PEMBANDINGAN TIGA METODE KOREKSI UMUR UNTUK CATATAN PRODUKSI SUSU ANAK PADA EVALUASI PEJANTAN FRIES HOLLAND DI BALAT PEMBIBITAN TERNAK BATURRADEN

A. T. Ari Sudewo, Dr. Ir. Jovita Maria Astuti, M.Sc.; Ir. Ristianto Utomo, M.S.

1991 | Tesis | S1 PETERNAKAN

Penelitian untuk membandingkan penggunaan faktor koreksi umur metode | Impro i 103 (DHIA), metode perkal metode Dairy Herd Improvement Association (DHIA) metode penambahan pada evaluasi pejantan, 335 catatan produksi S0 harian laktasi pertama sampai dengan ketiga, dari periode pencatatan tahun 1978 ampai dengan 1988 di Balai Pembibitan ternak (BPT) Baturraden., Catatan produksi susu tersebut berasal dari 141 ekor induk, keturunan dari 9 pejantan. Catatan produksi susu dikelompokkan dalam setiap nomer laktasi yaitu 3 kelas umur dalam setiap nomer laktasi dengan interval 12 bulan. Faktor koreksi umur metode penambahan dan perkalian diturunkan dari least squar constant dan least sqguares 1 kelas umur yang bersangkutan, Faktor kore umur metode DHIA adalah faktor koreksi umur yang dipublikasikan pada tahun 1953 oleh USDA. Hasil penelitian menunjukkan bahwa faktor koreksi metode DHIA, metode perkalian dan metode penambahan efektif dalam menghilangkan pengaruh umur pada data produksi susu . Pengaruh nomer laktasi juga berkurang dengan penggunaan faktor koreksi umur metode DHIA dan metode perkalian. Hasil penelitian menunjukkan pula bahwa tahun beranak berpengaruh terhadap produksi susu, baik pada data terkoreksi maupun data nyata. Pengaruh pejantan pada produksi susu tidak nyata, dan didapat pengaruh yang linear dari jumlah hari Jlaktasi pada produksi susu dengan korelasi sebesar 0,82, Penggunaan faktor koreksi umur metode DHIA, metode perkalian dan metode penambahan pada evaluasi pejantan berdasarkan least squares constant maupun nilai pemuliaannya diperoleh perlngkat pejantan yang hampir sama, serta nilai rank-korelasi yang mendekati satu. Kecermatan ratarata uji keturunan pada penggunaan faktor koreksi umur metode DHIA, metode perkalian dan metode penambahan masing-masing adalah 0,72, 0,71 dan 0,68, Hasil tersebut menunjukk bahwa penggunaan faktor koreksi umur metode DHIA, metode ian dan metode penambahan mempunyai kecermatan yang sama.

Dairy Herd Improvement Association (DHIA) method, multiplicative method and additive method of age correction factors for milk production were compared in dairy sire evaluation study. 335 daily milk production records of first, second and third lactation, during 1978 to 1988 from Baturraden Breeding Center were used in this study The records were from 141 cows daughters of 9 sir records were grouped by lactation numbers and there were 3 age groups within lactation with 12 month interval, Additive and multiplicative age correction factors were derived from the least squares constant and least squares mean of age concern. The DHIA method of age correction factors were the age correction factors published in 1953 by USDA. The study indicated that DHIA, multiplicative and additive method of age correction factors were effective in removing the effect of age on milk production to some extent. The effect of lactation numbers were also decreased by DHIA and multiplicative method of age correction factors. The results also showed that year of calving affected milk production either in corrected or uncorrected record. The effect of sire on milk production was not significant. A linear effect of length of lactation on milk production was detected and a correlation of 0.82 was obtained. A similar rank of sire’s least squares constant and sire’s breeding value were obtained when either DHIA or multiplicative or additive method of age correction factors were used. This was also indicated by the value of Spearman’s coefficient of rank correlation which was c¢lose to one. The accuracy of progeny test estimated base on the records corrected by DHIA, multiplicative and additive method of age correction factors were 0.72, 0.71 and 0.68 respectively. This result also indicated that the same accuracy was obtained in using DHIA, multiplicative and additive method of age correction factor for milk production in sire evaluation.

Kata Kunci : metode Dairy Herd Improvement Association (DHIA); produksi susu; Pejantan Fries Holland; Metode koreksi umur