Potential benefits of precision nutrition to increase reproductive efficiency under grazing conditions

Abstract

Recent development in automatic sheep management systems based on radio frequency tags, in-race readers and automatic drafting equipment creates opportunities for strategic nutritional management of individual animals. This paper describes a simple simulation model for investigating the implications of different supplementary feeding systems in terms of potential benefits of increased lambing percentages. Four different feeding systems are compared: (i) feeding each animal according to its individual requirements to reach a weight of 52 kg prior to joining; (ii) feeding 0.3 kg daily to each animal; (iii) feeding the same amount of feed as in (ii) but given twice per week to the whole group; and (iv) as for (iii), but with variation in intake randomly allocated across all weight ranges. Feed conversion efficiency (FCE) was set at 8:1 for twice weekly feeding and at 5:1 for daily feeding. Although the highest lambing percentage was achieved using the feeding system in scenario (i), the most profitable feeding regime was (ii). The results confirm that feeding restricted amounts of supplement twice weekly may not be a cost-effective way of increasing ovulation rate and lambing percentage. On the other hand, precision nutrition, in conjunction with electronic sheep management systems, may increase efficiency and profitability of the ewe flock. Although the current study deals only with lambing rate, it is likely that precision nutrition may be cost-effective in managing ewe nutrition prior to lambing. New methods of feeding management and feed preparation may be needed to get the most value from computer-based feed management systems.