Introduction

Pulmotil (tilmicosin) is a feed-grade antimicrobial product labelled for the control of swine respiratory disease due to Actinobacillus pleuropneumonia and Pasteurella multocida at an inclusion rate of 181-363g/0.907metric ton.1 A feed medication program targeting Pasteurella was initiated to determine whether targeted control of Pasteurella would lead to a derived benefit of improved average daily gain (ADG) in the nursery and finishing phases when compared to a control diet utilizing Mecadox (carbadox).

Materials and Methods

A 1200 sow PRRS positive farrow to finish farm located in an area with moderately high swine density was used for the study. All pigs involved were housed indoors. All piglets were individually identified at birth using two numerically identical ear tags. The pigs were weaned from the sow into the nursery at approximately three weeks of age. The nursery and finishers are operated in a continuous flow fashion where one barn is emptied of the oldest pigs, then refilled with pigs just entering the respective phase of production.

The nursery feeding program involved a three stage diet for both treatment and control groups. Both had chlortetracycline (400g/0.907metric ton) for the first week, followed by either three weeks of Mecadox (25g/0.907metric ton) or Pulmotil (181g/0.907metric ton), and ending up the nursery phase with three weeks of Tylan (40g/0.907metric ton).

The flow of the farm is such that two farrowing rooms fill one 500 head nursery, with two 500 head nurseries then used to fill one 900 head finisher over a two week time span. For the study, three nurseries (approximately 1500 pigs per treatment) were fed the control diet, with the next three nurseries then receiving the Pulmotil diet. This resulted in the first finisher receiving control pigs, the second receiving both control pigs and Pulmotil pigs, and the third receiving only pigs that were fed Pulmotil in the nursery. All pigs were weighed individually at entry into the nursery, and at exit from the nursery, with additional individual carcass weights obtained from the abattoir. All other vaccinations and treatments for both groups occurred per farm normal protocol.

Results were analyzed using ANOVA and Least Squares Means via the SAS program.

Results

Pigs in the Mecadox group weighed 5.36kg at weaning and 19.12kg at the end of the nursery phase while those receiving Pulmotil weighed 5.13kg at weaning and 20.5kg at exit. The cumulative ADG over the seven week nursery stage for the Pulmotil fed group (0.368kg/day) was significantly better (P=0.03) than the Mecadox group (0.329kg/day).

The percentage of light weight pigs exiting the nursery was dramatically improved. 14.2% of pigs receiving Pulmotil in the nursery weighed less than 15.9kg at exit from the nursery compared to 21.75% of the control diet pigs (P=0.0093). Additionally, the percentage of pigs receiving Pulmotil that weighed less than 9.1kg was 0.63% compared to 1.58% of the control pigs (P=0.049).

Since live weights were not available at slaughter, hot carcass weight (HCW) was used as well as total days of age (TDA) to give a measure of daily carcass gain. HCW/TDA for the Mecadox fed pigs was 0.4239kg/day while the HCW/TDA for the Pulmotil fed pigs was 0.4408kg/day (P=

Discussion

The pigs fed Pulmotil in the study not only showed a 0.039kg ADG nursery phase advantage over the pigs receiving Mecadox, but also showed a modest 0.0169kg HCW/TDA advantage (P=0.0001) as well. This small number equates to 3.55kg in total weight advantage at the end of the finishing phase as the pigs spent three weeks in lactation, seven weeks in the nursery phase, and another twenty weeks in the finishing phase.

In relation to the ending nursery weights, the 1.38kg advantage in body weight shown by the Pulmotil treated pigs translated to the 3.55kg carcass weight advantage at slaughter even though the Pulmotil pigs actually started the nursery phase 0.227kg lighter in average body weight. Thus, the 1.38kg live weight advantage coming out of the nursery was not only retained, but actually translated into two and a half times the carcass weight advantage over the Mecadox pigs at the end of the finishing phase.

References

1. Elanco United States Pulmotil Label. 2007