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Consequences of extending the voluntary waiting period for insemination on reproductive performance in dairy cows.
- Source :
-
Animal Reproduction Science . Sep2022, Vol. 244, pN.PAG-N.PAG. 1p. - Publication Year :
- 2022
-
Abstract
- The aim of the study was to evaluate the effect of extended voluntary waiting period (VWP) on ovarian cyclicity and reproductive performance of dairy cows. Holstein-Friesian dairy cows (N = 154) were blocked and randomly assigned to one of 3 groups with different VWP (50, 125 or 200 d: VWP-50 , VWP-125 or VWP-200). Milk samples were collected 3 times a week and analysed for progesterone concentration. Ovarian cycles were classified as: normal (18–24 days), short (<18 days) or prolonged (>24 days). For cows that became pregnant within 100 days after VWP, a VWP-200 d was related with fewer days until pregnancy after end of the VWP (19.4 d) compared with VWP-50 or VWP-125 (35.5, 37.3 d respectively). During 100 days (−50 until 50 d) around the end of VWP, cows in VWP-200 had a greater percentage of normal cycles (91.9 vs 58.0 %, P < 0.01) and a lower percentage of prolonged cycles (6.0 vs 32.7 %, P = 0.01) compared with cows in VW P -50. In the 4 weeks around the end of the VWP, cows in VWP-125 and VWP-200 had a lower milk yield compared with cows in VWP-50 (32.0, 27.5 vs 37.4 kg/d, P < 0.01). Inseminations continued until 300 days in milk, resulting in fewer pregnant cows for longer VWPs. In conclusion, extending the VWP from 50 to 125 or 200 days resulted in a greater percentage of cows with normal ovarian cycles and a lower milk yield around the end of VWP. Moreover, VWP-200 reduced days open after the end of the VWP, compared with VWP-50. • The voluntary waiting period (VWP) was extended from 50 to 125 or 200 days. • Extending VWP resulted in more cows with normal ovarian cycles. • Extending VWP till 200 days resulted in less days till pregnancy after VWP. • Extending VWP can improve reproductive success in dairy cows. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03784320
- Volume :
- 244
- Database :
- Academic Search Index
- Journal :
- Animal Reproduction Science
- Publication Type :
- Academic Journal
- Accession number :
- 158744257
- Full Text :
- https://doi.org/10.1016/j.anireprosci.2022.107046