Sow herd culling and mortality rates continue on the upswing. Although 2001 PigCHAMP recordkeeping data has yet to be summarized, a 12-month snapshot (June 1, 2000 to May 31, 2001) verifies the trend and provides some insight into the reasons sows drop out of the breeding herd.

For the nearly quarter of a million sows with complete parity records represented in the removal analysis, half were culled from the herd during the 12-month period and nearly 8% died (see accompanying table).

Sow removal is tabulated in three broad categories — culled, death or destroyed. Within each category is a menu of reasons sows are removed. Space limitations dictated that only the most prevalent data lines in each category could be presented.

Reasons for Culling

At first glance, it appears that “old age/parity” is the leading reason sows are culled (12.9%). However, a closer look at the reason-for-culling list shows a significant number of sows and gilts, across all parities, failed to get bred or stay pregnant. Specifically, in the report, this would include sows that: aborted (2.8%), did not conceive (10.3%), failed to farrow (1.2%), fertility failure (1%), found not pregnant (1.9%), no heat (7.9%) and pregnancy tested negative (1.7%).

Death & Destroyed

Perhaps more striking is the 12.8% death loss. As recent as 1999, the annual PigCHAMP summary shows death loss at just half that — 6.9%. The cause of death for nearly half of those losses is classified as “other” or “unknown” (1.1% and 5.1%, respectively), so specific answers for these losses cannot be pinpointed.

Lameness and downer sows are the most noted causes of death or need to destroy sows, and in combination, represent 16% of the sows in the analysis.

The analysis also showed that the average parity for sows culled was 3.8, while the average parity of sows that died or were destroyed landed at 2.3.

Gilts and Sows Selected for the Removal Analysis (entered the herd or farrowed) in the Report Period, June 1, 2000 - May 31, 2001

Parity 0 1 2 3 4 5 6 7+ Total
Gilts Entered Or Sows Farrowed 128,462 133,489 102,034 82,847 79,315 64,239 49,084 64,858 704,328
Complete Parity Records 43,960 38,492 28,637 26,523 29,331 23,564 20,193 30,423 241,123
Moved To Next Parity Waiting To Be Bred 32,605 23,330 19,270 17,005 18,014 13,151 8,951 9,012 141,338
Total Number Removed 22,408 23,629 14,599 14,947 15,912 14,283 14,807 26,457 147,042
Gilts and Sows Culled 18,059 18,220 11,080 11,533 12,756 11,877 13,054 24,326 120,905
Entry - First Service 14,710 - - - - - - - 15,124
Weaning - First Service - 15,747 9,379 9,773 11,052 10,430 11,808 22,619 90,815
First Service - Farrow 3,342 2,376 1,646 1,702 1,642 1,395 1,194 1,669 14,966
Gilt and Sow Deaths 3,213 3,765 2,452 2,335 2,342 1,772 1,341 1,555 18,775
Entry - First Service 2,581 - - - - - - - 2,727
Weaning - First Service - 3,327 2,145 2,010 2,034 1,517 1,149 1,339 13,521
First Service - Farrow 632 406 285 300 288 231 179 206 2,527
Transfers Farm to Farm 473 427 284 302 143 101 76 120 1,926
Other Removals 663 1,217 783 777 671 533 336 456 5,436
Percent of Complete Parity Records Gilts and Sows Culled 41.1 47.3 38.7 43.5 43.5 50.4 64.6 80.0 50.1
Entry - First Service 33.5 - - - - - - - 6.3
Weaning - First Service - 40.9 32.8 36.8 37.7 44.3 58.5 74.3 37.7
First Service - Farrow 7.6 6.2 5.7 6.4 5.6 5.9 5.9 5.5 6.2
Gilt and Sow Deaths 7.3 9.8 8.6 8.8 8.0 7.5 6.6 5.1 7.8
Entry - First Service 5.9 - - - - - - - 1.1
Weaning - First Service - 8.6 7.5 7.6 6.9 6.4 5.7 4.4 5.6
First Service - Farrow 1.4 1.1 1.0 1.1 1.0 1.0 0.9 0.7 1.0
Gilts and Sows Selected for the Removal Analysis Were Removed in the Report Period


Parity 0 1 2 3 4 5 6 7+ Total % of Total
Reason Culled 18,059 18,220 11,080 11,533 12,756 11,877 13,054 24,326 120,905 82.6
Aborted 913 613 459 467 604 454 280 328 4,118 2.8
Body Condition 614 817 406 566 530 330 263 217 3,743 2.6
Depopulation 100 424 598 582 352 211 222 224 2,713 1.9
Did Not Conceive 3,341 2,797 1,799 1,755 1,779 1,242 1,168 1,208 15,089 10.3
Fail To Farrow 458 317 152 194 176 150 146 161 1,754 1.2
Farrowing Productivity 101 394 442 689 1,024 1,197 1,402 1,887 7,136 4.9
Fertility, Sow 232 284 184 212 166 123 99 211 1,511 1.0
Found Not Pregnant 661 590 355 310 257 253 198 185 2,809 1.9
Lactation/Weaning Productivity 27 240 259 437 637 783 827 825 4,035 2.8
Lameness 2,126 2,092 1,272 1,114 1,147 930 681 745 10,107 6.9
No Heat 4,299 3,409 1,122 765 830 517 353 297 11,592 7.9
Old Age/Parity 56 124 112 248 581 1,372 3,561 12,891 18,945 12.9
Other 315 395 204 187 251 232 217 340 2,141 1.5
Pregnancy Check Negative 511 475 297 295 283 229 165 227 2,482 1.7
Small Litter Size 1 105 135 257 387 456 430 580 2,351 1.6
Unthrifty 212 289 147 177 215 166 141 145 1,492 1.0
Unknown Reason 2,355 2,529 1,729 1,747 1,671 1,588 1,416 2,139 15,174 10.4
Cause of Death 3,213 3,765 2,452 2,335 2,342 1,772 1,341 1,555 18,775 12.8
Difficult Farrowing 160 384 191 147 146 127 99 128 1,382 0.9
Downer 233 342 208 198 214 135 92 62 1,484 1.0
Lameness 166 217 137 130 120 80 74 54 978 0.7
Other 318 291 209 182 170 153 129 127 1,579 1.1
Retained Pigs 43 135 58 61 47 50 50 32 476 0.3
Ulcer 169 300 137 120 133 93 48 39 1,039 0.7
Unknown Reason 1,352 1,371 987 946 915 694 483 675 7,423 5.1
Destroyed 589 1,049 706 645 546 468 304 398 4,705 3.2
Downer 207 339 273 255 180 167 91 142 1,654 1.1
Lameness 156 286 162 154 152 110 90 91 1,201 0.8
Unknown Reason 76 133 90 82 52 54 40 61 588 0.4
Transfer 473 427 284 302 143 101 76 120 1,926 1.3
Complete Parity Records 43,960 38,492 28,637 26,523 29,331 23,564 20,193 30,423 241,123
Total Culled 18,059 18,220 11,080 11,533 12,756 11,877 13,054 24,326 120,905 82.6
Performance Culls, % 59.0 53.6 49.7 50.0 53.4 50.3 43.2 27.6 47.0
Non-Performance Culls, % 27.9 32.5 34.7 34.8 33.5 36.4 45.9 63.6 40.4
Unknown Culls, % 13.0 13.9 15.6 15.1 13.1 13.4 10.8 8.8 12.6
Total Deaths & Destroyed 3,802 4,814 3,158 2,980 2,888 2,240 1,645 1,953 23,480 16.0
Total Removes 21,861 23,034 14,238 14,513 15,644 14,117 14,699 26,279 146,311 100.0