Oral Presentation Australian and New Zealand Metabolomics Conference 2018

Effect of fodder beet or ryegrass diets during pregnancy on lamb growth, carcass characteristics, meat quality and meat metabolites (#5)

Linda M Samuelsson 1 , Nicola N Schreurs 2 , Catherine McKenzie 3 , Kirsty Hammond 4
  1. Food Nutrition & Health Team, AgResearch Ltd, Palmerston North, New Zealand
  2. School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
  3. Bioinformatics & Statistics Team, AgResearch Ltd, Palmerston North, New Zealand
  4. Animal Nutrition & Physiology Team, AgResearch Ltd, Palmerston North, New Zealand

Feeding fodder beet (FB; Beta vulgaris) to New Zealand livestock has increased considerably in the last ten years. FB is energy-rich (high sugar content), making it a suitable finishing diet for cattle and sheep. However, the suitability of feeding FB during pregnancy and lactation is virtually unexplored, with even less known about FB’s carryover effect on offspring growth and meat quality. Our aim was to investigate the effect of ewes grazing FB vs. ryegrass-dominant pasture (RG) from mid-to-late gestation on offspring performance.

Twin-bearing ewes grazed either FB (n=100) or RG (n=100) diets from mid-to-late gestation, and pasture from parturition onwards. From birth, lambs were managed on pasture and were weighed at docking (30 days), weaning (90 days) and slaughter (160 days) to measure growth rates. Carcass characteristics, meat quality and meat metabolites were measured at slaughter to assess the effect of diet during pregnancy on offspring.

Lambs born to FB-fed ewes were 400 g lighter (p=0.002) than those born to RG-fed ewes at birth. This live weight difference increased over time, indicating that the lambs born to ewes fed FB did not have the capacity to grow as fast as lambs born to ewes fed RG. The lamb live weight difference was reflected in the carcass characteristics, with the carcass weight significantly lower (p=0.0003) for the lambs born to FB-fed ewes. Maternal diet had no effect on lamb meat quality parameters. Polar and lipid metabolites in the lamb meat were measured by 1H-NMR spectroscopy and LC-MS, respectively. 44 polar metabolites were identified and quantified in lamb meat including well-known meat metabolites carnitine, anserine, carnosine, inosine monophosphate, inosine. Results on lamb meat metabolite profiles and maternal diet effects are pending.

This study indicates that a diet dominant in FB is unable to meet the nutritional requirements of twin-bearing ewes and their progeny, and that a maternal FB diet, compared to RG, influences performance traits in the offspring right through to slaughter.