João Paulo Guimarães Soares

Estimativas de Consumo do Capim-Elefante (Pennisetum purpureum Schum), Fornecido Picado para Vacas Lactantes Utilizando a Técnica do Óxido Crômico

O consumo de materia seca (CMS) de vacas mesticas Holandes-Zebu, fistuladas no rumen, em lactacao, foi medido pela diferenca de peso do alimento oferecido e das sobras e estimado com auxilio do oxido cromico (Cr2O3) pela producao fecal (PF) e indigestibilidade do alimento. O delineamento experimental foi em tres quadrados latinos (3x3) e os tratamentos consistiram de capim-elefante cortado nas idades de 30, 45 e 60 dias. A digestibilidade in vitro da materia seca (DIVMS) foi determinada nas amostras do capim-elefante e estimada a partir do consumo medido diretamente e pela producao fecal obtida com o Cr2O3. A producao fecal foi tambem calculada (PFc) a partir dos valores do consumo (direto) e da DIVMS e foi estimada pela relacao do indicador administrado/indicador excretado. Foram observadas diferencas entre os CMS obtidos nas tres idades de corte do capim-elefante pelos dois metodos avaliados. Os CMS medios obtidos pelo metodo direto foram de 8,00; 10,00 e 11,02 kg/vaca/dia, respectivamente, para o capim cortado com 30, 45 e 60 dias. Os CMS estimados com auxilio do Cr2O3 foram de 9,00; 11,10 e 12,00 kg/vaca/dia, para os mesmos tratamentos. As estimativas de consumo utilizando o Cr2O3 foram superestimadas em 9,25% em relacao aos resultados obtidos pelo metodo direto.

Estimativas do Consumo e da Taxa de Passagem do Capim-Elefante (Pennisetum purpureum Schum.) sob Pastejo de Vacas em Lactação

The voluntary dry matter intake (DMI), rate of passage and mean retention time in the rumen and gastrointestinal tract were estimated using 18 crossbred Holstein-Zebu lactating cows grazing elephantgrass. The voluntary DMI and fecal output estimations the models proposed by QUIROZ et al. (1988) and POND et al. (1989) were used. The data of rate of passage and those of retention time in the rumen the model suggested by GROVUM and WILLIAMS (1973) was chosen. The elephantgrass pasture were fertilized and managed in a rotational system with three days paddock occupation and 30 days resting. The stocking rate was 6 cows/ha. The DMI was estimated using the relation fecal output/forage indigestibility of extrusa samples. For the fecal production calculations, neutral detergent fiber was chromium mordanted. Using the models of POND et al. (1989) and QUIROZ et al. (1988) to compare the total diet DMI (12.5 and 13.9 kg/cow/day) and elephantgrass DMI (7.7 and 9.2 kg/cow/day) they did not differ, respectively. However, the rate of passage and the mean retention time in the gastrointestinal tract did differ among the three used models. The results of this trial showed that the model proposed by QUIROZ et al. (1988) was the one that better describes the DMI data.

A comparative study of production performance and animal health practices in organic and conventional dairy systems

Health and production management strategies influence environmental impacts of dairies. The objective of this paper was to measure risk factors on health and production parameters on six organic and conventional bovine, caprine, and ovine dairy herds in southeastern Brazil over six consecutive years (2006–2011). The organic operations had lower milk production per animal (P ≤ 0.05), lower calf mortality (P ≤ 0.05), less incidence of mastitis (P ≤ 0.05), fewer rates of spontaneous abortions (P ≤ 0.05), and reduced ectoparasite loads (P ≤ 0.05) compared to conventional herds and flocks. Organic herds, however, had greater prevalence of internal parasitism (P ≤ 0.05) than conventional herds. In all management systems, calves, kids, and lambs had greater oocyte counts than adults. However, calves in the organic group showed lower prevalence of coccidiosis. In addition, animals in the organic system exhibited lower parasitic resistance to anthelmintics. Herd genetic potential, nutritive value of forage, feed intake, and pasture parasite loads, however, may have influenced productive and health parameters. Thus, although conventional herds showed greater milk production and less disease prevalence, future research might quantify the potential implications of these unreported factors.

Avaliação Agronômica de Variedades de Cana-de-Açúcar para Fins Forrageiros em Rondônia

The agronomic performance of sugarcane varieties (RB 72-454, RB 78- 5148, RB 73-9735, RB 73-9359, RB 83-5486, SP 71-1406, SP 79-1011, CB 45-3, CB 47-355, NA 56-79 and test) introduced in Rondonia - Brazil was evaluated. It was used a randomized blocks design, with three replications. The plantation was carried out in November of 1999 and the harvesting occurred in June of 2001. The plants presented average height of 3,69 m. The RB 83- 5486 presented smaller height and RB 73-9359 was higher than another varieties. RB 78-5148 presented the largest DM content and RB 72-454 the smallest (P 0.01). The average yield of GM and DM were of 208 and 55 t/ ha, respectively, with RB 73-9735 reaching the largest ones, not being different of RB 72-454, RB 78-5148, RB 71-1406, SP 79-1011, CB45-3, CB 47-355 and NA 56-79 (P>0.01). The plants showed average values of 88.0, 7.0, 4.0 and 1.0% of stems, tip, green and dry leaves, respectively. The varieties RB 73-9735, RB 78-5148, RB 73-9359 and CB 47-355 where presented the best general performance, with regard to forage production, sugar content and steam participation.

Parasitism level by helminths and weight gain of calves kept in organic and conventional grazing

Silva J.B., Fagundes G.M., Soares J.P.G & Fonseca A.H. 2013. Parasitism level by helminths and weight gain of calves kept in organic and conventional grazing. Pes- quisa Veterinaria Brasileira 33(5):586-590. Laboratorio de Imunoparasitologia, Departa- mento de Patologia Veterinaria, Facudade de Ciencias Agrarias e Veterinarias, Universida- de Estadual Paulista (Unesp), Via de Acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, SP 14884-900, Brazil E-mail: jenevaldo@hotmail.com Sustainable production is a principle in which we must meet the needs of the present wi- thout compromising the capacity of future generations. Despite the successful development of pesticides against endo and ectoparasites found in domestic ruminants, these parasites are still the major problem of the herbivore production system. The purpose of this study was to know the population of gastrintestinal parasites and their influence on weight gain of calves kept in organic and conventional grazing. Thus, organic and conventional calves were randomly selected in 2008 and 2009. The fecal egg count (FEC) indentified the follo- wing genders of helminths: Haemonchus, Trichostrongylus, Oesophagostomum, Cooperia, Strongyloides, Trichuris and oocysts of Eimeria. There was no significant difference (p>0.05) between FEC in organic and conventional animals. Calves younger than 6 months showed significant higher infection (p<0.05) than calves between 7 and 12 months of age. The wei- ght gain observed during the study was of 327g/day and 280g/day for conventional and or- ganic systems animals, respectively. Consequently, the combination of sustainable practices of grazing associated with the selective application of anthelmintics may be a feasible alter- native for nematode control in a conventional system and in transition to an organic one.

Impactos ambientais do manejo agroecológico da caatinga no Rio Grande do Norte

O objetivo deste trabalho foi avaliar os impactos ambientais do manejo agroecologico da caatinga, em unidades de producao familiar no Rio Grande do Norte, pelo metodo Ambitec de producao animal - dimensao ambiental, desenvolvido pela Embrapa Meio Ambiente. Foram avaliadas sete unidades de producao familiar, em quatro projetos de assentamentos de reforma agraria do Municipio de Apodi, RN. Os dados para o levantamento foram obtidos por meio de questionarios aplicados aos representantes das unidades produtivas familiares, que atribuiram, a cada variavel estudada, um valor que representou a alteracao proporcionada pela implementacao da tecnologia. Apos a insercao dos coeficientes de alteracao de cada variavel dos indicadores por unidade de producao, o coeficiente de impacto foi automaticamente calculado por meio da planilha Ambitec. O manejo agroecologico da caatinga resultou num impacto ambiental positivo, e suas maiores contribuicoes foram relacionadas aos efeitos positivos dos seguintes indicadores: capacidade produtiva do solo, uso de insumos materiais, qualidade do produto e diminuicao da emissao de poluentes a atmosfera. Dois indicadores geraram efeitos negativos: o uso de energia e o uso de recursos naturais. Pela superioridade dos beneficios gerados, o manejo agroecologico da caatinga e uma inovacao tecnologica geradora de impactos ambientais positivos.

Normativa de Produção Orgânica no Brasil: a percepção dos agricultores familiares do assentamento da Chapadinha, Sobradinho (DF)

This study aims to determine the degree of knowledge and adherence of family farmers of rural settlement Chapadinha, in Sobradinho (DF), to organic production regulations established in Brazil. The research methodology used included open interviews that intended to assess the perceptions and knowledge of the producers on the most important regulations for organic production in Brazil: Law 10831/2003, Decree 6323/2007 and the Normative Instruction 46/2011; these standards had been integrated into three units of analysis: guidelines of systems and production, marketing processes and control mechanisms. The paper points out that the documentation is the biggest bottleneck in smallholder certification process, as these requirements are complex, and there is less training related to the proper understanding of these documents. In relation to the marketing process and control mechanisms it was identified that the producers have a degree of incomplete knowledge related to some of the rules of the parameters related to these aspects, damaging time for certification, requiring greater technical guidance and monitoring.

Degradabilidade ruminal e digestibilidade intestinal da proteína de capim-elefante com três idades de corte

The potential degradability (PD) and intestinal digestibility of ruminal escape protein (IDREP) of elephant-grass at 30, 45, and 60 days of regrowth were determined and the mobile bag technique (in situ) was compared to the three-stage method (in vitro). Thus, six cross-bred steers with rumen and duodenum canulas were used and fed exclusively with chopped elephant grass. The degradability trial was carried out with grass samples incubated in rumen by 3, 6, 9, 12, 24, 48, 72, 96, and 120 h. The intestinal digestibility was determined using 24-h ruminal incubation residue. In the in situ technique, residues in nylon bags were placed in duodenum and recovered in feces. In the in vitro method, residues were digested with solution of HCl-pepsin-pancreatin. In samples of grass at 30, 45, and 60 days of age, the values of protein PD were 87.5, 87.8, and 83.8%, respectively. The IDREP ranged with grass age and it was similar between in situ and in vitro methods only for 60-day old grass. Considering the changes in elephant-grass chemical composition due to aging, the in situ method supplied a more coherent estimative of intestinal digestibility.

Consumo de capim-elefante com diferentes idades fornecido para vacas leiteiras

The 30, 45 and 60 day-old elephant grasses were evaluated by monitoring their nutritional profile and DM (DMI) and NDF (NDFI) intake by crossbred lactating cows in a 3 x 3 Latin square trial, where the split-plots were the rumen evacuation times: 0, 2, 4 and 6 h after meal. Chemical composition, in vitro dry matter digestibility and ruminal content ranged with grass age. Means (in kg/cow/day) of DMI and NDFI of 30 day-old grass (8.0 and 5.3) were lower than those of grasses with 45 days (10.0 and 6.6) and 60 days (11.0 and 7.3). The maximum of rumen fill was observed at 4:22, 3:55 and 3:49 hours after feeding for treatments with 30, 45 and 60 day-old elephant grass, respectively. Rumen fill did not limit the DMI and NDFI of elephant grass, but the dry matter intake of 30 day-old grass may be affected by the wet content.