Pigs differ in their genetic potential to deposit lean (muscle) and fat tissue, and in the pattern of development of these tissues. Some genotypes gain both of these body-component tissues rapidly throughout the grower- finisher period, whereas others gain both lean and fat slowly. Other genetic lines fit into a slow-rapid or rapid-slow pattern of these two body components. High lean-gain pigs are defined in this publication as pigs that deposit lean (fat-free muscle) tissue at 0.7 lb. or higher per day during the grower-finisher period. This generally results in > 50% fat-free lean in the carcass at slaughter and a 10th rib backfat thickness of 0.6 to 0.9 inches. Although there are leaner pigs available, this is considered leaner than the "industry average" pigs. The latter group is considered to have < 49% fat-free lean, and a 10th rib backfat thickness of 0.9 to 1.3 inches.
The rate and composition of weight gain during the grower-finisher period can affect the amino acid and energy needs of the pig perhaps more than other nutrients. A rapid rate of lean gain increases the need for amino acids because these nutrients are used for protein synthesis, most of which is muscle tissue. On the other hand, lean deposition will require less energy than fat deposition.
To formulate diets accurately for different genetic lines, it is necessary to know the rate and pattern of lean deposition and the feed intake for the specific genetic line. Unless the seedstock supplier provides this information for the progeny from their genetic line, the collection of feed intakes at two- to three-week intervals and subsequent slaughter data with market pigs may be desirable. This will allow one to better formulate the diets for the herd. As we gain information about specific amino acid and mineral needs for body growth, we will be able to calculate the pig's nutrient requirements more precisely. Currently, the most accurate method for assessing the lean composition of the pig is to measure the backfat thickness and the loin muscle area with a ruler and grid, respectively, after a group of pigs have been slaughtered. The formulas presented here are currently used to calculate the amount of lean deposited per day. ("Days on test" in the formulas presented refers to the length of the entire feeding period.)
When carcass measurements are available, daily lean gain can be determined by the general formula presented. The information calculated can therefore be used to determine the lean gain per day. The recommendations in Tables 4 and 5 can be used to balance the diets for the genotype of the pigs you are feeding.
LEAN GAIN = (lbs. of lean in carcass at slaughter) - (lbs. of initial lean in feeder pig)
---- ----
Lean | 7.231 + 0.437 x adj. warm carcass wt., lb. |
Gain = 0.95 x | - 18.746 x 10th rib fat depth, in. |
| + 3.877 x 10th rib LMA*, in. 2 | -[(0.418 x live wt., lb.)-3.65]
| |
---- ----
_____________________________________________________________________________________________
Days on test
When fat and muscle depth data are obtained electronically, the following formula can be used:
---- ----
Lean | 2.827 + 0.469 x adj. warm carcass wt., lb. |
Gain = 0.95 x | - 18.470 x fat depth, in. | -[(0.418 x live wt., lb.)-3.65]
| + 9.824 x muscle depth, in. |
| |
---- ----
______________________________________________________________________________________________
Days on test
*LMA = loin muscle area
| Table 4. Nutrient Recommendations for Grower-Finisher Pigs (High Lean-Gain, High Health). | ||||||||
|---|---|---|---|---|---|---|---|---|
| Weight Range | ||||||||
| Weight, lb.: | 50 to 100 | 100 to 150 | 150 to 200 | 200 to Market | ||||
| Sex: | Gilt | Barrow | Gilt | Barrow | Gilt | Barrow | Gilt | Barrow |
| Item | Expected Performance Responsesa | |||||||
| Daily gain, lb. | 1.5-1.8 | 1.7-2.0 | 1.6-2.0 | 1.7-2.0 | 1.6-2.1 | 1.7-2.2 | 1.6-2.1 | 1.6-2.3 |
| Daily feed, lb. | 3 - 4 | 3.5-4.5 | 4 - 5 | 4.5-5.5 | 4-6 | 4.5-7 | 4.5-7 | 5-8 |
| Daily feed, lb. (amount to obtain suggested lysine) | 3.6 | 3.7 | 4.6 | 4.7 | 5.1 | 5.3 | 5.6 | 5.9 |
| Item | Dietary Recommendations (As-Fed Basis)b | |||||||
| Protein, % | 18- 22 | 17- 20 | 17- 20 | 16- 19 | 16- 19 | 15- 18 | 14- 17 | 13- 16 |
| Amino acids (total), c,d | ||||||||
| Lysine, % | 1.10 | 0.95 | 1.00 | 0.85 | 0.90 | 0.75 | 0.75 | 0.60 |
| Lysine, g/day | 18 | 16 | 21 | 18 | 21 | 18 | 19 | 16 |
| Tryptophan, % | 0.20 | 0.17 | 0.18 | 0.15 | 0.16 | 0.14 | 0.14 | 0.11 |
| Threonine, % | 0.72 | 0.62 | 0.65 | 0.55 | 0.58 | 0.49 | 0.49 | 0.39 |
| Methionine + Cystine, % | 0.66 | 0.57 | 0.60 | 0.51 | 0.54 | 0.45 | 0.45 | 0.36 |
| Macro-mineralsd | ||||||||
| Calcium, % | 0.72 | 0.72 | 0.72 | 0.72 | 0.58 | 0.58 | 0.58 | 0.58 |
| Phosphorus (total), % | 0.60 | 0.60 | 0.60 | 0.60 | 0.48 | 0.48 | 0.48e | 0.48e |
| Phosphorus (available), % | 0.30 | 0.30 | 0.30 | 0.30 | 0.21 | 0.21 | 0.21 | 0.21 |
| Sodium, % | 0.11 | 0.11 | 0.11 | 0.11 | 0.11 | 0.11 | 0.11 | 0.11 |
| Chloride, % | 0.09 | 0.09 | 0.09 | 0.09 | 0.09 | 0.09 | 0.09 | 0.09 |
| (Salt, %) | 0.25 | 0.25 | 0.25 | 0.25 | 0.25 | 0.25 | 0.25 | 0.25 |
| Trace mineralsf | ||||||||
| Copper, ppm | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 |
| Iodine, ppm | 0.17 | 0.17 | 0.17 | 0.17 | 0.17 | 0.17 | 0.17 | 0.17 |
| Iron, ppm | 85 | 85 | 85 | 85 | 55 | 55 | 55 | 55 |
| Manganese, ppm | 7 | 7 | 7 | 7 | 6 | 6 | 6 | 6 |
| Selenium, ppm | 0.3 | 0.3 | 0.2 | 0.2 | 0.15 | 0.15 | 0.15 | 0.15 |
| Zinc, ppm | 85 | 85 | 85 | 85 | 55 | 55 | 55 | 55 |
| Vitaminsf | ||||||||
| Vitamin A, IU/lb. | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 |
| Vitamin D, IU/lb. | 110 | 110 | 110 | 110 | 110 | 110 | 110 | 110 |
| Vitamin E, IU/lb.g | 22 | 22 | 22 | 22 | 11 | 11 | 11 | 11 |
| Vitamin K, mg/lb. | 0.55 | 0.55 | 0.55 | 0.55 | 0.55 | 0.55 | 0.55 | 0.55 |
| Niacin, mg/lb. | 11 | 11 | 11 | 11 | 8 | 8 | 8 | 8 |
| Riboflavin, mg/lb. | 3 | 3 | 3 | 3 | 2.5 | 2.5 | 2.5 | 2.5 |
| Pantothenic acid, mg/lb. | 8 | 8 | 8 | 8 | 7 | 7 | 7 | 7 |
| Vitamin B12, µg/lb. | 11 | 11 | 11 | 11 | 6 | 6 | 6 | 6 |
| a A range is denoted that reflects different environmental conditions. b These nutrients need to be supplemented to diets. Other nutrients are usually adequate. c If gilts and barrows are fed together, use an average of the values given. d Values are total dietary levels. e The phosphorus level can be reduced to 0.35% during this phase if calcium is at the same time reduced to 0.40%. DO NOT FEED THESE LOW Ca and P DIETS to REPLACEMENT GILTS! f Values are supplemental levels. g The vitamin E level needs to be increased as the unsaturated fatty acid (PUFA) level in the diet increases. (3 IU Vit. E/g PUFA). | ||||||||
| Table 5. Nutrient Recommendations for Grower-Finisher Pigs (Industry Average). | ||||||||
|---|---|---|---|---|---|---|---|---|
| Weight Range | ||||||||
| Weight, lb.: | 50 to 100 | 100 to 150 | 150 to 200 | 200 to Market | ||||
| Sex: | Gilt | Barrow | Gilt | Barrow | Gilt | Barrow | Gilt | Barrow |
| Item | Expected Performance Response | |||||||
| Daily gain, lb. | 1.1-1.6 | 1.1-1.6 | 1.4-1.8 | 1.4-1.8 | 1.5-2.0 | 1.5-2.0 | 1.6-2.1 | 1.6-2.1 |
| Daily feed, lb. | 3-5 | 3-5 | 4-6.5 | 4-6.5 | 4-7 | 4.5-7.5 | 4.5-8.5 | 5-9 |
| Daily feed, lb. (amount to obtain suggested lysine) | 3.5 | 3.6 | 4.6 | 4.9 | 5.5 | 6.0 | 6.0 | 6.4 |
| Item | Dietary Recommendations (As-Fed Basis)b | |||||||
| Protein, % | 17-20 | 15-18 | 16-19 | 14-17 | 15-18 | 13-16 | 13-15 | 12-14 |
| Amino acids (total)cd | ||||||||
| Lysine, % | 0.95 | 0.85 | 0.82 | 0.72 | 0.72 | 0.63 | 0.63 | 0.55 |
| Lysine, g/day | 15 | 14 | 17 | 16 | 18 | 17 | 17 | 16 |
| Tryptophan, % | 0.17 | 0.16 | 0.15 | 0.13 | 0.13 | 0.11 | 0.11 | 0.10 |
| Threonine, % | 0.62 | 0.55 | 0.53 | 0.47 | 0.47 | 0.41 | 0.41 | 0.36 |
| Methionine + Cystine, % | 0.57 | 0.51 | 0.49 | 0.43 | 0.43 | 0.38 | 0.38 | 0.33 |
| Macro-mineralsd | ||||||||
| Calcium, % | 0.65 | 0.65 | 0.60 | 0.60 | 0.50 | 0.50 | 0.45 | 0.45 |
| Phosphorus (total), % | 0.55 | 0.55 | 0.50 | 0.50 | 0.45 | 0.45 | 0.40e | 0.40e |
| Phosphorus (available), % | 0.28 | 0.28 | 0.23 | 0.23 | 0.20 | 0.20 | 0.15 | 0.15 |
| Sodium, % | 0.10 | 0.10 | 0.10 | 0.10 | 0.10 | 0.10 | 0.10 | 0.10 |
| Chloride, % | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 |
| (Salt, %) | 0.25 | 0.25 | 0.25 | 0.25 | 0.25 | 0.25 | 0.25 | 0.25 |
| Trace mineralsf | ||||||||
| Copper, ppm | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 |
| Iodine, ppm | 0.15 | 0.15 | 0.15 | 0.15 | 0.15 | 0.15 | 0.15 | 0.15 |
| Iron, ppm | 75 | 75 | 75 | 75 | 50 | 50 | 50 | 50 |
| Manganese, ppm | 6 | 6 | 6 | 6 | 5 | 5 | 5 | 5 |
| Selenium, ppm | 0.3 | 0.3 | 0.2 | 0.2 | 0.15 | 0.15 | 0.15 | 0.15 |
| Zinc, ppm | 75 | 75 | 75 | 75 | 50 | 50 | 50 | 50 |
| Vitaminsf | ||||||||
| Vitamin A, IU/lb. | 900 | 900 | 900 | 900 | 900 | 900 | 900 | 900 |
| Vitamin D, IU/lb. | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Vitamin E, IU/lb.g | 20 | 20 | 20 | 20 | 10 | 10 | 10 | 10 |
| Vitamin K, mg/lb. | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
| Niacin, mg/lb. | 10 | 10 | 10 | 10 | 7 | 7 | 7 | 7 |
| Riboflavin, mg/lb. | 2.5 | 2.5 | 2.5 | 2.5 | 2 | 2 | 2 | 2 |
| Pantothenic acid, mg/lb. | 7 | 7 | 7 | 7 | 6 | 6 | 6 | 6 |
| Vitamin B12, micro-g/lb. | 10 | 10 | 10 | 10 | 5 | 5 | 5 | 5 |
| a A range is denoted that reflects different environmental conditions. b These nutrients need to be supplemented to diets. Other nutrients are usually adequate. c If gilts and barrows are fed together, use an average of the values given. d Values are total dietary levels. e The phosphorus level can be reduced to 0.30% during this phase if calcium is at the same time reduced to 0.34%. DO NOT FEED THESE LOW Ca and P DIETS to REPLACEMENT GILTS! f Values are supplemental levels. g The vitamin E level needs to be increased as the unsaturated fatty acid (PUFA) level in the diet increases. (3 IU Vit. E./g PUFA). | ||||||||