Nutritional Strategies to Mitigate the Effects of Negative Energy Balance on Reproductive Performance of Early Postpartum Does

Abstract

The objective of this study was to research nutritional strategies to mitigate the effects of Negative Energy Balance (NEB) on reproductive performance of early postpartum does. Twenty seven does in their second week of lactation and their kids were randomly assigned to three levels of supplement diet, replicated three times. The diets were: (1) Low Energy/Protein supplement level (LEP; Control), (2) Medium Energy/Protein supplement level (MEP), or (3) High Energy/Protein supplement level (HEP). The LEP (control) diet was fed at 0.95%, MEP at 1.50% and HEP at 1.90% of BW on a DM basis. The study lasted 28 days. Supplement level did not (p>0.10) reverse the expected loss in doe body condition during the early stages of lactation. The does lost on average 0.056 kg day^-1 through the duration of the study. The average body condition score of the does at the start of the experiment was 1.80 (on a scale of 1-5) and 1.75 at the end. The HEP kids tended (p<0.10) to gain faster than LEP kids; no difference (p>0.10) between HEP and MEP or MEP and LEP kids. The HEP kids gained 0.087 kg day^-1; MEP kids gained 0.061 kg day^-1 whereas LEP kids gained 0.022 kg day^-1. In conclusion, something in addition to high energy/protein supplement level may be needed to mitigate the effects of NEB which is in part responsible for delayed return of ovulatory events in early postpartum does.