; 3- crossbred animals (Landrace x Large White); 4- non selected genetic line. Two animals were housed per pen and they received isonutrient and isoenergetic and feed and water ad libitum. The experimental design was completely randomized in a 4x2 factorial arrangement (genetic lines, genders). A greater average daily gain was observed to hybrid animals selected for lean meat production compared to animals selected to prolificacy and a greater feed conversion was observed for the hybrid animals for lean meat (P&lt;0.05). Total feces production (natural matter basis) had a lower level (P&lt;0.05) for the hybrid animals for lean meat production compared to the hybrid group for prolificacy and non-selected genetic group. The animals without selection showed lower digestibility indexes for natural matter (P&lt;0.05) and the nonselected genetic group and crossbred animals (Large White x Landrace) showed the lowest digestibility index for phosphorous. Pigs select for growth and lean meat production are more efficient in converting food into meat and have less fecal production. According the gender, the females are more efficient to the performance parameters.

Sunflower meal concentrations in Massai grass silage

ABSTRACTObjetive. This experiment was conducted to evaluate the best sunflower meal concentration in Massai grass silage. Materials and methods. The treatments were composed of 0, 8, 16, and 24% sunflower meal (natural matter basis) during ensiling of Massai grass, with four repetitions. Results. The regression equation showed that the inclusion of sunflower meal between 2.14% and 13.91% obtained a silage dry matter between 25 and 35%, which are the values recommended for the production of high quality silage. The addition of sunflower meal showed a linear increase in crude protein, reaching 18% DM with the highest concentration of sunflower meal. The highest feed value index was obtained with the addition of 24% sunflower meal in the silage. The estimated total digestible nutrient of silage increased linearly with sunflower meal concentration. The silage pH values had a quadratic effect, reaching the lowest value (4.1) with 15% sunflower meal addition. Conclusions. Based on the chemical composition and forage quality, a concentration of 14% sunflower meal should be used for high-quality silage with good nutritional value..

Chemical composition and fermentative losses of sugar cane ensilage with different Brix degrees, with or without calcium oxide

The objective of this study was to evaluate the effect of sugar cane ensilage with different Brix degrees, with or without the addition of 0.5% of calcium oxide (lime) on the chemical composition and fermentation losses of silages. A complete random design in a 9 × 2 factorial arrangement was used. Experimental silos were used, ensilage was done every 15 days with Brix measuring, and they were opened after 30 days of fermentation. As the Brix degree of the ensiled material increased, the contents of dry matter (DM) increased and contents of ash, crude protein (CP) and fibers (neutral and acid detergent fiber corrected for proteins - NDFap and ADFap) reduced. After fermentation, DM content of the silage presented a linear increase with the Brix degree content concentration, positively correlating with content of lime, but the contents of ash, CP, EE and NDFap were linearly reduced with the Brix increase. Content of ADFap suffered linear reduction for the treated silage whereas quadratic behavior was found in the untreated silage. Production of ethanol was presented in a quadratic manner for the silages without lime, and cubically in silages with lime, according to the Brix degree. The treated or untreated silages presented an average pH of 3.98 and 3.50, respectively. Contents of acetic acid and butyric acid were not affected by the lime content and Brix degree. Untreated silages presented reduction of contents of propionic acid as the Brix degree increased. The higher the Brix degree value, the higher the total losses of dry matter in the sugar cane silages with or without treatment. The treatment of the sugar cane with 0.5% calcium oxide on the natural matter basis is effective in reducing the undesired fermentation of the ensilage material.

Comportamento ingestivo em caprinos alimentados com dietas contendo cana-de-açúcar tratada com óxido de cálcio

Objetivou-se avaliar o efeito do tratamento da cana-de-açúcar com óxido de cálcio (CaO) sobre o comportamento ingestivo em caprinos. Foram utilizados oito caprinos da raça Saanen, machos castrados, com peso corporal médio de 22,6 kg e 4 meses de idade, distribuídos em dois quadrados latinos 4 × 4, com quatro períodos experimentais de 14 dias. Os animais foram mantidos em baias individuais de 1,2 m², com piso ripado de madeira, providas de comedouros e bebedouros individuais. As dietas foram formuladas para ser isoproteicas e conter 14% de proteína bruta (PB) e apresentaram 70% de cana-de-açúcar tratada com 0; 0,75; 1,5 ou 2,25% de óxido de cálcio (com base na matéria natural) corrigida com 1% de ureia e 30% de concentrado fornecidas a vontade. A cana-de-açúcar com a adição das doses de óxido de cálcio, foi triturada em desintegradora estacionária, pesada e acondicionada em baldes plásticos de 50 L, tratada com o óxido de cálcio e fornecida aos animais após 24 horas de armazenamento. Os tempos despendidos em alimentação, ruminação (min/dia, min/kg MS e min/kg FDN) e ócio (min/dia) não foram afetados pela adição de óxido de cálcio à cana-de-açúcar. A adição de óxido de cálcio à cana-de-açúcar não influenciou a eficiência em alimentação e ruminação, mas provocou redução do tempo médio despendido por período de alimentação. O comportamento ingestivo de caprinos em crescimento não é afetado pela utilização de dietas contendo cana-de-açúcar tratada com até 2,25% de óxido de cálcio.

Sugar cane treated with calcium hydroxide in diet for cattle: intake, digestibility of nutrients and ingestive behaviour

The objective of this work was to evaluate, in bovines, the intake and apparent digestibility of nutrients, ingestive behaviour and content of total digestible nutrients (TDN) of diets based on sugar cane treated with calcium hydroxide. It was used four cows with average body weight of 412.06 kg ± 37.3 kg. The study included inclusion of calcium hydroxide at the doses 0, 8, 16 and 24 g/kg of sugar cane in natural matter basis fed in diets with 65% of roughage and 35% on concentrate, based on dry matter (DM). It was used a 4 × 4 Latin square experimental design with four treatments and four periods. Calcium hydroxide doses affected nutrient intake: DM intake was 7.88 kg/day at the dose of 14.99 g of calcium hydroxide, organic matter (OM) intake was 6.75 kg/day at 10.94 g; intake of neutral detergent fiber (NDF) of 3.33 kg/day with a dose of 13.93 g; and intake of acid detergent fiber (ADF) of 2.12 kg/day with a dose of 10.51 g. Digestibility coefficients showed a quadratic effect for doses of inclusion of calcium hydroxide. Dry matter digestibility was 72.88% with a dose of 11.65 g of calcium hydroxide, OM digestibility was 75.12% with 12.09 g; NDF digestibility was 58.67% with 12.11 g; ADF digestibility was 52.97% with 9.36 g and TDN digestibility was 71.42% with 10.92 g. There was no effect of the treatment for activities of rumination and total idle. Chewing time, number of bolus chewed and time for rumination of each bolli presented effect. Calcium hydroxide enabled greater intakes and digestibility of nutrients, especially from the cell wall, favoring the use of nutrients from the diet containing sugar cane, recommending a dose of 8-12 g.

Desempenho e digestibilidade aparente dos nutrientes em ovinos alimentados com dietas contendo bagaço de cana-de-açúcar tratado com óxido de cálcio

Foram estudados os efeitos da adição de 0,0; 0,75; 1,5 e 2,25% de óxido de cálcio no bagaço de cana-de-açúcar (com base na matéria natural) com o objetivo de avaliar o desempenho, o consumo de nutrientes e a digestibilidade aparente das dietas e dos nutrientes em ovinos mestiços da raça Santa Inês e raças nativas. Vinte e quatro ovinos, mantidos em total confinamento, foram distribuídos em delineamento inteiramente ao acaso, com quatro níveis de óxido de cálcio e seis repetições. Os animais foram mantidos em baias individuais, por 77 dias. Os primeiros 14 dias foram de adaptação e, então, seguiram-se três períodos de 21 dias de coleta de dados. Na determinação da digestibilidade, utilizou-se o método de coleta total de fezes, que foi realizada nos quatro últimos dias do período experimental. As fezes foram coletadas três vezes ao dia, às 7, 13 e 18 h. O uso do óxido de cálcio não influenciou os consumos de matéria seca, proteína bruta, fibra em detergente neutro, fibra em detergente ácido e nutrientes digestíveis totais, mas houve efeito linear sobre ganho de peso, com o aumento nas doses de óxido de cálcio, mas não sobre a conversão alimentar e os coeficientes de digestibilidade aparente da matéria seca, proteína bruta e fibra em detergente ácido. Entretanto, foi observado efeito quadrático para o coeficiente de digestibilidade aparente da fibra em detergente. A utilização do bagaço de cana hidrolisado com óxido de cálcio em níveis a partir de 1,5% da matéria natural promove melhoras no desempenho de ovinos e aumenta a digestibilidade apenas da fibra em detergente neutro.

Consumo e digestibilidade aparente em novilhas alimentadas com dietas contendo cana-de-açúcar tratada com óxido de cálcio

Desenvolveu-se este estudo para avaliar o consumo e a digestibilidade aparente dos nutrientes em novilhas alimentadas com dietas contendo cana-de-açúcar tratada com óxido de cálcio. Avaliou-se também a eficiência de predição do consumo de matéria seca e do valor energético dos alimentos. Utilizaram-se 20 novilhas mestiças Holandês-Zebu com peso corporal médio inicial de 200 kg, distribuídas em delineamento inteiramente ao acaso, com quatro dietas e cinco repetições. As dietas foram formuladas para ser isoproteicas e fornecer 14% de proteína bruta e foram compostas de 71% de cana-de-açúcar tratada com 0; 0,75; 1,5 ou 2,25% de óxido de cálcio (com base na matéria natural) e corrigida com 1% da mistura ureia e sulfato de amônio (9:1) e 29% de concentrado. Os consumos de matéria seca (MS), matéria orgânica (MO), extrato etéreo (EE), fibra em detergente neutro (FDN), fibra em detergente neutro corrigida para cinzas e proteína (FDNcp), fibra em detergente neutro indigestível (FDNi), carboidratos totais (CT), carboidratos não-fibrosos corrigidos para cinza e proteína (CNFcp) e nutrientes digestíveis totais (NDT), em kg/dia, não foram afetados pela adição de óxido de cálcio à cana-de-açúcar. Os consumos de MO, FDN, FDNcp e NDT (% PV) reduziram linearmente com as doses de óxido de cálcio. As digestibilidades de MO, FDN, FDNcp, carboidratos totais e CNFcp e o teor de NDT das dietas não foram afetados. Entretanto, o tratamento da cana-de-açúcar com óxido de cálcio provocou redução na digestibilidade da MS e PB. As equações propostas pelo National Research Council subestimaram os consumos de MS e NDT e de PB e CNF digestíveis e superestimaram os de FDN digestível. O tratamento da cana-açúcar com óxido de cálcio não melhora o consumo nem a digestibilidade dos nutrientes em novilhas. As equações propostas pelo National Research Council não são eficientes para estimar o consumo de MS e o valor energético de alimentos nas condições experimentais.

Comportamento ingestivo de ovinos alimentados com silagens de capim-elefante contendo casca de café, farelo de cacau ou farelo de mandioca

Um experimento foi conduzido para avaliar o comportamento ingestivo de ovinos alimentados com dietas contendo silagem de capim-elefante com diversos aditivos. Foram utilizados 20 ovinos machos, não-castrados, em um delineamento inteiramente casualizado, com 4 tratamentos e 5 repetições. Os animais receberam dietas com média de 11% de proteína, compostas de 60% de volumoso e 40% de concentrado, com base na matéria seca (MS). Como volumoso, utilizou-se silagem de capim-elefante sem aditivo ou com 15% de casca de café, farelo de cacau ou farelo de mandioca, misturados ao capim-elefante no momento da ensilagem, com base na matéria natural (peso/peso). As variáveis comportamentais foram obtidas a cada dez minutos, durante 24 horas de observação. Os tempos despendidos em alimentação e ruminação foram semelhantes entre as silagens utilizadas nas dietas. Contudo, os animais que consumiram silagem de capim-elefante com farelo de mandioca apresentaram maior tempo de ócio. O consumo de matéria seca e as eficiências de alimentação (g de MS e de FDN/hora) e ruminação (g MS/hora) foram maiores nos animais alimentados com a silagem contendo 15% farelo de mandioca, o que indica que esse subproduto é um bom aditivo para utilização na ensilagem de capim-elefante. A inclusão de farelo de mandioca na ensilagem de capim-elefante melhora alguns parâmetros do comportamento ingestivo.

Desempenho de ovinos mantidos com dietas com capim-elefante ensilado com diferentes aditivos

Avaliaram-se os efeitos da adição de 15% de casca de café, farelo de cacau ou farelo de mandioca, com base na matéria natural (peso/peso), à forragem verde de capim-elefante no momento da ensilagem sobre o consumo de nutrientes e o desempenho de 20 ovinos Santa Inês em confinamento. Os animais tinham 5 meses de idade, peso inicial de 22,27 ± 3,24 kg e o peso final foi de 28,6 ± 3,78 kg. Utilizou-se um delineamento experimental inteiramente ao acaso, com quatro tratamentos e cinco repetições. Os tratamentos foram: capim-elefante ensilado sem aditivo ou ensilado com 15% de casca de café, farelo de cacau ou farelo de mandioca. A utilização da casca de café, do farelo de cacau e do farelo de mandioca na ensilagem de capim-elefante aumentou o consumo de matéria seca. Os maiores consumos de proteína bruta foram observados nas silagens contendo farelo de cacau e farelo de mandioca. Os consumos de fibra em detergente neutro foram semelhantes e o consumo de nutrientes digestíveis totais foi maior na silagem contendo farelo de mandioca. A conversão alimentar dos animais não foi afetada pela inclusão dos aditivos na ensilagem. A inclusão de farelo de mandioca na ensilagem de capim-elefante aumenta o ganho de peso (140,5 g/dia) em ovinos Santa Inês.

Fracionamento de carboidratos e proteínas de silagens de capim-elefante com casca de café, farelo de cacau ou farelo de mandioca

Este experimento foi conduzido para avaliar as frações que compõem os carboidratos e as proteínas da silagem de capim-elefante com 15% casca de café, farelo de cacau ou farelo de mandioca. A adição dos co-produtos no momento da ensilagem foi realizada na base da matéria natural (peso/peso), com dez repetições por tipo de silagem. O maior teor de carboidratos totais foi observado na silagem com farelo de mandioca e o menor, na silagem com farelo de cacau, seguida das silagens controle e com casca de café. Maiores valores de carboidratos não-fibrosos (A+B1) também foram verificados para as silagens com farelo de mandioca. Os menores valores de fração indigestível (C, %CT) foram observados para a silagem com farelo de mandioca, enquanto as silagens com casca de café e farelo de cacau apresentaram os maiores valores desta fração. A silagem com farelo de cacau apresentou os maiores valores de proteína bruta e foi seguida das silagens com casca de café, controle e com farelo de mandioca. A presença dos aditivos influenciou as frações protéicas da silagem de capim-elefante: os maiores valores de fração A (%PB) foram determinados nas silagens controle e com farelo de mandioca. Apesar do maior valor protéico, as silagens com farelo de cacau e casca de café apresentaram os maiores valores de fração indigestível de proteína (C, %PB). A adição de farelo de cacau e casca de café ao capim-elefante no momento da ensilagem aumenta as frações indigestíveis de carboidratos e de proteína da silagem. O farelo de mandioca ensilado com capim-elefante é um bom aditivo para a produção de silagem.