Jocélio dos Santos Araújo

Soil microbial biomass in an agroforestry system of Northeast Brazil

Agroforestry systems (AFS) are considered alternative land use options to help prevent soil degradation and improve soil microbial biomass and organic C status. However, it is unclear how different densities of babassu palm [ Attalea speciosa (syn. Orbignya phalerata )], which is an important tree in Northeast Brazil, affect the soil microbial biomass. We investigated the soil microbial biomass C and activity under AFS with different densities of babassu palm associated with Brachiaria brizantha grass. Soil microbial biomass C (MBC), soil microbial biomass N (MBN), MBC:total organic C ratio, fluorescein diacetate hydrolysis and dehydrogenase activity showed highest values in plots with high density of babassu palm. On the other hand, the respiratory quotient (qCO 2 ) was significantly greater in plots without babassu palm. Brachiaria brizantha in monoculture may promote C losses from the soil, but AFS with high density of babassu palm may increase the potential of soils to accumulate C. Keywords: Enzyme activity, tropical soil, babassu palm, silvopastoral system, soil quality. DOI: 10.17138/TGFT(3)41-48

Características de carcaça e peso de vísceras em suínos alimentados com rações contendo baixos teores de proteína bruta

One experiment was conducted in the Animal Science Department of University of Lavras (UFLA) to evaluate the effects of rations with low crude protein, supplemented with essential and non essential amino acids, in carcass characteristics and weight visceral organs of swine of the 32 to the 57kg. Thirty crossbred barrows were divided in five treatments that had consisted of rations with different crude protein (CP) levels (10; 12; 14; and 16%). A fifth treatment added to non essential aminoacid in the ration with less CP level (10+NNE) was included. After it slaughter visceral organs had been removed, emptied and weighed. The nitrogen consumption did not influence (P>0.05) the weight of the liver, pancreas, kidneys and heart. The weight of the total gastrointestinal tract and the weights of the TGI plus organs have been bigger (P<0.05) in treatments 14 and 16 in comparison with treatments 10+NNE and 10. It is concluded that crude protein level does not has effect in the weight of viscera intestines, but modifies the weight of the gastrointestinal tract of growing swine.

Predição do conteúdo de aminoácidos essenciais do grão de milho

An experiment was conducted to evaluate the relationship between amino acids and nitrogen fractions of corn grain (Zea mays L.) and verify whether it is possible to use such relations to estimate amino acid contents. Forty five samples of corn hybrids cultivated in West of the State of Parana were obtained and grouped in three categories according to the level of crude protein (low, medium and high). Afterwards, a random sub-sample was taken from each of the previous categories, resulting in a sub-sample of 15 corn hybrids that were taken out and submitted to amino acid and non-protein nitrogen (NNP) analysis. The content of corrected crude protein (CCP) was obtained by reducing the NNP concentration of CP values. The relation between variables was studied by Pearson Correlation and lineal regression models adjusted by the minimum square method. The angular coefficients of the first limiting amino acids for birds and swine (lysine, methionine and threonine) were positive and significant (LYS=0.1080+0.0140CP, R2=0.39; MET=0.1015+0.0084CP, R2=0.43, THR=0.1268+0.0184CP, R2=0.51). However, the determination coefficients of equations were lower than 0.51, showing that CP explains only part of the variation in the amino acid content of corn grain. The prediction of limiting amino acids did not improve when CCP was used as an independent variable. Based on the regression analysis, it is not possible to estimate precisely the content of essential amino acids of corn grain using as independent variables crude protein or corrected crude protein.

Increasing levels of concentrate digestibility, performance and ingestive behavior in lambs

The objectives of this research were to determine the effects increasing levels of concentrate on nutrients digestibility, performance, economic viability of diets and ingestive behavior of lambs. Fifteen crossbred lambs were used in a randomized complete block design according to initial body weight and age. Lambs were penned individually during 55 days, being 10 days for adaptation of diets and 45 days for data collection. The treatments consisted in three isonitrogenous diets with increasing levels of concentrate: 40, 60, or 80%, in dry matter basis. No effect (P>0.05) were observed on dry matter intake, crude protein intake, crude protein digestibility and neutral detergent fiber digestibility, whereas the dry matter digestibility was lower (P<0.01) for lambs fed diets with 40% of concentrate. The addition of 80% concentrate decreased (P<0.05) neutral detergent fiber intake, however this treatment provided higher average daily gain, followed by 60 and 40% of concentrate. In relation to feeding behavior, the animals fed80% concentrate spent more time with feeding (P<0.05) compared to the other treatments. It is concluded that supplementation of concentrate between 60 to 80% improves dry matter digestibility and performance of crossbred lambs without relevant affect dry matter intake and ingestive behavior. A diet with 80% concentrate provides positive gross margin of profit.

Características químicas e valores energéticos de farelos de soja do oeste e sudoeste do Paraná

Foi realizado um estudo para determinar a variabilidade de caracteristicas quimicas e valores energeticos de farelos de soja (FS) do oeste e sudoeste do Parana. Foram estudadas 40 amostras colhidas em 10 processadores e distribuidores durante quatro meses consecutivos. Houve diferencas (P<0,05) entre os teores de materia seca (MS) dos farelos de soja (FS) analisados. O FS 10 apresentou menor (P<0,05) teor de MS (86,72%) em relacao aos FS 2, 4, 5, 6 e 9 (88,96, 90,60, 89,19, 89,08 e 88,72%, respectivamente). O FS 4 teve menor conteudo de Ca (0,31%), enquanto os FS 5 e 7 mostraram os maiores teores de Ca (0,36 e 0,36%, respectivamente). Ocorreram diferencas (P<0,05) entre os valores de energia metabolizavel verdadeira (EMVn) calculados, com o FS 8 apresentando a maior concentracao (2,65Mcal kg-1) e os FS 5 e 10 os menores teores de energia calculados (2,51 e 2,50Mcal kg-1, respectivamente). Pode-se concluir que a composicao quimica dos farelos de soja das regioes oeste e sudoeste do Parana apresenta pouca variacao e, exceto para a fibra em detergente neutro, fibra em detergente acido, ferro e manganes, os valores encontrados sao proximos daqueles citados na literatura.

The physiological response, feeding behaviour and water intake of feedlot lambs supplemented with babassu oil or buriti oil

ABSTRACT The objectives in this experiment were to compare the effects of adding babassu oil or buriti oil in the diet of sheep on physiological response, feeding behaviour and water intake. Twenty-one lambs (24.6 ± 3.8 kg BW, mean ± SD) were distributed in an unbalanced randomized block design, using three diets: (1) basal diet without added oil (Control, CON); (2) 4% FA.kg−1 DM of babassu oil (BAO) and (3) 4% FA.kg−1 DM of buriti oil (BUO), containing 30% roughage. The addition of vegetable oil to the diet did not change the body temperature and rectal temperature; however, BAO decreased (P < 0.05) the respiratory rate. Additionally, BAO decreased (P < 0.05) dry matter (DM) intake, but did not affect: feeding, rumination and idle activities. The diets supplemented with vegetable oils reduced the efficiency of rumination of DM and neutral detergent fibre (NDF), the total water ingested, water intake per kg of DM and total water intake per kg of DM intake. Therefore, diets supplemented with vegetable oil modified the rumination efficiency and decreased the water intake of lambs in feedlots, especially with the addition of BAO with higher saturated fatty acids; it reduced the DM intake and respiratory rate.

PRODUÇÃO DE FORRAGEM E CARACTERÍSTICAS MORFOFISIOLÓGICAS DO CAPIM-MULATO CULTIVADO EM LATOSSOLO DO CERRADO EM FUNÇÃO DE DOSES DE NITROGÊNIO E POTÁSSIO

The maintenance and productivity of forage plants may have their efficiency maximized bynincreased use of fertilizers. In this sense, this work aimed to determine the influence of combinations of thesennutrients in the productive (forage production, tillering and leaf area estimates) and morphophysiologicaln(RSE, NLL, NLT, LBL, LAR, RELB, RLS and LL) characteristics during three stages of growth of Brachiarianhybrida cv. Mulato. The experiment was carried out in a greenhouse at CCAA/UFMA. A completely randomizedndesign with factorial arrangement 4 x 2 (four doses of N and two doses of K) were used, comprising eightntreatments and five replicates, totaling 40 experimental units. The treatments consisted of increasing dosesnof nitrogen: 0, 75, 150 and 225 kg/ha and two levels of potassium fertilization: 20 and 60 kg/ha of K2O. For the production characteristics, in the first cut, there was effect for the production of fodder, in whichnthe behavior of the equation was similar to the doses of 20 and 60 kg/ha of K2O, but the magnitude of responsenwas higher for the dose of 60 kg/ha of K2O, which did not occur to tillering of the grass that regardless ofnthe dose of K, in which the higher the dose of N, greater was the tillering. For the estimation of leaf areanthere was no statistical difference of any factor studied. In the second and third cuts, the total forage yield,ntillering and leaf area were influenced only by rates of N. In all cases, the equations fitted the linear regressionnmodel. Like the production characteristics, the morphophysiological characteristics have different responsesnover the cuts, which show that the management of Mulato grass should not be generalized, because it dependsnon the stage of growth/development of plants. The N influenced positively the productive and morphophysiologicalncharacteristics of Mulato grass being the influence more evident through the supply of 60 kg/ha of K2O.