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Use MSA guidelines for lamb and sheepmeat to improve product eating quality.
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Weigh and fat score lambs pre-sale or pre-slaughter and use the information to better manage the production system and meet target specifications.
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Use dressing percentage to convert live animal weight into carcase weight of each sale consignment.
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Understand management factors affecting skin values. |
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Key decisions, critical actions and benchmarks
Weigh and/or fat score lambs Weighing all or a representative 20% sub-sample of lambs is recommended before sale. Make adjustments for wet or damp sheep and wool length. After weighing, draft lambs into liveweight categories and then use fat scoring to assess the range in fatness.
Fat scoring of sale lambs (see tool 3.3) is an important pre-sale procedure when targeting a market. The fat scores are based on the live animal tissue thickness (both fat and lean tissue) at the GR site (110mm from the carcase midline over the 12th rib). A practical option is to draft lambs into liveweight categories then fat score a 20% sub-sample of the animals. This is used to estimate the amount of fat cover on the carcase and fat scores or MSA processing classes from 1 (leanest) to 5 (fattest).
Calculating dressing percentage
Australian lambs generally have a standard dressing percentage of 45-49% hot weight, 2‑3 hours off feed.
Use dressing percentage to convert live animal weight into carcase weight (as per figure 3.3). Figure 3.3 Converting live weight to carcase weight
Factors affecting dressing percentage include:
- Breed type - at the same fatness, more muscled animals dress higher; Merinos tend to dress lower. Border Leicester/ Merino and Merino lambs will generally dress 1.5% to 3.5% less than second cross lambs.
- Age - older animals have a lower dressing percentage (suckers > carryover lamb > ewe mutton). Tool 3.3 tables these differences.
- Fat score - higher fat score animals have a higher dressing percentage (see tool 3.3)
- Time off feed and water prior to weighing - increased time held off-feed increases dressing percentage (see tool 3.3).
- Seasonal feed conditions - low digestibility pasture will reduce dressing percentage by as much as 3%
- Sex – wether lambs dress higher than ewe lambs (see tool 3.3)
- Skin weight (wool length, wet or dry) – a 75mm (3inch) skin, just too wet to shear, holds 0.2-0.5kg of water. Make no adjustment for dry skins.
Apply Meat Standards Australia™ (MSA) sheepmeat guidelines
Use of MSA guidelines for lamb and sheepmeat will improve the eating quality of lamb, hogget, young mutton and mutton.
When applying MSA standards make sure that:
- First and second cross lambs gain at least 100g/day weight for the two weeks before consignment and sale.
- Merino cross and pure bred lambs gain at least 150g/day before consignment and slaughter.
- Sheep are at least fat score 2 at slaughter.
- Sheep are gaining weight for at least 2 weeks before consignment for slaughter.
Tool 3.5 provides the MSA on-farm production guidelines and tool 3.6 presents the MSA processing guide.
Livestock Quality Systems
Livestock Quality Systems (LQS) provides certification and verification systems that instil confidence in on-farm food safety practices.
LQS consists of five major programs:
- Livestock Production Assurance (LPA) – a new on-farm food safety certification program designed to help the red meat industry strengthen the food safety systems currently in place.
- National Vendor Declarations (NVD) - the key tool used by sheep producers to declare valuable information about the food safety status of the livestock being sold in Australia.
- Electronic Declaration Program - download software programs that provide electronic versions of the LPA NVD/Waybill.
- Livestock Fodder Declarations - obtained from the supplier of livestock fodder at purchase to indicate the chemicals used.
- Livestock Integrity (LI) - issues dealing with livestock residues, livestock feeding, and livestock disease.
The National Livestock Identification Scheme (NLIS) for Sheep and Goats
All sheep and goats born in or after January 2006 must have an NLIS breeder tag in most cases before being sent to a saleyard or another property. From 1 January 2007 in Queensland and 1 January 2009 in other states and territories, all sheep and farmed goats, irrespective of the date of birth must be identified with an approved NLIS tag prior to movement.
Some processors currently require all sheep to have an NLIS tag regardless of the date of birth. Sale of any sheep or goats requires a National Vendor Declaration.
The sheep identification requirements are designed to enhance the previous state regulations, and to improve the speed and accuracy of traceback and traceforward of sheep and goats.
The National Residue Survey
The National Residue Survey is an Australian Government program that monitors agricultural products and meat producing animals for residues of agricultural and veterinary chemicals, as well as some environmental and industrial contaminants.
The general purpose of residue monitoring is to confirm that residues in products are within internationally accepted limits and to alert responsible authorities when limits are exceeded so that corrective action can be taken, and affected product removed from the food chain.
The survey is designed to confirm Australia’s status as a producer of clean meat. Abide by withholding periods for a range of chemicals to avoid residues in sheep meat.
Signposts  |
Read Making the Most of Mutton
Winning against seeds
MLA Live Assessment Yard Book - Sheep and lamb
MLA Tips & Tools - MSA Sheepmeat Information Kit
Order any of these MLA publications by:
View
MLA Livestock Quality Systems (LQS): certification and verification systems for meat sheep. Visit:
http://www.mla.com.au/LivestockQualitySystems
National Livestock Identification System (NLIS) for sheep and goats.
Visit: www.mla.com.au/NLIS |
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Recording the amount of feed on offer from forage and/or supplementary feeding systems.