Sire Evaluation from Five-Month Daughter Records

Vleck, Van; Dale, Laura

doi:10.2527/jas1962.213633x

Cited by 5 publications

(2 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Searle (1961);Van Vleck & Henderson (1961a); Van Vleck (1962) and McDaniel (1969) reported that part records could be used to obtain sire summaries and early evaluation of sires even though a larger number of records and probably more herds would be needed for this to be as efficient as full records. Angelov & Susanin (1979) observed that Bulgarian Brown cattle with different selection intensities for milk and milk fat resulted in similar response to direct (305 d yield) and indirect (120 d yield) selection.…”

mentioning

confidence: 99%

Projection of lactation milk yield from part records in crossbred dairy cows

Yadav

Sharma

Dutta

1984

Journal of Dairy Research

View full text Add to dashboard Cite

SummaryFirst lactation records of a total of 242 Jersey (JH), Brown Swiss (BH) and Holstein-Friesian (FH) halfbreeds from Hariana cows were studied for projecting 300 d milk yield from 12,14,16,18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38 and 40 weeks’ milk yield. The correlation coefficients between 300 d milk yield and part records ranged from 0·84 to 0·9 in the JH, 0·80 to 0·90 in the BH and 0·72 to 0·86 in the FH groups. Prediction equations and standard errors of estimation for prediction of 300 d milk yield for an individual animal are presented. It is suggested that part records up to 16, 22 and 22 weeks may be used for projecting 300 d yield with sufficient accuracy in the JH, BH and FH groups respectively.

show abstract

mentioning

confidence: 99%

Projection of lactation milk yield from part records in crossbred dairy cows

Yadav

Sharma

Dutta

1984

Journal of Dairy Research

View full text Add to dashboard Cite

show abstract

“…Famula and Van Vleck (6) also concluded that little accuracy in estimation of a sire's genetic merit was lost when part records of approximately 5 mo were extended and used to replace 305-day information. High genetic correlations between partial yields and complete yields also suggest evaluating sires on partial lactation records (14,17). In spite of the apparent high correlation between extended incomplete and complete records, there appear to be problems in the use of part-lactation records and extended records.…”

Section: Introductionmentioning

confidence: 99%

Extension Factors for Trimester Yields of Milk and Fat

Agyemang¹,

Clapp²,

Vleck³

1985

Journal of Dairy Science

View full text Add to dashboard Cite

Evidence of problems with sire proofs of extended incomplete records suggests the desirability of another method of evaluating dairy bulls for milk that minimizes the need for extending records by instead considering yields of three parts of a lactation (days 1 to 90, 91 to 180, and 181 to 270) as distinct and separate traits. Records of less than 90 days (or 180 or 270 days) require extension to 90-day (or 180-or 270-day) equivalents. Last sample day production of 17,826, 15,282, and 12,115 firstlactation records of Holstein cows was used to calculate extension factors to predict remaining yields to days 90, 180, and 270 for months of freshening and days in milk. Cumulative remaining yield was computed as the product of days remaining to day 90, 180, or 270, yield on last sample day, and the appropriate extension factor. There were no differences in factors due to age, but factors were different for months of freshening and number of days in milk.

show abstract

Comparison of methods of extending part lactation records for sire evaluation

Rao

Sundaresan

1980

J. Agric. Sci.

View full text Add to dashboard Cite

SummaryThe first lactation records of 684 Sahiwal, 157 Brown Swiss × Sahiwal (BS × S) and 255 Friesian × Sahiwal (F × S) constituted the data for this study. The 300-day yield was estimated from part lactation yields of 13, 17, 21, 26 and 30 weeks post partum by four methods, namely, regression, ratio, gamma and inverse polynomial functions. The duration of the part record and the method of estimation were evaluated for their reliability in estimating the 300-day yield and sire evaluation.The correlations between part records and 300-day yield ranged from 0·76 to 0·95, thecorrelations being higher in F × S. The error, absolute error and standard deviation of error weresmaller for ratio and regression methods than for the gamma and inverse polynomial functions. The part records of 30 weeks or more were found to be necessary to estimate 300-day yield within 15% of the actual yield with regression or ratio methods.The rank correlations and product moment correlations between sire indices calculated with part records and 300-day yield were found to be highly significant. The part records of 17 weeks or more extended by ratio or regression could be used to evaluate sires as accurately as with 300-day yield by increasing the progeny group size by 7–10% in Sahiwal and by about 20% in F × S. Theloss of efficiency in sire evaluation amounted to about 10–15% with part records of 17 weeks or more compared with 300-day yield.

show abstract

Sire Evaluation from Five-Month Daughter Records

Cited by 5 publications

References 16 publications

Projection of lactation milk yield from part records in crossbred dairy cows

Projection of lactation milk yield from part records in crossbred dairy cows

Extension Factors for Trimester Yields of Milk and Fat

Comparison of methods of extending part lactation records for sire evaluation

Contact Info

Product

Resources

About