Seasonal infertility is a major issue for the U.S. swine industry, resulting in substantial economic losses due to decreased farrowing rate, reduced litter sizes and increased non-productive days. Heat stress during the lactating period induces physiologic and metabolic changes in sows, leading to the mobilization of body reserves to offset nutrient deficiencies. This excessive mobilization of body tissues compromises the reproductive performance of sows.
Ensuring that lactating sows meet their amino acids and energy requirements is crucial for optimal milk production, maintenance of body reserves and reproductive outcomes. While enhancing farrowing room environments through ventilation management is critical, equal attention must be paid to the nutrition and feeding of sows. Here are five strategic recommendations for feeding lactating sows during the summer months:
1. Preparing Sows for Farrowing and Lactation
The feeding management of sows during gestation significantly influences their body condition at farrowing, which is a pivotal factor for feed intake during lactation. Over-conditioned sows typically reduce feed intake, whereas under-conditioned sows lack adequate body reserves to sustain lactation. In addition, when transitioning sows into farrowing rooms, a carefully regulation of the feed amount provided to sows can prevent complications and stillborn pigs. When feasible, hand-feeding sows around farrowing can facilitate close monitoring of feed intake and timely identification of sows requiring medical intervention.
2. Water Availability and Quality
Water, often overlooked, is one of the most important nutrients as it’s involved in almost every function of the body. Sufficient clean and fresh water is essential to ensure optimal sow health and milk production. The key to effective water management lies in ensuring availability and quality. Before placing sows into farrowing rooms, check your water systems. This should include an inspection of the drinkers to confirm that they are properly positioned and delivering the adequate flow. Maintaining a recommended water flow rate of 1 L/min or 4 cups/min for sows in the farrowing room is critical.
3. Sow Nutrition
To compensate for the reduced feed intake during summer months, consider using high-dense diets, balancing feed cost and sow performance. As the use of added fat in lactation diets is carefully considered to increase the energy density of diets, we recommend its use to meet the minimum intake of essential fatty acids. Our research has shown that providing lactating sows with a minimum of 100 g/d of linoleic acid prevents pregnancy loss in the subsequent cycle. Meeting amino acid requirements is particularly critical for younger sows that are at a higher risk. If a separate lactation diet can be delivered to young sows, consider providing them with 59 g/d SID Lysine. Additionally, dietary osmolytes like betaine have been shown to be beneficial. Feeding 0.2% dietary betaine during the summer months to mature lactating sows was reported to improve the subsequent litter size by 1.2 total pigs born.
4. Sow Feed and Feeders
Make feed quality a priority. High levels of mycotoxins can further reduce feed intake, so it’s crucial to monitor these in key ingredients like corn, soybean meal, distiller’s dried grains with solubles (DDGS), among others. Keep feed fresh and feeders clean because feed tends to spoil in warm temperatures, which sows will reject. Consider adjusting the feeding times to cooler hours of the day. During the day, provide smaller meals more frequently and closely monitor off-feed sows, as they may need medical attention.
5. Some Practical Considerations
Minimizing stress for sows during summer months is a proactive step to maintain their health and productivity. Move sows during the cooler parts of the day. When placing sows into farrowing rooms, group them by age and body condition. This strategy allows caretakers to focus their attention on the high-risk females, promoting better water and feed intake and enabling close monitoring and rapid intervention on sows that go off-feed. Ensure that farrowing rooms are well-prepared prior to the sows’ arrival, with fully functional feeders, feed systems, drinkers, and ventilation systems.
Develop a comprehensive summer plan with your team, focusing on these key strategies to ‘beat the heat’ and minimize seasonal infertility.
David Rosero is an assistant professor in animal science at Iowa State University.
References:
Knauer, M.T., and D. J. Baitinger. The sow body condition caliper. Appl Engineering Agr 31, 175-178 (2015).
Mendoza, S.M., Boyd, R.D., Remus, J. Sow performance in response to natural betaine fed during lactation and post-weaning during summer and non-summer months. J Animal Sci Biotechnol 11, 69 (2020). https://doi.org/10.1186/s40104-020-00471-0
Menegat, Mariana B., Robert D. Goodband, Joel M. DeRouchey, Mike D. Tokach, Jason C. Woodworth, and Steve S. Dritz. Kansas State University Swine Nutrition Guide: Water in Swine Nutrition (2019)
PIC. PIC Nutrition and Feeding Guidelines. (2021). Access on April 2 2024. Available on: https://www.pic.com/wp-content/uploads/sites/3/2021/03/PIC-Nutrition-Manual_English-Imperial.pdf
Rosero, D.S., Boyd, R.D., McCulley, M., Odle, J., van Heugten. Essential fatty acid supplementation during lactation is required to maximize the subsequent reproductive performance of the modern sow. Anim Reprod Sci 168, 151-163. (2016)
