Work at Prairie Swine Centre indicates that sows in group housing systems will maintain room temperatures between 9 to12 0C, leading to approximately 78% reduction in energy consumption when compared to gestation rooms maintained at pre-set temperature of 16.50C.
Conversion of gestation sow housing from stalls to group systems has been mandated in the recently revised Canadian Code of Practice for the Care and Handling of Pigs, with all sow farms expected to adopt this practice by July 2024 (NFACC, 2014). In order to take advantage of these legislative changes, the hog industry is looking for management options that will take advantage of potential merits of group sow housing, in order to ensure successful implementation group housing systems in all farms.
One such advantage of group housing systems is that sows can better interact with and control their immediate environment, including thermal conditions. Research results at Prairie Swine Centre indicate sows housed in groups have the freedom to exhibit thermoregulatory behaviour such as huddling to maintain comfort even when the temperature in the barn is lowered. Temperatures currently maintained in barns when sows are housed in stalls are based on the current published lower critical temperature (LCT). Allowing the temperature to drop below this LCT will require additional feed to maintain the sow body condition and weight gain over the gestation period.
It has been widely thought that sows housed in groups may have LCT values significantly lower than 15°C when given the ability to utilize behavior such as huddling. If group-housed sows can maintain body condition and weight gain at temperatures lower than currently maintained in sow barns without the need for additional feed, the potential exists to significantly reduce energy costs for heating and ventilation, reducing the overall cost of production. Currently, energy/utility costs rank third in total cost of production, only behind feed and labour cost.
However, some issues anticipated with group-housed sows include the potential for higher activity levels and aggression among sows. These problems are heightened when sows are put on a restricted feeding regime, which is a common practice for gestating sows to maintain optimal body condition. The sensation of feeling “full” is improved when high-fiber diets are fed; these diets are also known to reduce the urge to feed continuously, reducing the sow overall activity, and repetitive behaviours.
Dietary fiber increases heat production in sows without increasing digestible energy. As such, adding fiber to the diet can be a means of reducing activity and limiting aggression in sows under reduced barn temperature. The addition of fiber to the diet could be a means of addressing behavioral issues associated with grouped-sows as well as contributing to the energy balance of sows under reduced barn temperature.
What temperatures do group-housed sows prefer? This is one of the questions the study set out to answer.
The project consisted of two phases of experiments; the first phase utilized environmental chambers followed by tests in actual group-housed gestation rooms. Results from the first phase of the study indicated that throughout the trial a pattern was observed where temperature changes occur mainly during the day when sows are mostly active, as barn operations were carried out (between 7 AM-3 PM); beyond this period, lights in both chambers are turned off. Room temperatures at the time sows activated the operant mechanism was also recorded. Average temperature when the operant mechanism was activated was considerably lower at 12.5°C for the sows fed with high heat-increment (high fibre) diet. This suggests the sows could tolerate lower temperatures before calling for supplemental heat compared to sows fed with standard gestation diet.
In terms of performance, sows fed with standard gestation diet had an ADG of 0.16 kg/day on average over the trial period. While sows fed with high heat-increment diet were able to tolerate lower temperatures and performed slightly better with average ADG of 0.20 kg/day.
The second phase of the project configured two barn rooms for group housing, with each room housing 28 gestating sows. One room was operated at a typical set-point temperature (16.5°C) while an operant mechanism was installed in the other room, allowing the sows to control the temperature. Similar to Phase 1, temperature fluctuations occurred mainly during the day (7AM-3PM) when sows are mostly active and when the actual switch presses occurred. Preliminary results for Phase 2 of the project have shown that sows could tolerate temperature lower than the typical 16.5°C set-point maintained in gestation barns with sows maintaining temperatures about 5 °C lower than in a pre-set room, leading to about 78% reduction in energy consumption. At current energy prices, this 78% reduction in energy consumption would improve the producers’ profitability by more than $5.00/hog during the heating season
After energy, protein is the second most expensive nutrient in swine rations but utilization tends to be low. Retention of dietary nitrogen in pigs ranges from 30% to 60% of intake with much of this inefficiency the result of catabolism of excess amino acid/protein intake or unbalanced amino acid supply. This catabolism represents an energetic cost to the animal, reducing performance, and results in an increase in nitrogen excretion into the environment. Due in part to the contribution of dietary protein to total feed costs and the environmental impact of feeding excess protein, considerable research has been conducted to determine dietary requirements for essential amino acids.
While essential amino acid requirements are well-defined, there has been a general lack of research into requirements for non-essential amino acids and total dietary nitrogen. With the increased availability of affordable crystalline amino acids, it has become possible to feed reduced protein diets while maintaining essential amino acid content and growth performance. However, the endogenous production of non-essential amino acids requires a source of nitrogen, therefore, in situations where total dietary nitrogen is limited, as could be the case in reduced protein diets with supplemental crystalline amino acids, essential amino acids will be used to meet requirements for non-essential amino acid production.
A concept familiar to ruminant nutritionists is the provision of sources of non-protein nitrogen (i.e., urea and ammonia) and reliance on production of amino acids by rumen microbes. In addition to dietary supplementation with non-protein nitrogen, it has been well established in both non-ruminant and ruminant animals that a proportion of urea produced from amino acid catabolism enters the gastrointestinal tract where gut microbes are capable of utilizing the urea for amino acid production. This process, referred to as urea recycling, represents an important salvage mechanism to improve nitrogen retention during times of protein deficit, and presents an opportunity to both reduce feed costs and improve efficiency. However, the contribution of microbial amino acid production to meeting amino acid requirements in non-ruminants is not clear.
In order to more fully understand the utilization of nitrogen for lean gain in growing pigs, a series of studies were performed at the University of Guelph. These studies were designed to determine the ability of pigs to utilize sources of non-protein nitrogen under a variety of dietary conditions.
Study 1 – Utilization of non-protein nitrogen in pigs fed a diet limiting in an essential amino acid
A nitrogen-balance study was performed to determine the impact of infusion of urea or casein in the hindgut on whole-body nitrogen retention in growing pigs (n = 10; 22 ± 1.8 kg initial body weight) fed a valine-limiting diet (cornstarch-soybean meal based). Pigs were assigned to receive an infusion of saline (control), urea, or casein (40% of dietary protein intake) into the cecum in a Latin square design. Fecal and urine output were measured daily and samples obtained for determination of nitrogen output and nitrogen retention. A continuous infusion of isotopically labelled urea (15N15N-urea) was given for determination of urea production, urea excretion, and urea recycling. It was hypothesized that nitrogen is absorbed from the hindgut as ammonia which may contribute to the amino acid supply of the pig through urea recycling and microbial amino acid production in the small intestine. The majority of the infused nitrogen was absorbed and protein deposition (114, 128, and 130 g/d; P < 0.01) was improved with infusion of both casein and urea, but did not differ between the two treatments. Urea flux and urinary nitrogen excretion increased similarly for both nitrogen infusions indicating that nitrogen absorbed from the hindgut is in the form of ammonia. The efficiency of utilizing nitrogen absorbed from the hindgut was approximately 18%. This indicates that while pigs can utilize non-protein nitrogen to correct an essential amino acid deficiency, this is likely not efficient enough to be a viable dietary alternative.
Study 2 – Utilization of non-protein nitrogen in pigs fed a nitrogen-limiting diet
A nitrogen-balance study was performed to determine the impact of infusion of urea or casein in the hindgut on whole-body nitrogen retention in growing pigs (n = 9; 17 ± 0.3 kg initial body weight) fed a cornstarch-soybean meal based diet formulated to be limiting in non-essential amino acids (high essential to total nitrogen ratio) but met requirements for essential amino acids. Pigs were assigned to receive an infusion of saline (control), or urea at 1.5 g/d or 3.0 g/d into the cecum in a Latin square design. Fecal and urine output were measured daily and samples obtained for determination of nitrogen output and nitrogen retention. A continuous infusion of isotopically labelled urea (15N15N-urea) was given for determination of urea production, urea excretion, and urea recycling. It was hypothesized that nitrogen absorption from the hindgut can be used for endogenous non-essential amino acid production and increase body protein deposition in pigs fed a diet deficient in non-essential amino acids. Whole-body nitrogen retention (4.86, 6.40, and 7.75 g/d; P < 0.01) and average daily gain (267, 314, and 360 g/d; P < 0.05) were improved with increasing amounts of urea infused into the hindgut but there was no impact on urea kinetics. The efficiency of utilization of nitrogen in this study was nearly 100% for both amounts of urea infused indicating that non-protein nitrogen absorbed from the hindgut can be used efficiently for body protein deposition under conditions of dietary non-essential amino acid deficiency.
Study 3 – Dietary supplementation with ammonia and growth performance
A study was performed to determine the effect of addition of different sources of nitrogen to a diet limiting in non-essential amino acids on growth performance of growing pigs. A total of 36 growing pigs (15 ± 1.0 kg initial body weight) were fed a cornstarch-casein based diet deficient in non-essential amino acids (control) but met requirements for essential amino acids and supplemented with either urea, ammonium citrate, glutamate, or a mix of non-essential amino acids, each at two levels (1.37 or 2.75% additional dietary protein). Average daily gain (367, 399, 404, and 402 g/d; P < 0.01) and gain:feed (0.38, 0.42, 0.42, 0.42 kg/kg; P < 0.01) was lowest when supplemental urea was provided but was similar on all other sources of non-essential nitrogen and improved with increasing level of nitrogen provided (363, 387, 429 g/d ADG for 0, 1.37, and 2.75%, respectively; P < 0.001). These results indicate that pigs can utilize a source of non-protein nitrogen as efficiently as non-essential amino acids for growth when fed a diet deficient in total nitrogen.
Overall, these studies demonstrate that pigs are capable of utilizing non-protein nitrogen for body protein deposition and growth in diets limiting in either essential amino acids or total nitrogen. However, the results from these studies need to be interpreted with caution since conditions under which utilization were measured (for example, use of cornstarch based diets) do not replicate commercial practices. With increased use of alternative ingredients and co-products with potentially lower protein digestibility and continued use of crystalline amino acids in reduced-protein diets, it may become increasingly important to consider total dietary nitrogen supply and, therefore, further research into nitrogen utilization is required.
The research in this article was performed at the University of Guelph. Funding for this research was provided by Ontario Pork, Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA), the Natural Sciences and Engineering Research Council of Canada (NSERC), Swine Research and Development Cluster, Swine Innovation Porc, and Evonik Industries AG.
Keeping on top of new technologies is critical for businesses to remain competitive and profitable. Technology for data recording is becoming increasingly important and more affordable in pork production whether you are a commercial hog producer, a swine genetics company or involved in the packing and processing of pork. It simply comes down the old adage that you can’t improve what you don’t measure. But of course, there is much more to it than simply adopting every technology that you hear or read about. There is a need to identify technologies that can truly help your business and be sure the technologies can work as promised. It can be challenging, if not impossible, for individual businesses to adequately assess and test many of the promising technologies that are out there. Collective efforts by the industry can address this challenge and with that in mind, the Canadian Centre for Swine Improvement (CCSI) is coordinating a large collaborative project on novel technologies. Some of the technologies tested can help monitoring pigs from nursery through to market weight. Others measure carcass and pork quality attributes. There are even technologies able to predict carcass and pork quality on the live animal.
The project includes the following pilot studies, three on live pigs and five on carcass and pork quality:
- Automated recording of feed/water intake and 3D vision systems to estimate weight/conformation
- Infrared thermography diagnostic platform to monitor swine to health and predict feed efficiency
- Use of accelerometers to automatically assess pig behaviour and welfare
- Using 3D vision for rapid and objective hog carcass quality assessment
- Rapid in vivo prediction of pork composition and quality traits using near-infrared spectroscopy
- Determination of the age of bruises on pig carcasses at slaughter
- Application of rapid methods for non-invasive assessment of pork quality
- Quick, non-invasive technology for prediction of loin marbling in fresh loins on the cutting line
These pilot studies are underway in research facilities and will be completed during 2016. The results will help the industry to make informed decisions about these technologies. In each case we need to consider the value of what is being measured as well as the accuracy, the cost and the practicality. Knowing which technologies are not ready yet is just as important as knowing which technologies are ready for commercial testing. From those that are deemed ready, the goal is to work with industry partners to test each selected technology on a total of at least 1000 pigs and carcasses.
One of the technologies that is now being considered for commercial tests is the automated recording of water intake. In the pilot study the water intake on individual pigs has been found to correlate highly with feed intake. As well, sudden changes in water intake can be indicators of individual pig health. The technology may also be helpful in assessing and reducing water wastage which was found to vary considerably amongst individual pigs. This could lead to a practical tool which can improve efficiency and pig health while also reducing environmental impact.
The overall project is assessing several novel technologies which can help producers to monitor health, welfare and feed efficiency while also offering tools to predict and enhance carcass value. There are also technologies for packers to better evaluate carcass and pork quality. This will allow them to get more value from each carcass and also to provide signals back to producers to motivate further improvement. The importance of attracting investment in new technologies is apparent as all industries are benefiting from greater data management and process control through electronically controlled devices. An added advantage of moving toward novel technologies and more electronically controlled devices is the attraction of new employees seeking to use their technical skills and interest as part of their career, thus a benefit in the pork industry to attract younger and well qualified personnel.
This project is funded by Swine Innovation Porc within the Swine Cluster 2: Driving Results Through Innovation research program. Funding is provided by Agriculture and Agri‐Food Canada through the AgriInnovation Program, provincial producer organizations and industry partners.
About the Canadian Centre for Swine Improvement (CCSI)
CCSI is a non-profit organization created in 1994 to provide support to the Canadian pork industry by providing leadership, innovation and coordination in national genetic evaluations; database establishment and maintenance; program standards; and research and development. Members include Canadian Pork Council, Canadian Meat Council, Canadian Swine Breeders Association, regional swine improvement centres and users of the Canadian Swine Improvement Program.
Feed is the single largest cost associated with producing pork, ranging from 50-70% of the total cost of production. When looking to save money in their feeding programs, producers typically consider the finishing herd as it represents approximately two-thirds of the total feed cost. One area that can be easily overlooked is lactation feeding strategies and delivery.
Traditionally most producers feed lactating sows manually, feeding sows up to three times per day in order to maximize feed intake and optimize litter performance. However, providing large quantities of feed may result in increased feed wastage or spoilage. One technology pork producers have utilized to maximize lactation performance is electronic feeding systems for sows during lactation. These systems have multiple advantages over manual feed delivery including collection of feed intake data, controlled delivery of fresh feed, reduced feed wastage, and lower labour costs, however, these feed systems can be costly to install and maintain.
A project at Prairie Swine Centre set out to develop a modified feeding system which provides the advantage of the delivery of fresh feed to the sow without the expense of the electronic feeding system. A simple feeding system was developed which consisted of a feed drop tube which extends to approximately one inch above the base of the feeder, requiring the sow to manipulate the tube to release small quantities of feed.
A total of 45 sows and litters were randomly assigned to 1 of 3 feeding systems, consisting of manual feeding, a commercially available electronic sow feeder, and the modified system. Sow body weight, back fat, and body condition score were recorded when moved into the farrowing room and at weaning, 21 days post-farrowing. Sow feed intake was recorded daily with any spoiled feed being removed, weighed, and feed intake adjusted. Litter growth performance was measured weekly over the 3 week lactation.
What did we find?
The type of feeding system used had no effect on sow body weight, body condition score, or back fat. There was a slight decrease in litter average daily gain in the third week post-farrowing on the electronic feeding system when compared to manual feeding, however, this did not result in a difference in overall litter weight. Sow feed intake was significantly higher with manual feeding when compared to the other two feeding systems in the first two weeks of lactation, but this difference was no longer evident in the third week.
For pork producers, what’s the most important impact?
This study demonstrated that manual feeding of sows during lactation can result in higher feed usage with no corresponding increase in sow or litter productivity. At today’s feed prices the reduction in feed intake associated with the electronic or modified feeding system would save producers an estimated $8.50 per lactation when compared to manual feeding. Therefore, the electronic and modified feeding should be considered to minimize feed wastage and maximize returns. While both systems would reduce feed usage and labour costs associated with feeding, higher costs associated with the electronic feeding system needs to be weighed against additional benefits, such as automatic recording of feed intake when considering which system to implement in their facility.
It has been estimated that on any given day about 1 million pigs are being transported in the United States. To move that many hogs, it also has been estimated that approximately 3,000 trucks are zig-zagging across the country. Hogs aren’t the only things carried by these trucks and trailers, as it has been widely recognized that transportation is a significant risk for transmission of swine diseases.
The presence of porcine epidemic diarrhea virus has reinforced the importance of ensuring that transport trailers are properly washed, disinfected and inspected for organic debris and microbial contamination prior to use. Most of the time, producers and haulers rely on visual inspection of equipment to confirm cleanliness after washing, cleaning, disinfection and drying. Occasionally, microbiological testing via culture method has been used.
Floor space allowance is a complex issue in swine production, and one that is critical for both economic and welfare reasons. The quantity of space provided substantially affects pig welfare by influencing behaviour, stress and social interactions, and has significant economic impacts on productivity and the total pig throughput possible on a farm. It’s important that recommendations for the minimum floor space allowance for groups of pigs are not arbitrary, but based on sound biological and economic research. The current space allowance requirements specified in the Canadian Code of Practice for the Care and Handling of Pigs are largely based on research performed on grower-finisher pigs. However, comparatively little is known on the effects of space allowance on nursery pigs, and current space allowance requirements may overestimate the requirements for nursery pigs due to their increased willingness to overlie one another. The objective of this project is to determine a precise value for the minimum space allowance for nursery pigs which provides an optimal and scientifically defensible balance between profitability and animal welfare.
Effective enrichments have been shown to reduce aggression and injuries, and can be an effective tool to improve the management of group-housed sows. This project set out to identify the most effective forms of enrichment based on attractiveness, durability, and sustainability of a range of enrichment objects. The objects identified as most effective within this study will be used in a future enrichment study.
Groups of 28 multiparous sows and gilts were housed in walk in/lock in stalls with a partially slatted loafing area. Five treatments were examined over five days, including: 1) a horizontal piece of wood (4”x4”), suspended on chains between two posts; 2) a block of wood (18”x 2”x 4”), attached to a chain allowing the block to rest at a 450 angle; 3) three items (rope, chain, and wood block) hung together on a chain; 4) straw provided in two metal racks; and 5) straw placed on the solid floor at 300g/day/sow.
When looking at the overall interaction, the percentage of sows interacting with enrichment items on day 1 far exceeded those on days 3 and 5. This habituation response was expected. There was an increase in sows lying down throughout the five day treatment with the swing, straw on the floor, and straw in a rack treatment groups. Ranking the enrichment treatments according to durability, safety, and sow attractiveness resulted in the following ratings (first to last): straw on the floor, straw in a rack, three-item enrichment, and the block of wood. Based on these results, the straw, cotton rope and the wooden block treatments will be further examined in the next phase of the study.
This study investigated whether pre-weaning creep consumption can be increased through stimulating exploratory behaviour in piglets, and whether this is best achieved through provision of enrichment (E) or through presentation of creep in a large shallow feeder. In order to examine differences between farms , studies were conducted at Prairie Swine Centre (PSC) as well as two commercial farms.
The enrichment treatment (E) consisted of cotton ropes hung in the farrowing pens, and was compared to pens with no enrichment. Each pen was also given one of two types of feeders; a standard feeder or a large tray feeder, giving four different treatment combinations. Results indicate that piglets provided with E interacted with it in 5% of observations. Overall, the tray feeder resulted in a greater frequency of piglet visits to the creep feeder compared to a standard round feeder, but there was no effect of enrichment. Fecal swabs indicated that over 50% of animals with access to a tray feeder were eaters prior to weaning.
The provision of a large tray feeder that encourages social feeding, appears to have a greater influence than rope enrichment on attracting piglets to creep feed. While the increased creep disappearance found with the tray feeder indicates that more piglets were interacting with the creep, no benefits to growth rate were found.
The newly weaned piglet is abruptly transferred from a liquid milk diet, containing about 8% fat to a dry diet with approximately 5% fat. Moreover, fat digestibility of milk fat by the suckling pig approaches 95% while the digestion of dietary fat by the piglet shortly after weaning is only about 75% (cited by Price et al. 2013). Thus, supplementing dietary fat to the diet of the newly weaned piglet does not alleviate the deficit in energy intake experienced at this time.
Price et al. (2013) showed that the addition of lecithin to the diet of newly weaned piglets improved digestibility of long-chain fatty acids. However, similar to the results of others, this did not result in an improved growth rate. Lecithin, which is primarily phosphatidylcholine, is commonly added to food, because it is an emulsifier. It is listed in CFIA, Schedule IV. We hypothesized that Lyso-lecithin will improve digestibility of tallow, resulting in a performance response when the pigs are limiting in energy.
Proper washing and disinfection of swine transport trailers is an important step in maintaining biosecurity. This study examined the feasibility of using adenosine triphosphate (ATP) bioluminescence as a rapid and effective swine trailer cleanliness assessment tool. Samples were taken from newly-cleaned, dry trailers using an ATP swab by swabbing an area of 10 cm x 10 cm and were tested for microbial contamination level using an ATP bioluminescence meter.
The results obtained from ATP testing were compared to the co-located samples taken using standard microbiological techniques with MacConkey and R2A agar contact plates (diameter Ø = 60 mm). From a total of more than 500 samples collected from 16 commercial swine transport trailers across Saskatchewan, a significant correlation (r = 0.206; p=0.001) was found between ATP bioluminescence method and standard microbiological technique using R2A agar plates. Lower correlation (r = 0.154; p=0.002) was observed between ATP method and MacConkey agar plate counts. Unlike R2A that detects a wider group of bacteria, MacConkey agar supports only the growth of selected gram-negative bacteria while ATP bioluminescence detects ATP from both microbial and organic sources.
Assessing the effectiveness of swine transport trailer cleaning protocol using ATP bioluminescence method threshold values were established with readings of less than 430 RLU per 100 cm2 as ‘Pass’ while higher than 850 RLU per 100 cm2 as ‘Fail’ or has high risk of disease propagation. With these assessment criteria, ATP bioluminescence method can be used as a supplementary tool for monitoring surface cleanliness of transport trailers in a rapid, simple, inexpensive and reliable way, to complement the procedures specified in CSHB (2011) guidelines.