Effect of calf stimulation on milk ejection in reindeer (Rangifer tarandus)
Authors: Gjøstein Hallvard , Holand Øystein , Bolstad Tore , Hove Knut , Weladji Robert B. 
Published: February 2013

<p>The objective of this study was to establish methods for stimulating the milk ejection in reindeer kept for milking purpose. Calves were used to stimulate milk does&rsquo; let down. In experiment 1, five does were allowed olfactory, acoustic and visual contact with their calves during milking, whereas four does were milked in isolation. The treatment of the groups was alternated every day during the eight days experiment. Olfactory, acoustic and visual contact with the calf did not influence the doe&rsquo;s milk yield. The milk yield varied significantly between individual females within treatment (P &lt; 0.01). In experiment 2, the calves were allowed to suckle their mother for a short period (two seconds) prior to milking being initiated. The same alternate design as in experiment 1 with groups consisting of three and two animals respectively was used, and the experiment lasted four days. The pre-suckling stimulation significantly increased the milk ejection measured as milk yield (P &lt; 0.05), and the residual milk after the treatment was negectible. Moreover, the milk ejection varied between individual females within treatment (P &lt; 0.05). We conclude that it is possible to achieve a complete milk removal by machine milking after the does have been pre-stimulated by suckling of calves. Olfactory, acoustic and visual contact with calves during milking failed to influence the milk ejection in this study. However, the results have to be interpreted with caution due to limited sample size.</p><p>Abstract in Norwegian / Sammendrag: Form&aring;let med dette fors&oslash;ket var &aring; pr&oslash;ve ut ulike metoder for &aring; stimulere nedgivninga av melk hos rein. Kalvene ble tatt i bruk for &aring; stimulere nedgivninga. I fors&oslash;k 1 hadde simla lyd-, lukt og synskontakt med kalven mens melkingen p&aring;gikk. Vi benyttet et &rdquo;switch back design&rdquo; der fem simler hadde kontakt med kalven under melkingen og fire ble melket uten kontakt. Behandlingen ble byttet om annenhver dag i de &aring;tte dagene fors&oslash;ket varte. Lyd-, lukt og synskontakt med kalven under melking hadde ingen innvirkning p&aring; melkemengden ved maskinmelking. Det var imidlertid individuell variasjon i hvor mye melk man oppn&aring;dde hos simlene (P &lt; 0.01). I fors&oslash;k 2 lot vi kalvene suge simlene en kort stund f&oslash;r simlene ble melket. Kalven ble sluppet inn til simla og sugingen ble avbrutt etter to sekunder. Deretter ble simla f&oslash;rt inn for maskinmelking. Fors&oslash;ket varte i fire dager og vi benyttet samme &rdquo;switch back design&rdquo; som i fors&oslash;k 1, med grupper best&aring;ende av henholdsvis to og tre dyr. Stimuleringa med suging hadde en signifikant innvirkning p&aring; nedgivninga. (P &lt; 0.05), og mengden gjenv&aelig;rende melk var minimal. Dessuten var det en signifikant individuell variasjon i melkemengden innen behandlingen (P &lt; 0.05). Vi konkluderer med at det er mulig &aring; oppn&aring; en fullstendig t&oslash;mming av juret ved maskinmelking dersom simlene f&oslash;rst er blitt stimulert med suging av kalven. Lyd-, lukt- og synskontakt med kalven under melking hadde ingen innvirkning p&aring; nedgivninga av melk i dette fors&oslash;ket. Resultatene m&aring; imidlertid tolkes med varsomhet siden det statistiske utvalget er begrenset.</p>