Later weaning age may be more appropriate to maximising financial output in current economic conditions, according to BPEX’s Mike Varley.
Speaking at JSR’s annual conference, he said although a younger weaning age may be an easy route to 28pigs/sow/year and after doing some financial calculations it would be the “accountants decision to wean early”, in reality pig prices and general feedstuffs actually determine what the optimum weaning age would be.
“The final solution to weaning age will vary from farm to farm and also over time and that is why farming businesses need to continually review weaning age and ask themselves whether it is being optimised, as weaning age can have a marked effect on the financial output of a business.”
Dr Varley also said, although many large scale companies simply do the mathematics, they often don’t factor in to account the physiology.
“Although weaning age isn’t something that can be changed too easily, accountants may calculate annual sow production as being optimised with earlier weaning. However, in reality this doesn’t take in to account the effect of other physiological factors.
“For example, research shows the weaning to oestrus interval increases and is more variable with earlier weaning, as well as conception rate also reducing with earlier weaning.
“Litter size can also be reduced with earlier weaning and this could be because embryo survival is better where pigs have been weaned later. So in reality after taking in to account these factors, annual sow production would be maximised with later weaning,” explained Dr Varley.
A computer simulation model using 2009 costs shows, at about 30 days weaning cost/kg/gain was 0.5p compared to 0.7p at about 17 days weaning.
The model also shows the financial gross margin a sow is currently maximised at 35 days weaning with a gross margin of £300/sow weaned at 35 days compared to less than £100/sow gross margin for a sow weaned at 21 days. “The ratio of feed cost index to pork price is a good determinant when looking at what age to wean. Obviously in the UK we are bound by legislation to weaning at 28 days, so in the medium-term it would be worth looking at whether financial output could be maximised by extending the weaning age.”