Effect of concentrate supplementation during early lactation on plasma IGF-I concentrations and reproductive performance of dairy cows
| dc.contributor.author | Obese, F.Y. | |
| dc.contributor.author | Stirling, T.E. | |
| dc.contributor.author | Stockdale, R.C. | |
| dc.contributor.author | Macmillan, K.L. | |
| dc.contributor.author | Egan, A.R. | |
| dc.contributor.author | Humphrys, S. | |
| dc.date.accessioned | 2012-09-12T10:29:22Z | |
| dc.date.accessioned | 2017-10-14T11:56:44Z | |
| dc.date.available | 2012-09-12T10:29:22Z | |
| dc.date.available | 2017-10-14T11:56:44Z | |
| dc.date.issued | 2011 | |
| dc.description.abstract | An experiment was conducted to assess the effects of body condition score (BCS) at calving and level of feed supplementation during early lactation on the Insulin-like growth Factor-I (IGF-I) and reproductive performance in 72 Holstein cows in a pasture-based system following seasonally-synchronized calving. At the start of the seasonal breeding, plasma IGF-I concentrations in cows that had recommenced ovarian activity with detected oestrus were compared with those in anoestrus. The cows (n = 72) were managed over a period of five months to calve in a BCS of 4, 5 or 6 - using a scale from 1 (thin) to 8 (obese). The cows were maintained on pastures and supplemented during early lactation with either 1 or 6 kg grain per day. The BCS at calving did not affect plasma IGF-I concentrations. The plasma IGF-I concentration at week 10 was elevated at the higher level of grain supplementation (87.8 vs. 72.1 ng/mL). Higher conception rate following the first insemination of cows calving with a BCS of 6 (71% vs. 46% and 37% for a BCS of 4 and 5, respectively) was associated with more cows in that group conceiving during the first three weeks of the artificial insemination (AI) programme (75% vs. 46% and 46% for a BCS of 4 and 5, respectively). At weeks 0 and 10, cows that commenced ovarian activity by the start of the intensive AI programme, recorded higher plasma IGF-I concentrations than anoestrous cows. These findings indicate that diet can affect the plasma IGF-I levels, which in turn may be involved in affecting the resumption of cyclic ovarian activity and conception in dairy cows. | en_US |
| dc.identifier.citation | South African Journal of Animal Science 41(4):360-367 | en_US |
| dc.identifier.uri | http://197.255.68.203/handle/123456789/1785 | |
| dc.language.iso | en | en_US |
| dc.subject | BCS | en_US |
| dc.subject | conception | en_US |
| dc.subject | dairy cows | en_US |
| dc.subject | IGF-I | en_US |
| dc.subject | postpartum period | en_US |
| dc.title | Effect of concentrate supplementation during early lactation on plasma IGF-I concentrations and reproductive performance of dairy cows | en_US |
| dc.type | Article | en_US |
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