8:30 am - 9:30 am
4-10C Agricultural/Forestry Centre, University of Alberta, Edmonton AB
Event details: A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Final Exam Seminar by Janine Soderstrom. This seminar is open to the general public to attend.
MSc with Dr. Ruurd Zijlstra.
Thesis Topic: Digestibility of Diets Containing Canola Expeller and Wheat Millrun Fed with a Multi- Enzyme Blend to Weaned Pigs
Pork production in Canada faces many hurdles to maintain economic or environmental sustainability, and feeding co-products to nursery pigs opens doors to improve both. Feeding co- products, however, is not without unique challenges when fed to nursery pigs in terms of nutrient digestibility. Fibre can be detrimental to nutrient digestibility and subsequent growth performance; however, supplemental dietary enzymes can mitigate some of the risks by increasing the digestibility of the fibre and other nutrients. As a novel co-product from pressing of canola seed for oil, canola expeller (CE) has a high oil content, which can add energy to weaned pig diets. In Chapter 2, a multi-enzyme blend was added to diets containing 250 g CE/kg and fed to ileal cannulated weaned pigs. Two different samples of CE were fed to determine the difference in processing facilities on nutritive value. Twelve cannulated weaned-pigs (body weight (BW) 12-18 kg) were fed in a double 6 (pig) × 3 (period) Youden square. The coefficient of apparent ileal and total tract digestibility (CAID and CATTD) was measured and compared to a basal control diet. CE decreased the CAID and CATTD of dry matter (DM), crude protein (CP) and gross energy (GE). Conversely, CE increased the digestible energy (DE) and net energy (NE) value compared to the basal diet. Despite variances in proximate analyses of the CE samples (CP, fibre and crude fat), digestibility did not differ between the two CE sources. Multi- enzyme inclusion did not affect diets containing CE but did increase the CATTD of DM and GE and NE value of the basal diet. Canola expeller inclusion can increase the energy content of diets and thus assist weaned pigs in meeting their energy requirements without added canola oil. Wheat millrun (WM) is a valuable co-product from flour milling that is usually fed to livestock, including older pigs. In weaned pigs, the fibre content prevents the inclusion in diets to ensure optimal growth and efficiency during a critical production stage. In chapter 3, 75 g WM/kg was included in 4 experimental diets. The positive (PC) had a lower energy value and lysine content than the negative control (NC), while the remaining experimental diets contained either 0.2 or 0.4 g/kg of the multi-enzyme blend to determine a dose effect. The experimental diets were fed to ileal cannulated weaned pigs (BW: 11-15 kg) in a double 4 × 5 Youden square. As expected, the CAID and lysine, and DE and NE values was greater for the PC than NC diet. However, effect of the enzyme dose on the digestibility of the NC diet were not observed. In summary, adding a single or double dose of multi-enzyme did not increase the CAID and CATTD of DM, CP, GE and AA compared to the PC.
In conclusion, adding 250 g CE/kg to weaned pig diets creates an opportunity to maintain or increase the energy; however, there was no effect on enzyme inclusion specifically on CE digestibility. Similarly, inclusion of two multi-enzyme doses did not affect digestibility of diets containing WM. The findings from this thesis provide evidence supporting dietary enzyme and co-product inclusion in weaned pig diets; however, for both co-products specifically, the optimal enzyme blend, activity and substrate still needs to be evaluated.