1. Activity patterns of free-ranging beef cattle in Norway
Morten Tofastruda, Hilde Hegnesa, Olivier Devineaub and Barbara Zimmermannb
aFaculty of Applied Ecology, Agricultural Sciences and Biotechnology, Department of Agricultural Sciences, Inland Norway University of Applied Sciences, Hamar, Norway; bFaculty of Applied Ecology, Agricultural
Sciences and Biotechnology, Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Koppang, Norway
ABSTRACT
The aims of this study were to: 1) build a model to classify cattle activities based on locomotion and neck movement data and 2) study the daily time budget of non-native beef cattle in the boreal forest of
southeastern Norway. We used GPS collars programmed to take positions and activity measures every five minutes on 18 cows during the grazing seasons 2015–17, together with behavioural observations in the
field. The model classified the collar data into Grazing, Low (resting behaviours) and High (other active behaviours) activity with an accuracy of 79.4%. The cows spent 8.1 ± 0.5 (mean ± SD) hours per day
grazing, corresponding to 34% ± 0.5% of their daily time budget. Daily grazing time increased during summer and was longer for lactating than dry cows and at low compared to high stocking density.
KEYWORDS
Activity sensor; cattle; classification tree; GPS; grazing behaviour; Scandinavian boreal forest zone
2. Effects of sensor location during in situ measurements on pH in caecal digesta of the horse, and post-observational treatment of sensor data
J. A. Næsset, K. Hove and R. B. Jensen
Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway
ABSTRACT
Measurements of caecal pH are useful when studying the effect of a ration on the hindgut environment in horses. Frequent in situ measurements of caecal pH have been used to measure short-term
changes in pH. However, this method also results in a large and complex data set. Transient random influxes of alkaline content from the small intestine might result in short-time elevations in caecal pH that
complicates data processing. We used two caecal-cannulated horses fed two different rations in a cross-over design experiment. We compared frequent in situ measurements of caecal pH measured with an
unweighted and a weighted pH electrode. Based on our results, we recommend to use a weighted pH electrode situated in the deeper layers of the caecum compared to an unweighted. If an unweighted
electrode is used, we present a peakdetecting algorithm to eliminate short-time elevation peaks caused by the ileal influx.
KEYWORD S
Cannula; pH logging; hindgut; fermentation
3. Incorporation of observations with different residual error variances into existing complex test-day models
T. J. Pitkänena, E. A. Mäntysaaria, U. S. Nielsenb, G. P. Aamandc, P. Madsend, J.-Å. Erikssone and M. H. Lidauera
aAnimal Genetics, Natural Resources Institute Finland (Luke), Jokioinen, Finland; bThe Knowledge Centre for Agriculture, Cattle, Denmark; cNordic Cattle Genetic Evaluation, Aarhus, Denmark; dCentre for
Quantitative Genetics and Genomics, Aarhus University, Aarhus, Denmark; eVäxa, Eskilstuna, Sweden
ABSTRACT
Automated milking systems (AMS) have become popular on dairy farms. Due to a different test-day recording scheme the variation of test-day observations differ from AMS differ from those of conventional
milking system (CMS). An approach is presented for upgrading the genetic evaluation model for production traits milk, protein and fat yield by including residual covariance matrices for AMS and CMS test-day
observations. Residual variances were found to be 16–37% smaller for milk and protein yields and 42–47% larger for fat yield when recorded under AMS herds compared to CMS herds. Daily heritability was
higher for milk and protein yield and lower for fat yield when traits were recorded under AMS compared to recording under CMS. No difference was found between AMS and CMS in 305-day heritability for milk
and protein yield except for second lactation milk yield. 305-day heritability for fat was lower for all lactations under AMS.
KEYWORD S
Automatic milking system; residual error variance; genetic evaluation model; Nordic Holstein
4. On farm observations to increase genetic gain in breeding schemes for village poultry production – A simulation study
Thinh Tuan Chua,b, John W.M. Bastiaansenb, Elise Norberga,c and Peer Berga,c
aCenter for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University Tjele, Denmark; b Wageningen University & Research, Animal Breeding and Genomics,
Wageningen, The Netherlands; cDepartment of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway
ABSTRACT
To improve genetic gain of breeding programs for village poultry production, breeding schemes with observations obtained in village production systems using individual (VIO) and group recording (VGO) were
examined under different levels of genotype-by-environment-interactions (GxE). GxE was modeled by varying the correlation between traits measured in the breeding station and village environments for
bodyweight ( rg_BW) and egg production ( rg_EP). Relative and absolute genetic gains obtained from VIO and VGO were used for comparison between the schemes. Results showed that village observations
significantly improved genetic gains compared to the scheme without birds tested in the village. The improvement was only slightly larger with individual observations than with group observations. Higher rg_BW
and rg_EP led to lower relative genetic gain, but a higher absolute gain of VIO and VGO. It is recommended to apply a breeding scheme using group recording of village performance when strong GxE in breeding
for village poultry is expected.
KEYWORD S
Breeding scheme; GxE; group recording; stochastic simulation; village poultry
5. Piglet mortality – A parallel comparison between loose-housed and temporarily confi ned farrowing sows in the same herd
Anne-Charlotte Olsson , Jos Botermans and Jan-Eric Englund
Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Alnarp, Sweden
ABSTRACT
In literature, piglet mortality is described as a multifactorial complex influenced by factors as litter size, age and health of the sow, farrowing system, management etc. In this study, a parallel comparison was
made between two farrowing systems; a temporarily confined (TC) (farrowing – 3 days after) versus a loose sow (L). On average, 0.4 more pigs per litter survived until weaning if the sow was temporarily
confined (TC) compared with being loose (L). Cause of death was recorded according to a strict template. Underweight and crushing was the most common causes. For crushing, during 1 –3 days after birth, an
interaction between sow age and farrowing system was observed, with differences between farrowing systems only for intermediate-aged and older sows (>parity 2). There were no significant differences
between systems regarding farrowing duration or number of stillborn pigs, but a significant increase in farrowing problems was recorded for TC-sows.
KEYWORD S
Piglet mortality; farrowing system; temporarily confi ned; loose sows; underweight; crushing
6. Ranking cows’ methane emissions under commercial conditions with sniffers versus respiration chambers
G. F. Difforda,b, D. W. Olijhoeka,c, A. L. F. Hellwingc, P. Lundc, M. A. Bjerringc, Y. de Haasb, J. Lassena and P. Løvendahla
aDepartment of Molecular Biology and Genetics, Center for Quantitative Genetics and Genomics, Aarhus University Tjele, Denmark; bAnimal Breeding and Genomics Centre, Wageningen University Wageningen,
Netherlands; cDepartment of Animal Science, Aarhus University, AU-Foulum Tjele, Denmark
ABSTRACT
This study assessed the ranking of dairy cows using individual-level correlations for methane (CH4) emission on-farm using sniffers and in respiration chambers. In total 20 lactating dairy cows, ten Holstein and
ten Jerseys were recorded using sniffers installed in milking robots for three weeks of lactation and subsequently in respiration chambers (RC) where they were each recorded on three occasions within the RC.
Bivariate linear mixed models were used to determine the individual-level correlations (rI) between sniffer and RC phenotypes as proxies for genetic correlations. Despite differences in feeding and management,
the predicted CH4 production from sniffers correlated highly with RC CH4 production rI = 0.77 ± 0.18 and CH4 breath concentration correlated nearly as well with RC CH4 production rI = 0.75 ± 0.20. These
correlations between sniffers on-farm and RC demonstrate the potential of sniffers measurements as largescale indicator traits for CH4 emissions in dairy cattle.
KEYWORD S
Methane; sniffers; breath concentration; respiration chambers
7. The effect of feed barrier design on displacements during feeding of dairy cows in small herds
K. E. Bøea, G. Hansena and L. E. Ruudb
aDepartment of Animal- and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway; bDepartment of Agricultural Sciences, Inland Norway University of Applied Sciences, Ridabu, Norway
ABSTRACT
The aim of this study was to investigate the effect of feed barrier design on displacements in dairy cows fed only roughage diets in the bunk in small commercial dairy herds. Six Norwegian dairy herds with open
barriers (OB) and six herds with individual headspace barriers (IHB) were randomly selected. Number of displacements and withdrawals without physical contact was somewhat higher, but not significantly
higher, in the IHB herds than in the OB herds but the variation between herds within the type of barrier were very large. The number of pushes and buttings directed towards the front part of the body of cows was
significantly higher in the OB herds than in the IHB herds whereas pushes and butts directed towards the side of cows were significantly higher in the IHB herds than in the OB herds.
KEYWORD S
Feed barrier design; displacements; dairy cows
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