Diego Bitencourt de David

Silagem da parte aérea de cultivares de mandioca

Silages of aerial part of three cultivars of cassava were evaluated. The produtive, fermentative, bromatological parameters were determined as well the in vitro digestibility, the mineral elements, the carbohydrates and nitrogen fractions. The experimental design was blocks at random, with three repetitions per treatment, being the results submitted to ANOVA and the averages compared by Tukeyx92s Test to 5% of mistake probability. The cultivar FRITA showed the highest production per unit of area, while the fementative parameters for all cultivars demonstrated silages with good quality. The S 60-10 and Fepagro RS 13 showed the larger contents of crude protein, the FRITA had smaller value of the fraction C of the carbohydrates than S 60-10. Fepagro RS 13 and the S 60-10 showed larger quantities of the fraction A of the protein. Considering that cultivars studied showed differences in some parameters, it is recommended the continuity of evaluations trying to identify cultivars that conciliate larger productivity and nutritional value. The cultivar Fepagro RS 13 presented the best balance between yield and quality for silage making.

Características fenológicas, produtivas e qualitativas de híbridos de girassol em diferentes épocas de semeadura para produção de silagem

The objective of this study was to estimate the effect of three sowing dates: October (early), November (normal) and December (late), on the phenological, yield and qualitative traits of four sunflower hybrids: Rumbosol-91 (forage), M-734 (double purpose), C-11 (double purpose) and BRS-191 (grain) grown for silage making. A 4 x 3 factorial treatment combination (four hybrids x three sowing dates) was allocated in a randomized block design with four replications. The October sowing brought about longer cycle, higher plant height, and smaller seed head diameter and contribution due to the prevailing climatic conditions of lower temperature, insolation and photoperiod during the crop growth period. The Rumbosol-91 and BRS-191 hybrids sowed in November showed higher lodging plus stalk breaking proportion of about 49.6 and 65.7%, respectively. The BRS-191 and M-734 hybrids sowed in December showed higher biomass yields of 39.71 and 43.76 t ha-1 fresh matter and 11.31 and 11.41 t ha-1 drymatter, respectively. While the CP content increased, the NDF, ADF and ADL contents decreased from the stem, to the leaf and to the head plant fractions. The whole plant DM values ranged from 23.2% in the Rumbosol-91 hybrid sowed in November to 47.9% in the C-11 hybrid sowed in December, indicating that the hybrids have differentiated moisture retention capacity at similar physiologic maturity of the culture (R-9 phase). The CP values ranged from 7.0 to 15.7%, an evidence of the high protein content of the culture. The ADL values of the whole plant ranged among 6.5 to 12.4%, with lowest values for the M-734 hybrid sowed in December and C-11 hybrid sowed in October. The M-734 hybrid sowed in December has better relationship among phenology, yield and bromatological composition, traits required for the making of high quality silage.

Composição química, digestibilidade e cinética de degradação ruminal das silagens de híbridos de girassol em diferentes épocas de semeadura

The objective of this trial was to estimate chemical composition, digestibility and ruminal degradation kinetics of silages from four sunflower hybrids: Rumbosol-91 (forage), M-734 (double purpose), C-11 (double purpose) and BRS-191 (grain) sowed in October (early), November (normal) and December (late). A randomized complete block design in a 4 x 3 factorial arrangement (four hybrids x three seeding dates) with three replicates was used. Dry matter values ranged from 23.2 to 43.0%, pH from 4.0 to 5.1, and NH3-N%/TN from [...]The objective of this trial was to estimate chemical composition, digestibility and ruminal degradation kinetics of silages from four sunflower hybrids: Rumbosol-91 (forage), M-734 (double purpose), C-11 (double purpose) and BRS-191 (grain) sowed in October (early), November (normal) and December (late). A randomized complete block design in a 4 x 3 factorial arrangement (four hybrids x three seeding dates) with three replicates was used. Dry matter values ranged from 23.2 to 43.0%, pH from 4.0 to 5.1, and NH3-N%/TN from 5.3 to 16.8%. Ash values increased from October to December ranging from 6.8 to 8.8%. The Rumbosol-91 showed the lowest content of EE and the highest contents of N in the cell wall, unavailable N and total carbohydrates (TC). Crude protein contents increased from October to December while the opposite was observed for TC. November sowing and the C-11 gave the lowest contents of NDF, NDFcp and ADF. The C-11 sowed in November gave the lowest ADL values. October sowing and the Rumbosol-91 gave the highest content of ADL%/NDF. The Rumbosol-91 gave higher IVDMD and IVNDFD. November sowing and the C-11 and M-734 hybrids gave the highest value of TDN. Only one degradation profile was necessary to fit DM disappearance data. The proportion of undegradable NDF (I) increased from October to December sowing, being the BRS-191 sowed in December gave the highest values. The extent (Vf1) and rate (k1) of degradation of soluble fractions of rapid digestion decreased from October to December sowing, being the Rumbosol-91 sowed in October gave the highest values. The overall nutritive value measured by chemical composition, digestibility, total digestible nutrients and ruminal degradation kinetics was better for the M-734 and C-11 hybrids sowed in November.

Faecal index to estimate intake and digestibility in grazing sheep

SUMMARY The current research was carried out to evaluate the use of crude protein and fibre components in faeces for estimating intake and digestibility in sheep fed with pearl millet (Pennisetum americanum (L.) Leeke). The equations were developed from four trials in metabolism cages with 16 sheep in each trial. Eachanimal received a different quantityof millet leaves in the diet: 0·015, 0·020 and 0·025 dry matter (DM) as a proportion of liveweight (LW) and ad libitum with at least 0·2 of daily feed refusals. Organic matter intake (OMI, g/day) was measured, through the difference between offer and refusals; total faeces were collected for 5 days, which was used to determine faecal crude protein (CPf, g/day and g/kg of organic matter (OM)), faecal neutral detergent fibre (NDFf, g/day and g/kg OM), faecal acid detergent fibre (ADFf, g/day and g/kg OM) and OM digestibility (OMD). Linear regression equations were calculated to determine the relationship between OMI and CPf (P<0·001, R 2 =0·90, relative prediction error (RPE=14·02%). A multiple linear equation was generated for OMI including CPf and NDFf (P<0·001, R 2 =0·94; RPE=9·25%). Hyperbolic (single and multiple) and exponential models were tested to estimate OMD, where the hyperbolic multiple model including CPf and NDFf showed lower RPE (3·90%). These equationsforestimatingOMIandOMDwereevaluatedonsheepgrazingP.americanumfertilized withincreasing levels of nitrogen (N) (50, 100, 200 and 400 kg N/ha), comparing measured and estimated OMI. The intake estimated by multiple regression (CP and NDFf) showed a higher R 2 (0·98) and lower RPE (5·25%) than the simple (CPf only) linear equation (R 2 =0·94; RPE=20·45%). The results demonstrated the feasibility of using the faecal index generated in metabolism cages for estimating intake and digestibility in sheep grazing P. americanum.

Nutritional value of black and white oat cultivars ensiled in two phenological stages

Avaliaram- se a producao das culturas, a qualidade fermentativa e o valor nutricional da silagem de cultivares de aveia- branca (Avena Sativa L.) e aveia- preta (Avena Strigosa Schreb) submetidas ao corte em dois estadios de maturacao. O delineamento experimental foi de blocos ao acaso, num arranjo fatorial 4 x 2, composto por quatro cultivares de aveia (dois de aveia- preta: Comum e UTFP 971; e dois de aveia- branca: ER 91156- 121 e SI 98105- b), com quatro repeticoes. Os cultivares foram ensilados nos estadios de floracao e grao pastoso. O corte da aveia no estadio de grao pastoso, sobretudo dos genotipos de aveia- branca, possibilita obter silagem de maior qualidade, tanto produtiva quanto qualitativa. O cultivar, o genotipo e o estadio de maturacao influenciam o fracionamento das proteinas e dos carboidratos de silagens de aveia.