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<strong>AGRONOMIJAS</strong> VĒSTIS (Latvian Journal of Agronomy), No.10, LLU, 2008krišana, jo dzīvnieki netiek pietiekoši novēroti un uzmanīti. Pētījuma laikā, veicot novērojumusdzīvnieku un cilvēku savstarpējo attiecību izpausmēs, konstatējām, ka nav atšėirības bioloăiskajāsun konvencionālajās dzīvnieku audzēšanas sistēmās, jo dzīvnieki ir aktīvi, ar šėirnei un sugaiatbilstošu raksturojumu un rakstura īpatnībām, ziĦkārīgi, nebaidās no kontakta ar cilvēku. Līdz arto, apkopojot iegūtos novērojumu rezultātus, konstatējām, ka apsekotajās bioloăiskajās unkonvencionālajās saimniecībās dzīvnieku labturība ir pieĦemama.SecinājumiBioloăiskajā lauksaimniecībā ar kazkopības produkcijas realizāciju tirgū nodarbojas vairākkā 30% kazkopības saimniecību.Bioloăiskajās saimniecībās salīdzinājumā ar konvencionālajām saimniecībām no kazasiegūts par 17% zemāks piena izslaukums, turpretī piena tauku, laktozes un olbaltumvielu saturs irievērojami augstāks (attiecīgi par 5.9, 11.8 un 12.4%).Bioloăisko kazu pienā novērots par 18% vairāk somatisko šūnu nekā konvencionālajāpienā. Tas liecina par kĜūdām dzīvnieku labturības ievērošanā, kā arī dzīvnieku vajadzībāmneatbilstošu ēdināšanu.Bioloăiskajās saimniecībās praktiski netiek veikta nekāda izēdinātās barības uzskaite,zemniekiem nav priekšstata par barības devu lielumu un dzīvnieku fizioloăiskajām vajadzībām.Bioloăiskajās saimniecībās pamatā dzīvnieku ēdināšanai tiek izmantoti pašražotie barībaslīdzekĜi – siens, ganību zāle, auzu, griėu milti un skābsiens, turpretī konvencionālajās saimniecībāsblakus pašražotajai zāles lopbarībai tiek iepirkta Dobeles dzirnavnieka vai Tukuma “Straumes”pilnvērtīgā barība ar paaugstinātu enerăijas, proteīna, koptauku, Ca un P saturu; kas arī Ĝauj šīmsaimniecībām iegūt par 17% augstākus izslaukumus.Bioloăiskajās saimniecībās dzīvniekiem novērojam vairāk problēmu, kas saistītas arveselības nodrošināšanu.Bioloăiskajās saimniecībās pārsvarā ziemas periodā netiek nodrošināts optimāls dzīvniekublīvums uz 1 m 2 , tas ietekmē dzīvnieku labturību (stress), kā arī veselību (mikroklimats).Konvencionālajās saimniecībās dzīvnieku mītĦu labiekārtošanai tiek pievērsta lielākauzmanība, līdz ar to dzīvniekiem tiek nodrošināti optimālāki turēšanas faktori.Bioloăiskajās saimniecībās ir nepieĦemami dzīvnieku ēdināšanas faktori – dzīvnieki netieknodrošināti ar brīvu piekĜuvi ūdenim un minerālvielām, kas savukārt var izsaukt veselībasproblēmas un produktivitātes samazināšanos.Apsekotajās bioloăiskajās un konvencionālajās saimniecībās dzīvnieku labturība irpieĦemama.Literatūra1. Culleton N., Barry P., Fox R., Schulte R., Finn J. (2001) Principles of Successful Organic Farming. -Teagasc, UK, 162.2. Lampkin N. (1992) Organic farming. - Farming Press, 703.3. Nutrient Requirements of Goats: Angora, Dairy and Meat Goats in Temperate and Tropical Countries.National Research Council, National Academy Press, 1981, 91.4. Sprūžs J. (2005) Latvijā audzēto kazu ēdināšanas normas. Jelgava, 16.5. Sprūžs J., ŠeĜegovska E., Remeza I., VasiĜjeva S. (2006) Importance of feed additives and assessment ofgoat welfare in organic Farming. Proceeding of the 12 th Baltic animal breeding conference. Jurmala,Latvia, 169-176.292
<strong>AGRONOMIJAS</strong> VĒSTIS (Latvian Journal of Agronomy), No.10, LLU, 2008ESTIMATES OF BREEDING VALUES FOR DAIRY CATTLE USING TEST – DAYMILK YIELDSZutere R.Latvia University of Agriculture, Liela iela 2, Jelgava, Latvia, LV – 3001AbstractThe aim of the study was to analyze the improvement of reliability and the changes in therankings of bulls using different models. There were build up 4 Test day model (TDM) groups with2 fixed effects and 108 or 450 defined lactation curves. The results of TDM were compared withthe results calculated with LM used in a routine genetic evaluation. A total of 362 043 first threelactation test day records were used from 23 949 Latvian Brown breed cows, int. al. daughters of687 sires and cows of 1849 herds and 400 districts. Estimated breed ing values (EBV)showed large a variation for three productivity traits in all study groups. EBV were obtained inrange from -1013.9 to 1965.7 kg with average values from 6.2 kg to 63.9 kg for milk yield, from -40.75 to 93.59 kg with average EBV from 0.18 to 2.37 kg for fat yield and from -37.33 to 59.86 kgwith average values from 0.13 to 1.99 kg for protein yield. There were not significant differencesbetween EBV of different groups for fat yield. EBV of milk yield and protein yield showedsignificant differences between groups where different fixed herd – test day (HTD) or fixed district– test day (DTD) effect included in the model (p< 0.01). The ranking of bulls by EBV were similarfor all productivity traits. There were 6 bulls for milk yield, 8 bulls for fat yield and 7 bulls forprotein yield and are included in the top list of the 10 best bulls in all groups. The averagereliability (REL) of EBV are in a range from 70 to 82 %, from 69 to 81 % and from 72 to 83 %,respectively for milk, fat and protein yield by the test – day model (TDM). These values werelower 3 to 20 % using the lactation model (LM).Key wordsTest day (TD), regression model (RM), estimated breeding value (EBV)IntroductionIncreased computer power and the development of computational techniques has madepossible an increase in the complexity of models, thus reducing the likelihood that factors that arenot included in the model will bias genetic estimates. Thus, to account for environmental variance,records are usually grouped in herd-year-season classes. The 305-day milk yield is computed onthe basis of single test day records.An alternative approach to genetic evaluation is an analysis of individual test day records.Ptak and Schaeffer (1993) suggested a repeatability TD model, which assumes that covariancesbetween successive test days are equal to those between test days that are far apart. The modelproposed by Ptak and Schaeffer (1993) was a first lactation, single-trait repeatability model, inwhich genetic variance was assumed constant throughout lactation, and genetic correlations amongdifferent TD records were assumed to be 1.It is assumed in the fixed regression model that there are constant animal and permanentenvironmental effects throughout the course of the lactation. The heterogeneous variances atdifferent lactation stages are not taken into account and correlations between any two tests areassumed to be equal. Although cows belonging to different sub-groups, e.g. age–parity–seasonclasses, are allowed to have different average lactation curves, deviations from the average curvesare not modeled by the fixed regression model (Liu, Jamrozik, Jansen, 1998).The fixed regression model developed in the early stages of modeling TD data (Ptak,Schaeffer, 1993) was a simplified version of the random RM. TD models have recently gainedconsiderable interest because they are more flexible in handling records from different recordingschemes. Compared with only using records of complete lactations they can reduce the generationinterval through frequent genetic evaluation with the latest data (Swalve, 2000).293
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