Determining the Optimum Stocking Density in Nursery Pigs

Posted in: Pork Insight Articles, Prairie Swine Centre, Production by admin on October 26, 2015 | No Comments

Producers must balance the potential negative consequences of high stocking densities and the economic incentive to maximize production when determining the number of pigs placed per pen or building unit. The minimum space requirement in the Canadian Code of Practice for the Care and Handling of Pigs (k= 0.0335) is based on extensive research on grower-finisher pigs. However, comparatively little research has been done on nursery pigs, and there is speculation that these requirements over-estimate the space needs of nursery pigs. The aim of this research project is to determine the optimal density for nursery pigs that considers both production goals and animal welfare. The three year project will be completed in two phases, with phase 1 studies taking place at Prairie Swine Centre and phase 2 taking place in two commercial production barns (one in SK and one in MB). Both phases will compare the effects of six different density treatments in nursery pigs.

INTRODUCTION

Floor space allowance is a complex issue in swine production, and one that is critical for both economic and welfare reasons. There is currently a significant body of research on the effects of space allowances in grow-finish pigs (Edwards et al., 1988, Ekkel et al., 2003, McGlone and Newby, 1994, Pastorelli et al., 2006). The values established have been used as the basis for space allowance requirements for nursery pigs (NFACC, 2014). Relatively little is known regarding the effects of stocking density on nursery pigs (EFSA, 2005, Gonyou et al., 2006). Because nursery pigs are commonly observed to overlie one-another when resting, the k value which is appropriate for finishing pigs may in fact overestimate the space requirements of nursery pigs.

Although individual pig growth declines at higher densities, overall farm productivity can increase as higher numbers of pigs are produced per unit of building space (Kornegay and Knotter, 1984). Thus, the economic optimum for space may be lower than that for achieving maximum growth rate. However, stocking at higher densities can also negatively affect the welfare of the pig, with risk of immune suppression and increased disease susceptibility (Turner et al., 2000) or restriction of pigs’ ability to express normal behaviour.

It has been recommended that evaluations of space requirements for pigs should include changes in the behaviour of pigs, and establish the welfare relevance of such changes, to support calculation of space allowances based on what space an animal needs rather than solely on the basis of production performance (Ekkel et al., 2003). Group size and seasonal differences should also be evaluated or controlled for as these factors may also influence growth and behavior (Hyunh et al., 2005, Spoolder et al., 2012),. It has been suggested that larger groups of pigs may require less space, due to the sharing of free space (McGlone and Newby, 1994). However, this has also been disputed (Street and Gonyou, 2008).

This study will examine measures of productivity and welfare in nursery pigs, and will include an economic analysis comparing space allowance treatments above and below the Code requirement of k= 0.0335.

MATERIALS AND METHODS

Phase 1

Animals: Density studies at PSCI were conducted using 1,200 newly-weaned pigs that were housed in the nursery for 5 weeks. Piglets were housed at one of six different densities (k= 0.023, 0.0265, 0.0300, 0.0335, 0.0370, and 0.0390) in pens of either 10 or 40 pigs/group. For four replicate trials were completed over a one year period, with one replicate per season.  Pigs were weighed weekly and pen size was adjusted weekly to the prescribed density based on the predicted average body weight. Two temperature and humidity monitors (iButtons) were placed in each pen, suspended approximately 15cm above pig height to monitor conditions at pig level. An additional iButton was suspended in the center of the room to monitor room temperature and humidity throughout the trial.

Data collection: Video cameras were placed above each pen to record pig behaviour for a 24 period once per week. An infra-red setting was used during the hours of darkness. Scan sampling at 15 minute intervals was used to identify laying postures and overlying behavior.  The time budgets of four focal piglets, including the amount of time spent feeding, drinking, standing, lying and socializing were also evaluated for each week. Standard nursery diets were provided ad libitum, and feed weigh backs were recorded weekly. Total feed consumption and animal weights were recorded on a weekly basis.

Lesion scores were assessed weekly as pigs were weighed, and used as an estimate of aggression (Table 1). Saliva samples were collected weekly from four focal pigs for determination of cortisol as an indicator of stress. The immune response was tested in six pigs per pen, with  pigs receiving vaccines for Mycoplasma hyopneumonie. Serum samples were collected at three time points to determine M.hyo specific IgG as a measure of immune competence.

Phase 2

Animals: Two commercial operations with good health status and levels of productivity were identified through industry contacts and provincial pork agencies. One site was selected in Manitoba and the second in Saskatchewan. The same six density treatments used in phase I will be tested. Unlike phase I, pens in phase 2 will kept at a constant size, and the number of pigs per pen will be adjusted based on the expected weight at nursery exit (approximately 25 kg). Animals are fed and cared for following the standard management practices on each farm and information on temperature and humidity within the rooms will be collected using iButton data loggers, similar to the methods used in phase I.

Data collection: Pigs on trial will be weighed to determine average daily gain. At the same time skin lesions, ear tip necrosis, tail biting and general health will be assessed by a trained observer. Morbidity, mortality and any treatments will be recorded throughout the trial. At three time points, time lapse videos will collected over 7 hours. Postures and lying behaviours of the pigs will be assessed using scan sampling, as described for phase I.

Determining the Optimum Stocking Density in Nursery Pigs

Posted in: Pork Insight Articles, Prairie Swine Centre by admin on August 18, 2015 | No Comments

Floor space allowance is a complex issue in swine production, and one that is critical for both economic and welfare reasons. There is currently a significant body of research on the effects of space allowances in grow-finish pigs (Edwards et al., 1988, Ekkel et al., 2003, McGlone and Newby, 1994, Pastorelli et al., 2006). The values established have been used as the basis for space allowance requirements for nursery pigs (NFACC, 2014). Relatively little is known regarding the effects of stocking density on nursery pigs (EFSA, 2005, Gonyou et al., 2006). Because nursery pigs are commonly observed to overlie one-another when resting, the k value which is appropriate for finishing pigs may in fact overestimate the space requirements of nursery pigs.

Although individual pig growth declines at higher densities, overall farm productivity can increase as higher numbers of pigs are produced per unit of building space (Kornegay and Knotter, 1984). Thus, the economic optimum for space may be lower than that for achieving maximum growth rate. However, stocking at higher densities can also negatively affect the welfare of the pig, with risk of immune suppression and increased disease susceptibility (Turner et al., 2000) or restriction of pigs’ ability to express normal behaviour.

It has been recommended that evaluations of space requirements for pigs should include changes in the behaviour of pigs, and establish the welfare relevance of such changes, to support calculation of space allowances based on what space an animal needs rather than solely on the basis of production performance (Ekkel et al., 2003). Group size and seasonal differences should also be evaluated or controlled for as these factors may also influence growth and behavior (Hyunh et al., 2005, Spoolder et al., 2012),. It has been suggested that larger groups of pigs may require less space, due to the sharing of free space (McGlone and Newby, 1994). However, this has also been disputed (Street and Gonyou, 2008).

This study will examine measures of productivity and welfare in nursery pigs, and will include an economic analysis comparing space allowance treatments above and below the Code requirement of k= 0.0335.

Zinc Oxide and Antimicrobial Resistance in Pigs

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The objective of this research was to investigate whether therapeutic use of zinc oxide (ZnO) in swine production creates selective pressure for the emergence of methicillin-resistant Staphylococcus aureus (MRSA) due to co-location of the zinc-resistance gene (czrC) and methicillin-resistance gene (mecA) within the staphylococcal cassette chromosome mec (SCCmec). A randomized-controlled trial was completed using 110 pigs that were naturally colonized with czrC-positive MRSA. The prevalence of MRSA was significantly higher when pigs were fed a ration containing 3000 ppm of zinc oxide compared to the control group (100 ppm zinc). In an observational study of 26 farms, it was found that the use of therapeutic levels of zinc oxide (>2000 ppm) was associated with a higher likelihood of finding MRSA in nasal swabs of weanling pigs. The overall conclusion from these studies is that high levels of zinc oxide in starter rations are associated with a higher prevalence of pigs carrying MRSA.

Compounding Iron Dextran with NSAIDs for Use in Piglets at Time of Processing

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The objective of this project was to evaluate whether the mixing (compounding) of NSAIDs (anti-inflammatory/analgesic agents), such as meloxicam or flunixin meglumine, with iron dextran for administration to piglets at the time of processing has any effects on the availability of the NSAID. In a series of experiments, we evaluated the stability and systemic availability of both NSAIDs when mixed with iron dextran in the same bottle for administration to piglets at the time of processing.  We also evaluated the effects of this practice on iron dextran’s ability to increase piglet hemoglobin concentrations.   We found that the amount of NSAID recovered from the bottle was reduced beginning shortly after mixing.  We also found that blood drug levels measured in piglets for each NSAID when compounded with iron dextran was significantly lower than when each NSAID was administered alone to piglets.  We did not find any significant effects of mixing NSAIDs with iron dextran on iron dextran’s ability to increase hemoglobin following administration to piglets.  The overall conclusion from these experiments is that the mixing of NSAIDs with iron dextran in the same bottle for administration to piglets at the time of processing results in a suspected drug interaction that reduces the shelf-life of the formulation and the amount of NSAID available for therapeutic effects.

Reducing Energy Cost in Swine Production Facilities

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Specific project funding was provided by Saskatchewan Ministry of Agriculture’s ADOPT program.

Feeder Adjustment is Important to the Bottom Line

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Specific project funding was provided by Saskatchewan Ministry of Agriculture’s ADOPT program.

Auto Sort Systems for Finishing Pigs

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Specific project funding was provided by Saskatchewan Ministry of Agriculture’s ADOPT program.

Application of Nano-Particles for controlling disease-causing microorganisms in pig barns

Posted in: Pork Insight Articles, Prairie Swine Centre by admin on August 17, 2015 | No Comments

Laboratory-scale tests conducted were to evaluate the effectiveness of various types of commercially-available nanoparticles on the levels of microorganisms commonly encountered in swine barns.  Results indicate Zinc oxide (ZnO) nanoparticles had the highest antimicrobial efficacy among all the nanoparticles tested. Further experiments carried out in the barn indicated that partial filtration of barn air with a filter loaded with ZnO nanoparticles in the ventilation recirculation system achieved reduction in bioaerosol levels at the animal- and human-occupied zones. During sanitation, 10 mg/mL of ZnO nanoparticle solution sprayed on concrete pen floor surfaces showed significant decrease in total bacterial counts on surfaces four hours after application. Microbial population, however, started to increase after new nursery pigs were brought into the room.

In assessing the feasibility of the use of ZnO nanoparticles as part of sanitation procedures between batches of animals, the total cost associated with the application of ZnO nanoparticles was compared to the cost incurred when using the conventional chemical disinfectant. Using the application rate identified from the room-scale trials (10 mg/mL), the total amount of ZnO nanoparticles required to disinfect a 100-head grow-finish room at the end of each room cycle was estimated to be about 0.7 kg. The duration to prepare and apply the treatment would be about 3 hours per cycle. In addition, the total cost for the required materials included the cost of mixing containers, weighing scale and funnels. Summing up all these estimates, the total cost associated with ZnO nanoparticles as a disinfectant in a grow-finish stage of operation was around CAD$1.14 per finished pig. This was just CAD$0.12 per pig higher than the use of the conventional disinfectant (CAD$1.02 per finished pig). The unit price per kilogram of the conventional disinfectant was slightly higher than ZnO nanoparticles but because of its higher water solubility, the time to prepare and apply the treatment was lower than with ZnO nanoparticles. Nevertheless, the slim margin of the total cost associated with ZnO nanoparticle solution compared to the conventional chemical disinfectant can be compensated by its effectiveness to reduce further the levels of microorganisms on surfaces when preparing the room for next growth cycle.

Optimizing Market Weights

Posted in: Economics, Pork Insight Articles by admin on July 23, 2015 | No Comments

Optimizing market weights means essentially maximize the profit in your production system. Pre-requisite for optimizing the market weight is the understanding of the production costs and parameters, knowing the target market weight of your pigs for your packer buying matrix. Also components as herd health, availability and cost of feed ingredients, barn space, time availability, market prices, packer buying programs and animal welfare are important. Having a complete plan includes solid production practices, a clear understanding of the economic factors in production and marketing, using those to determine the optimum market weight for your system, and delivering a pig in good condition to your abattoir will contribute to an overall profitability of the system. Knowing all your systems capabilities, strengths and weaknesses, and working together with experts from the industry can improve the profit of your production.

Piglet Health and Welfare in the Nursery

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Piglets experience intense stress at weaning. The reason is the sudden change in their physical environment, social group and diet. Weaning under typical farm conditions can result in weight loss, aggression, belly nosing and the increased chance of diarrhoea and other diseases, which is connected with the reduction of the productivity.  The problem appears to be largely psychological, as young pigs are not prepared to handle so many changes at once.

Obviously the weaning age in the industry is earlier and more abrupt than natural it is important to prepare piglets for their big step of weaning. This is possible with stimulate the pigs with feed pre-weaning by using tray feeders, providing mash feed and the use of enrichment to encourage exploring. Next to an early start of feeding, all kind of increased social interaction before weaning helps to reduce weaning stress. To emphasize is the use of enrichment, especially for nursery pigs, because it can distract pigs from negative behaviour and increase the exploration activity and the feeding acceptance. The further research also has to look on alternative farrowing pens, flavored feed and use of enrichment to decrease the stress of the weaning process.