A pressure chamber technique was used to estimate hydraulic root resistance in rough lemon (Citrus jambhiri Lush.) seedlings. The effect of previous water stress on hydraulic root resistance was evaluated. A factorial 3 × 3 design with four replications was established with potted rough lemon seedlings in a growth chamber. Three water‐stress treatments were applied by watering at intervals of 1, 2 and 3 days, and root resistance measurements were made after 6, 12 and 18 days of treatment. Plants that had experienced mild and severe water stress (irrigation interval of 2 and 3 days, respectively) had higher hydraulic root resistances after several drying cycles than those plants irrigated daily. Additional cycles had no significant effect. The increase in root resistance was not due to decreased root growth but apparently to changes in the permeability of the root cell membranes or to increased suberin deposition in the cell walls of the cortical cells. In a short‐term experiment (1 h), temperature strongly affected water flow through rough lemon roots in the range 5 to 35°C. Temperature influenced root membrane permeability, since reduced blow could not be explained by changes in water viscosity.
RESUMO -Objetivou-se propor uma metodologia de análise de sistemas de produção, tomando-se como base o fluxo quantitativo intra-anual e as características qualitativas do leite entregue pelos produtores de leite à indústria. Foram coletados dados referentes a 1.196 produtores de leite durante os anos 2005 e 2006 utilizando-se as variáveis produção mensal; teores de gordura, proteína, lactose e sólidos totais; contagem de células somáticas e contagem padrão em placas. A metodologia de análise utilizada foi a análise de componentes principais e a classificação hierárquica ascendente (tipologia). As variáveis mais importantes na construção do primeiro componente principal (CP1) são os teores de gordura, proteína e sólidos totais do leite, que explicaram 32,5% da diversidade de sistemas de produção e podem ser consideradas indicadores da qualidade nutricional do leite. Na construção do segundo componente principal (CP2), as variáveis mais importantes são teor de lactose, contagem de células somáticas e contagem microbiana do leite, que explicaram 24,04% da diversidade e representam a qualidade higiênica do leite. A distribuição intra-anual da produção não é importante para explicar a diversidade entre as unidades produtoras de leite. Para a tipologia dos sistemas de produção, foram considerados os três primeiros componentes principais, cuja explicação da variabilidade total foi de 70,52%. As 1.196 propriedades rurais produtoras de leite pertencem a 17 grupos de sistemas de produção com características de qualidade do leite próprias.Palavras-chave: análise multivariada, componentes principais, classificação hierárquica ascendente Typology of production systems based on the milk characteristicsABSTRACT -The objective of the study was to propose a methodology of production systems analysis, considering intraannual quantitative flow and the qualitative characteristics of the milk delivered by the farmers to the industry. The data were collected from 1,196 milk producers from 2005 to 2006 using month production variables, fat content, protein, lactose and total solids, counting of somatic cells, and standardized counting in plates. The method of analysis used was the main component analyses and ascending hierarchical classification (typology). The most important variables in the construction of the first principal component (PC1) are fat content, protein and total milk solid contents, which explained 32.5% of the diversity of production systems, and they can be considered as the indicator of milk nutritional quality. In the construction of the second principal component (PC2), the most important variables are lactose content, counting of somatic cells and milk microbial counting, which explained 24.04% of the diversity and represent the hygienic quality of the milk. The intra-annual distribution of the milk production is not important to explain the diversity among milk production units. For the production system typology, it was considered the first three main components whose explanation of the total variability was of...
Animal production systems and agribusiness Full-length research article Typology of dairy production systems that meet Brazilian standards for milk quality ABSTRACT-We aimed to compare the typology of dairy production systems (DPS) that meet Brazilian quality standards with that of non-compliant DPS. Semi-structured questionnaires were applied in 128 DPS located in Santa Izabel do Oeste, Paraná, Brazil (25°49'16" S and 53°29'04" W). In addition, milk quality reports of each DPS were analyzed. Dairy production systems were segregated into two groups: G1-DPS that were in accordance with Brazilian regulations on milk quality, and G2-DPS that did not comply with Brazilian regulations. Exploratory factor analysis was performed on structural, production, and technical variables. Two factors were defined: F1production scale and bargaining power, and F2-autonomy and production control. Groups 1 and 2 were evaluated according to their structural, production, and technical characteristics as well as their F1 and F2 values. A small fraction (6.25%) of DPS met the minimum quality standards for milk. Dairy production systems that comply with quality regulations have larger production scale, higher productivity, and greater autonomy and control of milk production. Consequently, they have better bargaining power with the industry for the marketing of milk.
RESUMO -Foram utilizados 27 cabritos Boer x Saanen (15 machos e 12 fêmeas, 25,75 ± 3,80 kg PV) distribuídos em delineamento inteiramente casualizado para avaliar os os efeitos da substituição de casca do grão de soja (CGS) por grão de milho moído (GMM) sobre o desempenho e a digestibilidade aparente dos nutrientes da dieta. As rações foram compostas de feno de grama-estrela (Cynodon spp.), farelo de soja, milho, casca do grão de soja e minerais, sendo os tratamentos constituídos de 0 (GMM), 50 (CGS50) e 100% (CGS100) de substituição do milho pela casca do grão de soja. O período experimental foi de 42 dias e a digestibilidade dos nutrientes foi determinada utilizando-se a FDN indigestível como indicador. Os tratamentos não diferiram quanto às ingestões de MS, MO e PB, ao ganho de peso médio diário e à conversão alimentar. A utilização da CGS resultou em diminuição dos coeficientes de digestibilidade da MS, MO e PB e aumento dos coeficientes de digestibilidade da FDN e do amido. A digestibilidade in vitro da MS foi maior no tratamento GMM, mas a da parede celular não diferiu entre os tratamentos. A casca do grão de soja apresentou 23,87; 0,19; 55,89 e 20,05% das frações A, B1, B2 e C dos carboidratos e 35,22; 8,19; 31,61; 15,46 e 9,52% das frações A, B1, B2, B3 e C da proteína. A casca do grão de soja, quando utilizada em até 100% de substituição ao milho nas rações, não altera o desempenho de cabritos em crescimento, mas diminui a digestibilidade da MS, MO e da proteína e aumenta a da FDN.Palavras-chave: caprinos, digestão, ganho de peso, subprodutos Effects of replacing ground corn with soybean hulls on performance and apparent digestibility of nutrients in feedlot Boer x Saanen kidsABSTRACT -Twenty-seven Boer x Saanen goat kids (15 males and 12 females) averaging 25.75 ± 3.80 kg of initial BW were used in a completely randomized design to evaluate the effects of replacing ground corn grain (GCG) with soybean hulls (SH) on performance and apparent digestibility of nutrients. Diets contained star grass hay (Cynodon spp.), soybean meal, minerals, and one of the following levels of SH: 0% (GCG diet), 50% (SH50) or 100% (SH100). The experimental period lasted 42 days and indigestible NDF was used as the internal marker to estimate fecal output and apparent total tract digestibility of nutrients. There was no difference among treatments for the intakes of DM, OM, and CP as well as for the average daily gain and feed conversion. Replacing GCG with SH in the diet decreased the apparent total tract digestibilities of DM, OM, and CP and increased those of NDF and starch. The in vitro DM digestibility was greatest on GCG, intermediate on SH50, and lowest on SH100 diet while no significant differences were observed for cell was digestibility across treatments. Performance of growing kids was not affected by replacing all dietary GCG with SH. However, digestibility of DM, OM, and CP decreased while that of NDF increased by including SH on diets of growing kids.
; Ely Mitie Massuda 5 ResumoCom o objetivo de caracterizar 18 sistemas de produção leiteiros quanto à gestão zootécnica e resultados para produção e qualidade do leite, foi conduzido um estudo na região noroeste do estado do Paraná, em cinco municípios. Os dados de gestão dos sistemas foram colhidos via entrevista, orientada pelo método do diagnóstico rápido participativo e os dados da qualidade e produção do leite foram obtidos a partir de amostragens desses sistemas e posteriormente analisados em laboratório. Foram utilizadas para a análise dos dados técnicas de estatística multivariada; Análise de Correspondências múltiplas -ACM e a Análise Classificatória Hierárquica. Obtiveram-se quatro grupos homogêneos de produtores quanto às estratégias de gestão zootécnica influenciando na produção de leite, de acordo com a análise de variância, tendo os grupos como fatores e os indicadores de qualidade e produção como variáveis resposta. Foram detectados diferentes perfis de ação quanto ao manejo da ordenha, estrutura da propriedade, porém as diferenças mais marcantes entre grupos foram quanto ao nível tecnológico e continuidade da atividade em função do perfil etário dos grupos. As ações sobre os grupos (ATER), portanto, devem ser direcionadas ao perfil de cada grupo e não homogeneizadas como é usual, para atingir a todos os sistemas e viabilizá-los. Palavras-chave: Diversidade, variáveis qualitativas, permanência no campo AbstractThere was carried a research with 18 dairy systems aiming typify these farms concerning their zootechnical conduct and comparing that against the production and quality indicators of the milk as a product. The study was placed in northwest Paraná state region, in five municipalities. Data was obtained using DRP -Fast Participative Diagnosis, by means of an interview. Milk was sampled in each farm and analyzed as follows. Data analysis was made using a multivariate techniques Multilple Correspondence Analysis and Cluster's Analysis. Were obtained four homogeneous groups (clusters) concerning to conduct that influenced (p<0,05) the quality and production indicators of the milk. This was obtained using analysis of variance with clusters as factors and milk variables as response variables. There were identified four distinct dairy farmer profiles. These concerning to: general structure of the
Milk production in Brazil is complex, as it depends on a wide base of small-scale producers employing diverse strategies. In recent years, the supply chain has undergone considerable structural changes, increasing the need for knowledge and characterization of milk-production activities. Therefore, the objective proposed in this study was to characterize rural properties according to various aspects of production in order to identify the dairy cattle production systems of Western Paraná. To this end, 735 interviews were conducted through semi-structured questionnaires administered to dairy farmers using a questionnaire tab for the diversity of management practices in production systems. Data were tabulated and processed by SPSS-v.18, using multiple correspondence analysis: ACM and cluster analysis (hierarchical cluster). The first two dimensions grouped 71.9% of the total variance: DIM1 as 49.4% and DIM2 as 22.5%. Using cluster analysis, five distinct and homogeneous groups (G1, G2, G3, G4, and G5) of production systems were formed. These systems shared the common feature of small properties and were supported primarily by manual labor performed by family members. It is concluded that various milk producing groups exist in the city, with respect to the characteristics of production systems: ownership structure, squad, and how producers mobilize and act on the factors of production. The typology carried out from these characteristics demonstrates a useful tool for action and technical assistance in developing strategies for the industry. Key words: ACM, management, property, questionnaire ResumoA produção de leite no Brasil é de natureza complexa, pois depende de uma base constituída de elevado número de produtores de baixa escala de produção e grande diversidade de estratégias. Nos últimos anos, essa cadeia produtiva tem sofrido consideráveis modificações estruturais, aumentando a necessidade do conhecimento e caracterização da atividade. Desta forma, o objetivo proposto neste estudo foi caracterizar propriedades rurais segundo aspectos produtivos a fim de identificar os diferentes sistemas de produção de bovinos leiteiros do Oeste do Paraná. Para tanto, foram realizadas 735 entrevistas através de questionários semiestruturados, com produtores de leite, utilizando um questionário guia referente às práticas de manejo da diversidade dos sistemas de produção. Os dados foram tabulados e tratados no programa estatístico , utilizou-se a análise de correspondências múltiplas -ACM e análise de conglomerados (cluster hierárquico). As duas primeiras dimensões agruparam 71,9% da inércia, sendo a DIM1 49,4% e a DIM2 22,5%. Utilizando a análise de cluster, formaram-se cinco grupos distintos e homogêneos (G1, G2, G3, G4 e G5) de sistemas de produção. Esses sistemas tinham em comum serem propriedades de pequeno porte e de apresentarem em sua maioria mão-de-obra familiar. Conclui-se que existem diferentes grupos de produtores de leite no município, com relação às características dos sistemas de produção no que diz respe...
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