ACCURACY OF MILK YIELD ESTIMATION IN DAIRY CATTLE FROM MONTHLY RECORD BY REGRESSION METHOD
Abstract: This experiment was
conducted to estimate the actual milk yield and to compare the estimation
accuracyof cumulative monthly record to actual milk yield by regression method.
Materials used in this experimentwere records relating to milk yield and
pedigree. The obtained data were categorized into 2 groups i.e. AgeGroup I (AG
I) that was cow calving at < 36 months old as many as 33 cows with 33
lactation records andAG II that cows calving e” 36 months old as many as 44
cows with 105 lactation records. The first three toseven months data were used
to estimate actual milk yield. Results showed that mean of milk yield/
head/lactation at AG I (2479.5 ± 461.5 kg) was lower than that of AG II (2989,7
± 526,8 kg). Estimated milk yieldsfor three to seven months at AG I were
2455.6±419.7; 2455.7±432.9; 2455.5±446.4; 2455.6±450.8; 2455,64± 450,8; 2455,5
± 459,3 kg respectively, meanwhile at AG II was 2972.3±479.8; 2972.0±497.2;
2972.4±509.6;2972.5±523.6 and 2972.5±535.1 respectively. Correlation
coefficients between estimated and actual milkyield at AG I were 0.79; 0.82;
0.86; 0.86 and 0.88, respectively, meanwhile at AG II were 0.65; 0.66;
0.67;0.69 and 0.72 respectively. In conclusion, the mean of estimated milk
yield at AG I was lower than AG II.The best record to estimate actual milk
yield both at AG I and AG II were the seven cumulative months.
Author: I.S. Kuswahyuni, E.
Kurnianto, N.L. Nuringtias, S. Johari
Journal Code: jppeternakangg090027
