By Jack Bosworth, Director, FJ Bosworth & Sons. Published 18 March 2024.

I hope everyone is well.

The forecast is finally looking as if we may have a week of dry weather. It has been a challenging start to Ed’s first spring on the arable here, with very limited opportunities to get onto the land. He has been able to get some contract spreading down and is up to date with spraying and fertiliser, which is no small thing given the conditions.

Optimising the gilt feed plan

Elsewhere, on the pigs, we have been looking to optimise feed plans for gilts during gestation. Alex and Gemma are taking a keen interest in getting the data we need to analyse our current position, and to understand where we can enhance performance to better equip our young breeding stock for consistency and longevity in the herd.

This is the kind of work that does not deliver instant results. It pays off in the next generation of sows and the one after that.

Our targets, in numbers

These are the targets we are working toward for gilts:

MeasureTarget
Weight at first service160 kg
Age at first service254 days
Weight gain during gestationApproximately 70 kg
Weight moving into farrowingApproximately 230 kg
Allowable body condition loss (excluding 20 to 25 kg of litter and placenta)6 to 8 per cent

Right now, our body condition loss is sitting above the target window, and that is the figure we want to bring back in.

What the most recent batch actually showed

Gilts weaned on 14 March 2024:

  • Averaged 215 kg going into farrowing, around 6.5 per cent under our target.
  • Averaged 164 kg at weaning.
  • Body weight loss across gestation and lactation: 13.73 per cent, excluding average litter and placenta weight.

The 13.73 per cent loss is the figure I am focused on. It tells us, in plain percentage terms, that the gilts are working harder than we want them to be across the cycle.

The current feed plan we are working with

The plan as it stands looks like this:

Days post-inseminationFeed allowance
0 to 7Around 2 kg per day
7 to 50Increasing by approximately 35 per cent across that window
50 to 100Peak of the curve, up to 3.1 kg per day
100 onwards (pre-farrowing move)Around 3.0 kg per day

Amounts are also adjusted along the way according to body condition score, which is currently decided by Alex and Gemma at the unit.

What we want from a few tweaks

Hopefully, some adjustments to the feed plan will allow us to:

  • Increase weight at farrowing, closer to that 230 kg target.
  • Improve litter size.
  • Reduce body condition loss back into the 6 to 8 per cent window where it should sit.

It is the same principle that has worked for us before with parity 2. Small, deliberate changes to feed allocation at the right stage, with the right monitoring in place to see what is actually happening.

I will report back as the data comes through.


About the author

Jack Bosworth is a fourth-generation farmer and Director of FJ Bosworth & Sons, an arable and pig farming business at Spains Hall, Willingale, Essex. The farm has been in the family since 1919, and Jack farms alongside his father Stuart Bosworth, who was named Farmers Weekly Pig Farmer of the Year in 2011. The business is Red Tractor assured and runs an integrated farm-to-fork model, with home-grown cereals milled on site using solar-generated electricity.

You can follow Jack’s articles on fjbosworth.com, or get in touch via the WhatsApp link on the site.

Written by Jack Bosworth

Fourth-generation farmer at Spains Hall, Willingale. Runs the contracting team and writes most of what appears here.