Study On The Grunting Of The Sow During Nursing And The Sucking Behaviour Of The Piglet

Two experiments were carried out to study the gruuting of 12 sows during nursing and thesucking behaviour of piglets.In experiment I, six Yorkshire sows and their litters were observed and the sows weremanaged in farrowing crate. In experiment Ⅱ, six Harbin White sows and their litters wereselected and were housed in farrowing pens.The nursing was recorded by pickup camera.The results show that the characteristic pattern of grunting by the sows consists of aninitial period of rhythmic grunting at a fajrly constant rate, followed by a period of more rapidgrunting, and then a decline toward the completion of the nursing. The pattrm of vcalizationof the mother bears a reliable relationship to the sucking behaviour of the piglets. The rate ofgrunting varied little during phase 1 and phase 2. The beginning of phase 3 usuall occurredduring or just after the increase in grunt rate. Phase 4 began 15─25 seconds after the period ofmost rapid grunting, following the decrease of grunt rate. Then, the nursing ended Besides,there was individuality in sows' grunting patterns.It is found that vocalizations attract the piglets to the sow and the synchronize pigletssucking activities, but the pre-massaging time and numbers of pigletS massaging influence thegrunting pattern and the onset of the milk ejection. As more piglets were involved bymassaging,the grunting rate peak is higher,the faster the milk ejection.The results indicate that the most obvious changes in sows and litters are found aslactation progressed the willingness to nurse of sow is getting weak and the proportion ofsuckling emitted by the mothers secreased gradually,but the proportion of suckling terminatedby sows increased obviously.The average time for let-down decreased. the time of finalmassaging decreased by contrast,the time of pre-massaging increased. the time of finalmassaging decreased. These changes showed that there could be conflict between the interestsof mother and his offsprings, it may suggest the weaning is in process.The result showed that the sow does not eject nursing until some time (40-55min) haspassed boe the PrevioUS milk dectioIL nd hectha bo was op~ cmn in- wto besan ch 40 ch ds the ~ ed dds.Mnd callate: Li JianhOngbot boai forSuPervisor' Bao JUn...