Pregnancy and lactation are two different processes, but they are physiologically and nutritionally linked. Nutrients supplied during gestation not only affect the development of the litter, but they can also influence the sow's productivity during lactation. A balanced diet fed throughout the reproductive cycle is critical and should contain the better-quality feed grains. The latter is extremely critical as mycotoxins are higher in poorer quality grains. The mycotoxins can result in serious reproductive consequences.
Many high-producing sow lines not only produce more pigs but also produce more milk. Both of these traits result in heavier litter and pig weaning weights. Consequently, differences in sow genotype will directly affect sow nutrient requirements during both reproductive phases. A comparison between the sows of two different productivities is presented in Table 9 and can be used as a guide for your herd. The genetic capability of the sow affects her reproductive performance, but nutritional adequacy during both phases has a direct affect on her longevity in the herd.
| Table 9. Characteristics of Sow Production Capabilities. | |||
|---|---|---|---|
| Criteria | Industry Average | High-Producing | |
| Gilt breeding weight, lb. | 240-250 | 280-300 | |
| Pigs born, no. | 9 - 11 | 10 - 14 | |
| Pig birth wt., lb. | 2.75 - 3.25 | 2.75 - 3.25 | |
| Pigs weaned, no. | 7.5 - 9.0 | 9.0 - 11.0 | |
| Pig weaning weight, lb. | |||
| 14-day | 7.0 - 9.0 | 9.0 - 11.0 | |
| 21-day | 11.0 - 12.5 | 12.5 - 14.0 | |
| 28-day | 13.5 - 19.0 | 16.0 - 18.0 | |
| Litter weight (21 day), lb. | 90 - 110 | 130 - 160 | |
| Rebreeding interval, daya | 5 to 10 | 5 to 10 | |
| a First-parity rebreeding intervals are generally two to three days longer than for older sows. | |||
The annual culling rate of sows in the United States currently ranges between 30 to 40%, but swine producers should target a goal of retaining at least 75% of the sows for five or more parities. The major reasons for culling sows are:
Culling of sows, however, is not only attributable to inadequate nutrition, but also to genotype, facilities, equipment, and management practices. These factors can independently or mutually affect the reproductive performance of the sow herd. Because of the different productivities of parity-one animals compared with older sows, the nutritional recommendations in Tables 10 and 12 allow for these conditions for two different sow genotypes or productivities. Each producer should establish the average lactation feed intake and productive capacity of their sow herd and then provide a diet that will meet the sow's nutrient needs.
| Table 10. Nutrient Recommendations for Gestation (Based on Productivity and Age). | |||||
|---|---|---|---|---|---|
| Item | Parity 1 | Parity 2 and Later | |||
| Industry Average | High-Producing | Industry Average | High-Producing | ||
| Expected Performance | |||||
| Feed intake, lb.a | 4.0 | 4.3 | 4.3 - 5.0 | 4.6 - 5.5 | |
| Feed intake (2 to 3 wk prefarrow), lb.b | 4.5 - 5.0 | 5.5 - 6.5 | 5.4 - 7.0 | 5.0 - 8.0 | |
| Gestation gain (0 - 114 d), lb. | 100 | 125 | 75 - 100 | 90 - 110 | |
| Gestation gain (0 - farrow), lb. | 60 | 100 | 50 - 80 | 60 - 90 | |
| Body score at farrowing (0 - 5) | 3.5 | 3.5 | 3.5 | 3.5 | |
| Backfat thickness (last rib), inch.c | 0.8 - 1.2 | 0.8 - 1.0 | 0.8 - 1.0 | 0.8 - 1.0 | |
| Breeding weight, lb. | 240-280 | 270-320 | - | - | |
| Nutrient Requirements (As-Fed Basis) | |||||
| Energy, Mcal ME/lb. | 1.4 | 1.4 | 1.4 | 1.4 | |
| Protein, % | 14 | 15 | 12 | 13 | |
| Amino Acids (total)d | |||||
| Lysine, % | 0.65 | 0.75 | 0.55 | 0.60 | |
| Tryptophan, % | 0.10 | 0.11 | 0.08 | 0.09 | |
| Threonine, % | 0.42 | 0.48 | 0.31 | 0.36 | |
| Methionine + Cystine, % | 0.39 | 0.45 | 0.32 | 0.35 | |
| Macro-mineralse | |||||
| Calcium, % | 0.90 | 0.90 | 0.90 | 1.00 | |
| Phosphorus (total), % | 0.70 | 0.70 | 0.70 | 0.80 | |
| Phosphorus (available), % | 0.42 | 0.42 | 0.42 | 0.45 | |
| Sodium, % | 0.20 | 0.20 | 0.20 | 0.20 | |
| Chloride, % | 0.16 | 0.16 | 0.16 | 0.16 | |
| (Salt, %) | 0.50 | 0.50 | 0.50 | 0.50 | |
| Trace-mineralsf | |||||
| Copper, ppm | 15 | 15 | 15 | 15 | |
| Iodine, ppm | 0.15 | 0.15 | 0.15 | 0.15 | |
| Iron, ppm | 100 | 100 | 100 | 100 | |
| Manganese, ppm | 10 | 10 | 10 | 10 | |
| Selenium, ppm | 0.3 | 0.3 | 0.3 | 0.3 | |
| Zinc, ppm | 150 | 150 | 150 | 150 | |
| Vitaminsf | |||||
| Vitamin A, IU/lb. | 2,000 | 2,000 | 2,000 | 2,000 | |
| Vitamin D, IU/lb. | 200 | 200 | 200 | 200 | |
| Vitamin E, IU/lb. | 30 | 30 | 30 | 30 | |
| Vitamin K, mg/lb. | 0.50 | 0.50 | 0.50 | 0.50 | |
| Biotin, mg/lb. | 0.10 | 0.10 | 0.10 | 0.10 | |
| Choline, g/lb. | 0.25 | 0.25 | 0.25 | 0.25 | |
| Folic acid, mg/lb. | 0.75 | 0.75 | 0.75 | 0.75 | |
| Niacin, mg/lb. | 6 | 6 | 6 | 6 | |
| Riboflavin, mg/lb. | 2 | 2 | 2 | 2 | |
| Pantothenic acid, mg/lb. | 8 | 8 | 8 | 8 | |
| Vitamin B12, Micro-g/lb. | 8 | 8 | 8 | 8 | |
| a Housing outdoors will increase feed (energy) intake requirements. The intake values presented in this table reflect feeding once daily under indoor conditions in individual feeding stalls. b The quantity to be provided will depend upon sow body-fat score. For scores less than 3.5, feed at the upper level; whereas if the body fat score is > 4.0, the lower levels should be fed. c Measurements at the end of gestation. If backfat thickness is measured at the 10th rib, the value will be about 10% higher. d Total amino acid recommendations reflect a diet composed of a corn-soybean meal mixture. The amino acids listed are those that are commonly limiting. e Values reflect total dietary concentration, unless noted otherwise. f Values reflect the supplemental level to be added to the diet. | |||||