Proper Lactation Feeding Critical to Sow Longevity

Adequate feeding throughout lactation is paramount to the maintenance and longevity of high-producing females in the breeding herd.

In a Pork Checkoff-funded study, 1,275 sows from a Minnesota herd were analyzed for the association of farrowing and lactation factors during lactation (including reported diseases) on the likelihood of removal from the herd before the next farrowing.

The effect of low daily feed intake (less than 9 lb.) for the first two weeks of lactation, on sow removals before next farrowing, was specifically addressed.

Overall, results indicated that the risk of sow removal declined as average daily feed intake and the number of piglets born alive increased.

The likelihood of removal from the herd dropped by 11% with every pound increase in average daily feed intake during lactation.

Also, the odds of removal from the herd decreased by 7% for every additional piglet born alive.

Parity 1 and 2 sows and Parity 3-5 sows had 47% and 44% less chance, respectively, of removal from the herd, compared to sows of Parity 6 or higher.

Other factors such as mummies, stillbirths, farrowing induction, farrowing assistance and reported diseases during lactation, didn't appear to influence sow longevity in this study.

Sows consuming less than 9 lb. of feed on a single day during the first two weeks of lactation had 27% greater chance of removal from the herd.

The study suggested that ensuring adequate feed intake from the start of lactation may reduce sow removals in breeding herds.

Deficient feed intake in sows results in excessive weight loss and may have adverse reproductive consequences, resulting in reduced sow longevity.

Researchers: Sukumarannair S. Anil, DVM; Leena Anil, DVM; and John Deen, DVM, University of Minnesota. Contact Sukumarannair S. Anil by phone (612) 625-4243, fax (612) 625-1210 or e-mail sukum001@umn.edu.

Floor Space Requirements Lowered For Finishing Pigs

University of Illinois research has concluded that growth rates of finishing pigs can be optimized when housed at much lower floor space requirements than previously reported.

Two studies in a commercial wean-to-finish production system confirm that a space allowance of 7.3 sq. ft./pig will achieve maximum growth rates, compared to previous minimum requirements of 8.8-9.0 sq. ft./pig.

If implemented in grow-finish barns, these findings could increase throughput and provide new welfare guidelines for the pork industry.

Study 1 used 3,132 pigs grown from 75 lb. to 255 lb., allotted to three floor spaces: 6.6, 7.3 and 8 sq. ft./pig.

Study 2 used 1,740 pigs grown from weaning (about 17 days of age) to 265 lb., allotted to five floor spaces: 6.2, 6.6, 7.0, 7.4 and 7.9 sq. ft./pig.

Pigs were housed in groups of 29 pigs/pen, and pen sizes were adjusted to the required floor spaces.

Data on pig weights and feed delivery and disappearance were recorded for both studies.

Pigs at the lowest floor space (6.2 and 6.6 sq. ft./pig) had reduced growth rates in both studies compared to the highest floor spaces tested.

Morbidity and mortality levels were also highest in the first study for pigs reared at the lowest floor space treatment. But floor space did not affect morbidity and mortality rates in the second study.

In both studies, pigs raised at the lowest floor spaces had the highest percent lean and least backfat.

Again, both studies suggest that growth rate was maximized at a floor space allowance of 7.3 sq. ft./pig, much lower than published values for the minimum floor space allowance for maximum growth rate.

Researchers: B.A. Peterson, M. Ellis, J.M. DeDecker, M.J. Ritter and C.R. Bertelson, University of Illinois; B.F. Wolter and R. Bowman, The Maschhoffs, Inc.; N. Williams and C. Zeir, PIC USA. Contact Ellis by phone (217) 333-6455, fax (217) 333-7088 or e-mail mellis7@uiuc.edu.

Severity of Claw Lesions Analyzed Over a Parity Cycle

A study of a commercial farm in Minnesota revealed that the severity of claw lesions may become more severe over a parity cycle.

In the Pork Checkoff-funded trial, the feet of 98 sows (Parities 1-8) were individually examined between 110-114 days of gestation when the sows were in farrowing stalls.

Lesions consisted of erosions, cracks and overgrowths. Lesions were scored and examined again in their subsequent parity.

Results indicated that the intensity of lesions (front and hind feet) increased over a parity in the lateral (outside) claws and decreased in medial (inside) claws. The intensity of lesions increased in the hind leg lateral claws (toes) in the subsequent parity, whereas front feet lateral claw scores did not differ greatly between parities.

Within the hind leg lateral claws, overgrown heels and intensities of lesions on side walls and white lines increased, while the severity of lesions at heel-sole junction decreased in the next parity.

Within the front leg medial claws, the intensity of white line lesions was reduced in the following parity.

The intensity (irrespective of the orientation of legs and claws) of overgrown heels increased, and intensity of lesions at heel-sole junction decreased in the subsequent parity. The presence of overgrown heels increased, and the presence of lesions at heel-sole junction decreased in the hind feet in the subsequent parity.

The presence of overgrown heels in the front feet was higher in the subsequent parity.

Regardless of the orientation of hooves and legs, the presence of lesions at heel-sole junction decreased, and overgrown heels increased in the subsequent parity.

Results suggest that lesions on hind leg lateral claws may increase in severity over time.

The development of hoof lesions is the result of a complex interaction of floor surface and the horn of the foot. Lesions don't develop equally on all hooves. More lesions have been reported in lateral claws than in medial claws due to greater weight-bearing surface in the lateral claws.

The increase in area of the weight-bearing surface is obviously not corresponding to the increase in weight of the modern breeds that are developed for rapid growth.

As bodyweight increases, the pressure exerted on the hoof area increases the chance of injuries. This may also increase the risk of hoof lesions with the advancement of parity, adding to the number of sows that are culled due to lameness at a younger age than those removed for other reasons.

Researchers: Sukumarannair S. Anil, DVM; Leena Anil, DVM; and John Deen, DVM, University of Minnesota. Contact Sukumarannair S. Anil by phone (612) 625-4243, fax (612)625-1210 or e-mail sukum001@umn.edu.