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Westensee, Germany

The aim of the study is to get substantial information about the suitability of milk urea content (MUC) as selection trait for reducing the nitrogen excretion of dairy cows. After extensive evaluation of the best suited model genetic variability of MUC and genetic correlations to the most important milk production traits were estimated. Milk recording data of 17,281 first and second parity cows from 1,443 farms of the region Ostfriesland located in the Northwest of Germany were considered. The first calving of all cows was in 2005. MUC, milk, fat, protein and somatic cell score between the 5th and the 330th day of lactation were analysed. The best fitting model for analysis of MUC contains the function of Ali and Schaeffer for describing the general lactation curve. The random regression coefficients of the permanent environmental and additive genetic effects of the cow are best fitted by the Legendre polynomials of third and second degree. Also, heterogeneous residual variances for different lactation stages should be included. Genetic correlations of rg > 0.90 between first and second lactation allow the use of a repeatability model for estimation of variance components and breeding values for MUC. Estimated heritabilities range consistently between 0.13 and 0.23 for both lactations. Genetic correlations between MUC and the yield traits milk, fat and protein are changing with increasing days in milk from slightly negative to slightly positive coefficients (rg = -0.32 to 0.24). In second lactating cows fat and protein content are predominantly positively correlated to MUC (rg = -0.13 to 0.58). For somatic cell score the estimated genetic correlations to MUC are changing after 60 days in milk from negative to positive coefficients (rg = -0,16 to 0.27). Assuming a close genetic relationship between MUC and nitrogen excretion the routinely recorded MUC can be used as a suitable animal specific selection trait for reducing the nitrogen excretion. © Verlag Eugen Ulmer, Stuttgart. Source

Kern G.,University of Kiel | Kemper N.,University of Kiel | Traulsen I.,University of Kiel | Henze C.,University of Kiel | And 2 more authors.
Small Ruminant Research | Year: 2010

The lifetime performance of female sheep is one of the most important economic traits in sheep husbandry. In this investigation, a Weibull model was used to study the effects of 'breed', 'number of lambings', 'age at first lambing', 'type of birth' and 'farm' on the length of productive life (LPL). The data included records of 5191 female sheep of four different breeds on 236 breeding farms in northern Germany. The observation period in which the sheep were born or were removed from the farm ranged from January 2003 to December 2007. About 12% of the records were right-censored. All variables had a significant effect on LPL at a level of p < 0.001 except 'type of birth'. The German Blackheaded Mutton breed showed the lowest risk ratio with 0.77 (SE = 0.17), while the Texel had the highest hazard rate (1.00). The relative culling risk initially decreased from the first (5.73, SE = 0.09) to the seventh lambing (0.36, SE = 0.12), and then increased until lambing number nine. The highest relative culling risk was calculated at an age of 395 to less than 455 days at first lambing (1.00). Animals younger than 395 days at first lambing showed the lowest risk ratio (0.56, SE = 0.05). The culling risk for the effect 'farm' ranged from 0.3 to 3.1. A differentiation of environmental, housing or management effects was not feasible with this data. But the results offer some interesting options for further studies. © 2010 Elsevier B.V. All rights reserved. Source

Scheffler K.,University of Kiel | Stamer E.,TiDa Tier und Daten GmbH | Traulsen I.,University of Kiel | Krieter J.,University of Kiel
Applied Animal Behaviour Science | Year: 2016

Fighting among pigs is a normal behavioural pattern to establish a stable rank order. Enhanced aggressive behaviour in pigs in groups lead to increasing stress and injuries especially in mixing situations used as a common procedure in modern pig production systems. In such systems, it is usually not possible to avoid re-housing with unacquainted conspecifics. Hence, due to the lavish analysis of direct or video observations of the agonistic interactions in such mixing situations, there is a necessity to receive easy measurable and practical indicators for predicting individual agonistic behaviour. Possible indicators are standardised behavioural tests such as the backtest and the human approach test. The backtest was performed twice. In each test, the pigs were laid on their backs and held loosely for one minute (n =1382). The number of escape attempts (NEA) was recorded. In addition to this test, a human approach test was performed four times with weaned pigs (n =1318) and once with gilts (n =272). Here, the stockperson recorded the latency of the pigs to approach and touch the person, i.e. the latency count (LC). The agonistic interactions were recorded in a video observation period of 17h while the traits number of fights (NF) and number of initiated fights (IF) were recorded in mixtures of weaned pigs (n =1111), growing pigs (n =446) and gilts (n=279). The estimations of phenotypic and genetic correlations between these different traits were carried out with animal models in bivariate analyses. The IF trait of weaned pigs and NEA were slightly positively correlated (r g =0.18). Pigs which initiated more fights after weaning had more escape attempts in the backtests. However, there were negative genetic correlations between the agonistic interactions traits NF and IF traits and the NEA backtest trait of growing pigs (r g =-0.14 and r g =-0.28). The genetic relation between the agonistic NF and IF traits of weaned pigs and the human approach test LC trait of weaned pigs were on a medium level (r g =-0.50 and r g =-0.45). The genetic correlations between IF and NF of growing pigs and gilts and the human approach test LC trait in weaned pigs were lower but also negatively correlated. Hence, pigs with more NF and IF in mixing had shorter latencies during the human approach tests. Concluding, the backtest and the human approach test might be able to predict the agonistic behaviour of pigs in mixing situations. Nevertheless, the reliability of the predictions of the behavioural tests depends on the age of the pigs at mixing and the previous experiences of these animals. © 2016. Source

Scheffler K.,University of Kiel | Stamer E.,TiDa Tier und Daten GmbH | Traulsen I.,University of Kiel | Krieter J.,University of Kiel
Applied Animal Behaviour Science | Year: 2014

The most recent development in pig production has focused increasingly on the well-being of the individual pig and animal-friendly housing conditions, i.e. the launch of the group housing of sows in the EU. In this regard, however, standard procedures which may be stressful to the animals and thus have an impact on their health and welfare (i.e. mixing, iron injections, vaccinations) are undertaken in all commercial farm production. Therefore, there is a need to assess individual pig behaviour in such situations and furthermore to take into consideration differences related to age. Hence, in this study, pigs were evaluated for their response to two standardised stress situations-the backtest and the human approach test. The data were collected on one research farm using German Landrace, Large White and crossbred pigs. The backtest (n=1382) was performed on pigs at 12 and 19 days of age and the number of escape attempts (NEA), the duration of escape attempts (DEA) and the latency to the first escape attempt (LEA) were recorded. Additionally, the human approach test was performed four times with weaned pigs (n=1317) and once with gilts (n=272) while recording the latency (LC) of the pigs to touch the human. The heritabilities of the different traits were estimated univariately and correlations between all observed variables were obtained from bivariate analyses with the average information-restricted, maximum-likelihood procedure as implemented in the DMU software package. The random litter effect had the largest impact on the LEA backtest variable (15%). Smaller values for NEA and DEA were obtained. The LEA backtest variable and the LC variable of the human approach test of weaned pigs and gilts were not influenced by the litter effect. The highest heritability was estimated for LEA (h2=0.29) and NEA (h2=0.19), followed by DEA (h2=0.10) and the heritability of the human LC approach test variable of weaned pigs was similar with h2=0.20. However, the heritability of the LC of gilts was low (h2=0.03) but the estimation provide no reliable values due to the small number of gilts. The genetic correlations between LEA and DEA were very high (rp=-0.88). Also, the first and second backtests for all variables were highly genetically correlated (rp=0.69-0.90). This means that the variables and the first and second backtests shared the same genetic base. Therefore, performing just one backtest is sufficient for practical breeding purposes. The genetic correlations between four LC human approach test variables of the weaned pigs were very high (rp=0.65-0.87) especially between consecutive tests. Hence, under practical conditions, the performance of one human approach test might be sufficient since the behaviour shown in all the human approach tests with weaned pigs depended on the same genetic base. The genetic correlations between backtest variables and human approach test variables of weaned pigs and gilts were very low, which indicates that both tests partly measure different behavioural patterns and that the reactions of the pigs in the tests were not related. © 2014 . Source

Stukenborg A.,University of Kiel | Traulsen I.,University of Kiel | Stamer E.,TiDa Tier und Daten GmbH | Puppe B.,Leibniz Institute for Farm Animal Biology | And 2 more authors.
Livestock Science | Year: 2012

The aim of the present study was to estimate heritabilities for different agonistic behavioural traits after mixing female pigs of three age classes and to compare the agonistic behaviour between these age groups. The behavioural patterns were observed over a 48-h period, directly after weaning (PIG-28; n=884), 40 day later (growing pigs, PIG-68; n=351) and immediately after mixing gilts (GILTS; n=389) with an average age of about 242 day. Agonistic interactions were observed by noting the time of the start and finish of the interaction, the identity of the aggressor and receiver and the winner or loser of a fight. Starting from this, the frequency and the time involved were calculated for ten agonistic behavioural traits. Intermediate heritabilities were estimated for growing pigs, with the highest heritability for the number of won fights (h 2=0.37). In comparison, the heritabilities for weaned piglets were at a lower level with the highest heritability for the duration spent in initiated fights (h 2=0.20). Concerning gilts, moderate heritabilities were only found for the number of received aggressions (h 2=0.42), the time spent in received aggressions (h 2=0.15), the number of lost fights (h 2=0.13) and the time spent in lost fights (h 2=0.09). Within all three age groups, the correlations between the numbers of initiated and won fights were stronger than the correlations between the numbers of initiated and lost fights, indicating that pigs which initiated most of their fights also won the majority of their fights. Moderate correlations were found between the behavioural traits of growing pigs and gilts, but the number of relationships between the weaned piglets and older age groups was low. In conclusion, the results indicate that more aggressive growing pigs tend to also become more aggressive gilts. Additionally, the agonistic behaviour of weaned piglets cannot be compared with that of other age groups since the agonistic behaviour of weaned piglets is probably related to playfulness while in older pigs it is related to the establishment of dominance hierarchies. © 2012 Elsevier B.V. Source

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