Cheyenne Nicholson
Early weaning has been shown to have benefits for the management of feed and the prioritisation of lamb growth. The concern with early weaning is that there will be nutritional stress or behaviour constraints which may limit energy intake, reduce growth rate and alter carcase composition resulting in lighter carcases at slaughter, a downgraded carcase and potentially meat quality issues.
Previous trials have shown that a herb-clover mix forage for lambs can result in meat that is more tender compared to the meat from lambs grazing perennial ryegrass-white clover pastures.
A study recently presented at the New Zealand Society of Animal Production at Massey University, looked at whether weaning lambs early, at eight weeks of age, on to a high-nutritive value plantain-clover mix would influence the meat quality characteristics of lamb compared to lambs weaned conventionally at 14 weeks and finished on perennial ryegrass pastures. Herb-clover mixes have a higher drymatter digestibility and metabolisable energy content which allows for higher voluntary feed intake and nutritive value compared to perennial ryegrass pastures.
The study, undertaken at Massey Univesity’s Tuapaka farm included 43 Romney ewes rearing twin lambs. Ewes and lambs were allocated to four treatments:
- Early weaned lambed (eight weeks old) on a plantain-clover mix
- Lambs with dam grazing a plantain-clover mix
- Lambs with dam grazing pasture > 1200kg DM/ha and
- Lambs with dam grazing <1200kg DM/ha. Meat samples were collected from each lamb and analysed for ultimate pH, meat colour, drip loss, and shear force.
All lambs were slaughtered at a set minimum liveweight of 35kg. Weaning age played a role in carcaseweight with early-weaned lambs yielding lighter carcaseweights when compared to lambs that were with their dam on the plantain-clover mix. This was attributed to the milk the lambs were obtaining from their mother providing a high-energy food source which is more efficiently utilised by lambs for growth.
The lambs on ewes who were on low pasture allowance had the lightest carcaseweights showing the importance of ewe feed allowance during early lactation influencing the nutritional intake of the lamb at foot.
Weaning age did not impact carcase characteristics or meat quality. IMF (intramuscular fat) and VIAscan GR were the same for all treatment groups (likely due to lambs being slaughtered at a minimum set live weight) and objective meat-quality measures were similar among the treatments. IMF and ultimate pH can influence meat tenderness. pH can also influence other meat-quality traits like colour and water-holding capacity.
- More? www.nzsap.org/system/files/proceedings/brief-communication-comparison-meat-quality-characteristics-lambs-weaned-eight-or-14-weeks-age.pdf
KEY POINTS
- Diet can influence meat quality characteristics.
- Early weaning has benefits in farm management and lamb growth prioritisation but also has some pitfalls to be considered.
- Early weaning and low plane of nutrition cause lighter carcaseweights.
- Early weaning on to a plantain-clover forage does not impact carcase characteristics and won’t have a negative impact on eating quality.
