Uso de funções discriminantes para comparação de cultivares dos gêneros Cynodon e Digitaria quanto à produção de matéria seca e teores de macronutrientes.

Foi realizado um experirnento no Centro Nacional de Pesquisa de Agrobiologia, Seropédica-RJ, com objetivo de comparar as gramineas Coast cross e Tifton 85, do gênero Cynodon, e as gramíneas Suazi (Digitaria swazilandensis) e Transvala (D. decumbens), do gênero Digitaria, quanto a produção de matéria seca (MS) e teores de macronutrientes da parte aérea e sistema radicular, em 15 amostras de cada cultivar, coletadas no período das chuvas (primavera/verão). A análise discriminante demonstrou que as variáveis Mg, Ca e MS na parte aérea e P e N na raiz foram importantes no processo de discriminação dos cultivares estudados. O cultivar Suázi foi diferente dos dernais avaliados quanto a produção de MS e aos teores de Mg e Ca na parte aérea, além do P e N na raiz. Os cultivares Tifton 85 e Coast cross, apesar de serem do mesmo gênero, diferem quanto a produção de MS e aos teores de Mg e Ca na parte aérea, alem do P e N na raiz. Algumas amostras dos cultivares Tifton 85 e Coast cross apresentaram semelhança com O capim Transvala, com relação a produção de MS e aos teores de Mg e Ca na parte aérea, alem de P e N na raiz. An experiment was carried out at the National Center of Research of Agrobiology, Seropedica--RJ, with objective of evaluating the grasses Coast cross (Cynodon spp.) and Tifton 85 (Cynodon dactylon (L.)), of the Cynodon genus, and the grasses Suazi (Digitaria swazilandensis) and Transvala (Digitaria decumbens), of the Digitaria genus, through the discriminant analysis. The evaluated variables were: dry matter production (DMP) and contents of nitrogen (N), phosphorus (P), magnesium (Mg) and calcium (Ca) in the shoot and root on 15 samples of each grasses, accomplished in the period of the rains (spring/ summer). The discriminant analysis demonstrated that the variables Mg, Ca and dry matter production (DMP) in shoot, and P and N root are important in the discrimination process of the Coast cross, Tifton 85, Suazi and Transvala cultivars. Suazi cultivar is clearly different from the others cultivars, in relationship to Mg and Ca contents and DMP at the shoot, P and N at the root. O Tifton 85 and Coast cross cultivars, in spite of being of the same genus, differ in relationship to Mg and Ca contents and DMP at the shoot, match and N at the root. Some samples of the Tifton 85 and Coast cross cultivars can be similar to the grass Transvala, in relation to the Mg, Ca and DMP contents in shoot, P and N root.Parceria: UFV; PESAGRO-Rio/ESS; UFRRJ; ESALQ

Influência da adubação nitrogenada na forma de chorume bovino na matéria seca e nutrientes acumulados nas raízes de gramíneas forrageiras.

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Efeito da aplicação de nitrogênio, sob a forma de chorume bovino, na qualidade e produção do pasto Tanzânia (Panicum maximum).

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Carcass traits and meat quality of lambs fedwith cactus (Opuntia ficus indica Mill) silage and subjected to an intermittent water supply.

The present study aimed to evaluate the effect of cactus silage and an intermittent water supply for lambs on carcass traits and meat quality. Thirty-six crossbreed lambs with an initial average weight of 19.8 ± 2.1 kg and average age of 6 months were randomly assigned to a 3 × 3 factorial design comprising three addition ratios of cactus silage to the diet (0, 21, and 42% based on dry matter) and three water supply intervals (0, 24, and 48 h) with four replicates. There was no interaction (P > 0.05) between the cactus silage ratio and intermittent water supply for any of the evaluated variables, with the exception of the yield of the half carcass commercial cuts. There was no significant effect of intermittent water supply (P > 0.05) on the carcass characteristics or meat quality. The addition of forage cactus silage as a substitute for Tifton hay affected the morphometric measurements (P 0.05). The addition of forage cactus silage to the lambs? diet affected (P < 0.05) the composition of some saturated fatty acids in the meat. A water supply interval of up to 48 h does not influence carcass characteristics and meat quality. Therefore, the use of cactus silage can be recommended in situations of water scarcity without harming the production or meat quality of crossbreed lambs

Effect of inoculation with preactivated Lactobacillus Buchneri and urea on fermentative profile, aerobic stability and nutritive value in corn silage.

The current study aimed to evaluate the application effects of the preactivated Lactobacillus buchneri and urea on the fermentative characteristics, chemical composition and aerobic stability in corn silages. The design was completely randomized, in a 6 × 5 factorial arrangement, with six types of additiveand five opening times. The treatments consisted of corn silage; corn silage with freeze-dried inoculant; corn silage with freeze-dried inoculant +1.0% urea; corn silage with activated inoculant; corn silage with activated inoculant +1.0% urea, and corn silage with 1.0% urea. Populations of lactic acid bacteria stabilized at the 70th day, with average values of 8.91 and 9.15 log cfu/g for corn silage with freeze-dried inoculant +1.0% urea and corn silage with freeze-dried inoculant, respectively. In contrast, the silages without additives showed significantly lower values of 7.52 log cfu/g forage at the 70th day. The silages with urea (isolated or associated with the inoculant) increased the total nitrogen content. The maximum temperature values were highest in the corn silages without additives, indicating that these silages were more prone to deterioration. The use of Lactobacillus buchneri activated proved to be more efficient in improving the fermentative profile of corn silages than the freeze-dried inoculant. The use of urea as an additive reduced the losses and improved the nutritional value and aerobic stability of corn silages. Additionally, the combination of Lactobacillus buchneri activated and urea may be used as a technique to improve the fermentative profile, chemical composition and aerobic stability of corn silages

Effect of urea on gas and effluent losses, microbial populations, aerobic stability and chemical composition of corn(Zea mays L.) silage.

We evaluated the effects of urea addition on gas and effluent losses, fermentation profile, microbial populations, aerobic stability and chemical composition of corn silages. A completely randomised design with five levels of urea (0, 0.5, 1.0, 1.5, and 2.0% based on dry matter) and five replicates was used. A decreasing linear effect of urea levels on effluent losses in corn silages was observed. In parallel, an increasing linear effect of urea levels on pH, increasing from 3.49 to 4.12 in silages without urea in relation to silages with the maximum urea level, was also observed. Urea addition improved the aerobic stability of the silages, with 62 h for the silages without urea and from 90 to >96 h for the silages with urea. Based on the results of the principal components, two groups (I and II) could be distinguished. The most discriminating variables in group I were dry matter (-0.9), pH (-1.2) and lactic acid bacteria (-0.9), while in group II, effluent losses (1.0), ethanol (1.0), acetic acid (0.8) and gas losses (0.8) were most important. The use of urea at inclusion levels of around 2% in corn silage reduced gas losses, improved the nutritive value and promote the aerobic stability of silages

Mixed silages of cactus pear and gliricidia: chemical composition, fermentation characteristics, microbial population and aerobic stability.

The present study aimed to evaluate the chemical composition, profle and fermentative losses, microbial population and the aerobic stability of mixed silages of cactus pear and gliricidia. The treatments corresponded to the addition levels of gliricidia (Gliricidia sepium (Jacq.) Steud), in the silages of cactus pear (Opuntia fcus indica Mill.), at ratios 0%, 25%, 50%, 75% and 100% gliricidia. The data were subjected to analysis of variance and regression to evaluate the efect of the addition levels of gliricidia. The average related to the opening days were compared by the Tukey?s test and the average hours of exposure to air were compared by the Student?s t-test. The addition of gliricidia in cactus pear silage provided a linear increasing efect for pH, crude protein (CP), neutral detergent fbre (NDF), acid detergent fbre (ADF), acid detergent lignin (ADL), neutral detergent insoluble protein (NDIP), and increased aerobic stability (AS). The highest dry matter recovery was estimated in the silages with 58% gliricidia. Based on the fermentative, chemical composition and silage losses, all the silages tested were adequate. However, considering aerobic stability, the addition of at least 25% gliricidia is recommended to provide the animal a feed with important quality and high nutritional value

Effect of various salt concentrations on the ruminal parameters of goats.

The objective of this study was to evaluate the effects of various concentrations of sodium chloride (NaCl), magnesium chloride (MgCl2), and calcium chloride (CaCl2) on the growth and in vitro fermentation of cellulolytic, glycolytic, and amylolytic microorganisms from the rumen of a goat. Six concentrations of each salt were tested separately, namely 0 mg/dL, 100 mg/dL, 200 mg/dL, 400 mg/dL, 800 mg/dL, and 1600 mg/dL in the culture medium. The experiments were conducted in a completely randomized design, in a 6 x 3 factorial arrangement of salt concentration and substrate (starch, cellulose, and glucose) with three replications of each treatment combination. Concentrations of microbial protein, ammonia (NH3-N), and volatile fatty acids (acetate, propionate, and butyrate) were measured. A quadratic effect of CaCl2 concentration on the production of microbial protein was observed in the cellulose medium. The effect of MgCl2 on NH3-N production in the cellulose medium decreased linearly. Propionate concentration decreased linearly with increasing levels of NaCl and MgCl2 in the media containing starch. There was a decreasing linear effect of MgCl2 on the concentration of butyrate in the media containing glucose. In conclusion, concentrations of NaCl and CaCl2 up to 1,600 mg/dL did not affect the microbial activity of starch, cellulose, and glucose-fermenting organisms. However, the microbial activity of starch-fermenting microbes was inhibited at salt concentrations above 800 mg/dL. Thus, brackish water could be used by goats in semiarid regions, but its use should be managed carefully so that it does not have a negative impact on rumen microbial populations

Isolation and identification of lactic acid bacteria in fresh plants and in silage from Opuntia and their effects on the fermentation and aerobic stability of silage.

The current study aimed to select the strains of lactic acid bacteria (LAB) isolated from forage cactus plants and silage and assess their effects on silage fermentation and aerobic stability. Forty wild isolates from plant and cactus silage, classified as LAB, were evaluated for metabolite production and identified by 16S ribosomal DNA sequencing. These wild isolates were identified as Lactobacillus plantarum, Weissella cibaria, Weissella confusa and Weissella paramesenteroides and the LAB populations differed among the silage. The use of microbial inoculants did not influence gas or effluent losses in forage cactus silage. The silage inoculated with the microbial strain GP15 showed the highest number of LAB populations. The amounts of water-soluble carbohydrates (WSC) and ammonia nitrogen differed among the silage. The silage inoculated with the GP1 strain presented the highest WSC. Populations of enterobacteria and yeasts and moulds were below the minimum detection limit (<2.0 log cfu/g silage) in all the silage studied. The predominant action of inoculants was to maximize dry matter recovery of the silage, which could be the criterion adopted to select the strains of LAB for use as inoculants in Opuntia silage

PCR identification of lactic acid bacteria populations in corn silage inoculated with lyophilised or activated Lactobacillus buchneri.

This study aimed to evaluate the effect of inoculation with lyophilised and/or activated Lactobacillus buchneri on lactic acid bacteria populations in corn silage. Experimental treatments consisted of corn silage without additives or silage with the inoculants of L. buchneri (1 x 105 cfu/g) applied according to the manufacturer’s recommendations (1 g/tonne fodder) in the forms of the lyophilised inoculant and pre-activated inoculant. Purified isolates from corn silage with and without the inoculant were identified, and 93% of the isolates corresponded to the lactic acid bacteria of the species Lactobacillus plantarum. Among the isolates, no bacteria of the species L. buchneri were detected. The application of lyophilised or activated L. buchneri improved the microbiological profile and reduced ethanol production in corn silage, even without being identified among the isolates captured 70 days after ensilage.On line