Dynamics of production and forage utilization on elephant grass pastures managed with different post-grazing heights

This study was conducted to evaluate the daily production of forage and its morphological components, as well as the potential of forage utilization in pastures of Pennisetum purpureum cv. Napier managed with three post-grazing heights (30, 50 and 70 cm). Two experiments were carried out: one from February to May 2009 and another from December 2009 to May 2010, characterizing months of summer and fall. The experimental design was of completely randomized blocks with three replicates. The grazing was performed by crossbred heifers of approximately 270 kg body weight, when the sward intercepted 95% of the incoming light. In both experiments, the pastures managed with post-grazing height of 30 cm, in the summer months (December to March), presented lower daily production of leaves and stems, as well as less daily leaf senescence, which resulted in lower daily forage production and accumulation in comparison with those managed at 70 and 50 cm. In the period from February to March 2009 (experiment 1) and December 2009 to March 2010 (experiment 2), pastures presented greater daily production of leaves and forage, greater daily forage accumulation and more daily leaf senescence in relation to the months of April and May 2009 and 2010. On the other hand, the daily production of stems was higher in the fall, in comparison with the summer. Therefore, elevation in the post-grazing height, especially in the summer, increases the regrowth vigor of elephant grass cv. Napier

Agronomic divergence of sorghum hybrids for silage yield in the semiarid region of Paraiba

The objective of this study was to evaluate the agronomic divergence of 25 sorghum hybrids (Sorghum bicolor L. Moench) in the semiarid region of Paraiba. A randomized block design with three replications was used for evaluation of plant height (PH), total natural matter production (TNMP) and total dry matter production (TDMP) and the percentage of components of DM (panicle, leaf blade, stem and dead matter) of the following hybrids: 866005, 866019, 866033, 866034, 866035, 866036, 866037, 866040, 866041, 866042, 866043, 866044, 870025, 870031, 870035, 870041, 870051, 870067, 870081, 870085, 870095, 1F305, BRS 610, Volumax, and XBS60329. Hybrid 1F305, followed by hybrid 866034, presented the highest average PH. There was a range from 7.679 to 20.948 kg/ha (average of 13,799 kg/ha) for TDMP. Hybrids 1F305, BRS 610 and Volumax presented less potential, and hybrids 866,041 and 866,042 were the most productive. Based on cluster analysis and subjective cut in 50% of dissimilarity, it was possible to establish four hierarchical groups, from which two stood out concerning productive characteristics. The group formed by hybrids Volumax, BRS 610, and XBS60329 presented lower averages for yield and lower percentage of panicle. Hybrids 866041 and 866042 show a higher total dry matter production, with values around 20,000 kg/ha

Avaliação das proporções dos cortes da carcaça, características da carne e avaliação dos componentes do peso vivo de cordeiros Evaluation of carcass cuttings proportion, meat characteristics and evaluation of live weight components of lambs

Objetivou-se, neste trabalho, avaliar a composição física da carcaça, as características da carne e a proporção dos não-componentes da carcaça do peso vivo de cordeiros abatidos aos 28 kg submetidos a diferentes sistemas alimentares. Dezoito cordeiros (Ile de France x Texel ) foram distribuídos aleatoriamente, com as respectivas mães, em três tratamentos: PCA - pastagem cultivada de azevém (Lolium multiflorum Lam.), CON - confinamento sem alimentação privativa e CCF - confinamento com alimentação privativa para os cordeiros. A alimentação privativa foi oferecida aos cordeiros pelo sistema de creep feeding. Não houve diferença para o percentual do pescoço entre PCA, CON e CCF, com valores de 9,27; 9,17 e 8,72%, respectivamente. Para o percentual de perna, os animais da CON (34,02%) e CCF (34,17%) apresentaram valores semelhantes entre si e superiores aos da PCA (31,73%). A maciez medida na porção do Longissimus dorsi entre a 9ª e 12ª costelas foi semelhante entre os animais dos três tratamentos, de 2,33; 3,03 e 3,08 para PCA, CON e CCF, respectivamente. Não houve efeito dos tratamentos sobre a palatabilidade e suculência da carne. O percentual de pele dos animais da PCA (11,05%) e do CON (10,50%) foram semelhantes entre si, enquanto o PCA apresentou valores mais elevados que o percentual dos animais do CCF (9,70%). Para o percentual do conteúdo gástrico, os valores observados para os animais do CCF (11,47%) foram superiores àqueles da PCA (5,09%) e semelhantes aos obtidos para os animais do CON (8,72%).<br>This study aimed to evaluate carcass physical comp0sition, meat characteristics and live weight carcass no component of lambs slaughter at 28 kg under different feeding systems. Eighteen lambs (Ile de France X Texel) were randomly allotted, with their respective mothers, to three treatments: RP - ryegrass pasture (Lolium multiflorum Lam.), COM - confinament of lamb and sheep together and CCF - confinament with creep feeding. A private feeding by creep feeding system was offered for the lambs. There were no difference in the neck percentage among RP, COM and CCf, with values of 9.27, 9.17, and 8.72%, respectively. In relation to the legs, COM (34.02%) and CCF (34.17%) animals expressed similar values and were superior than RP(31.73) animals values. The softness measured in the loin portion (Longissimus dorsi), from 9th to 12th rib was the same in the animals submitted to three treatments: RP, COM and CCF, with respective values of 2.33, 3.03 and 3.08. There were not effects in the treatments according to juiceness (SUC) and taste (TASTE). The skin percentage of RP (11.05%) and COM (10.50%) were no treatment effects to the through the panel, palatability and juiceness. The skin percentages of RP (11.05%) and CON (10.50%) animals were similar, and RP showed higher values than CCF (9.70%). The values of gastric content percentage for CCF (11.47%) animals were higher than the RP animals (5.09%) and showed similar value for CON (8.72%)

Estrutura fitossociológica em área natural e antropizada de uma vereda em Uberlândia, MG Phytosociological structure of natural and disturbed palm swampy vegetation near Uberlândia, MG

O objetivo do estudo foi de comparar a área natural e antropizada de uma vereda quanto à estrutura fitossociológica e às características do solo. O trabalho foi realizado em uma vereda no município de Uberlândia, MG (19º11'40" S e 48º24'31" W). Para as análises químicas foram coletados solos em três profundidades: 0-1 cm, 1-16 cm e 16-32 cm. No levantamento fitossociológico utilizou-se o método transecto de linha. Duas classes de solos foram encontradas: Gleissolo Háplico e Gleissolo Melânico, que tiveram, em média, baixos valores de pH e bases disponíveis. Os maiores percentuais de matéria orgânica e umidade ocorreram no fundo da vereda. Foram amostradas 101 espécies e 29 famílias vegetais. A riqueza de espécies foi menor na vertente preservada. Poaceae, Cyperaceae e Asteraceae foram as famílias que tiveram o maior número de espécies, 33, 13 e 10, respectivamente. Schizachyrium tenerum, Echinolaena inflexa, Loudetia flammida e Erianthus asper tiveram maior frequência no ambiente preservado e Schizachyrium tenerum, Hypogynium virgatum e Ageratum fastigiatum no antropizado.<br>The study aimed to compare the natural and disturbed areas of a palm swamp vegetation according to its soil characteristics and phytosociological structure. The study was done at a site near Uberlândia, MG (19º11'40" S and 48º24'31" W). Chemical analysis was carried out at threes depths: 0-1 cm, 1-16 cm and 16-32 cm. The phytosociological survey was done by the line intercept method. Two classes of soil were found: Relatively Humic Glei and Humic Glei, which had low values of pH and available bases. The highest percentage of organic matter occurred in the lowest depth of the palm swamp area. Some 101 species and 29 families were sampled. The preserved slope had a lower species richness than the disturbed area. Poaceae, Cyperaceae and Asteraceae were the families with the highest number of species, 33, 13 and 10, respectively. Schizachyrium tenerum, Echinolaena inflexa, Loudetia flammida and Erianthus asper were more frequent in the preserved area and Schizachyrium tenerum, Hypogynium virgatum and Ageratum fastigiatum in the disturbed area