2 resultados para Fertility

em Repositório Científico da Universidade de Évora - Portugal


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Conservation Agriculture (CA) is mostly referred to in the literature as having three principles at the core of its identity: minimum soil disturbance, permanent organic soil cover and crop diversity. This farming package has been described as suitable to improve yields and livelihoods of smallholders in semi-arid regions of Kenya, which since the colonial period have been heavily subjected to tillage. Our study is based on a qualitative approach that followed local meanings and understandings of soil fertility, rainfall and CA in Ethi and Umande located in the semi-arid region of Laikipia, Kenya. Farm visits, 53 semistructured interviews, informal talks were carried out from April to June 2015. Ethi and Umande locations were part of a resettlement programme after the independence of Kenya that joined together people coming from different farming contexts. Since the 1970–80s, state and NGOs have been promoting several approaches to control erosion and boost soil fertility. In this context, CA has also been promoted preferentially since 2007. Interviewees were well acquainted with soil erosion and the methods to control it. Today, rainfall amount and distribution are identified as major constraints to crop performance. Soil fertility is understood as being under control since farmers use several methods to boost it (inorganic fertilisers, manure, terraces, agroforestry, vegetation barriers). CA is recognised to deliver better yields but it is not able to perform well under severe drought and does not provide yields as high as ‘promised’ in promotion campaigns. Moreover, CA is mainly understood as “cultivating with chemicals”, “kulima na dawa”, in kiswahili. A dominant view is that CA is about minimum tillage and use of pre-emergence herbicides. It is relevant to reflect about what kind of CA is being promoted and if elements like soil cover and crop rotation are given due attention. CA based on these two ideas, minimum tillage and use of herbicides, is hard to stand as a programme to be promoted and up-scaled. Therefore CA appears not to be recognised as a convincing approach to improve the livelihoods in Laikipia.

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Este trabalho refere-se às atividades do estágio de Mestrado Integrado em Medicina Veterinária, apresentando-se casuística no âmbito dos planos sanitários e atividade clínica acompanhados. Como tema para discussão optou-se pela avaliação de touros através do exame andrológico. Após revisão bibliográfica analisaram-se dados obtidos pela VetAl (2008- 2012) caracterizando a população dos touros de carne no Sul de Portugal. Dos 184 touros avaliados foram aprovados 72,28 %, aumentando a probabilidade de reprovação tendencialmente com idade. Em parâmetros reprodutivos importantes como perímetro testicular existe influência de: idade (p<0,001), raça (p<0,05) e Pontuação da Condição Corporal (PCC) (p<0,05). Encontraram-se correlações significativas entre parâmetros tais como perímetro testicular e idade (p<0,001; r=0,52), PCC e parâmetros seminais microscópicos (p<0,05) e dos vários parâmetros entre si. O exame andrológico é essencial para estimar o potencial reprodutivo dos touros e importa fomentar a sua realização em Portugal para melhorar os níveis de fertilidade e rentabilidade das explorações; Abstract Rating of bulls’ reproductive potential through breeding soundness evaluation This document reports the activities of the traineeship for the Master in Veterinary Medicine, including the presentation of the number of cases attended during herd health plans and clinical activity. The theme chosen for discussion was bull fertility through breeding soundness evaluation. Data obtained by Vetal (2008-2012) were analyzed, according to the state of the art, with the aim of characterizing beef bulls’ population in Southern Portugal. Out of 184 bulls evaluated, 72,28 % were approved, unsuccessful outcome apparently increases with age. Scrotal circumference was significantly influenced by: age (p<0,001), breed (p<0,05) and Body Condition Scoring (BCS) (p<0,05). Correlations were significant between scrotal circumference and age (p<0,001; r=0,52), between BCS and microscopic semen evaluation parameters (p<0,05) and between these semen evaluation parameters. The breeding soundness evaluation is essential to assess bulls’ reproductive potential and routine performance of this exam should be encouraged in Portugal to improve fertility and herd profitability.