Epsilon Archive for Student Projects

Abstract

Automatic milking systems (AMS) provide the opportunity for less manual labour and an increased milking frequency. But in order to reach an optimal milking frequency a well-functioning cow traffic is crucial. There are many factors affecting cow traffic but one factor that has not been studied thoroughly yet is the effect of different light intensities during the night, 22.00 h to 05.00 h. Therefore the aim of this study was to determine the effect of different light intensities during the night on number of selection gate passages (GP), milking frequency and milk yield. The study was conducted as a Latin square were three light intensities were applied: LOW (11 ± 3 lux), INT (33 ± 1 lux) and HIGH (74 ± 6 lux), in three different herds. There were in average 69 ± 4 primiparous cows and 133 ± 4 multiparous cows in each treatment. The dairy cows were housed in loose house barns with automatic milking and a Feed First™ cow traffic system. No effect of treatment was found on either number of selection GP per 24 hour and cow or on milking frequency. Only a slight decrease in selection GP per hour and cow during night time was observed when cows were exposed to treatment LOW, but the decreased activity did not affect milking frequency. The effect on milk yield was hard to determine due to disturbance during the experimental period but no differences in milk yield between treatments LOW and HIGH were found.

Automatiska mjölkningssystem kan medföra fördelar som mindre manuellt arbete och en ökad mjölkningsfrekvens. Men för att nå en optimal mjölkningsfrekvens krävs en väl fungerande kotrafik. Många faktorer påverkar kotrafiken men en faktor som inte har studerats är effekten av olika ljusintensiteter under natten, 22.00 h till 05.00 h. Syftet med studien var därför att studera effekten av olika ljusintensiteter under dygnets mörka timmar på antal passeringar genom selektionsgrinden, mjölkningsfrekvens och mjölkavkastning. Studien genomfördes som en Latin Square med tre ljusintensiteter under dygnets mörka timmar: LOW (11 ± 3 lux), INT (33 ± 1 lux) och HIGH (74 ± 6 lux), i tre olika besättningar. I genomsnitt inkluderades 69 ± 4 primiparous kor och 133 ± 4 multiparous kor per behandling. Mjölkkorna hölls i lösdrifter med robotmjölkning och ett Feed First™ kotrafikssystem. Ingen effekt av behandling hittades på antalet antal passeringar genom selektionsgrinden per 24 timmar och ko eller på mjölkningsfrekvensen. Endast en liten minskning i antal passeringar genom selektionsgrinden per timme och ko nattetid kunde observeras under behandlingen LOW men den minskade aktiviteten påverkade inte mjölkningsfrekvensen. Effekten av ljusintensitet på mjölkavkastningen var svår att avgöra eftersom korna var utsatta för störningar under försöksperioden men inga skillnader i mjölkavkastning mellan behandlingarna LOW och HIGH kunde påvisas.