Maximising Productivity in Lamb Finishing Systems

Growth Curve: Animal growth follows a Sigmoid growth curve; nutrition is the primary driver of performance.
Ewe Nutrition: Proper nutrition during the first $8$ weeks of the lamb's life maximizes the Daily Liveweight Gain (DLWG) at approximately $300\,g/day$ .
Post-Weaning: Management is vital to maintain a target DLWG of at least $200\,g/day$ .

Diversity: There are approximately $90$ breeds of ewe, including about $60$ purebred varieties categorization into Hill, Upland, and Lowland types.
Selection Tools: Productivity is driven by Terminal Sire Breed Estimated Breeding Values (EBVs) and Maternal Genetics.

Finished Lamb: Defined as a lamb reaching a desired carcass grade, typically at an average age of $7$ months. Includes New Season Lamb (NSL) and Old Season Lamb (OSL).
EUROP Grid: Classification is based on Conformation (E, U, R, O, P) and Fat Class ( $1$ , $2$ , $3L$ , $3H$ , $4L$ , $4H$ , $5$ ).
Market Misses (2024 Data):
- NSL: $3.5\%$ were too fat and $17.6\%$ were poor.
- OSL: $5.6\%$ were too fat and $26.2\%$ were poor.
- In $2018$ , $42\%$ of finished lambs failed to meet ideal target specifications.

Grass Finishing: Used for March/April born lambs. Low cost and labor, but risks include weather, fly strike, and Nematodirus. DLWG: $50-200\,g/day$ .
Grass + Creep: Earlier finishing and smoother weaning. DLWG: $300-400\,g/day$ .
Indoor (Creep Fed): Fastest finishing and leaves grazing for ewes, though costs and labor are higher. DLWG: $350-400\,g/day$ .
Indoor (Silage): Requires high-quality silage; may need supplementation. DLWG: $100-200\,g/day$ .

Store Lambs: Lambs not finished in their original system (e.g., Hill lambs, late May lambs). Ages range from $10-12$ months.
Systems by Duration:
- Short Keep: Less than $6$ weeks; total gain $5-6\,kg$ ; DLWG $140-160\,g/day$ .
- Medium Keep: $6-12$ weeks; total gain $6-12\,kg$ ; DLWG $90-110\,g/day$ .
- Long Keep: Over $12$ weeks; total gain $12-18\,kg$ ; DLWG $80-100\,g/day$ .
Typical Forage Crops: Stubble turnips, kale, fodder beet, swedes, and forage rape. DLWG on crops: $80-160\,g/day$ .

Vaccination: Essential for Pasteurellosis (Mannheimia haemolytica) and Clostridial diseases (e.g., lamb dysentery, tetanus, pulpy kidney).
Parasites: Monitoring required for Nematodirus battus, Telodorsagia, Trichostrongylus, Haemonchus contortus, and Coccidiosis.
Trace Elements:
- $-Co$ (Cobalt): Pine/B12 deficiency.
- $-Cu$ (Copper): Swayback.
- $+Cu$ : Toxicosis (sudden death/jaundice).
- $-Se$ (Selenium) and Vit E: White Muscle Disease (WMD).
Weaning: Recommended at $12-16$ weeks. Lambs should be vaccinated approximately $2$ weeks before weaning.

Key Performance Indicators (KPIs):
- Technical: Pre/post-wean DLWG, Mortality, Food Conversion Efficiency (FCR/FCE).
- Financial: Price per lamb sold (ppkg), Full Economic Cost of Production, Net Margin.
Weight Targets: Average $8$ -week weight should be >20\,kg; weaning weight at $90$ days should be >30\,kg.
Marketing Methods:
- Liveweight ( $52\%$ ): Competitive bidding, immediate payment, but no carcase feedback.
- Deadweight ( $48\%$ ): Paid on carcase weight with feedback, but stock cannot be withdrawn.
Matched Groups: Selling in matched groups can provide a premium return of over $£3.00$ per lamb compared to mixed lots.