Farmer Focus: Finding balance between growth and fat cover

As expected, batch A did very well. In fact, it turned out to be our second-best batch in terms of growth rate.

We sent a total of 933 pigs to slaughter between 2 January (118 days old) and 11 February (158 days old). 

Within this group, 90% were classified as bacon weight (>65kg deadweight), which is roughly 87kg liveweight.

The batch as a whole averaged 111kg liveweight and 83.3kg deadweight, at an average of 149 days old, and 847g was gained a day from weaning (7.85kg at 28 days) to finish. 

See also: Liquid feeding weaners improves pig finishing performance

If we analyse just the bacon pigs, they reached an average of 114kg liveweight/85.7kg deadweight at 151 days old and gained 863g a day. 

The first 200 bacon pigs sent to Tesco at 144 days old reached 117.5kg, therefore gaining 940g a day from wean to finish.

We sent some real flyers at only 126 days old which grew at an average of 962g a day, reaching a liveweight of 102.8kg.

We are really pleased with these results, but considering our contract allows us to go up to 100kg deadweight, we are certainly missing out on some extra kilos of growth.

However, we are limited by space and have to clear the batch by the time they are 22.5 weeks old. 

What is pleasing though is our post-wean mortality has averaged only 3% for the past five batches, and for the last quarter our antibiotics use was 6mg/kg, which is well under the industry target of 90mg/kg.

Unsurprisingly, with an increase in slaughterweight, we have also seen back fat levels go up. 

This is something that hasn’t really concerned us in the past, but we are seeing more pigs fall outside of our contract specification.

This is not because they are overweight, but because back fat levels are too high.

We could look at reducing the energy in the diet, but this would affect growth. However, what we would lose in kilogrammes would not make up for the current penalties we are receiving for pigs with back fat at the P2 site (rib fat over the rib muscle) of more than 15mm.

Sophie Hope is a Farmer Focus writer from near Cheltenham. Read her biography