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Managing hyperprolific sows with a focus on the litter. F. Bortolozzo, Universidade Federal do Rio Grande do Sul
Brazil has 2,015,000 sows and 71.5% are concentrated in the south (Porto Alegre). Prolificacy has been rising +0.2 total piglets born each year from 2008 to 2023 and in the most efficient farms by +0.22. This has resulted in greater variation in litter size, reduced litter viability, increased farrowing duration, and increased mortality of nursing piglets and sows. Thirty percent of sows farrowed for more than four hours (348 minutes) compared to 40% today. A significant percentage of sows farrow for more than six hours. Piglets born from these farrowings have a lower body temperature and sows have a lower voluntary feed intake in the following days.
Colostrum production is lower in sows that take more than 5 hours to farrow, in gilts and they also observed a partial retention of placentas associated with an increase in stillbirths. Piglet preweaning mortality has increased due to weight dispersion, the presence of more piglets with low weights, and the loss of body temperature in environments with temperatures below 25ºC (they take longer to recover their body temperature), which triples or quadruples mortality in the first seven days of life.
They consider that 30% of dead piglets in lactation are explained by a colostrum intake of less than 200 grams. The number of functional teats compared to the number of born alive is another limiting factor. Strategies to increase survival in nursing piglets focus on three areas: nurse sows, management of cross fostering, and supplementing starter feed.
They select sows with better body condition and higher appetite. As limiting factors, they take into account the spread of infectious agents (PRRS, influenza), as well as the subsequent coming into estrus and fertility. Extra supplementation of colostrum, milk replacers, or energy concentrates can increase survival. The practice of cross fostering allows us to wean more piglets per sow, approximately one more per farrowing with no change in weaning weight per piglet or per litter. The average weaned piglet weight (13-14 litter size) at 21 days of life is around 4.8-5.8 kg live. We can identify sows that foster piglets with better prognosis by analyzing their history: parity 2, 3, 4, and 5, lower mortality in previous lactations, lower stillbirth rate, and higher milk production (more than 10 liters/day, higher weaning weights, higher feed consumption, especially at day 5-7 after farrowing).
Sweltering swine: How gestational heat stress shapes sow pregnancy and offspring development. J. Johnson, University of Missouri
Fertility from September through March is better than during the summer months. Today's sows are more productive, have an increased metabolism with higher endogenous heat production, and are more sensitive to heat stress. The balance between heat gain and heat loss depends on their body temperature, environmental conditions, metabolic processes, and behavioral changes. The biological response to heat stress includes reduced feed intake, body condition, and milk production, poorer welfare, higher mortality, and productivity losses.
They estimate the economic impact at $55-79.20/sow, with a 17.4% reduction in fertility rates in the summer months. Temperature fluctuations in the pre-insemination phases can also lead to a reduction in litter size of 1-1.5 piglets. This is caused by increased inflammation and its impact on ovarian function, increased insulin resistance and glucose utilization, reduced viable embryos (variable depending on studies), and increased embryonic mortality. Logically, the range of temperatures that cause heat stress is critical (moderate 26-32ºC and high 33-36ºC), and is higher at high temperatures, which results in a smaller litter size and increased stillbirths when there is acute heat stress in the days leading up to farrowing.
In utero heat stress (IUHS) is associated with negative economic effects on fetal programming, related to a 10% reduction in average daily gain and a 9% poorer feed conversion ratio. It also results in increased levels of hormones related to stress response and animal welfare (aggression, stereotypies, and reduced activity). IUHS piglets have an increased proinflammatory cytokine response, with increased cortisol levels, and its possible impact on morbidity and mortality is being studied. Mortality in nursing piglets from sows subjected to heat stress is higher. The placenta of heat-stressed sows has fewer uterine muscle fibers and numerous epigenetically related genes have been identified.
Solutions include management practices (effective cooling systems are essential for sows in lactation, weaning, at estrus, and in the first month of gestation), optimizing nutrition practices, and enhancing the thermo-tolerance of genetics. The heat stress index in swine was developed in 1959 by Thom and considered relative humidity and temperature. Today the HotHog app is available on both iOS and Android.
At the nutritional level, we must reconsider the maintenance needs of sows during gestation because of the positive energy balance (64% of the maintenance energy needs are required during heat stress). Genetically, increased productivity is negatively correlated with thermo-tolerance. Elevated temperatures increase body temperature, but heat loss mechanisms fail, potentially causing the animal to collapse. Heat tolerance and heat sensitivity do not go hand in hand when it comes to biologically assessing their genetic diversity. They are currently working on identifying biomarkers that predict tolerance to heat stress, analyzing the variability of the microbiome to predict it, evaluating transgenerational epigenetic effects, and measuring parameters in sows (increase in body temperature at different points), prioritizing survival over productivity.
Augmenting piglet survival as litter size increases. M. Knauer, North Carolina State University (Sponsored by the National Pork Board)
From 2020 to 2024, the U.S. went from weaning 11.05 to 11.78 piglets/litter on average (MetaFarms). The triad of nutrient access by the piglet, personnel, and facilities is at the core of maximizing piglet survival. Managing colostrum intake is essential, taking into account the teats available and the attendant's quality of work. If done well, split suckling by groups of piglets every two hours yields good results. The farrowing stall design and dimensions influence piglet survival, with controversial results in the literature. In recent unpublished work (Knauer), going from 198 to 213 cm per sow increases survival by 5 points (they recommend a minimum of 200 cm/sow). We must take into account the increase in the size of current sows. Vargovil (2022) reports an inverse relationship between stillbirths and piglet survival with the area available to the sow in the farrowing pen. Stillbirths are reduced (9% to 5.6%) by providing several feedings daily before farrowing. Stillbirths are directly related to farrowing duration. Feeding two feedings daily is better than using calcium chloride to reduce stillbirths.
They do not find consistent feeding strategies to increase piglet birth weight. Colostrum production is critical and is increased by better feeding practices in the prefarrowing period (more intake), knowing that increasing litter size reduces the average amount of colostrum per piglet and that the more functional teats the higher the colostrum intake per piglet. Litter weight at weaning is higher with increasing colostrum intake, with a positive correlation with preweaning survival (each additional teat provides 2.5% greater survival). They conclude with the importance of identifying the number of functional teats in each sow.
The changing environment of boar studs. D. Reicks, Reicks Veterinary Research & Consulting, Minnesota
The presentation focuses on 30 research papers and 30 years of field experience as a consultant. Between 2000 and 2024, the use of air filtration systems has reduced the frequency of PRRS cases from 15% to 1% in insemination centers. Few filters are needed with a high electrical cost ($10-40/boar). Purebred boars are less resistant to heat stress and problems with bacterial contamination of semen due to high humidity increase. It is important to consider the positive pressure of the system (16-18 yr). It is important to consider the longevity of the building as well as its ability to control environmental conditions against heat stress and biosecurity measures for high health.
The cost of space per boar in an insemination center in the USA has gone from $1,500 in 1996 to $3,600 in 2008, $6,000 in 2018, and $11,000 in 2024, going from $0.25 to $0.50 and $1.50/dose. In Europe, the space standards per boar are 6 m2. We must take into account other factors in their housing, such as safety in their handling for people, ease of work, type of bedding (straw, slat) together with their biosecurity, and the flow of boars within the center. The majority of boar deaths are due to euthanasia (50-75%), implying a high replacement rate due to locomotor problems, some of them due to osteochondrosis (OCD) at 8-10 months of life. Since 2020, they have observed an increase in the percentage of boars culled due to mobility problems that lead to increased pressure in tissues, low feed/water consumption, and lower blood supply in osteoskeletal tissues. As for biosecurity measures, they have increased the period between visits to other centers to 7 days and the use of hot rooms, where the material entering the center is left for a time together with disinfection measures (ultraviolet). For early detection of PRRS virus, by PCR is more efficient to monitor in the blood (saphenous vein or auricular vein) than in semen, where alterations in semen quality appear later after the onset of infection. The use of oral fluids is an alternative to consider. Upon the slightest suspicion in the laboratory or in clinical results, we should suspend the distribution of semen to the sow farms. Likewise, we must take care of the quality of semen and manage the risk that it poses for its impact on productivity. Contamination by Serratia bacteria kills spermatozoa and causes agglutination. This bacterium can be found in the foreskin and feces of boars. The correct collection of samples, conservation, and analysis are critical in its determination.
Sow housing: Challenges and opportunities in a changing environment. T. Parsons, University of Pennsylvania
Their studies focus on food security and its relationship with production, which must be socially acceptable: legitimate, credible, and true. Gestation facilities have a reactive component, considering that the baby boomer generation is largely unfamiliar with them, and the more they learn, the more they reject them. Social expectations must be considered from the animals' perspective, rather than from a profitability standpoint, making understanding the animal experience of interest.
They observe certain variations in gestating sows' preference in their behavior regarding their presence at the feeding point and the time spent in and out of the shoulder length stall. This depends on numerous factors such as time available, space, previous experience, parity, timing of gestation, position in the hierarchy, and individual behavior.
Regarding farrowing rooms, we can be proactive and define the factors to consider for the best solutions- ones that are both economically viable and socially acceptable. Permanent confinement (3.3 x 4.6 m2) versus free housing (6 x 9.2 m2) and temporary confinement (3.3 x 4.6 m2) are the options under consideration. In Europe the former are banned in Switzerland, Norway, and Sweden, tending to do so in Germany (2036) and Austria (2033), with pressure in the rest of Europe, and also New Zealand (2025). It is less clear in the rest of the world, including the USA - where the issue will be addressed within the next decade and where the National Pork Board (NPB) has developed a five-year research plan to study future farrowing rooms.
Farrowing systems must consider two parts: the sow and the piglets, considering environmental, nutritional, and pre-weaning mortality factors, which have also been aggravated with modern more prolific genetics, where numerous management practices to improve their survival are confronted with free farrowing. Sow welfare focuses on limiting mobility, manifesting their natural behavior, and interacting with their litter. Animal management and health aspects are also contradictory in free farrowing. The hybrid system (confined <7 days) favors all management patterns focused on the first few days. In this system, the extra work for the personnel, the worsening of the crush rate of older piglets, the maintenance of farrowing crate hygiene, and the risk of injury to the workers must be considered. No differences in pre-weaning mortality were observed after 4 or 7 days of confinement.
20 years of group housing at CVFF: Achievements and key lessons learned. C. Roudergue, Country View Family Farms. Pennsylvania
The sixth generation works today in the vertically integrated family business founded in 1923. It has 115,000 sows and 2.8 million pigs slaughtered per year (11th in the U.S.). They work with loose-housed gestation with both electronic and automatic feeding stations where they house the sows at different times during gestation (at weaning, at insemination, before or after implantation).
After several trips to Europe, they have worked with loose housing gestation since 2002, with all farms Proposition 12 certified since 2023. In 2007 they inaugurated the first farm with an electronic feeding system. They opted for static gestation flows, minimizing animal mixing and space underutilization. They also ran dynamic groups with weekly mixing while testing a modification of static flow gestation having some free stalls that then moved sows >70 days gestation (“parking area”). Each batch is segregated by parity (nulliparous, first parity, and second parity onward) and strict body condition. This requires pre-station training of future breeding sows and placing first parity sows together to recover their body condition after weaning.
In transitioning from crates to loose hosing, the systems with feeding troughs with small groups of animals (4-9) eating once a day worked well, managing the body condition per group and not altering the feeding behavior of the sows, being simple to operate and maintain by the workers.
In their experience, managing dominant sows in large groups is easier than in small groups. Electronic feeding systems (ESF) provide important solutions such as sows eating one at a time. They spend more time in locomotion. Precise hierarchies are established at feeding time which is more susceptible to varying consumption curves and the flow of animals in each station, which is a problem if we place sows in pre-implantation phases and in times of high temperatures where the hours when the sows will eat are altered, impacting the relationship between conception rate and farrowing rate. In their experience, when they house sows before implantation, they lose 2-3% and 3-4% when they are in static groups or dynamic groups, at the same time sow mortality goes up 2-3% compared to individual housing. Regarding locomotor problems, they pay attention to the selection of future breeding sows, reduce wet surfaces (attention to the location of drinkers), and avoid metal bars, screws, or protrusions that cause trauma. They also pay special attention and care in the early detection of leg injuries or any individual problem, performing quick and accurate treatments (1-2 people per 5,000 sows), which positively contributes to reducing sow deaths/culls. Individual attention and care of the animals is essential in their practice.
Breeding herd labor retention in a changing environment. J. Christensen, Eichelberger Farms Inc. Iowa
Their company values are passion, integrity, growth, and empowerment. They started their business in 1972 and have 66,500 sows at 16 sites, mostly owned in Iowa and Missouri. They produce 1.55 million pigs to market with 260 employees. It focuses on three main areas: industry profits, farm health, and the working team.
Sixty percent of the employees are on the sow farms, hence the importance of the role of the sow farm manager. For example, on a 5,000-head sow farm, the farm is valued at $15 million, the weaned piglets are valued at $5.5 million, and the sows are valued at $1.5 million. The qualities of such a person should focus on animal care, biosecurity, job security, and maintaining the human team. Efficiency in recruiting people to the work team is essential. When a new worker arrives at the farm, on the first day they make a checklist of their tasks, followed by two weeks of transition (training, restricted tasks and times to perform the work including use of materials/means necessary for their work, completion of reports and chain of transmission of information both horizontally and vertically), ending with the verification of the work performed. The training process includes the theoretical part, the practical application, and the verification, with the achievement of the different milestones supervised by the person in charge and centrally controlled in the company.
For example, in developing a manager's training, the points are his or her identification as a leader (thinking style, intra- and interpersonal emotional intelligence, and situational leadership), self-awareness, connection with the people on the team, and optimization of production data. The tasks the manager is to carry out are identifying, scheduling, and delegating. Strategies to retain staff include providing a competitive salary and additional benefits (health insurance, dental insurance, travel, extra vacation, bonuses, meals, and events) both at the collective and individual levels. Communication is an important factor within the company culture based on results, experiences, needs, and contributions. Farm visits and interaction with staff are considered essential to give visibility to people's work within the company.
Technologies for improving swine production. S. Leonard, North Carolina State University (Sponsored by the National Pork Board)
Precision livestock farming (PLF) uses technologies to improve management, productivity, health, welfare, and profit. They can make management more precise at the department, room, or individual level, improve productivity per animal and person, improve human-animal interaction, improve sustainability, reduce costs, and make work more attractive (plug & play). But it also has limitations such as abandonment, it is not fully autonomous, it has maintenance to keep it in perfect working order, it does not fully replace the human aspect, and it can deviate from what we tell it to do.
Such technologies have several components focused on data collection, analysis, action/decision/suggestions, and registration. This must have its feedback. Before acquiring these technologies we must analyze if they solve problems in our company, provide value, are aligned with our needs and future objectives, and provide benefits supported by data from universities, private companies, or other producers. It is necessary, of course, to conduct a return on investment study, analyzing the costs (initial payment, maintenance, replacement, and the time to learn to use them) and the benefits (improvement of production parameters, increased financial profit, reduced time, reduced frustration, and increased job satisfaction).
Within the management of the environment, we have numerous precision systems such as automatic sensors that monitor relative humidity and gas concentration, configure ventilation systems, automatically collect data and alerts, and operate with remote control based on the cloud data service. The average life of the sensors depends on the washing and calibration practices, which we must consider within their maintenance costs. The electronic control systems of water consumption per pen or room help us to detect pathologies and thermal stress, allowing data to be compared between groups, farms, stations, and production phases, and relate it to production parameters.
Included in such precision farm systems are data analysis software (Pig Champ, Metafarms), electronic sow feeding systems (Jyga technologies, Osborne) that must be recalibrated from time to time for maximum accuracy. The same applies to electronic weighing systems, and weight estimation chambers, which also have to be adjusted to different genetics. Activity monitoring systems using visual cameras allow us to assess the behavior and welfare of the animals, giving us information on their water and feed consumption patterns and health.
The use of thermal cameras paired to a phone allows us to analyze the microclimate of different areas and of the animals themselves, although they are not very accurate for detecting fevers. They mention estrus detectors based on the sows' visits to the boar and the sows' activity and postural changes detected by 3D cameras and accelerometers. For its practical use, we must consider the volume of data and the frequency and speed of information in our facilities, specifying the present and future connection and accessibility needs, the time and cost of data storage, data security and privacy, as well as technological support.
Heat stress in sows: Impacts and strategies for improving production and welfare. J. Johnson, University of Missouri
Global pig production has quadrupled in the last 50 years. Metabolic heat production in modern sows has increased by 133%, so heat tolerance is lower, and sensitivity to heat stress in both gestation and lactation is greater. This implies that reproductive parameters and mortality may be impaired. The impact of heat stress in the USA in September 2024 has been estimated at $511 million. Heat stress in utero has negative effects on immune response, embryo/fetal development, and energy metabolism, and reduces feed intake to balance heat production/loss, altering maintenance costs and nutrient partitioning (nutrient absorption). Heat stress during gestation does not impair feed intake. Recent studies show that maintenance cost in sows increases during the heat stress phase in different species, including swine. In finishing pigs, they estimate differences of -590 and -430 kcal/day of metabolic maintenance costs between 30-50 and 60-90 kg live, respectively, which implies an increase in the energy level of feed in these situations.
Heat stress negatively affects the corpora lutea in breeding sows. No relationship was found on its effect on mammary development. They are currently studying how it may affect colostrum and milk quality. They do observe increased fattening in sows subjected to heat stress. The negative effect on lactogenesis was already studied in 1966 in dairy cows at the University of Missouri and is similar in lactating sows. Sixty percent of milk production is lost with lower feed intake, with a critical break point occurring when actual intake drops more than 20% from expected. To estimate heat production and measure the energy balance we can use an indirect calorimeter, a method used in their study. They observed a 20.4% increase in heat production metabolism under heat stress with the same percentage reduction in litter weight at weaning.
Farrowing room cooling strategies as a first line of defense should be used proactively to avoid these severe negative effects in lactating sows. In a study of 97 farms in several states, they observe varying critical temperature responses from which they detect heat stress on farms. As early as 1998, the temperature-humidity stress index for finishing pigs was developed (for humans in 1959 and for cattle in 1970). The recommendations are 12.6-15.6ºC at the end of gestation and 13.2-16.4ºC in non-pregnant sows and during the first two months of gestation as preferences for sows in their thermoregulation ranges. They estimate that moderate heat stress begins at 24-25ºC, severe at 30-32ºC, and medium between 25-30ºC. They use the HotHog program available on iOS and Android to assess the thermal index in practice on farms.
Managing seasonal variation and herd capacity constraints. M. Knauer, North Carolina State University
Genetic improvement, body condition maintenance, and sow management are three pillars for understanding sow behavior in the face of seasonality. In the U.S., they estimate an annual loss of $450 million due to high temperatures on pig farms. Piglets produced per sow are reduced in the winter months, with seasonal variation.
In a study of 44,000 sows with an abortion rate of 0.65% to 3.5% in late summer and early fall, analyzing numerous factors, they observed that the rate is lower on farms with cooling systems and sufficient fans. It is interesting to analyze where on the farm the abortions occur (air inlet or outlet points, more or less proximity to fans, areas with higher relative humidity, insulation levels, and barn insolation). The abortion rate is lower when sows eat more in lactation (1 lb/day = -0.22% abortions), while in gestation, on the contrary, overconsumption increases the abortion rate. In a recent study, they observed an increase in feed intake of 5.8 to 6.6 kg/day/sow associated with cooling systems in lactation. Body condition and parity are two additional factors related to summer infertility. Excessive loss of body condition will increase the wean-to-estrus interval and result in poorer fertility (WSI as a predictor of fertility).
The role of farm personnel in controlling these variables and individual sow care have a positive impact on reducing problems associated with productivity losses due to abortions and returns to estrus.
Opportunities to reduce sow mortality: a South American perspective. F. Bortolozzo, Universidade Federal do Rio Grande do Sul, Brazil
Brazil has 2,015,000 sows, 71.5% are concentrated in three southern states. In terms of health, they are PRRS negative and CSF positive, with farms with natural ventilation in greater numbers and more workers per number of breeding sows (1:150-200 sows). The factors associated with sow mortality are related to the birth weight of future breeding sows. The number of sows that reach the third parity and have less replacement rate is important. The mortality rate increases with increasing farm size from 8.4% to 12% in farms with <1000 to >5000 sows. In terms of sow productivity, mortality does not vary significantly (26.6 to 32 piglets/sow/year). The environment is an important factor. At >30°C mortality in peripartum is multiplied, being higher in summer than in winter. As for the type of flooring, mortality varies little. During farrowing and perifarrowing mortality is 50%.
In their study of 88 farms in Brazil, mortality averaged 8-10%. Prolapse accounts for 19% of losses, gastric ulcers 9.9%, liver torsion 8.3%, and suppurative arthritis 8.2%. As part of the strategies to reduce sow mortality based on a study in a system of 30,000 sows where they had 15% mortality, they reduced it by 2.5% by implementing greater sow care/attention associated with accurate information on the sows, a daily inspection of all animals (legs, feed consumption, fever, vomiting, activity) and early identification of sows at risk of problems in the area of mating and gestation, performing the necessary treatments.
An important point is to check the water consumption, for which it is necessary to know the real daily water consumption at the farm level and to check that each sow drinks what it needs. We must take into account the water temperature since high temperatures drastically reduce feed consumption, and this has consequences in gestation and especially in lactation.
Group size and body condition in gestation are points of special attention. Small groups of 11-20 sows are easier to control. The sow replacement plan is essential to maintain a continuous flow of production and an adequate retention rate, so the quality of the sows in terms of age, weight, health, and conformity is essential. Sow nutrition to maintain good body condition while avoiding overweight sows aims to reduce mortality. Maintaining a correct body condition from birth to the second gestation (350 days of life) is considered an opportunity to reduce the mortality rate.
Antonio Palomo Yagüe
