Swine Grist
A PERIODIC NEWSLETTER PRODUCED BY GRAND VALLEY FORTIFIERS VOLUME 24, ISSUE 2 | SUMMER 2022
Dear Friends, Already well into July, with winter wheat starting to be harvested, and frequent prayers going up for rain to supply moisture to other crops in the ground, we are pleased to provide various information updates and suggestions to assist our customers in providing the best possible production at the lowest possible cost. As with almost any serious topic these days, feeding regime decision making strategies are multifactorial and complicated as ingredient availability, and landed cost change significantly each day with the market volatility that we are all experiencing. In recent weeks, we have witnessed grain and some oil seed futures markets drop significantly but current cash prices remain stubbornly high soy meal especially. Gratefully, we have been blessed with historically high market hog prices in North America this past year, allowing for the potential of profits at the farm gate in spite of extraordinarily high input costs. Although always the case, current market realities augment the need for a focus on alternative feedstuffs, amino acid supplementation and very mindful ration formulation, seeking to minimize feed cost per tonne, optimize feed efficiency and animal performance and maximize profit per kg of pork produced on farm. We trust that the articles contained in this summer’s edition of the Swine Grist, authored by our Swine Valley Fortifiers Specialists and Nutritionists will assist in your decision making and strategic plans for your operation. As David Ross describes below, we are sincerely looking forward to having the opportunity to reconnect in person with our customers from across the province at Canada’s Outdoor Farm Show in Woodstock in September. Until then, may the Lord bless you and your operation with timely and adequate rain for your crops, efficient production in your livestock operation and good health and happiness within your family. Sincerely, Ian Ross, President & CEO
NUTRITIONAL STRATEGIES TO ALLEVIATE HEAT STRESS IN SOWS
ompared to other animals, pigs are naturally more sensitive to heat as they lack sweat glands and have relatively small lungs compared to their body size, making it harder for them to release heat by panting. The thermoneutral zone for sows ranges from 15 to 22°C with 60 to70 % relative humidity. Therefore, when the temperature rises above the sow’s upper critical temperature (24 -25°C), a sow is unable to or has more difficulty maintaining her homeostatic body temperature. This in turn means she will suffer from “heat stress”. The impact of heat stress on sows has been well documented. However, many underestimate how heat stress negatively influences sow performance and longevity. Modern pigs are more prone to heat stress compared to the ones from decades ago as they are leaner and more productive which contributes to generating more body heat.
increased blood pH. Respiratory alkalosis causes imbalances of various biochemical and physiological functions in the sows body, therefore effort should be made to avoid it. Heat stress can also impair feed digestibility in sows, which can lead to negative energy balance, poor body condition and less milk yield. During heat stress, more blood flow is redistributed towards the periphery of the sow to release excess heat. This results in reduced blood flow to other organs including the gastrointestinal tract (GIT) which can result in inflammation, oxidative stress, and damaged tissues. Consequently, heat stress is in large part an immune response associated with “leaky gut.” Heat stress can also compromise reproductive efficiency. Sows exposed to high temperatures have smaller and slower follicular growth after weaning. This results in increased number of sows showing anestrus and silent estrus, ovulation failure, and longer weaning to estrus intervals (WEI). It is important to remember that the follicular size at weaning determines the WEI. Additionally, sows mated in the summer months tend to have lower farrowing rates, which is likely due to early pregnancy disruption. Given all the above, we can clearly see that managing heat stress is critical in sows.
Impact of heat stress in sows
Nutritional strategies to alleviate heat stress
by: YOUNGJI RHO Monogastric Nutritionist, Grand Valley Fortifiers
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Reduced feed intake (FI) is often seen in sows suffering from heat stress. The reduced FI can be due to the animal trying to reduce the heat produced by consuming feed. Heat stressed sows can also suffer from respiratory alkalosis. Blood alkalosis occurs when sows are panting excessively, leading to increased losses of CO2 in the body, resulting in GRAND VALLEY FORTIFIERS PO Box 726 Cambridge ON N1R 5W6 1-800-567-4400 grandvalley.com
There are environmental management and nutritional strategies to avoid or reduce the impact of heat stress on sows. Environmental strategies such as, better ventilation, drip/sprinkler cooling, floor cooling and reducing the pen density can be very effective. However, these environmental changes may not be possible at certain facilities and/or
Ian Ross, President & CEO | David Ross, VP & CMO Tom Reidy | Martin Clunies, Ph.D. | Tanka Khanal, Ph.D. | Adam Totafurno | Youngji Rho, Ph.D., Monogastric Nutritionists