10900

10042

كارشناسي ارشد

علوم دامي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1394

يازده، 55ص.: جدول

علي صادقي سفيد مزگي، سعيد انصاري مهياري

فرجاد رفيعي

1394/10/23

عباس پاكدل، قدرت اله سعيدي

مهندسي كشاورزي

ID10042

Milk losses due to Clinical and Sub Clinical Mastitis in Holstein Dairy Cattle of Iran Alireza Ghafouri a ghafouri@ag iut ac ir December 28 2015 Department of Animal Sciences Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor A Sadeghi Sefidmazghi Sadeghism@cc iut ac irAbstractThe aim of present study was to determine cut off point and to investigate milk loss caused by clinical andsub clinical mastitis in Iranian Holstein dairy cattle This research was conducted in large scale by usingdataset collected by Animal Breading of Iran The dataset consisted of 4932245 test day records ofsomatic calls count SCC gathered from 2002 to 2013 on 1281 dairy farms in Iran Moreover information of three herds with regular recording system in Isfahan province were collected to estimatemilk loss due to mastitis during 2011 2013 Statistical analysis were done by using SAS software Resultsshow that cut off point occurs at approximately 10 000 cell counts and milk loss caused by sub clinicalmastitis for primiparus multiparus and overall were estimated 2 9 5 21 and 4 8 kg d respectively Milkloss due to clinical mastitis calculated by mixed model for primiparus multiparus and overall were 195 406 and 276 kg for a lactation period In addition milk loss due to clinical mastitis were estimated bywood function Milk loss compared to milk yield for lact 1 lact 2 and lact are 5 1 7 7 and10 9 respectively As the age at record increases somatic cell count rises however milk loss doesn tpresent a linear trend Milk losses due to clinical mastitis were predictedKeywords Cut off Clinical Mastitis Sub clinical Mastitis Milk Yield and Holstein

علي صادقي سفيد مزگي، سعيد انصاري مهياري

فرجاد رفيعي

عباس پاكدل، قدرت اله سعيدي