I'm trying to help a friend out with their pigs. They have 2 barrows who both weighed in at 277 yesterday. They have 35 days till show, and can max out at 300. They look really good, but could still use some back and rib shape. I know they can really only gain about 0.8 lbs/day at most, and could be put on a Fitter 35/Depth Charge ration to keep gain low, but is there a way to do so and still add back and rib, without adding too much gain and pushing them over the limit?

Depth Charge will add rib. BTW a current weight of 277, max of 300, and 35 days calculates to 0.66 lb/day. (300 - 277) / 35 = 0.66

35 days is a long time to feed Fitter 35 as it burns fat.

Break it down into shorter periods of 10, 10, and 15 days:

1st 10 days:
(Total daily feed; divide into 2 equal meals):
Fitter 35. 3 lb
Depth Charge. 1/2 lb (8 oz).
Should gain 0.3 lb/day (3 lb total) and weigh 280 with 25 days left. (300 - 280) / 25 days = 0.80 /day (possible gain)

2nd 10 days:
(Total daily feed; divide into 2 equal meals):
Fitter 35. 3 lb
Depth Charge. 1 lb (16 oz)
Heavy Weight. 4 oz
Should gain about 0.50 lb/day (5 lb total) and weigh 285 with 15 days left. (300 - 285) / 15 days = 1.0 lb/day (possible gain)

So for the final 15 days:
(Total daily feed; divide into 2 equal meals):
Fitter 35 3 lb
Depth Charge. 1 lb (if needed increase to 1 1/2 lb)
Heavy Weight. 8 oz.
should gain about 0.8 to 0.9 lb/day

Mix the Heavy Weight with enough water to make a milk shake like consistency then add to the Fitter 35 and Depth Charge.

If the pig seems to be too lean at any point reduce Fitter 35 by 1/4 to 1/2 lb per day and increase Heavy Weight.

Excellent! Thanks again for the prompt response.

P.S. Not sure how I messed up the calculation, but thanks for the correction.