Effect of lactation length adjustment procedures on genetic parameter estimates for buffalo milk yield

被引:17
作者
Baldi, Fernando [1 ]
Massolini Laureano, Monyka Marianna [2 ]
Mansan Gordo, Daniel Gustavo [1 ]
Bignardi, Annaiza Braga [1 ]
Aspilcueta Borquis, Rusbel Raul [1 ]
de Albuquerque, Lucia Galvao [1 ]
Tonhati, Humberto [1 ]
机构
[1] Univ Estadual Paulista, Dept Zootecnia, Fac Ciencias Agr & Vet, BR-14884900 Jaboticabal, SP, Brazil
[2] Univ Fed Amazonas, Parintins, AM, Brazil
基金
巴西圣保罗研究基金会;
关键词
genetic correlations; heritability; lactation length; milk production; rank correlations; TEST DAY RECORDS; FAT; SELECTION; PROTEIN;
D O I
10.1590/S1415-47572011000100012
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The objectives of this study were to estimate the genetic parameters for milk yield unadjusted and adjusted for days in milk and, subsequently, to assess the influence of adjusting for days in milk on sire rank. Complete lactations from 90 or 150 days of lactation to 270 or 350 days in milk were considered in these analyses. Milk yield was adjusted for days in milk by multiplicative correction factors, or by including lactation length as a covariable in the model. Milk yields adjusted by different procedures were considered as different traits. Heritability estimates varied from 0.17 to 0.28. Genetic correlation estimates between milk yields unadjusted and adjusted for days in milk were greater than 0.82. Adjusting for days in milk affected the parameter estimates. Multiplicative correction factors produced the highest heritability estimates. More reliable breeding value estimates can be expected by including short length lactation records in the analyses and adjusting the milk yields for days in milk, regardless of the method used for the adjustment. High selection intensity coupled to the inclusion of short length lactations and adjustment with multiplicative factors can change the sire rank..
引用
收藏
页码:62 / 67
页数:6
相关论文
共 15 条
[1]  
BAJWA IR, 2002, P 7 WORLD C GEN APPL
[2]  
Bhat P. N., 1978, Indian Journal of Dairy Science, V31, P321
[4]   SELECTION ON TEST-DAY FAT PERCENTAGE AND MILK PRODUCTION [J].
KEOWN, JF ;
VANVLECK, LD .
JOURNAL OF DAIRY SCIENCE, 1971, 54 (02) :199-&
[5]  
Khan MS, 2000, J DAIRY SCI S1, V83, P223
[6]  
Kuralkar SV, 1997, INDIAN J ANIM SCI, V67, P798
[7]  
MADALENA FE, 1992, REV BRAS GENET, V15, P585
[8]  
Melo CMR, 2000, REV BRAS ZOOTECN, V292, P1060
[9]   RECENT STUDY OF AGE ADJUSTMENT [J].
MILLER, P .
JOURNAL OF DAIRY SCIENCE, 1973, 56 (07) :952-958
[10]   GENETIC-PARAMETERS OF TEST DAY RECORDS OF BRITISH HOLSTEIN-FRESIAN HEIFERS [J].
PANDER, BL ;
HILL, WG ;
THOMPSON, R .
ANIMAL PRODUCTION, 1992, 55 :11-21