| 1. |
- Ahlman, Therese, et al.
(författare)
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Culling reasons in organic and conventional dairy herds and genotype by environment interaction for longevity
- 2011
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 94, s. 1568-1575
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Tidskriftsartikel (refereegranskat)abstract
- Dairy cow longevity combines all functional traits and is thought to be especially important in organic production, which is an established, increasing part of Swedish dairy production, representing approximately 6% of the market. The aim of this study was to compare dynamics in culling reasons between organic and conventional production and to analyze genotype by environment interactions for longevity. The data contained information from all organic herds with information available from official recording (n = 402) and from approximately half of the conventional herds (n = 5,335). Records from Swedish Holsteins (n = 155,379) and Swedish Red cows (n = 160,794) that had their first calf between January 1998 and September 2003 were included. The opportunity period for longevity was at least 6 yr. Six longevity traits were defined: length of productive life; survival through first, second, and third lactations; fertility-determined survival; and udder health-determined survival. Twenty codes were used to describe the cause of culling, and these were divided into 8 groups: udder health, low fertility, low production, leg problems, metabolic diseases, other diseases, other specified causes, and unspecified cause. The main reason for culling cows in organic herds was poor udder health, whereas for cows in conventional herds it was low fertility. Furthermore, the shift in main culling reason from fertility, which was most common in first lactation regardless of production system, to udder health occurred at a lower age in organic production. Heritabilities and genetic correlations for the longevity traits expressed in organic and conventional herds were estimated from a bivariate animal model. The genetic correlations were close to unity (>0.88), except for fertility-determined survival in the Swedish Red breed (0.80). Heritabilities were low to moderate, and no clear pattern was identified for production system or breed. In general, the results indicate that farmers' culling criteria differ between organic and conventional production. Different preferences may influence the need for alternative selection indexes for organic production, with different weightings of traits, or a separate breeding program. However, no genotype by environment interaction of importance was found between the production systems.
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| 2. |
- Ahlman, Therese, et al.
(författare)
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Differences in preferences for breeding traits between organic and conventional dairy producers in Sweden
- 2014
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 162, s. 5-14
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Tidskriftsartikel (refereegranskat)abstract
- Development of sustainable breeding goals for dairy production has to consider the producers' preferences which are likely to differ between production systems. The number of dairy producers with herds certified according to the standards of organic production has increased during the last decades. Traditionally, organic producers use animals selected in conventional production systems but the traits important in organic herds have been suggested to differ due to the different production conditions. The aim of this study was to assess what traits Swedish organic and conventional daily producers consider to be important for the cows in their herds, and the relative importance of traits in the two production systems.An advanced web questionnaire with an underlying selection index was developed. The selection index was not shown to the respondents but it enabled them to weight traits against each other based on the genetic progress obtained. The questionnaire also included questions about what traits the producers intuitively considered important for the cows in their herds and how they ranked 15 given production and functional traits. The questionnaire was answered by 468 Swedish dairy producers of which 122 had a certified organic herd and 346 had a conventional herd.The results of this study show that the trait longevity was ranked first by both organic and conventional Swedish dairy producers. However, the ranking differed to some extent between the production systems for other traits, e.g. mastitis resistance and milk production. Swedish producers with organic herds tended to desire a higher genetic gain in disease resistance, including mastitis and parasite resistance, compared with producers with conventional herds. The results also reflect a somewhat lower interest in milk production level among producers with organic production. However, as the traits most important for Swedish producers with organic herds are already considered in the current Nordic breeding goal they can continue the use of this animal material. (C) 2014 The Authors. Published by Elsevier B.V.
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| 6. |
- Chalkias, Helena, et al.
(författare)
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Genetic analysis of functional and non-functional teats in a population of Yorkshire pigs
- 2013
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 152, s. 127-134
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Tidskriftsartikel (refereegranskat)abstract
- Litter size is included in the goal of most pig breeding programmes. With an increased litter size, the number of functional teats, which are needed to achieve piglet weight gain and uniform litters,becomes increasingly important. The non-functional (e.g. inverted, blind,or small) teats might have a lower value for the nursing of the piglets. In Sweden, within the pig breeding company Nordic Genetics, the total number of teats, as well as the numbers of functional and non-functional teats, are recorded for purebred Yorkshire pigs both at 3 weeks of age (identity marking) and at about 5 months of age (performance testing). In 2010, 13% of the Swedish purebred Yorkshire pigs had at least one non-functional teat at performance testing (100 kg live weight). The aim of this study was to analyse both genetic and phenotypic variation among the teat traits and to analyse the associations among the teat traits,age and side fat thickness at 100 kg live weight. In the phenotypic analyses there were significant differences between males and females for all analysed teat traits. Males showed a higher number of functional teats and females three times more non-functional teats at 100kg live weight. In the genetic analyses there cords for males and females were treated as representing different traits. The estimated heritability of total number of teats and the number of functional teats, both at 3 weeks of age and at 100 kg live weight, was in the range 0.36-0.42. The heritability of the number of non-functional teats at 3 weeks of age was low, 0.02, for both males and females. Surprisingly, at 100 kg live weight, the heritability of non-functional teats was moderate,0.29, for females, but still low, 0.03, formales. Further studies are required to investigate whether there is a biological explanation for this finding, or if there is a difference between the genders in the recording procedure of this trait.The only significant genetic correlation found between the teat traits and performance traits was for male pigs; the genetic correlation for the relationship between the number of non- functional teats at 3 weeks of age and the age at 100 kg was 0.2. Thus, slowly growing pigs have a lower number of non-functional teats. Our results show that the teat number efficiently can be improved by selection. However non-functional teats is a complex trait and further studies need to be performed to investigate the possibilities to improve selection against the non-functional teats.
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| 7. |
- Chalkias, Helena, et al.
(författare)
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Inverted teats (Mammillae invertitae) in gilts - Effect on piglet survival and growth rate
- 2014
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 92, s. 2587-2594
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Tidskriftsartikel (refereegranskat)abstract
- In the modern pig industry, the increasing number of piglets born per litter augments the importance of the number of functional teats in the sow. The aim of this study was to evaluate the function and importance of inverted teats during nursing and to analyze structural and functional differences between the mammary glands of inverted teats versus normal teats. Nine farrowing gilts (8 purebred Swedish Yorkshire gilts and 1 cross between Swedish Yorkshire and Norwegian Landrace) and 94 piglets (59 piglets suckling normal teats, 32 piglets suckling protruded teats [i.e., previously inverted], 2 piglets suckling inverted teats, and 3 piglets suckling considerably smaller teats) were included in the study. Teat fidelity (keeping the same teat between the nursings) was registered, excluding the first 48 h postpartum. Piglet weight was recorded daily during the first week of life and thereafter once a week until weaning at 4 wk of age. Weight and growth rate were analyzed using repeated observation mixedmodel analysis of variance. The 2 piglets that suckled the inverted teats were not able to emerge the teats and they were euthanized 4 and 8 d after birth, respectively, due to loss of BW. The average weight at weaning (28 d of age) was 8.1 kg (range 3.2-13.8 kg). In the normal teats (n = 53), the weight of the corresponding mammary gland tissue at necropsy was positively correlated to the piglet average daily weight gain during wk 2 (r = 0.33, P < 0.05), 3 (r = 0.55, P < 0.001), and 4 (r = 0.47, P < 0.001). In the protruded teats (n = 32), the weight of the corresponding mammary gland tissue was positively correlated to the piglet average daily weight gain during wk 2 (r = 0.63, P < 0.001) and 3 (r = 0.43, P < 0.05). Among the piglets nursing normal teats, 82% kept fidelity to its teat and the corresponding percent for the protruded teats was 26%. In 7 of the 9 sows, the weaning weight of the piglets suckling protruded teats was numerically lower compared to the piglets suckling normal teats, although the difference was not statistically significant. Piglets nursing small teats had lower weaning weight (4.8 kg) and the corresponding mammary tissue also had lower weight (335 g). This study indicates the importance of an adequate number of well-developed and well-functioning teats in healthy sows for the growth and development of the piglets but also emphasizes the complexity of the interaction between the nursing sow and her piglets.
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| 8. |
- Forabosco, Flavio, et al.
(författare)
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An algorithm for the identification of genetically modified animals
- 2013
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Ingår i: Trends in Biotechnology. - : Elsevier BV. - 0167-7799 .- 1879-3096. ; 31, s. 272-274
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The diffusion of genetically modified (GM) animals has generated a demand for accurate and unique identification to assure compliance with relevant national and international legislation. Individual identification of GM animals is essential to improve safety and traceability, as well as to fulfill the present and future expectations of producers, consumers, and authorities.
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| 9. |
- Forabosco, Flavio, et al.
(författare)
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Genetically modified farm animals and fish in agriculture : A review
- 2013
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 153:1-3, s. 1-9
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Forskningsöversikt (refereegranskat)abstract
- Developments in biotechnology over the past 25 years have allowed scientists to engineer genetically modified (GM) animals for use in various areas of agriculture and medicine. The great majority of GM animals and fish are currently only at the research stage. However, some animals with an anticipated use in food production are close to reaching the grocery shelf at least, they will be soon available for marketing. GM livestock include many different kinds of animals and species modified with the intention of improving economically important traits such as growth-rate, quality of meat, milk composition, disease resistance and survival. Pigs have been engineered to grow faster and to produce more meat with less feed; the composition of pork has also been improved for healthier human consumption. Scientists have paid particular attention to pig health, raising piglet survival rates, reducing the risks of infectious disease, and fortifying the porcine immune system. Sheep have been modified to improve wool production and immunity, and to reduce the risk of mortality following infections by bacteria and lethal viruses. Growth-rate in chickens has been increased with only limited success, because conventional selection has already improved this trait close to its biological limit. However, disease resistance (e.g. to H5N1) and the survival of newly hatched chicks have been improved. Udder health and survival are the most important traits improved by transgenic technology in cattle. GM cows with resistance to BSE have been bred. Similar traits are targeted in fish, dominated by salmon, carp and tilapia species, where the focus is on meat production, meat quality, and disease resistance. The number of GM farm animals and fish developed in laboratories is increasing, but for the present the number of species close to entering the market remains small.
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| 10. |
- Forabosco, Flavio, et al.
(författare)
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The current status and future prospects of genetically modified farm animals in Europe
- 2012
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Ingår i: Genomics and Quantitative Genetics. - 2157-9903. ; 5, s. 1-4
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Tidskriftsartikel (refereegranskat)abstract
- A transgenic farm animal is a genetically modified (GM) animal with genetic material that has been engineered using recombinant technology. Over the past 25 years the European Union (EU) has taken a process-based, case-by-case approach to risk assessment. Within the EU today GM organisms are authorized only if they have passed a rigorous safety assessment. Procedures for the release of GM organisms into the environment, and the requirements of evaluation and authorization, are set out in EU Directive 2001/18/EC and Regulation 1829/2003, respectively. Currently the EU's official list of approved genetically modified food, feed and organisms contains 42 registered plants and two GM microorganisms, with the latter recently joining the list. No GM mammals, birds, insects, fish or derived food products of animal origin are on the EU market. The European Food Safety Authority, under the mandate of the EU Commission, is developing an environmental risk assessment procedure for mammals, birds, insects and fish with the aim of assessing the possible direct or indirect, as well as immediate or delayed, risks to human health and the environment. The EU market is closed to GM farm animals, but will soon open for those who pass the environmental risk assessment.
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