Beef embryos in dairy cows: calfhood growth of Angus-sired calves from Holstein, Jersey, and crossbred beef dams.
Transl Anim Sci
; 7(1): txad096, 2023.
Article
em En
| MEDLINE
| ID: mdl-37799707
ABSTRACT
Improved reproductive management has allowed dairy cow pregnancies to be optimized for beef production. The objective of this sire-controlled study was to characterize the effects of beef or dairy maternal genetics and the dairy management system on calf growth. Pregnancies were created with a 2â
×â
2 factorial arrangement of dam breed (Holstein or Jersey) and mating type (artificial insemination or implantation of an in vitro produced embryo from a commercial beef cow oocyte). Resulting calves were reared in a calf ranch. Additionally, commercial beef cows were inseminated and reared resulting calves on range. Therefore, the five treatments were Angusâ
×â
Holstein (Aâ
×â
H; nâ
=â
19), Angusâ
×â
Jersey (Aâ
×â
J; nâ
=â
22), Angusâ
×â
beef gestated by Holstein (H ET; nâ
=â
18), Angusâ
×â
beef gestated by Jersey (J ET; nâ
=â
8), and Angusâ
×â
beef raised by beef (Aâ
×â
B; nâ
=â
20). Beginning at birth, calf body weight, cannon circumference, forearm circumference, top width, hip width, and hip height were measured approximately every 28 d until ~196 d of age. At birth, Aâ
×â
J calves weighed the least (Pâ
<â
0.01). At 150 d of age, body weight was greatest (Pâ
<â
0.05) among Aâ
×â
B calves, intermediate among H ET and Aâ
×â
H calves, and least among J ET and Aâ
×â
J calves (Pâ
<â
0.05). Morphometric differences were detected between treatments (multivariate analysis of variance, Pâ
<â
0.01). Primary discriminant function scores identified Aâ
×â
B calves having lesser values than Aâ
×â
J or Aâ
×â
H calves (analysis of variance [ANOVA], Pâ
<â
0.01); Aâ
×â
B calves had greater cannon circumference, greater top width, and less hip height (standardized loadings of -0.47, -0.48, and 0.63, respectively). Secondary discriminant function scores identified J ET and H ET to have greater forearm circumference-a key indicator of muscling-than Aâ
×â
J or Aâ
×â
H (ANOVA, Pâ
<â
0.01; standardized loading of 0.99). The dairy management system limited growth rate of beef genetics compared to the beef management system. In addition, Holstein dams transmitted greater growth potential than Jersey dams. Replacing maternal dairy genetics with beef genetics moderated frame size and created a more muscular phenotype.
Texto completo:
1
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Transl Anim Sci
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Estados Unidos