354 Awardee Talk: Midwest Cattle Feeding Over the Past 40 Years

The success of a cattle feeding region is dependent on many factors including resources and technology. Forty years ago, the once-dominant Midwest region had lost its competitive advantage in both areas. Today this industry has reinvented itself. This presentation reviews this journey and looks forward to new opportunities. There have been at least two disruptive technologies that affected cattle feeding, especially in this region over this time. The first is the convergence of microcomputer technology with the development of growth models based on the California Net Energy System. Decisions based on this new knowledge had a profound impact on feed conversion, growth and management. The second disruptive technology was the development of the ethanol industry and widespread availability of corn coproducts, especially high moisture corn coproducts. This development brought large quantities of a very high-quality feedstuff and inclusions in beef finishing diets became standard. Considerable research and education were needed to develop cost effective feeding programs with this new opportunity. Other changes have occurred across the cattle feeding industry over this time. Cattle size and carcass weights have continued a linear increase. Carcass quality and marbling has increased due to genetic selection, feeding endpoints and other factors. Improved growth technologies have continued to be developed and evaluated. Nutritional requirements of cattle for some nutrients have been fine-tuned but more work is needed. Disruptive technologies in the future may involve the convergence of precision livestock technology, smart sensors, artificial intelligence. Engineering developments and energy costs will affect the future of feed processing and delivery. Regardless of future technologies successful cattle feeding in the future will require access to feed resources, excellent nutrition and health management and strategies to manage risk.

PSVI-15 Effects of Dietary SID Lysine Restriction in the Growing Period and Number of Dietary Phases on Growth Performance of Growing-finishing Pigs

This study evaluated the effects of dietary SID lysine restriction in the growing period and number of dietary phases in the growing-finishing (GF) period on growth performance of GF pigs (32.7 ± 9.43 kg to 115.5 ± 8.18 kg BW). A RCBD (block = gender and start day) was used with a 3 × 2 factorial arrangement of treatments: 1) Dietary SID Lysine Level {Control [NRC (2012) recommendation]; Moderate Restriction [0.15% lower than Control]; Aggressive Restriction [0.30% lower than Control]} and 2) Number of Dietary Phases in GF (4 vs. 2). Lysine level treatments were applied from 32 to 64 kg BW. Diets were based on corn-soybean meal and corn coproducts, formulated to be isocaloric, and to meet or exceed recommendations of NRC (2012) for each phase, with the exception of SID lysine levels which were according to treatment. A total of 4,488 pigs were housed in single-sex groups of 34 pigs (22 replicates) with floor space of 0.63 m2/ pig. Pigs had ad libitum access to feed and water throughout and were weighed at start and end of the study; feeder additions were recorded. Pen was the experimental unit and data were analyzed using R version 3.6.2. The model accounted for the fixed effect of treatments, the interaction, and random effect of block. There were no treatment interactions (P > 0.05) and no effect (P > 0.05) of Number of Dietary Phases on overall growth performance. Decreasing dietary SID lysine linearly reduced (P < 0.05) overall ADG and ADFI with no effect (P > 0.05) on G:F. Restricting dietary SID lysine level to the extent used in this study reduced overall growth rate with no impact on feed efficiency.

PSVI-12 Phosphorous digestibility of corn ethanol co-products, from Brazil and USA, in growing pigs

The objective of this study was to determine the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P, and their respective digestible values, of two high protein (HP) corn dried distillers’ grains (DDG) and of two corn DDG with solubles (DDGS), from Brazil and USA, in pigs. Fifty crossbred barrows (38.3±5.2kg BW) were fed a semi-purified P-free basal diet (BD), used to determine endogenous P losses, or four diets composed of 40% of each ingredient, as the only source of P, substituting for starch in BD: Brazilian HP DDG (BHP); USA HP DDG (UHP); Brazilian DDGS (BDG) and USA DDGS (UDG). Animals were fed at 2.8 x maintenance (110 kcal of DE per kg of BW0.75) for 9 d (7 d adaptation and 2 d of partial feces collection). Titanium dioxide was used as an indigestible marker (0.3%) for digestibility calculations. A randomized block design was used, with 10 replicates, using the pig as the experimental unit. Results were submitted to ANOVA and Tukey’s test (P< 0.05). The ATTD of P of UHP and UDG were 47% greater (P< 0.05) than those verified in BHP and BDG. The STTD of P of UHP and UDG were 45% higher (P < 0.05) than that of BDG. The STTD of BHP was similar (P >0.05) to the values of BDG and UDG. The total and standardized digestible P of UDG (0.40-0.44%, respectively) were greater (P< 0.05) than those of BDG (0.33-0.38 %, respectively) and of UHP (0.28-0.32%, respectively), which were similar (P > 0.05), and higher than that of BHP (0.22-0.27%, respectively). In conclusion, corn distiller’s co-products from Brazil and USA presented different ATTD and STTD P values, and USA DDGS (UDG) showed the highest apparent total tract and standardized digestible P among all corn coproducts evaluated.

Xylanase supplementation in corn-based swine diets: a review with emphasis on potential mechanisms of action

Corn is a common energy source in pig diets globally; when financially warranted, industrial corn coproducts, such as corn distiller’s dried grains with solubles (DDGS), are also employed. The energy provided by corn stems largely from starch, with some contribution from protein, fat, and non-starch polysaccharides (NSP). When corn DDGS are used in the diet, it will reduce starch within the diet; increase dietary protein, fat, and NSP levels; and alter the source profile of dietary energy. Arabinoxylans (AXs) comprise the majority of NSP in corn and its coproducts. One strategy to mitigate the antinutritive effects of NSP and improve its contribution to energy is by including carbohydrases within the diet. Xylanase is a carbohydrase that targets the β-1,4-glycosidic bonds of AX, releasing a mixture of smaller polysaccharides, oligosaccharides, and pentoses that could potentially be used by the pig. Xylanase is consistently effective in poultry production and moderately consistent in wheat-based swine diets, but its efficacy in corn-based swine diets is quite variable. Xylanase has been shown to improve the digestibility of various components of swine-based diets, but this seldom translates into an improvement in growth performance. Indeed, a review of xylanase literature conducted herein suggests that xylanase improves the digestibility of dietary fiber at least 50% of the time in pigs fed corn-based diets, but only 33% and 26% of the time was there an increase in average daily gain or feed efficiency, respectively. Intriguingly, there has been an abundance of reports proposing xylanase alters intestinal barrier integrity, inflammatory responses, oxidative status, and other health markers in the pig. Notably, xylanase has shown to reduce mortality in both high and low health commercial herds. These inconsistencies in performance metrics, and unexpected health benefits, warrant a greater understanding of the in vivo mechanism(s) of action (MOA) of xylanase. While the MOA of xylanase has been postulated considerably in the literature and widely studied in in vitro settings, in wheat-based diets, and in poultry, there is a dearth of understanding of the in vivo MOA in pigs fed corn-based diets. The purpose of this review is to explore the role of xylanase in corn-based swine diets, discuss responses observed when supplemented in diets containing corn-based fiber, suggest potential MOA of xylanase, and identify critical research gaps.

Properties of Extrusion Processed Corn and Corn Coproducts

As the world population continues to grow, the demand for human food and animal feed grows exponentially. Aquaculture is the food sector which has been growing at the greatest rate for several years. Because of the expense of fishmeal in aquaculture fees, an inexpensive protein source could be corn-based proteins. Although many studies have focused on the effects of extruding corn-based blends along with other supplement ingredients, few studies have focused on the extrusion of individual corn-based ingredients. This study examined physical effects of extrusion on distillers dried grains with soluble (DDGS) and corn. Specific objectives included determining moisture content, water activity, color, unit density, durability, water stability, floatability, and bulk density for each corn-based extrudate. Blends were prepared with three levels of moisture (15, 25, and 35% db), and extrusion conditions included three screw speeds (50, 75, and 100 rpm) and three barrel temperatures (100, 125, and 150°C). Results showed that as the moisture content increased, the water activity increased in the raw ingredients, and the moisture content of the extrudates increased. As the screw speed increased, the bulk density decreased in the extrudates, and the mass flow rate increased. As the temperature increased, the floatability of the extrudates increased, while the bulk density decreased. The amount of protein and starch content in the corn products affected the physical quality of the pellets, which is important in aquaculture feed development.