Browsing by Author "Norrback, Josefin"

Gastrointestinal parasites (GIP) and resistance against anthelmintics are and will be one of the biggest challenges for the sheep husbandry. Research within this area is very important today and it is important to figure out new methods to identify individuals with high burden of parasites and to treat just these individuals. The aim of the study was to investigate the effects of GIP on activity patterns and weight gain in first season grazing lambs. A sub-study accompanied with the aim was to see if the manually made behavioural observations supported data from the sensors. The study took place at the Swedish University of Agricultural Sciences (SLU) during the summer of 2019. The study was divided into two experimental periods. In the first experimental period 30 ewes and their 60 twins were used. Of those, 58 lambs continued to the second experimental period. Two groups were dewormed with ivermectin (high group) and two groups were untreated (low group). All lambs were fitted with sensors, and the data was downloaded once a week, at the same time with the weighting of animals. Individual faecal samples were collected four times. The pasture where the lambs grazed was a first-year pasture. Sward height was measured, and herbage samples were collected three times during the experiment. Herbage samples were analysed for nutritional and mineral content. The manual behavioural observations were made two days a week during five weeks. The high group had higher weight (28.9 kg) in the beginning of the experiment, compared with the low group (28.1 kg). On the contrary, the high group had lower weight (42.7 kg), compared with the low group (44.8 kg) at the end of the experiment. According to data from the sensors there were differences in lying time and motion index (MI) during the 7-10 first days after weaning. The low group laid down more, compared with the high group. The low group had higher MI compared with the high group. During the whole experiment there were no differences in lying time, lying bouts or MI. The manual behavioural observations showed that “standing still” had significantly more registrations for the high group compared to the low group. It is possible to see differences in behaviour with sensors at an early stage of parasitic infection, even with low levels of parasites. This means, that there is a potential to use automatic behaviour observations as a diagnostics tool during infection of GIP.