• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Doctoral Thesis
DOI
10.11606/T.74.2012.tde-04072012-110329
Document
Author
Full name
Monalissa de Melo Stradiotto
Institute/School/College
Knowledge Area
Date of Defense
Published
Pirassununga, 2012
Supervisor
Committee
Negrão, João Alberto (President)
Dellova, Deise Carla Almeida Leite
Domingues, Paulo Francisco
Melo, Mariza Pires de
Paiva, Fernanda Alves de
Title in Portuguese
Respostas fisiológicas, produtivas e comportamentais de ovelhas Santa Inês submetidas a manejos considerados estressantes e desempenho de seus cordeiros
Keywords in Portuguese
Comportamento
Cortisol
Estresse
Peso ao desmame
Qualidade do leite
Abstract in Portuguese
Com o objetivo de avaliar a susceptibilidade de ovelhas ao estresse e a relação com a produção de leite, 50 fêmeas da raça Santa Inês foram submetidas durante 2 lactações sucessivas a quatro situações de estresse (1: estresse fisiológico padrão via administração de ACTH; 2: desmame; 3: primeira ordenha; 4: mudança de ordenhador). Foram avaliadas as respostas fisiológicas, produtivas e comportamentais das ovelhas e o comportamento e ganho de peso dos cordeiros. Na 1ª lactação, os cordeiros foram desmamados com 60 dias de idade e, na 2ª de acordo com os tratamentos: 1º Grupo com 60 dias de idade e o 2º Grupo com 45 dias de idade. A maior parte das ovelhas estudadas foi considerada medianamente susceptível ao estresse, portanto não foi possível classificá-las estatisticamente, pois poucos animais foram considerados muito ou pouco susceptíveis. Após a administração de ACTH e estresse de primeira ordenha, o cortisol apresentou as maiores concentrações aos 60 minutos sendo que após cinco horas as concentrações basais foram restabelecidas. Porém, após o desmame, o cortisol permaneceu elevado, apresentando maiores valores no grupo desmamado aos 45 dias (P<0,05). A mudança de ordenhador causou estresse e promoveu posteriormente maior liberação de cortisol (P<0,05). O comportamento observado na sala de ordenha foi correlacionado positivamente com o tempo de ordenha, produção de leite e reatividade, pois alguns animais apresentaram comportamento mais agitado e reativo na ordenha, com maior frequência de coices, sobre-passos e micção. A produção de leite foi significativamente maior (P<0,05) na segunda quinzena de lactação e a duração da lactação foi estimada em 75 dias. Para ambas as lactações, os teores de sólidos totais, gordura, lactose, minerais e proteína aumentaram (P<0,05) ao longo do período. Nas duas lactações, as frequências dos comportamentos materno-filiais observados diminuíram com o passar dos dias, em função do maior interesse pela alimentação sólida em detrimento ao leite. Não houve influência da lactação e nem da idade a desmama nos pesos dos cordeiros ao parto e a desmama (P>0,05), e as ovelhas recuperaram o peso corporal algumas semanas após o parto.
Title in English
Physiological, productive and behavioral responses of Santa Inês ewes subjected to stressful managements and performance of their lambs
Keywords in English
Behavior
Cortisol
Milk quality
Stress
Weaning weight
Abstract in English
With the objective to evaluate the susceptibility of ewes to stress and its relation to milk production, 50 Santa Ines females were submitted to four stressful challenges during two successive lactations (1: standard physiological stress through ACTH administration; 2: weaning; 3: first milking; 4: change of milker). In ewes, it were evaluated the physiological, productive and behavioral responses and in lambs behavioral responses and weight gain. In first lactation, lambs were weaned with 60 days of age and in the second according to the treatments: 1st Group with 60 days of age and the 2st Group with 45 days of age. Most of the studied ewes were considered median susceptible to stress, therefore, it was not possible to classify them statistically, as few animals were considered high or low susceptible. After ACTH administration and first milking stress, cortisol level presented the highest concentrations at 60 minutes and after 5 hours, basal concentrations were reestablished. However, after weaning, cortisol level remained high, presenting the greatest values in the weaned group at 45 days (P<0.05). The change of milker caused stress and later promoted higher cortisol release (P<0.05). The behavior observed in milking parlor was positively correlated with time of milking, milk production and reactivity, as some animals presented more restless behavior and reactive during milking with higher frequency of kicks, pawing and urination. Milk production was significantly higher (P<0.05) in the second fortnight of lactation and the duration of lactation was estimated in seventy five days. For both lactations, the contents of total solids, fat, lactose, minerals and protein increased (P<0.05) along the period. In both lactations, the frequencies of maternal-offspring behaviors observed decreased along the days, in function of higher interest for solid feed in detriment of milk. There was no influence of lactation and age at weaning in lambs weight at birth and at weaning (P>0.05) and ewes recovered body weight some weeks after birth.
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
DO6321569COR.pdf (1.96 Mbytes)
Publishing Date
2012-07-10
 
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
Centro de Informática de São Carlos
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2021. All rights reserved.