Introduction

Pulmotil (tilmicosin phosphate) is approved for use in swine at a rate of 181-363 grams per ton of complete feed for the control of swine respiratory disease associated with Actinobacillus pleuropneumoniae and Pasteurella multocida. The effects of feeding Pulmotil 363 grams/ton to sows in the lactation ration on subsequent performance of pigs in the nursery phase has been previously studied.1 However, the effect of feeding Pulmotil 181grams/ton to sows in lactation on nursery pig performance has not been reported. Furthermore, while the beneficial effects of feeding Pulmotil in the lactation ration and the beneficial effects of feeding Pulmotil to nursery pigs have been established through various clinical reports,2,3,4 the impact of feeding Pulmotil 181grams/ton in the lactation ration followed by Pulmotil in the nursery ration has not been reported.

Materials and Methods

The study was conducted in a 1300-sow multi-site farrow-to-finish operation with a history of swine respiratory disease associated with Pasteurella multocida and Actinobacillus pleuropneumoniae Type 7 (App7). Sows in 5 farrowing rooms supplied by a single feed bin were fed Pulmotil at 181g/ton throughout lactation for a total of 21 days treatment per sow (Lactation treatment = PL). Sows in 4 farrowing rooms supplied by a single feed bin were fed a lactation diet without antibiotics included (Lactation treatment = NL). Cross-fostering of pigs between treatment groups PL and NL was not permitted during the study period.

Pigs were grouped by week of weaning into separate rooms in a common nursery barn. Pigs weaned from Pulmotil-treated sows in lactation ration (PL) were randomly assigned to one of two nursery treatments. Likewise, pigs weaned from sows with no antibiotics in lactation (NL) were randomly assigned to one of two nursery treatments. The two nursery treatments were as follows:

  • Nursery treatment = PN: Pulmotil 363 grams/ton for 7 days followed by Pulmotil 181 grams/ton for 14 days for a total 21 days Pulmotil treatment.
  • Nursery treatment = DN: Denagard 35 grams/ton and chlortetracycline 400 grams/ton for the first two weeks after weaning followed by one week of Denagard 35 grams/ton.
  • For data analysis, pigs were identified as being in one of four overall treatment groups based on the treatment of their dams in lactation and on the nursery treatment (Table 1).

All pigs were individually identified with numbered Allflex tamper-proof ear tags and individual pig weights were recorded one day prior to weaning. All pigs were vaccinated at weaning with Suvaxyn PCV2 single-dose Porcine Circovirus Type 2 vaccine (Fort Dodge Animal Health). Pig identification and individual pig weights were recorded at 3-weeks post-weaning and again at 6-weeks post-weaning.

Results

No differences were observed in pre-weaning mortality or in the number of pigs weaned per litter between sows fed Pulmotil in lactation (PL) and sows with no antibiotics in the lactation ration (NL). However, pigs weaned from sows fed Pulmotil in lactation (PL) were 0.6 lbs. heavier at weaning than were pigs weaned from sows with no antibiotics in lactation (NL) (p<0.0001) (Table 2).
In addition, nursery mortality was reduced in groups of pigs weaned from sows treated with Pulmotil (PL) versus pigs weaned from non-treated sows (NL) (p=0.0177). Nursery mortality rate in the PL group was 1.7% versus 2.8% in the NL group (Table 2). Odds ratio calculations were used to estimate the relative risk of pig death in the nursery for pigs in the PL and NL treatment groups. Pigs weaned from sows with no antibiotics in lactation were 1.68 times more likely to die by 6 weeks post-weaning than were pigs from sows treated with Pulmotil in lactation (p=0.0426) (Table 3). Nursery mortality was not different between groups treated with Pulmotil in the nursery versus Denagard CTC in the nursery when evaluated independently of lactation treatment (Table 3).

Since there was interaction between nursery and lactation treatment on nursery gain (p=0.0062), and on 6 weeks post-weaning weights (p<0.0001), data was evaluated separately for each of the four combination treatments (Table 4). Average daily gain in the nursery was higher in pigs groups that received Pulmotil in lactation if they did not receive Pulmotil in nursery diets (PL-PN and PL-DN versus NL-DN) (p<0.05). There was no significant difference in nursery ADG in pig groups if they received Pulmotil either during lactation or in nursery diets (PL-PN vs. PL-DN vs. NL-PN) (p>0.05) (Table 4).

Upon review of average pig weights at 6 week post-weaning, pigs were heavier in groups that received Pulmotil either in the lactation or nursery diets as compared to groups receiving the Denagard CTC rations in the nursery and no antibiotic in lactation (PL-PN, PL-DN, and NL-PN vs. NL-DN) (p<0.05) (Table 3).

In addition, average pig weights at 6 weeks post-weaning were heavier in groups that had Pulmotil in lactation diets and Denagard CTC diets in the nursery as compared to groups that had Pulmotil diets in both areas (PL-PN vs. PL-DN) (p<0.05) (Table 4).

At 6 weeks post-weaning, 4.58% of pigs weaned from sows with no antibiotics in the lactation ration (NL) were ≤25 lbs. versus 2.60% of pigs weaned from sows fed Pulmotil in lactation (PL). Odds ratio calculations were used to estimate the relative risk of being lightweight, defined as ≤25 lbs., at 6 weeks post-weaning.  Pigs from sows with no antibiotic in lactation (NL) were 2.18 times more likely to be ≤25 lbs. at 6 weeks post-weaning than were pigs weaned from sows treated with Pulmotil (PL) (p=0.0134).  Furthermore, pigs that received Denagard CTC in the nursery ration were 1.93 times more likely to be ≤25 lbs. at 6 weeks post-weaning than were pigs that received Pulmotil in the nursery rations (p=0.0168). Overall, pigs that received no Pulmotil (NL-DN) were 1.93 times more likely to be ≤25 lbs. at 6 weeks post-weaning versus pigs that received Pulmotil in lactation, in the nursery, or both (PL-DN, NL-PN, and PL-PN) (p=0.0044) (Table 3).

Discussion

In this study, benefits to the offspring were observed from feeding Pulmotil for 21 days in lactation at 181g/ton.  These included increased wean weights, improved nursery survivability, and improved ADG of pigs in the nursery. Average pig weight at 6 weeks post-weaning was improved in groups from Pulmotil treated sows as well as pigs that received Pulmotil for the first three weeks after weaning even when their dams were not treated with Pulmotil. Looking at average daily gain and average weight at 6 weeks post-weaning would suggest that when feeding Pulmotil in lactation rations, an alternative feed medication program should be considered for the first three weeks after weaning.
Feeding Pulmotil either in the lactation ration or in the nursery ration had the added benefit of reducing attrition (culls, deads, and lights) in the nursery phase.  Pigs weaned from sows with no antibiotics in lactation were more likely to die before 6 weeks post-weaning than their cohorts that were weaned from Pulmotil-treated dams. Pigs in either Pulmotil treated groups in lactation or Pulmotil treated groups in the nursery were less likely to be lightweight (≤25 lbs.) at 6 weeks post-weaning than were pigs from groups that never received Pulmotil.

These data suggest that feeding Pulmotil in the early nursery phase is helpful at reducing attrition, and that feeding Pulmotil in lactation rations has added benefits over feeding Pulmotil directly to pigs in. It is thought that this benefit is a result of improved respiratory health of pigs which are weaned from sows treated with Pulmotil in lactation.1 In systems that cannot include Pulmotil in lactation rations, feeding Pulmotil in the first three weeks of the nursery improves nursery performance, as indicated by increased weight at 6 weeks post-weaning in this study and as illustrated in previous clinical reports.2,3,4 

Additional data analysis is needed to evaluate the economic impact of feeding Pulmotil in lactation rations and to understand the impact of Pulmotil in lactation on finishing performance of pigs.

Acknowledgments

The authors would like to thank Steven Radecki, Cindy Koerber, Kelly Bilyeu, and Todd Wolff for their contributions to data analysis and validation in this study.

References

  1. Dr. Glen Almond, North Carolina State University.  T5C370512, Elanco Animal Heath Data on File.
  2. Harker, JW and Keffaber, K 2006 The impact of Pulmotil feeding in the nursery on finishing performance of at-risk pigs. Proc. AASV pp. 127-130.
  3. Lehe, KE and Watkins, LE 2003 Case Study: Effect of Palmate on mortality and growth in nursery pigs with clinical PRDC initiated by PRRSv. Proc. AASV pp. 129-130.
  4. Harker, JW and Watkins, LE. 1999 Palmate efficacy against Porcine Respiratory Disease Complex in a Commercial Swine Herd Practicing AI/AO pigflow. Proc. AASV pp.175-178.