This article was downloaded by: [University of Florida] On: 17 February 2015, At: 03:14 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
British Poultry Science Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/cbps20
Incidence of non‐laying in domestic hens a
P. D. Lewis & S. E. Long
a
a
Department of Animal Husbandry , University of Bristol, School of Veterinary Science , Langford House, Langford, Bristol, BS18 7DU, England Published online: 08 Nov 2007.
To cite this article: P. D. Lewis & S. E. Long (1992) Incidence of non‐laying in domestic hens, British Poultry Science, 33:2, 289-295, DOI: 10.1080/00071669208417467 To link to this article: http://dx.doi.org/10.1080/00071669208417467
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/ terms-and-conditions
British Poultry Science (1992) 33: 289-295
INCIDENCE OF NON-LAYING IN DOMESTIC HENS P. D. LEWIS AND S. E. LONG Department of Animal Husbandry, University of Bristol, School of Veterinary Science, Langford House, Langford, Bristol BS18 7DU, England
Downloaded by [University of Florida] at 03:14 17 February 2015
Received for publication 9th July 1991
Abstract 1. Egg production records of 31 455 individually caged hens, 27 to 34 weeks of age and of 4 genotypes, were examined. 2. Sixty-nine non-layers were identified in the 30 to 40 week age group, and examined post mortem; an incidence of 2.1 per 1000. 3. Some of the 69 individuals had more than one abnormality. Fortytwo percent were internal layers, 34% had some form of neoplasia, 24% had an abnormal or diseased oviduct, 18% were sex reversals, 16% had a diseased ovary, 8% were of poor condition and considered culls, and 7% were in good condition, but with small, immature ovaries. 4. Of 54 birds not in lay at 27 weeks, 43 (80%) had come into lay by 34 weeks of age. 5. Genotype influenced the incidence of neoplasia and, in turn, the number of non-layers. INTRODUCTION
Under commercial management conditions most laying birds are either kept as flocks or in multi-bird cages. As a consequence, individuals which fail to come into lay, or commence laying abnormally late, go undetected. The mean age at 50% egg production of domestic hens entered in European Random Sample Tests in 1985 and 1986 was 22.1 weeks (155 d, Jones, 1989). However, data from individually-caged birds at Bristol University showed that some hens started egg laying at much later age (Lewis and Perry, 1989). The present investigation was designed to estimate the incidence and aetiology of non-laying in egg laying stock. MATERIALS AND METHODS
Thirty-one thousand four hundred and fifty-five individually caged brownegg hens, aged between 27 and 34 weeks, and housed on two progeny testing farms in Hungary, were used in the investigation. The birds were of 4 different genotypes; AB, BA and CX hybrids located on farm A, and DD pure line 289
Downloaded by [University of Florida] at 03:14 17 February 2015
290
P. D. LEWIS AND S. E. LONG
located on farm B, but kept under similar management conditions and represented on all cage tiers. Egg production records were kept of individual birds. Birds aged 30, 31 and 34 weeks (houses A2, A3 and Bl), whose records showed that no eggs had been laid, were slaughtered by cervical dislocation, and examined post mortem. Tissue samples were taken and fixed in formalsaline for histological examination. Histological preparations were made from standard paraffin wax embedded samples, cut at 5 {im, and stained with haematoxylin and eosin. The birds in house Al, which were 27 weeks of age when records were examined initially, were left in the cages and their records examined again at 34 weeks of age. These birds were not examined post mortem. Data on the incidence of non-laying on farm A were classified to house and genotype, and those for genotypes AB and BA subjected to an analysis of variance, using house and genotype as two variables. Significance was indicated by a probability of
British Poultry Science Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/cbps20
Incidence of non‐laying in domestic hens a
P. D. Lewis & S. E. Long
a
a
Department of Animal Husbandry , University of Bristol, School of Veterinary Science , Langford House, Langford, Bristol, BS18 7DU, England Published online: 08 Nov 2007.
To cite this article: P. D. Lewis & S. E. Long (1992) Incidence of non‐laying in domestic hens, British Poultry Science, 33:2, 289-295, DOI: 10.1080/00071669208417467 To link to this article: http://dx.doi.org/10.1080/00071669208417467
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/ terms-and-conditions
British Poultry Science (1992) 33: 289-295
INCIDENCE OF NON-LAYING IN DOMESTIC HENS P. D. LEWIS AND S. E. LONG Department of Animal Husbandry, University of Bristol, School of Veterinary Science, Langford House, Langford, Bristol BS18 7DU, England
Downloaded by [University of Florida] at 03:14 17 February 2015
Received for publication 9th July 1991
Abstract 1. Egg production records of 31 455 individually caged hens, 27 to 34 weeks of age and of 4 genotypes, were examined. 2. Sixty-nine non-layers were identified in the 30 to 40 week age group, and examined post mortem; an incidence of 2.1 per 1000. 3. Some of the 69 individuals had more than one abnormality. Fortytwo percent were internal layers, 34% had some form of neoplasia, 24% had an abnormal or diseased oviduct, 18% were sex reversals, 16% had a diseased ovary, 8% were of poor condition and considered culls, and 7% were in good condition, but with small, immature ovaries. 4. Of 54 birds not in lay at 27 weeks, 43 (80%) had come into lay by 34 weeks of age. 5. Genotype influenced the incidence of neoplasia and, in turn, the number of non-layers. INTRODUCTION
Under commercial management conditions most laying birds are either kept as flocks or in multi-bird cages. As a consequence, individuals which fail to come into lay, or commence laying abnormally late, go undetected. The mean age at 50% egg production of domestic hens entered in European Random Sample Tests in 1985 and 1986 was 22.1 weeks (155 d, Jones, 1989). However, data from individually-caged birds at Bristol University showed that some hens started egg laying at much later age (Lewis and Perry, 1989). The present investigation was designed to estimate the incidence and aetiology of non-laying in egg laying stock. MATERIALS AND METHODS
Thirty-one thousand four hundred and fifty-five individually caged brownegg hens, aged between 27 and 34 weeks, and housed on two progeny testing farms in Hungary, were used in the investigation. The birds were of 4 different genotypes; AB, BA and CX hybrids located on farm A, and DD pure line 289
Downloaded by [University of Florida] at 03:14 17 February 2015
290
P. D. LEWIS AND S. E. LONG
located on farm B, but kept under similar management conditions and represented on all cage tiers. Egg production records were kept of individual birds. Birds aged 30, 31 and 34 weeks (houses A2, A3 and Bl), whose records showed that no eggs had been laid, were slaughtered by cervical dislocation, and examined post mortem. Tissue samples were taken and fixed in formalsaline for histological examination. Histological preparations were made from standard paraffin wax embedded samples, cut at 5 {im, and stained with haematoxylin and eosin. The birds in house Al, which were 27 weeks of age when records were examined initially, were left in the cages and their records examined again at 34 weeks of age. These birds were not examined post mortem. Data on the incidence of non-laying on farm A were classified to house and genotype, and those for genotypes AB and BA subjected to an analysis of variance, using house and genotype as two variables. Significance was indicated by a probability of
