Physiological and behavioural effects of changeover from conventional to automatic milking in dairy cows with and without previous experience

Transcription

1 Vet. Med. Czeh, 50, 2005 (6): Originl Pper Physiologil nd ehviourl effets of hngeover from onventionl to utomti milking in diry ows with nd without previous experiene D. WEISS 1, E. MOESTL 2, R. M. BRUCKMAIER 1 1 Physiology Weihenstephn, Tehnil University Munih, Freising, Germny 2 Institute of Biohemistry, University of Veterinry Mediine, Vienn, Austri ABSTRACT: The effets of the hngeover from onventionl prlour to n utomti milking system (AMS) on ehviour nd physiologil prmeters in diry ows with nd without previous experiene in AMS milking were investigted. Hert rte inrese ws higher in unexperiened ows (UC) thn in experiened ows (EC) during the first AMS visit (31 ± 2 nd 12 ± 2 ets per min, respetively, P < 0.05). EC entered the utomti milking stll voluntrily without ny intervention y the stff. In ontrst, in UC the rte of voluntry visits ws 4, 26, 40, 49, 63, 72, 76, 89, 91 nd 94% during the first 10 d of AMS milking, respetively. Fel ortisol metolites were not ffeted y the hngeover. In UC milk ejetion ws distured during the first visits, i. e. men milk yield t the first milking in the AMS ws signifintly lower s ompred to tht in the prlour (67 ± 7%, P < 0.05), wheres milk ejetion in EC ws not distured. The totl milk yield of the first 15 milkings differed signifintly in UC (87.3 ± 2.4%) nd EC (108.8 ± 3.3%) s ompred to previous prlour yields (P < 0.05). In onlusion, ows with previous experiene to AMS milking did not need new dpttion period in the AMS fter trnsient period of prlour milking. In ontrst, UC do need n intensive dpttion to the AMS in order to minimise prodution loss. Dt lerly demonstrte tht n dequte dpttion is ruil for suessful milk prodution in AMS. Keywords: utomti milking; ehviour; oping; ortisol; diry ow; experiene; hert rte Cttle respond to hnged environment with physiologil nd ehviourl dpttions. Milking in utomti milking systems (AMS) is ssoited with environmentl hnges s ompred to onventionl prlour milking (Hopster et l., 2002; Weiss et l., 2004). In onventionl milking routines the ows re driven to the milking prlour, wheres in AMS the ows enter the milking stll voluntrily. However, ow s motivtion to get milked seems to e wek nd very vrile (Presott et l., 1998). Therefore severl pprohes to ttrt n AMS visit hve een intensively studied (Winter nd Hillerton, 1995; Ketelr-de Luwere et l., 1998; Hermns et l., 2003; Hrms nd Wendl, 2004). Conentrte feeding in the AMS milking ox positively reinfores AMS visits. Additionlly, fored or seletively fored ow trffi systems with roughge only ville fter pssing the AMS re ommon (Hrms nd Wendl, 2004). In dpted ows these speifi hnges did not negtively effet the physiologil regultion during milking s ompred to onventionl systems (Hopster et l., 2002). However, the hnge from onventionl to utomti milking is ssoited with elevted hert rtes nd dverse ehviour towrds the AMS during the first visits. Furthermore, the milk yield n e redued due to the hngeover (Weiss et l., 2004). These retions do not represent longterm negtive effet for ow s welfre. Diry ows re le to ope suessfully within dys to AMS milking. Comprle effets hve een demonstrted due to the hnge from tie stll milking towrds prlour milking (Mh et l., 1981). There re inditions for remrkle memory potentil in ttle (Kovlik nd Kovlik, 1986). This indites tht diry ows reognise previ- 253

2 Originl Pper Vet. Med. Czeh, 50, 2005 (6): ously known environment even fter longer period eing hndled elsewhere. However, the effets of previous experiene in eing milked utomtilly on the hnge from onventionl milking to AMS were to the est of our knowledge never intensively studied efore. The im of the present study ws to quntify the retions of diry ows, with nd without previous experiene in AMS milking, towrds the hnge from onventionl to AMS milking. The hypothesis ws tested tht the ow-individul retion differs ording to their previous experiene. MATERIAL AND METHODS Animls nd husndry. Nine ows with nd 17 ows without experiene to e milked in n AM system were used in the experiment. The experiened ows (EC) were previously milked during one whole lttion in the AMS. EC were dried off nd housed during the dry period in seprte rn. After prturition these ows were milked for 36 ± 5 d of their seond to sixth lttion in the onventionl milking prlour. The unexperiened ows (UC) were never efore milked in n AMS. UC were in their first to their fifth lttion, lttionl stges vried in UC etween 24 nd 316 in milk, with n verge of 176 ± 15 d. All ows elonged to herd of Red-Holstein/Simmentl rossreed ows (out 70% of Red-Holstein). The herd ws housed in one single rn under identil feeding nd mngement onditions (for detils of the rn lyout see Hrms nd Wendl, 2004). The diet onsisted of mize nd grss silge nd onentrte ording to the individul milk prodution. A mximum of 12 kg onentrte per dy (pproximtely 50% of the totl rtio) ws offered in onentrte feeders nd the AMS if dily milk yields exeeded 40 kg. Conentrte ws omitted when dily milk yields delined elow 14 kg. One hlf of the herd ws milked in the AMS VMS (DeLvl, Tum, Sweden), the other hlf in onventionl herringone milking prlour (DeLvl). Routine milking times in the prlour strted t nd t In the AMS ows were milked during their voluntry visits. A seletively fored ow trffi (Hrms nd Wendl, 2004; Weiss et l., 2004) ws pplied. The feeding re ws seprted from the resting re y one-wy gtes, whih llowed free ess to the uiles lso without eing milked. However, the ows were oliged to pss the AMS efore entering the feeding re. A ypss ws ville for those ows whih hd reently een milked. Cows hd to pss the milking stll if milk yields of more thn 7 kg were expeted. Additionlly onentrte feeding in the AMS milking stll positively reinfored AMS visits. When milking intervls exeeded 12 h the respetive ows were mnully driven to the AMS. UC were introdued in two groups in the AMS herd, lned for ge, lttionl stge nd milk yield, to prevent n overlod of the AMS s previously desried (Weiss et l., 2004). The first group of 8 UC ws nlysed wheres nother 30 ows were regulrly milked in the AMS. The seond group of 9 UC swithed to AMS milking in herd of 38 ows milked in the AMS. The 9 EC hnged from prlour to AMS milking wheres dditionlly 45 ows were milked in the AMS. UC experiments were performed in utumm 2001, wheres EC experiments were performed in winter 2002/2003. Experimentl proedure. UC were trined to the AMS during 3 d, nd the first milking ws performed 4 d fter the strt of the trining period (Figure 1). During the trining period UC were kept during dytime in the AMS re nd were twie dily mnully driven into the AMS stll. They were milked in the prlour twie dily nd remined in the prlour herd during the night. After the strt of milking in the AMS UC were driven to the AMS fter milking intervls exeeded 12 h. EC were moved fter the morning milking in the prlour to the AMS re. However, sine ll EC entered the AMS milking stll voluntrily within 5 h fter the hngeover to the AMS herd, no trining period ws pplied in EC. Strting t 13.00, EC were mnully driven to the AMS milking stll on d 1 to determine tet oordintes in the AMS milking stll. Exept for period of 24 h on d 3 of the trining period in UC the hert rte ws reorded ontinuously in UC nd EC throughout the experiment until d 6 of utomti milking (Figure 1). Furthermore hert rte ws reorded during two suessive prlour milkings in EC nd UC efore the hngeover. The hert rte ws mesured y mens of ommeril system developed for horses using eletrodes fixed to speil elt round the hest (Polr Horse Tester, Polr Eletro GmH, Büttelorn, Germny) (Hopster et l., 2002; Weiss et l., 2004). The hert rte signl ws sved s 15-s verges for further nlyses. To determine the ortisol metolites 11,17-Dioxondrostnes (DOA) fel smples were tken 254

3 Vet. Med. Czeh, 50, 2005 (6): Originl Pper Prlour milking Chngeover to the AMS re Milking still in prlor 1. Milking in AMS Hert rte Fees smples Milk yield, onstituents t 1 t 2 t Dys AMS trining Dys AMS milking Prlour milking Behviourl evlution Chngeover to the AMS re 1. Milking in AMS Hert rte Fees smples Milk yield, onstituents Behviourl evlution Dys AMS milking Experiened ows Unexperiened ows Figure 1. Experimentl protool: In unexperiened ow (UC) trining period of 3 d ws pplied, wheres in experiened ows (EC) the trining period ws omitted. In UC the first rrow indites the strt of the trining period. UC were driven twie dily to the utomti milking stll ut were still milked twie dily in the prlour. The seond rrow indites the strt of milking in the AMS, UC remined finlly in the utomti milking re. EC were immeditely milked in the utomti milking system. Milk reordings, hert rte mesurement nd fel smpling were rried out s indited y the rs twie dily t nd from the retum (out 10 g) nd were immeditely frozen t 20 C until further nlyses. The DOA onentrtions in the fees ws nlysed s previously desried y Moestl et l. (2002). The milk yield nd omposition ws reorded during prlour milking the lst 10 d efore the hngeover to the AMS nd during AMS milking until d 6. To determine milk yield nd for milk smpling Ltoorders (Werkzeug- und Mshinenu Blgh, 9436 Blgh, Switzerlnd) were used during prlour milkings. In the AMS the instlled stndrd milk meter nd smpling devie were used (DeLvl MM15). Milk smples were nlysed for ft, protein, ltose nd somti ell ount (Milko Sn 00, Foss GmH, Hmurg, Germny). Dt proessing nd sttistil nlyses. Dt re presented s mens ± SEM. Sttistil signifine ws set t P < Due to the vrile milking intervls in AMS, milk yields were hndled s prodution rte per hour. Prodution rte ws lulted s the quotient of the tul milk yield nd the orresponding intervl from previous milking (Weiss et l., 2002, 2004). To demonstrte effets of the hngeover, milk yields otined in the AMS were expressed s reltive vlues of men prlour yields during 10 d prior to AMS trining. Likewise the milk onstituents during AMS milkings were lulted s reltive vlues of prlour results. The men of the lower 30th perentile of the dtset of eh individul ow ws defined s sl hert rte. The hert rtes in the prlour nd in the AMS were defined s verge hert rte ove sl level (HAB) s previously desried (Weiss et l., 2004). Dt during the first 2 min fter entering the milking stll were nlysed. For sttistil evlution the MIXED proedure of the SAS 8.01 (SAS, 1999) progrm pkge ws used. The model inluded the dte, the time of the dy nd the lttion numer s rndom vriles. The numer of visits, the numer of milkings, the lttionl stge nd the tretment (UC nd EC) entered the model s fixed vriles. The ow ws inluded into the model s repeted effet using the ovrine struture ompound symmetry. Signifint differenes (P < 0.05) were lolized y using the lest signifint differene test. RESULTS Behviourl oservtions At their first visit during the trining period UC hd to e pushed mnully into the AMS stll. During the seond nd third visits the numer of UC inresed whih needed only gentle drive to the AMS stll to mke them enter. However, fter the third trining dy ll UC were le to enter the 255

4 Originl Pper Vet. Med. Czeh, 50, 2005 (6): Rte of voluntry visits (%) 40 x y y y y y y y y d d d y d d,d represent signifint differenes etween EC nd UC;,, ; x, y = mens without ommon supersript letter differ signifintly within tretment (EC nd UC) (P < 0.05) unexperiened ows (UC) experiened ows (EC) Dys of utomti milking Figure 2. Rte of voluntry visit (men ± SEM, n = 17 UC nd 9 EC) in the AMS milking stll during the first 10 d of utomti milking milking stll without physil fores fter they were driven into the witing re in front of the milking stll. All EC entered the AMS milking stll voluntrily within 5 h when they were moved to the AMS herd fter morning milking in the prlour. EC were one mnully driven to the AMS stll strting t to register the tet oordintes in the AMS stll. Therefter, EC needed no more to e mnully driven to the AMS during the experimentl period. The rtes of voluntry visits differing for UC nd EC re shown in Figure 2. Exept for the voluntry visit of one ow ll UC needed to e driven to the AMS on d 1 of milking. Throughout the first 10 d of milking stedily inresing rte of voluntry visits ws oserved in EC. The rte of 90% of voluntry visits in UC ws hieved not until d 9 of utomti milking. Hert rte The sl hert rte vried etween 61 ets per min (pm) nd 85 pm. HAB during the first 10 visits in the AMS milking stll re shown in Figure 3. HAB during prlour milking ws similr in UC nd EC. HAB ws higher during the first visit of UC in the AMS milking stll thn in the prlour nd lso higher thn t the first AMS visit of EC. During the 2nd visit HAB ws still elevted in UC s ompred to EC, ut did not signifintly differ from tht in the prlour. In UC HAB results of the 5th nd 6th visit re missing euse hert rte mesurements were not performed on d 3 of the trining period in UC (Figure 1). HAB in EC did not differ etween prlour nd AMS stll nd did not signifintly hnge with numer of AMS visits. HAB results during the first 10 AMS milkings re shown in Figure 4. Neither n effet of the numer of milkings nor n effet of previous experiene in AMS milking (UC vs. EC) ws oserved. Furthermore, HAB during prlour milking ws similr to tht otined in the AMS. 11,17-Dioxondrostne DOA onentrtions during prlour milking nd during the first dys in AMS re shown in Figure 5. DOA onentrtions did not differ etween morning nd evening smpling (159 ± 8, 184 ± 8 ng/g in UC nd 228 ± 13, 222 ± 12 ng/g in EC for morning nd evening smpling throughout the experimentl period, respetively). DOA onentrtions were signifintly higher in EC thn in UC during prlour milking nd t the 2nd nd 4th d fter the hngeover to AMS. However, the hngeover itself 256

5 Vet. Med. Czeh, 50, 2005 (6): Originl Pper Hert rte ove sl lever (ets per min) Hert rte ove sl level (ets per min) ,,,, MP Numer of AMS visits Figure 3. Hert rte ove seline (men ± SEM, n = 17 UC, 9 EC) during milking in the prlour (MP) nd during visits in the AMS stll represent signifint differenes etween EC nd UC;, = mens without ommon supersript letters differ signifintly (P < 0.05) unexperiened ows (UC) experiened ows (EC) 20 Hert rte ove sl lever (ets per min) MP Numer of AMS milkings Figure 4. Hert rte ove seline (men ± SEM, n = 17 UC, 9 EC) during milking in the prlour (MP) nd during visits were milking ws performed in the utomti milking system. Neither n effet y the tretment (EC vs. EC) ws oserved nor effets due to the numer of milkings unexperiened ows (UC) experiened ows (EC) hd no effet on DOA onentrtions, sine neither in UC nor in EC the DOA results otined in the prlor did not differ to ny dy fter the hngeover to AMS milking (effet of the dy: P = 0.48). Figure 6 presents men DOA onentrtions lustered for three levels of milk yield. DOA onentrtions were high in high yielding ows irrespetive of their previous experiene to utomti milking. DOA onentrtions tended to e lower (P < 0.1) in low yielding ows. Milk yield nd omposition The milk yield t the first milking in the AMS ws higher in EC (96 ± 2% of tht otined in the prlour) thn in UC (67 ± 7% of tht otined in the prlour). Milk yields nd omposition of the first 15 AMS milkings re presented in Figure 7. Individul milk yields in UC during the first milking vried etween 8% nd 96% of previous prlour yields. During 2nd, 3rd nd 4th AMS milking milk yields in UC were similr to prlour yields wheres in further milkings milk yields were signifintly redued. Exept for the seond milking, reltive milk yields were signifintly higher in EC thn in UC throughout the experimentl period. Individul milk yields of the first AMS milking in EC vried etween 85% nd 106%. Milk yield in EC did not signifintly differ from prlour yield. However, the milk yield during the first 15 AMS milkings ws higher in EC (108 ± 1% of tht otined in the 257

6 Originl Pper Vet. Med. Czeh, 50, 2005 (6): ,17-Dioxondrostnes (ng/g) Figure 5. 11,17-Dioxondrostnes (DOA) onentrtions in fees (men ± SEM, n = 17 UC, 9 EC) in the prlour (MP) nd during the first d in the utomti milking system represent signifint differenes etween EC nd UC (P < 0.05) 6 d of AMS milking in EC 3 d of trining nd 6 d of AMS milking in UC 50 0 MP Dys in AMS 11,17-Dioxondrostnes (ng/g) > 30 > 20 < 20 Milk yield (kg) Figure 6. 11,17-Dioxondrostnes (DOA) onentrtions in fees (men ± SEM) during the first 6 d of utomti milking in experiened ows (EC) nd during the first 9 dys in unexperiened ows (UC) lustered for dily milk yield (> 30 kg/d: 4 UC nd 9 EC, > 20 kg/d 9 UC, < 20 kg/d 4 UC), = mens without ommon supersript letters tended to e different (P < 0.1) unexperiened ows (UC) experiened ows (EC) prlour) thn in UC (87 ± 1% of tht otined in the prlour). Milk ompostion ws not signifintly ffeted y the hngeover. Reltive milk yields during the first 15 AMS milkings re shown in Figure 8. As indited reltive milk yield during the first 15 AMS milkings did not differ etween lttionl stges in UC. Reltive milk yield ws higher in EC thn in UC irrespetive of the stge of lttion. However it hs to e pointed out tht no intertion etween the stge of lttion nd the reltive milk yield fter the hngeover ws oserved in UC. The milking intervl for the first 15 AMS milkings ws shorter in EC (7.8 ± 0.2 h) thn in UC (9.8 ± 0.2 h). The milking frequeny ws therefore 3.07 ± 0.01 milkings per dy in EC nd 2.45 ± 0.02 milkings per dy in UC. DISCUSSION In the present study physiologil nd ehviourl effets of the hnge from onventionl to utomti milking were evluted. The investigted diry ows vried with respet to their previous experiene to milking in the AMS. Mngement nd feeding ws identil in oth herds, exept for the milking system. Furthermore, oth herds were housed in two omprtments of the sme rn. Therefore, the tested nimls hd to dpt only to the differenes in the milking system. Interestingly, EC entered the AMS instntneously without ny humn intervention fter they were moved to the AMS herd. The rte of voluntry visits on d 1 ws redued, euse it is essentil to djust the AMS ording to the tet oordintes of the individul 258

7 Vet. Med. Czeh, 50, 2005 (6): Originl Pper Reltive milk yield (%) ,,, Figure 7. Milk yield (men ± SEM, n = 17 UC, 9 EC) expressed s reltive vlues of prlour results (% = men prlour results of 10 d prior to the hngeover) represent signifint differenes etween EC nd UC;,, = mens without ommon supersript letters differ signifintly (P < 0.05) unexperiened ows (UC) experiened ows (EC) 120 Reltive ft ontent (%) Reltive protein ontent (%) Numer of AMS milkings ow efore the strt of the first utomti milking. However, this visit, euse of tehnil resons, ws the sole exeption of mnully moving EC to the AMS milking stll throughout the experimentl period. The ft tht EC did not use the AMS for out d (dry period of six wk nd 35 d prlour milking) nd their immedite voluntry visit of the AMS, douments the onsiderle memory pity of the diry ow. These findings orrespond to results of Kovlik nd Kovlik (1986). UC never entered the AMS voluntrily within the trining period. Although one ow entered the AMS voluntrily t the first dy of milking, the rte of voluntry visits did not hieve levels of more thn 90% until d 9 of AMS milking. The rte of voluntry visits dfter suessful dpttion to AMS Reltive milk yield (%) Figure 8. Milk yield (men ± SEM) expressed s reltive vlues of prlour results lustered for lttionl stge (< d in lttion: 6 unexperiened ows (UC) nd 9 experiened ows (EC), < 200 d in lttion: 3 UC, > 200 d in lttion: 8 UC; % = men prlour results of 10 d prior to the hngeover) 50 < <200 >200 Dys in in milk, = mens without ommon supersript letters differ signifintly (P < 0.05) unexperiened ows (UC) experiened ows (EC) 259

8 Originl Pper Vet. Med. Czeh, 50, 2005 (6): milking orresponds to previous investigtions in dpted ows (Winter nd Hillerton, 1995; Ketelrde Luwere et l., 1998; Hermns et l., 2003; Hrms nd Wendl, 2004). However, it hs to e pointed out tht this level ws not pprohed until d 9 of AMS milking. Therefore, onsidering the trining period of 3 d, suessful utomti milking, without n exessive use of lour to move the ows, did not tke ple until d 12 in the AMS. Hert rte ove sl level (HAB) in the individul ow ws lulted. This ws performed to prevent is to the lose orreltion etween seline hert rte nd dily milk yield s previously demonstrted (Weiss et l., 2004). During the first visit to the AMS the elevted HAB in UC indited high symptheti tivtion. The elevtion of hert rte ws omprle to results demonstrted y Hopster et l. (1995) fter ow-lf seprtion in diry ows. Rushen et l. (1999) demonstrted tht fer of diry ows of n versive hndler resulted in less pronouned hert rte elevtion ompred to the remrkle effets oserved during the first visit to the AMS. However, it hs to e onsidered tht lredy during the seond nd third visits the HAB ws similr to those reorded in the prlour. In greement to the previously disussed ehviourl results, HAB ws not elevted in EC during the first AMS visits. The present results re in ontrst to oservtions of Hopster et l. (2002), where redued hert rtes during AMS milking s ompred to prlour milking were oserved. This differene might e due to the ft tht Hopster et l. (2002) lulted solute hert rte vlues in ontrst to the present investigtion where hert rte ws lulted on HAB sis. Furthermore in the present study HAB were lulted s mens of the first two min fter losing the gte in AMS or fter entering the milking stll in the prlour wheres Hopster et l. (2002), demonstrted the progression during witing efore milking, until the end of milking. DOA onentrtions were not ffeted y the hngeover, wheres Plme et l. (2000) reported twie to trie fold inrese in DOA onentrtions s result of trnsporttion in ttle. Oviously, the hnge to AMS milking did not use prolonged tivtion of the hypothlmi-pituitry-drenl xis, neither in UC nor in EC. Although n elevtion in the symptheti tivtion in UC ws oserved, the hnge to AMS milking seems to e minor stressor. However, the differenes in DOA onentrtions etween UC nd EC nnot e explined. The mngement, the housing, the rn stff nd, exept for the used hrges of feed, the feeding ws similr in UC nd EC. Furthermore the time of the yer ws lmost similr, sine UC were tested in Otoer nd Novemer nd EC in Jnury. DOA onentrtions my e ffeted y the level of milk prodution. However, diret effet of the milk yield on plsm ortisol onentrtion is unlikely (Shwlm nd Tuker, 1978). With inresing milk yields the frtion of onentrte in the totl rtion is inresed, this might hnge the formtion of miroorgnisms in ows intestine. Possile this ould hve een ffeted fel DOA onentrtions (Moestl et l., 1999). Milk onstituents were not ffeted due to the hngeover proess. Therefore the oserved effet of redued milk yield in UC nd enhned milk yields in EC re proly due to lol effet in the mmmry glnd. As detiled disussed in previous study (Weiss et l., 2004), the milk ejetion in UC ws oviously redued during the first AMS milkings due to disturne of milk ejetion (Brukmier et l., 1992, 1996; Rushen et l., 2001). This resulted in dditionl residul milk in the udder. Milk left in the ovine udder n redue milk seretion nd immeditely enhnes poptosis of the mmmry seretory tissue y lol regultion (Peker nd Wilde, 1996; Stefnon et l., 2002). Contrry, in se of n inresed milking frequeny, these lol regultions n enhne milk seretion nd n enhne prolifertion of seretory tissue. Proly the enhned milk yields in EC were due to the sme regultory kground s the redued milk yields in UC. CONCLUSION In onlusion, the hnge from onventionl to utomti milking ws remrkly different etween diry ows with nd without previous experiene. This points t the onsiderle memory potentil of the diry ow. Even fter hndling in nother environment, experiened ows re immeditely le to ope with AMS onditions. However, the hnge to utomti milking is hllenge for unexperiened ows. Therefore gret efforts must e undertken to minimise negtive effets during the first few milkings. One ows re dpted suessfully to utomti milking, the hnge to AMS seems to e unprolemti. Dt demonstrte lerly the ruil effet of reful dpttion of ows for the suess of milking in the AMS. 2

9 Vet. Med. Czeh, 50, 2005 (6): Originl Pper REFERENCES Brukmier R.M., Shms D., Blum J.W. (1992): Milk removl in fmilir nd unfmilir surroundings onentrtion of oxytoin, proltin nd et-endorphin. Journl of Diry Reserh,, Brukmier R.M., Pfeilstiker H.U., Blum J.W. (1996): Milk yield, oxytoin nd et-endorphin grdully normlize during repeted milking in unfmilir surroundings. Journl of Diry Reserh, 63, Hrms J., Wendl G. (2004): Influene of ow trffi on milking nd niml ehviour in rooti milking system. In: Meijering A., Hogeveen H., de Koning C.J.A.M. (eds.): Automti Milking. Wgeningen, The Netherlnds Hermns G.G., Ipem A.H., Stefnowsk J., Metz J.H. (2003): The effet of two trffi situtions on the ehvior nd performne of ows in n utomti milking system. Journl of Diry Siene, 86, Hopster H., O Connell J., Blokhuis H.J. (1995): Aute effets of ow-lf sepertion on hert rte, plsm ortisol nd ehviour in multiprous diry ows. Applied Animl Behviour Siene, 44, 1 8. Hopster H., Brukmier R.M., Vn der Werf J.T., Korte S.M., Muhov J., Korte-Bouws G., vn Reenen C.G. (2002): Stress responses during milking; ompring onventionl nd utomti milking in primiprous diry ows. Journl of Diry Siene, 85, Ketelr-de Luwere C.C., Hendriks M.M.W.B., Metz J.H.M., Shouten W.G.P. (1998): Behviour of diry ows under free or fored ow trffi in simulted utomti milking system environment. Applied Animl Behviour Siene, 56, Kovlik K., Kovlik M. (1986): Lerning ility d memory testing in ttle of different ges. Applied Animl Behviour Siene, 15, Mh J., Dvork K., Msek N., Kimpl M. (1981): Adption of ows to loose housing nd to milking (in Czeh). Zivoisn Vyro, 26, Moestl E., Messmnn S., Bgu E., Roi C., Plme R. (1999): Mesurement of gluoortioid metolite onentrtions in fees of domesti livestok. Journl of Veterinry Mediine A, 46, Moestl E., Mggs J.L., Shrotter G., Besenfelder U., Plme R. (2002): Mesurement of ortisol metolites in fees of ruminnts. Veterinry Reserh Communitions, 26, Plme R., Roi C., Bumgrtner W., Moestl E. (2000): Trnsport stress in ttle s refleted y n inrese in fel ortisol metolite onentrtions. Veterinry Reord, 146, Peker M., Wilde C.J. (1996): Feedk ontrol of milk seretion from milk. Journl of Mmmry Glnd Biology nd Neoplsi, 1, Presott N.B., Mottrm T.T., Wester A.J.F. (1998): Reltive motivtions of diry ows to e milked or fed in Y-mze nd n utomti milking system. Applied Animl Behviour Siene, 57, Rushen J., De Pssille A.M., Munksgrd L. (1999): Fer of people y ows nd effets on milk yield, ehvior, nd hert rte t milking. Journl of Diry Siene, 82, Rushen J., Munksgrd L., Mrne P.G., DePssille A.M. (2001): Humn ontt nd the effets of ute stress on ows t milking. Applied Animl Behviour Siene, 73, SAS Stt (1999): SAS Mnul, relese 8. Cry, NC, USA. Shwlm J.W., Tuker H.A. (1978): Gluoortioids in mmmry seretions nd lood serum during reprodution nd lttion nd distriutions of gluoortioids, progesterone, nd estrogens in frtions of milk. Journl of Diry Siene, 61, Stefnon B., Colitti M., Gi G., Knight C.H., Wilde C.J. (2002): Mmmry poptosis nd lttion persisteny in diry nimls. Journl of Diry Reserh, 69, Weiss D., Hilger M., Meyer H.H.D., Brukmier, R.M. (2002): Vrile milking intervls nd milk omposition. Milhwissenshft, 57, Weiss D., Helmreih S., Moestl E., Dzidi A., Brukmier R.M. (2004): Coping pity of diry ows during the hnge from onventionl to utomti milking. Journl of Animl Siene, 82, Winter A., Hillerton J.E. (1995): Behviour ssoited with feeding nd milking of erly lttion ows housed in n experimentl utomti milking system. Applied Animl Behviour Siene, 46, Reived: Aepted fter orretions: Corresponding Author Rupert M. Brukmier, Physiology Weihenstephn, Tehnil University Munih, Weihenstephner Berg 3, D Freising, Germny Tel , fx , e-mil: rukmier@wzw.tum.de 261