Pete,
I don't think breed is your problem; the following is the result of a saddleback which killed out at 90kg
Cuts of Pork Total weight
3 Hand joints 3.26 kg
1 Rolled Topside Joint 1.24 kg
2 Chump Joints 2.87 kg
4 Rolled Loin joints 3.92 kg
4 Shoulder joints 5.15 kg
1 Leg of pork 3.93 kg
1 large Leg of Pork 4.96 kg
4 Rolled Belly joints 4.13 kg
2 Silverside joints 1.87 kg
Spring 0.98 kg
Fillet 0.46 kg
Knuckle joint 1.22 kg
Spare Ribs 1.61 kg
Belly Strips 3.70 kg
8 Top Rump Steaks 2.05 kg
Bag of Shoulder Chops 2.40 kg
Bag of Loin Chops 1.22 kg
Bag of Boneless Loin Chops 2.66 kg
Bags of Pork for casseroles 1.77 kg
Bags of Diced Pork 1.60 kg
Bags of Minced Pork 4.64 kg
Bone waste 12.6 kg
Fat & Rind waste 14.6 kg
Head 6.8 kg
TOTAL WEIGHT 89.64 kg
Now there are no magic formulas in pig keeping, even the commercial farms spend large amounts of time in tweaking diets, so the following are at best guidelines and some things to think about.
3 factors for you to consider
Age of pig
Amount of feed
Composition of feed
Age of pig
In essence you can kill a gilt pig or castrated boars from 8 weeks to any age and get good to sausages from it. Uncastrated Boars run a technical risk of boar taint, but that will start another issue, so will not discuss here.
Like most animals, nature designs a growing process. So whilst the following items will all grow, the emphasis is firstly on nervous system and bone (creating the framework). Next the pig will tend to build muscle - required for transporting the pig (including running away from danger), size (able to defend itself), and feeding (ability to dig/root). Once a pig has reached a certain size, the emphasis is to then lay down fat – as a pig never knows where its next meal is coming from, so storing energy is critical. This is a very simplistic explanation, and other factors such as sex, time of year (eg more fat in winter) play a part. I would re-iterate that all three (bone, muscle, fat) happen in parallel, but feed tends to be used differently as the pig grows.
Now the point of the above is that after 6 months of age, a pig has done most of its initial size growing, so tends to put extra feed more into fat than muscle, so whilst it will continue to grow muscle, the ratio tends to change.
So if to get from 8 weeks (weaner) to 8 months old you use 14 bags of feed at say £8 feed cost would be £112. To take to 12 months you would use 13 more bags, costing another £102. During this final 4 months, your pig will not double its muscle, and is very likely to add fat. Kill costs of 2 pigs vs. 1 will not materially affect the answer as they are much smaller than £100, so you would be much better off taking two pigs to 8 months than one to 12 months. So the short answer is kill earlier.
Amount of feed
So any excess feeding after 6 months can let the pig run to fat. Therefore at 6-8 months old, the feed input to meat output is probably at its best. After that the feed to take it to 12 months old will tend to be more into fat, so if you are to continue to keep, you must watch each pig, and adjust feed to ensure you are not just laying fat down. In winter, make sure bedding is sufficient, as if not, the pig will add fat for warmth.
You need to feel each pig regularly and adjust feed. This will let you get the best.
Type of feed
Pigs build fat/muscle/bone from proteins. Proteins are made from amino acids, and both the composition and the ratio needed for fat/muscle/bone is different.
For muscle 20 amino acids are needed. 12 of these the pigs can make itself, several others are found in almost all food, but there are a few key ones that pigs need. Lysine is the most often absent amino acid in raw pig feeds (wild boar get this from eating meat – carrion or killed). After that the most likely difficient are Threonine, Methionine, then tryptophan, then valine, then isoleucine.
Lysine is added to most commercial pig feed, but may not be present or sufficiently present in home mixes, or if other foods are used regularly in significant amounts (eg veg).
If the feed hasn’t the right composition for muscle, it may still be used for making fat (different amino acids and ratios needed) or poo’ed out as waste.
If you are not worried about cost as such, any bought in pig feed will grow a pig over time, and with watching fat, you can easily grow a great product. However as you are saying that you want a profit, then having the right feeds at the right time (eg grower and finisher) will get you more muscle and less risk of fat than say a sow mix, home mix or substituted foods.
So for a more profitable solution for sausages take off earlier, watch the amount you feed very carefully, and consider different feed regimes.
Topic: the right breed? (Read 5642 times)
