ÖZETDoğu-Anadolu Kırmızısı ırkı, Türkiye sığırlannm %28'2 sini teşki/eder. Bu ırkın süt verimleri, ağız ve normaı süt/erinin bi/eşifPi,süt yağlarmın fiziksel ve kimyasal (izeiliklerini, belirtmek gayesi ile buaraştırmaya girişi/miştir.Doğu Anadolu KımlZlsı ırkı süt verimi; lzmen (11/178) tarafindanmemleketimizin dnemli iki yerli, ırkı olan yerli Karalarda yıllık 842kg. günlük 3.46 kg ve Boz ırkta (l0/29) 655 kg. (yıllık) ve 3.9 kg. (günlük)olarak tesbit edilen verimlerden (inemli dlçüde yüksek bulunmuştur.Atatürk Universitesi Çiftliği ve köy şartlarındaki gruplar arasında sütverimi bakımından bire iki misli (1414 ve 711 kg.) fark giirü1milştür.Laktasyon müddeti de 1. grupta diğerinden uzundur. Buradan DoğuKırmızlSı ırkmda süt veriminin bi/gili bakım ve besleme ile artınlabileceğisonucu çıkmaktadır.lki deneme grubu süt bileşimleri arasındaki farklar istatistikfbakımdan %5 seviyesinde önemli bulunmamıştır. Süt yağı konstantlarıarasında Polenske sayıları hariç diğerleri arasındaki farklılık önemlideğildir.A STUDY OF MİLK YİELD, MİLK COMPOSİTİON, FİZİCAL ANDCHEMİCAL CONTANTS OF BUTTERFAT OF THE EASTERN-RED COWS.The Eastem Red Breed is thedominant and typical race of the sameregion. The Cows selected fromamong the cows of Atatürk Üniversityfarm and from among the cows wheregrown up under normal village condition.This inve~tigation have been carriedout to defermine the milk yield,composition of the normal milk andcolostrum, physcal and chemical contentsof butter fat. The results o[ theresearch are as follows.1- The milk yield of farm groupvaried from 603 - 2510 kg. and averagewas 1414, 790 kg. The annual milk yieldof village group varied from 552 868kg. with the average of 7i 1,517±31 kg. The lactation peryot is deterrninedas 236 days.2- The compasition of collostrummilk varied to a great deal for firtstwo and three days. The compasitionof colostral milk of the farm groupand village group was found to beclose similar to each other.3--The compasition of Red-Cowsnormal milk are as follows:a- Dry matter content varied from12,3978 to 15,5575 %with an averageof 13.2747±O.l968 % for farm groupand from 11.9613 % to 14.8858 %for village group. General averagewas found to be 13.4517 %'b- The water cantent varied from84.4425 to 87.6023 % with an averageof 86.8253 %for the farnı cows and forvillage cows from 85.1142 to 88.0387.%with an average of 86.4962±O.l942.Combined average was found to be86.5483±02227 %'c- Fat content varied between3.0656 and 6.7000 % with an averageof 4.0067±0.1991 % for larm cowsand 2.9450 to 5.4938 %with an averageof 4.481O± 1.7325 % for village cows.Combined average of both groUp was4.3450±0.2075 %'d- Non fat dry matter content variationrange was from 8.7950 to 9.6375 %, with an average of 9.1680±0.0492 % for farın group and 8.66399.8938% with an average of 9.0228±0.2870 % for village groups. Generalaverage was found to be 9.l067±0.0523 %'e- Protein content varied from 2.924& to 3.7894 % with an average of3.3İ95±0.0536 for farm group andfrom 2.5029 to 4.0507 % with an average3.1327±0.1007 for village cows.The combined average calculated to be3.2839±0.865 %'f- Laetose cantent: The generalaverage was 5.0967±0.1023 %, varyingfrom 4.3515 to 5.5604 % for[arrn group with an average of 5. 1182+0.0782 % and from 3.9971 to 5.7756% for viIIage group with an avrage of5.1822±0.1177 %'g- Specific Gravity varied from1.0300 to 1.0345 for farrn group withan average of i .0320±0.00 and from1.0293 to for village group with anaverage of 1.0312±0.00. Global ave-rage was 1.0315±0.0002 for both groups.h- 1. Theacidit} (S.H.) variedfrom 6.80 to 9.23. with an average of. i7.83±0.ö984 for farm group and from6.28 to. 8.57 with average of 7.97±0.1620 for village group. Combined averagewas found to be 7.90±0.1240.2- The aeidity (PH) varied from6.55 to 6.85 with an average of 6.72±_0.0648 for farm group; from 6.51 to6.86 with an average of 6.66±0.0262for 'lillage group. The average of bothfound to be 6.70±0.0237.3- The properties of butter fat:A) Physical properties:1. Solidifying point: Varied from19.75 to 24.40 oC for farnı group, withan average of 22.06±0.39 and from20.30°C to 24.40cC with an average of21.88±0.34 for village group. Theeombined average for borh groupwas 21.97±0.29°C.2. Meltİng point varied from 31.10to 34.80°C for butter fat of farm groupwith an average of 32.54 ±0.33°C,from 30.40 to 35.20°C for 'lillage groupwith an average of 32.48±0.34°C, totalaverage was 32.51 ±O.30°C.3. Refraetometer number variedfrom 41.5 to 46.3, refraetometer indexvaried from 1.4533 to 1.4568 withaverages of 43.4±0.29 and 1.4548±0.37 respeetive1y for farm group; forthese properties average, minimum anmaximum values are respectively 44.2±0.37 (42.2-47.5) and 1.4550±O.OO(1.4534± 1.4460) for 'lillage groupbutter fat.B) Chemkal propertİes:1. Free aeidity point varied from2.2 to 4,3 with an average of 3.15±0.14for farın group; from 2.5 to 3.8 withan average of 3.4±0.ıo for village group.Global average was 3.155±0.10.2. Neutralization number; variedfrom 219 to 237 w~th an average of231 ± 1.27 for farm group, from 212to 235 with an average of 225± 1.79for village group. Combined averagewas 228±0.01.3. Reichert-Meisş1 number variedfrom 22.49 to 29.86 with an averageof 25.56±0.56 for the butterfat offarnı eows, and from 19. i 5 to 28.35 withan average of 26.ıo±0.89 for villagegroup. Global average was 25.83±0.55.4. Polenske number averaged as1.66±0.03 for farm group and 1.89±O. i 5 for 'lillage group. Global averagewas 1.78+0.08.5. Butyne acid number varied from17.58 to 24.32 with aI:! average of 21.l0±0.57 for farnı group, from 15.50 to23.16 with an average of 20.93± 1.34for vjJlage goup. Global average was21.00±0.45.6. Iodine number average was36.00±O.66 or farın group varying from31.82 to 39.46; 37:83±O.79 varyingfrom 27.38 to 44.43 for village group.Combined average was 37.02±0.67.Physical, chemica1 contants, averagesof butterfat, regression coeffieients,correlation, eoeffieients of thebutterfat of the Eastem Red cowswere detetmined by emp10ying statisticalmethods.