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Heifer Pregnancy: Difference between revisions
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<span style="color:#680100;">'''''Phenotype'''''</span> | <span style="color:#680100;">'''''Phenotype'''''</span> | ||
[[Pregnancy Data | Pregnancy diagnosis ]] for first-calf heifers should be done within 60 to 65 days | [[Pregnancy Data | Pregnancy diagnosis ]] for first-calf heifers should be done within 60 to 65 days after the end of the breeding season. This allows for pregnant and open heifers to be identified, where selection can be focused on pregnant heifers. A [[Exposure Data | heifer exposure inventory ]] is necessary to ensure efficient use of pregnancy diagnosis data on heifers. | ||
<span style="color:#680100;">'''''Contemporary Group Information:'''''</span> | <span style="color:#680100;">'''''Contemporary Group Information:'''''</span> | ||
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<span style="color:#680100;">'''''Genetic Evaluation'''''</span> | <span style="color:#680100;">'''''Genetic Evaluation'''''</span> | ||
''Heifer pregnancy EPD'' estimates differences among individuals in the proportion of their daughters that will successfully conceive to calve at two years of age. Computation of | ''Heifer pregnancy EPD'' estimates differences among individuals in the proportion of their daughters that will successfully conceive to calve at two years of age. Computation of this [[Expected Progeny Difference | EPD]] requires [[Exposure Data | exposure data]] and pregnancy diagnosis results. ''Heifer pregnancy EPD'' is expressed as the probability of successful conception and predicts differences among individuals (typically sires) in the ability of their daughters to conceive and calve at two years of age. | ||
<span style="color:#680100;">'''''Usage'''''</span> | <span style="color:#680100;">'''''Usage'''''</span> | ||
Heifer pregnancy is an economically relevant trait because it will directly impact replacement heifers retained. | Heifer pregnancy is an economically relevant trait because it will directly impact replacement heifers retained. The number of breeds generating heifer pregnancy EPD has increased, therefore it is likely an across-breed heifer pregnancy EPD may be available. For increased reproductive efficiency in heifers, recommendations for exposing heifers should be followed. Structural characteristics and parental performance history should outweigh visual characteristics assumed related to reproductive performance (Sprott and Troxel, 2012). [[Scrotal Circumference | Scrotal circumference]] of yearling bulls can be used an indicator of their daughters' expected heifer pregnancy. | ||
<span style="color:#680100;">'''''Reference:'''''</span> | <span style="color:#680100;">'''''Reference:'''''</span> | ||
Sprott, L.R. and T.R. Troxel. 2012. Management of replacement heifers for a high reproductive and calving rate. Texas AgriLife Extension B-1213. [http://aglifesciences.tamu.edu/animalscience/wp-content/uploads/sites/14/2012/04/beef-mgmt-replacement.pdf] | Sprott, L.R. and T.R. Troxel. 2012. Management of replacement heifers for a high reproductive and calving rate. Texas AgriLife Extension B-1213. [http://aglifesciences.tamu.edu/animalscience/wp-content/uploads/sites/14/2012/04/beef-mgmt-replacement.pdf] | ||
Revision as of 12:44, 17 December 2019
Phenotype
Pregnancy diagnosis for first-calf heifers should be done within 60 to 65 days after the end of the breeding season. This allows for pregnant and open heifers to be identified, where selection can be focused on pregnant heifers. A heifer exposure inventory is necessary to ensure efficient use of pregnancy diagnosis data on heifers.
Contemporary Group Information:
1. Yearling Weight Contemporary Group Criteria
2. Heifer Pregnancy Management Code
3. Breeding Season Start and End Dates
4. Exposure
5. Breeding Pasture and/or Sire Effect
Genetic Evaluation
Heifer pregnancy EPD estimates differences among individuals in the proportion of their daughters that will successfully conceive to calve at two years of age. Computation of this EPD requires exposure data and pregnancy diagnosis results. Heifer pregnancy EPD is expressed as the probability of successful conception and predicts differences among individuals (typically sires) in the ability of their daughters to conceive and calve at two years of age.
Usage
Heifer pregnancy is an economically relevant trait because it will directly impact replacement heifers retained. The number of breeds generating heifer pregnancy EPD has increased, therefore it is likely an across-breed heifer pregnancy EPD may be available. For increased reproductive efficiency in heifers, recommendations for exposing heifers should be followed. Structural characteristics and parental performance history should outweigh visual characteristics assumed related to reproductive performance (Sprott and Troxel, 2012). Scrotal circumference of yearling bulls can be used an indicator of their daughters' expected heifer pregnancy.
Reference:
Sprott, L.R. and T.R. Troxel. 2012. Management of replacement heifers for a high reproductive and calving rate. Texas AgriLife Extension B-1213. [1]
