Relationship between dietary fiber physicochemical properties and feedstuff fermentation characteristics and their effects on nutrient utilization, energy metabolism, and gut microbiota in growing pigs

BACKGROUND

There is a growing focus on using various plant-derived agricultural by-products to increase the benefits of pig farming, but these feedstuffs are fibrous in nature. This study investigated the relationship between dietary fiber physicochemical properties and feedstuff fermentation characteristics and their effects on nutrient utilization, energy metabolism, and gut microbiota in growing pigs.

METHODS

Thirty-six growing barrows (47.2 ± 1.5 kg) were randomly allotted to 6 dietary treatments with 2 apparent viscosity levels and 3 β-glucan-to-arabinoxylan ratios. In the experiment, nutrient utilization, energy metabolism, fecal microbial community, and production and absorption of short-chain fatty acid (SCFA) of pigs were investigated. In vitro digestion and fermentation models were used to compare the fermentation characteristics of feedstuffs and ileal digesta in the pig's hindgut.

RESULTS

The production dynamics of SCFA and dry matter corrected gas production of different feedstuffs during in vitro fermentation were different and closely related to the physical properties and chemical structure of the fiber. In animal experiments, increasing the dietary apparent viscosity and the β-glucan-to-arabinoxylan ratios both increased the apparent ileal digestibility (AID), apparent total tract digestibility (ATTD), and hindgut digestibility of fiber components while decreasing the AID and ATTD of dry matter and organic matter (P < 0.05). In addition, increasing dietary apparent viscosity and β-glucan-to-arabinoxylan ratios both increased gas exchange, heat production, and protein oxidation, and decreased energy deposition (P < 0.05). The dietary apparent viscosity and β-glucan-to-arabinoxylan ratios had linear interaction effects on the digestible energy, metabolizable energy, retained energy (RE), and net energy (NE) of the diets (P < 0.05). At the same time, the increase of dietary apparent viscosity and β-glucan-to-arabinoxylan ratios both increased SCFA production and absorption (P < 0.05). Increasing the dietary apparent viscosity and β-glucan-to-arabinoxylan ratios increased the diversity and abundance of bacteria (P < 0.05) and the relative abundance of beneficial bacteria. Furthermore, increasing the dietary β-glucan-to-arabinoxylan ratios led to a linear increase in SCFA production during the in vitro fermentation of ileal digesta (P < 0.001). Finally, the prediction equations for RE and NE were established.

CONCLUSION

Dietary fiber physicochemical properties alter dietary fermentation patterns and regulate nutrient utilization, energy metabolism, and pig gut microbiota composition and metabolites.

Determination of energy values in pistachio shell powder and soybean hulls fed to gestating and lactating sows

Pistachio shell powder is a high-fiber co-product from the pistachio nut industry that may provide energy and nutrients in animal diets, but no data have been reported for the nutritional value of pistachio shell powder when fed to pigs. Two experiments were, therefore, conducted to test the hypothesis that apparent total tract digestibility (ATTD) of gross energy (GE), dry matter (DM), and total dietary fiber (TDF) and concentration of digestible energy (DE) in pistachio shell powder are not different from those in soybean hulls when fed to gestating or lactating sows. In experiment 1, 24 gestating sows were housed in metabolism crates and fed a corn-based basal diet or 2 diets that contained corn and 20% pistachio shell powder or corn and 20% soybean hulls. Sows were fed experimental diets for 13 d with feces and urine being quantitatively collected for 4 d after 6 d of adaptation. In experiment 2, 24 lactating sows were housed in farrowing crates and fed a diet based on corn and soybean meal (SBM) or 2 diets that contained corn, SBM, and 20% of either pistachio shell powder or soybean hulls, and feces were collected for 6 d after 7 d of adaptation to the diets. Results indicated that for gestating sows, the diet containing soybean hulls had greater (P < 0.05) ATTD of DM, GE, and TDF than the diet containing pistachio shell powder. The DE and metabolizable energy (ME) in the pistachio shell powder diet were less (P < 0.05) than in the basal diet and the diet containing soybean hulls. The ME in pistachio shells (2,606 kcal/kg DM) was less (P < 0.05) than in soybean hulls (3,645 kcal/kg DM). When fed to lactating sows, ATTD of DM, GE, and TDF in the diet containing pistachio shell powder was less (P < 0.05) than in the diet containing soybean hulls or in the basal diet. The DE in the diet containing pistachio shell powder was also less (P < 0.05) than in the soybean hulls diet. The DE in pistachio shell powder (1,664 kcal/kg DM) was less (P < 0.05) than in soybean hulls (2,795 kcal/kg DM). In conclusion, the ATTD of DM and GE and the DE in pistachio shell powder were less than in soybean hulls, and inclusion in lactation diets, therefore, needs to be limited.

Feeding a Multi-Enzyme Blend to Enhance the Nutrient Digestibility of Wheat-Canola Expeller Diets in Ileal-Cannulated Weaned Pigs

Canola expeller (CE) contains ~200 g/kg residual oil, but also fiber that impairs nutrient digestibility in weaned pigs. To study if feed enzymes increase digestibility, six diets containing either the basal or two CE samples mixed in at 250 g/kg (CE-A or CE-B) were formulated with or without a multi-enzyme blend containing cellulase, xylanase, glucanase, amylase, protease, invertase, and pectinase. The basal diet containing 620 g/kg wheat and 150 g/kg barley served as control. Twelve ileal-cannulated barrows (9-15 kg) were fed the six diets in a replicated 6 (pigs) × 3 (periods) Youden square. Ileal digestibility of gross energy and amino acids was 5% greater for basal than CE diets without differences between CE samples. Diet energy values were 4% greater for CE than basal diets due to residual oil in CE. Inclusion of the multi-enzyme blend increased total tract digestibility of energy of the basal but not CE diets by 2%. Net energy value was greater for CE-A than CE-B because CE-A contained more residual oil. In conclusion, feeding 250 g/kg CE increased diet energy values; thus, CE can substitute added fat in weaned pig diets. Feeding the multi-enzyme blend increased the energy digestibility of wheat and barley-based diets fed to weaned pigs. However, research is needed to identify enzyme combinations that increase the nutrient digestibility of CE.

Pork carcass composition, meat and belly qualities as influenced by feed efficiency selection in replacement boars from Large White sire and dam lines

This study evaluated carcass attributes, meat and belly qualities in finisher boars (n = 79) selected for feed efficiency (low, intermediate and high) based on estimated breeding value for feed conversion ratio within a Large White dam and sire genetic lines. The sire line had lower trimmed fat proportions and higher lean than the dam line (P < 0.01). Genetic lines expressed slight colour changes and drip losses (P < 0.05), with no differences in pH, marbling and cooking traits (P > 0.05). High-efficient animals presented the highest lean yield (P < 0.01), the lowest trimmed fat proportion (P < 0.01) and no effect on meat and belly quality attributes (P > 0.05) compared with other efficient groups. Interaction between efficiency group and genetic line was only detected for belly weight and thickness (P < 0.01). High-efficient animals offer a greater leanness level, with minimal impact on meat and belly quality traits.

Eco-friendly diet: nutrient digestibility, nitrogen and energy balances and growth performance of growing pigs

The traditional approach to formulating pig diets is based only on minimizing cost while meeting nutritional requirements and thus does not consider the environmental impacts associated with producing feed ingredients. To reduce the overall environmental impact of pork production, feed ingredients can be considered to formulate environmentally friendly diets. However, their potential effects on pig performance could decrease environmental benefits at the farm gate. The objective of this study was to quantify the effects of such eco-friendly pig diets on nitrogen (N) and energy (E) balances, the components of heat production (HP), and the performance of growing pigs. Digestibility coefficients of dry matter (84.5% vs. 88.2%, P < 0.01) and N (80.4% vs. 86.3%, P < 0.01) were significantly lower for the eco-friendly diet than the Control-diet (a commercial diet used in France). N excretion in feces was significantly higher for the group of pigs fed the eco-friendly diet than for the group fed the Control-diet (9.8 vs. 6.9 g/d, respectively, P = 0.01), while the N retention tended to be lower (27.8 vs. 30.3 g/d, respectively; P = 0.06). The metabolizable E:digestible E ratio did not differ between diets, but total HP was significantly lower for the eco-friendly diet group than for the Control-diet group (1,340 vs. 1,388 kJ/kg body weight0.60/d, respectively, P = 0.03). Using feed ingredients with lower environmental impacts, such as locally produced protein or co-products from wheat processing, is an effective way to decrease the environmental impacts of pig production. However, the nutritional composition of these eco-friendly ingredients could be overestimated, in particular the true digestibility of amino acids. This indicates the need to better estimate and consider the true digestibility of eco-friendly diets to decrease environmental impacts of livestock production without decreasing animal performance.

Response of growing pigs to the inclusion of hybrid rye in low or high-energy diets

Previous research has shown reduced feed intake and growth rate in pigs fed diets with hybrid rye replacing wheat. A reduction in growth rate caused by reduced feed intake will conceivably be counteracted by increasing the dietary energy level. Our objective, therefore, was to determine the effects of 40% hybrid rye inclusion replacing wheat in diets formulated to be either low or high net energy (NE) on growth, feed intake, energy digestibility, and lesion scores in growing-finishing pigs. We hypothesized that pigs fed 40% hybrid rye would perform better on the high than the low energy diets. A total of 160 pigs (body weight [BW] 70.1 kg) housed in 32 pens, 5 pigs per pen, were fed diets with 0% or 40% hybrid rye (var. 'KWS Bono'; KWS LOCHOW GMBH), either with low (2,350) or high (2,450) kcal NE per kg of diet over two growth phases (phase 1; 70 to 85 kg BW; phase 2; 85 to 130 kg BW). The BW, and feed disappearance were measured on days 0, 8, 17, 28, 42, and 50. Fecal samples obtained in phase 2 (~100 kg BW) were used to calculate apparent total tract digestibility (ATTD) of gross energy (GE). Lesion scores were measured weekly. The ATTD of GE was unaffected by rye inclusion and was reduced in low vs. high NE diets. Overall, (days 0 to 50), pigs fed the low-energy rye diet gained 0.08 kg/d less (P < 0.01) than those fed the high-energy rye diet or the low-energy diet without rye, which was caused by a reduced weight gain during the initial 17 d of the trial. Final BW and overall feed intake were not affected by rye inclusion or NE level. The NE intake was greater (P < 0.05) and feed efficiency (G:F) was reduced (P < 0.05) in pigs fed rye diets compared to those fed diets without rye, whereas there was no effect of NE level on NE intake or G:F. There was no effect of rye inclusion or NE level on lesion scores. In conclusion, pigs can be fed diets including 40% hybrid rye with only minor changes in growth performance. Increasing the NE level of the first phase diet in the grower-finisher barn may be useful to avoid a reduction in growth performance when feeding hybrid rye.

Review: Composition and utilisation of feed by monogastric animals in the context of circular food production systems

Food production has a major impact on environmental emissions, climate change and land-use. To reduce this impact, the circularity of future food production systems is expected to become increasingly important. In a circular food system, crop land is primarily used for plant-based food production, while low-opportunity cost feed materials (LCF), i.e. crop residues, co-products of the food industry, grass from marginal land and food waste form the basis of future, animal feeds. Animal diets thus contain much less cereals and soybean meal and include a higher proportion of diverse co-products, residues and novel human-inedible ingredients. These diets are characterised by a lower starch content, and a higher content of fibre, protein, fat, and phytate compared to present diets. In this review, possible consequences of the development towards a more circular food system for the type, volume and nutritional characteristics of feed materials and complete feeds are addressed and related research questions in the area of animal nutrition, physiology and metabolism are discussed. Additional attention is given to possible effects on intestinal health and gut functionality and to (bio)technological processing of LCF to improve their suitability for feeding farm animals, with a focus on the effects in pigs and poultry. It is concluded that an increased use of LCF may limit the use of presently used criteria for the efficiency of animal production and nutrient utilisation. Development of characteristics that reflect the efficacy and efficiency of the net contribution of animal production in a circular food system is required. Animal scientists can have an important role in the development of more circular food production systems by focussing on the optimal use of LCF in animal diets for the production of animal-source food, while minimising the use of human-edible food in animal feed.

Time-course effects of different fiber-rich ingredients on energy values, microbiota composition and SCFA profile in growing pigs

This study was to investigate time-course effects of different types of dietary fiber on the energy values, fecal microbiota and short-chain fatty acid (SCFA) concentration in growing pigs. A total of 24 barrows (initial body weight, 19.8 ± 0.5 kg) were assigned to 4 dietary treatments based on body weight (BW) in a completely randomized design, including a basal diet (CON) and 3 fiber-rich diets replacing corn, soybean meal and soybean oil in the CON diet with 20% sugar beet pulp (SBP), defatted rice bran (DFRB) or soybean hull (SBH), respectively. Fresh feces were sampled on d 7, 14 and 21, followed by 5 d total feces and urine collections. The results showed that there were no differences in DE and ME between any of the fiber ingredients on d 7, 14 or 21. However, fiber inclusion decreased the DE and ME of the diet (P < 0.05) regardless of the time effect. Principal coordinate analysis (PCoA) revealed distinctly different microbial communities on the DFRB diet and SBH diet across different times (P < 0.05) and the fecal microbiota of the 4 diet groups demonstrated notably distinct clusters at each time point (P < 0.05). With adaptation time increased from 7 to 21 d, cellulose-degrading bacteria and SCFA-producing bacteria (e.g., Ruminococcaceae _UCG-014, Rikenellaceae _RC9_gut_group and Bifidobacterium) increased in the fiber inclusion diets, and pathogenic genera (e.g., Streptococcus and Selenomonas) were increased in the basal diet (P < 0.05). Furthermore, the gut microbiota of growing pigs adapted more easily and quickly to the SBP diet compared to the DFRB diet, as reflected by the concentration of propionate, butyrate, isovalerate and total SCFA which increased with time for growing pigs fed the DFRB diet (P < 0.05). Collectively, our results indicated at least 7 d adaptation was required to evaluate the energy values of fiber-rich ingredients, as the hindgut microbiota of growing pigs may need more time to adapt to a high fiber diet, especially for insoluble dietary fiber.

Food system by-products upcycled in livestock and aquaculture feeds can increase global food supply

Many livestock and aquaculture feeds compete for resources with food production. Increasing the use of food system by-products and residues as feed could reduce this competition. We gathered data on global food system material flows for crop, livestock and aquaculture production, focusing on feed use and the availability of by-products and residues. We then analysed the potential of replacing food-competing feedstuff-here cereals, whole fish, vegetable oils and pulses that account for 15% of total feed use-with food system by-products and residues. Considering the nutritional requirements of food-producing animals, including farmed aquatic species, this replacement could increase the current global food supply by up to 13% (10-16%) in terms of kcal and 15% (12-19%) in terms of protein content. Increasing the use of food system by-products as feed has considerable potential, particularly when combined with other measures, in the much-needed transition towards circular food systems.

Greenhouse gases and performance of growing pigs fed wheat-based diets containing wheat millrun and a multi-carbohydrase enzyme

The objective of this project was to determine the impact of feeding growing pigs with high wheat millrun diets supplemented with a multi-carbohydrase enzyme (amylase, cellulase, glucanase, xylanase, and invertase activities) on nutrient digestibility, growth performance, and greenhouse gas (GHG) output (carbon dioxide, CO2; nitrous oxide, N2O; methane, CH4). Three experiments were conducted utilizing six treatments arranged as a 3 × 2 factorial (0%, 15%, or 30% wheat millrun; with or without enzyme) for the digestibility experiment or as a 2 × 2 factorial (0% or 30% wheat millrun; with or without enzyme) for the performance and GHG experiments. The digestibility, performance, and GHG experiments utilized 48 individually housed pigs, 180 pigs housed 5 per pen, or 96 pigs housed 6 per chamber, respectively. Increasing wheat millrun up to 30% in the diet of growing pigs resulted in decreased energy, nitrogen (N) and phosphorus (P) apparent total tract digestibility and net energy content (P < 0.01). Overall, average daily gain (ADG) and gain to feed ratio were reduced in pigs fed wheat millrun (P < 0.05). Enzyme supplementation had minimal effects on the digestibility or performance parameters measured. Feeding diets with 30% millrun did not affect GHG output (CH4: 4.7 and 4.9; N2O: 0.45 and 0.42; CO2: 1,610 and 1,711 mg/s without or with millrun inclusion, respectively; P > 0.78). Enzyme supplementation had no effect on GHG emissions (CH4: 4.5 and 5.1; N2O: 0.46 and 0.42; CO2: 1,808 and 1,513 mg/s without or with enzymes, respectively; P > 0.51). Overall, the carbohydrase enzyme had minimal effects on parameters measured, regardless of wheat millrun inclusion (P > 0.10). Although energy, N and P digestibility, and ADG were reduced, the inclusion of up to 30% wheat millrun in the diet has no effect on GHG emissions from growing pigs (P > 0.10).

Survey of zearalenone and type-B trichothecene mycotoxins in swine feed in the USA

New information is needed regarding the types and concentrations of mycotoxins in swine feed. We hypothesized that (1) the mycotoxins deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), 15-acetyldeoxynivalenol (15-AcDON), nivalenol (NIV), and zearalenone (ZEN) vary among swine ingredient and feed types, and (2) the inclusion of specific ingredients is associated with mycotoxin contamination in complete feed. A total of 707 samples were collected from cooperators in 14 states between June 2018 and January 2020 then analyzed for DON, 3-AcDON, 15-AcDON, NIV, and ZEN contamination using gas chromatography-mass spectrometry (GC-MS). Ninety-four percent (663/707) of samples contained DON, 33% (230/707) of samples contained 3-AcDON, 57% (404/707) of samples contained 15-AcDON, 1% (6/707) of samples contained NIV, and 47% (335/707) of samples contained ZEN. Seventy-three percent (514/707) of samples contained multiple mycotoxins. Resulting DON concentrations were below the national advisory limits for all sample types, and no advisory limits are imposed for the other mycotoxins studied. Increased incorporation of distiller's dried grains with solubles (DDGS) was associated with increased DON in complete feed (R² = 0.82).

Eco-Friendly Feed Formulation and On-Farm Feed Production as Ways to Reduce the Environmental Impacts of Pig Production Without Consequences on Animal Performance

Animal feeding has a major contribution to the environmental impacts of pig production. One potential way to mitigate such effects is to incorporate an assessment of these impacts in the feed formulation process. The objective of this study was to test the ability of innovative formulation methodologies to reduce the impacts of pig production while also taking into account possible effects on growth performance. We compared three different formulation methodologies: least-cost formulation, in accordance with standard practices on commercial farms; multiobjective (MO) formulation, which considered feed cost and environmental impacts as calculated by life cycle assessment (LCA); and MO formulation, which prioritized locally produced feed ingredients to reduce the impact of transport. Ninety-six pigs were distributed between three experimental groups, with pigs individually weighted and fed using an automatic feeding system from 40 to 115 kg body weight. Based on the experimental results, six categories of impacts were evaluated: climate change (CC), demand in non-renewable energy (NRE), acidification (AC), eutrophication (EU), land occupation (LO), and phosphorus demand (PD), at both feed plant gate and farm gate, with 1 kg of feed and 1 kg of live pig as functional units, respectively. At feed level, MO formulations reduced CC, NRE, AC, and PD impacts but sometimes increased LO and EU impacts. These formulations reduced the proportion of cereals and oil meals into feeds (feed ingredients with high impacts), while the proportion of alternative protein sources, like peas, faba beans, or high-protein agricultural coproducts increased (feed ingredients with low impacts). Overall, animal performance was not affected by the dietary treatment; because of this, the general pattern of results obtained with either MO formulation at farm gate was similar to that obtained at feed level. Thus, MO diet formulation represents an efficient way to reduce the environmental impacts of pig production without compromising animal performance.

Evaluation of energy values of high-fiber dietary ingredients with different solubility fed to growing pigs using the difference and regression methods

The objective of this study was to compare the energy values of high-fiber dietary ingredients with different solubility (sugar beet pulp [SBP] and defatted rice bran [DFRB]) in growing pigs using the difference and the regression methods. A total of 21 barrows (initial BW, 40.5 ± 1.2 kg) were assigned to 3 blocks with BW as a blocking factor, and each block was assigned to a 7 × 2 incomplete Latin square design with 7 diets and two 13-d experimental periods. The 7 experimental diets consisted of a corn-soybean meal basal diet and 6 additional diets containing 10%, 20%, or 30% SBP or DFRB in the basal diet, respectively. Each of the experimental periods lasted 12 d, with a 7 d dietary adaptation period followed by 5-d total fecal and urine collection. Results showed that the digestible energy (DE) and metabolizable energy (ME) of the SBP determined by the difference method with different inclusion levels (10%, 20%, or 30%) were 2,712 and 2,628 kcal/kg, 2,683 and 2,580 kcal/kg, and 2,643 and 2,554 kcal/kg DM basis, respectively. The DE and ME in the DFRB evaluated by the difference method with 3 different inclusion levels were 2,407 and 2,243 kcal/kg, 2,687 and 2,598 kcal/kg, and 2,630 and 2,544 kcal/kg DM basis, respectively. Different inclusion levels had no effects on the energy values of each test ingredient estimated by the difference method. The DE and ME of the SBP and the DFRB estimated by the regression method were 2,562 and 2,472 kcal/kg and 2,685 and 2,606 kcal/kg DM basis, respectively. The energy values of each ingredient determined by the regression method were similar to the values estimated by the difference method with the 20% or 30% inclusion level. However, the energy values of the SBP and DFRB estimated by the difference method with the 10% inclusion level were inconsistent with the values determined by the regression method (P < 0.05). In conclusion, the regression method was a robust indirect method to evaluate the energy values for high-fiber ingredients with different solubility in growing pigs. If the number of experimental animals was limited, the difference method with a moderate inclusion level (at least 20%) of the test high-fiber ingredient in the basal diet could be applied to substitute the regression method.

Effects of Collection Durations on the Determination of Energy Values and Nutrient Digestibility of High-Fiber Diets in Growing Pigs by Total Fecal Collection Method

Simple Summary

The total fecal collection method is the gold standard to estimate the energy values and nutrient digestibility of the swine diet. However, there is no standard collection duration for animals that should be sampled in swine research using the total fecal collection method. Thus, this study aimed to investigate the effects of different collection durations (3-day, 5-day, or 7-day) on energy values and nutrient digestibility of high-fiber diets in growing pigs by time-based total fecal collection method. The results showed that the digestible energy (DE), metabolizable energy (ME), and apparent total tract digestibility (ATTD) of gross energy (GE) and most nutrients in diets decreased linearly as the collection duration increased from a 3-day to a 7-day collection. However, there were no differences in the ATTD of GE and nutrient between the 5-day and 7-day collection durations. In addition, the energy values and the ATTD of GE and nutrient of high-fiber ingredients (sugar beet pulp (SBP) or defatted rice bran (DFRB)) were also not affected by the collection durations. Therefore, the results of this research suggest that a 5-day collection duration is adequate to determine the energy values and the ATTD of nutrient in diets containing high-fiber ingredients for growing pigs by time-based total fecal collection method.

Abstract

This study was conducted to evaluate the effect of collection durations on the energy values and nutrient digestibility of high-fiber diets in growing pigs with a time-based total fecal collection method. A total of 24 barrows (body weight (BW): 31.1 ± 1.5 kg) were allotted to a completely randomized design with three diets. Diets included a corn–soybean meal (CSM) basal diet and two additional diets containing 20% sugar beet pulp (SBP) or defatted rice bran (DFRB) by replacing corn, soybean meal, and soybean oil in the CSM diet, respectively. Each diet was fed to eight barrows for a 7-day adaptation period followed by a 7-day total feces and urine collection period. The 7-day collection duration was divided into three collection phases, namely, phase 1 (days 8 to 11), phase 2 (days 11 to 13), and phase 3 (days 13 to 15). Then, similar portions of feces and urine from the different collection phases were composited into three additional samples (days 8 to 11, days 8 to 13, and days 8 to 15, respectively). The results showed that the digestible energy (DE), metabolizable energy (ME), and apparent total tract digestibility (ATTD) of gross energy (GE) and nutrient in experimental diets decreased linearly as the collection durations increased from a 3-day to a 7-day collection (p < 0.05). However, there were no differences in the energy values, GE, and nutrient digestibility of diets and of high-fiber ingredients between the 5-day and 7-day collection durations. In conclusion, this study suggests that a 5-day collection duration is adequate to determine the energy values and nutrient digestibility of high-fiber diets containing SBP or DFRB in growing pigs by the time-based total fecal collection method.

Effects of Increasing Levels of Defatted Rice Bran on Intestinal Physical Barrier and Bacteria in Finishing Pigs

The aims of this study were to assess the effects of increasing levels of DFRB as a replacement for corns on intestinal physical barrier function and bacteria of finishing pigs. A total of 35 castrated finishing pigs (age: 158.5 ± 2.0 d, initial body weight: 62.9 ± 0.8 kg) were randomly divided into five dietary treatments (seven replicates/treatment) for a 28-day experimental period, i.e., a control diet with basal diet, and four experimental diets in which maize was replaced by 7%, 14%, 21%, and 28% DFRB, respectively. The results showed that serum endotoxins concentration and diamine oxidase (DAO) activity were both increased (linear, p = 0.0004, 0.001, respectively) with DFRB level. However, compared with control group, serum endotoxins concentration and DAO activity were not different in pigs fed with 7% DFRB in the diet. There was a quadratic response in serum D-lactate concentration to the increased DFRB (quadratic, p = 0.021). In the cecum, thickness of the intestinal wall significantly increased with increasing levels of DFRB in the diets (linear, p = 0.033), while crypt depth/thickness of the intestinal wall ratio significantly decreased with increasing level of DFRB in the diets (linear, p = 0.043). In the jejunum, total bacteria, Escherichia coli, and Bifidobacterium all responded quadratically to increasing levels of DFRB in the diets (quadratic, p = 0.003, 0.001, 0.006, respectively). Additionally, there was no difference in Escherichia coli in pigs fed 0%, 7%, and 14% DFRB diets. In the colon, there were quadratic responses in C. perfringens to the increased DFRB (quadratic, p = 0.023). C. perfringens reduced as the DFRB concentration increased from 0% to 14% and then increased. When D-lactate, total bacteria, Escherichia coli, Bifidobacterium, and C. perfringens were considered, the optimal substitution level of DFRB were 12.00%, 11.84%, 7.50%, 8.92%, and 15.92%, respectively. In conclusion, 7% DFRB had a beneficial effect on intestinal wall thickness, Bifidobacterium and C. perfringens, and had no adverse effect on intestinal permeability and Escherichia coli.

Defining a land boundary for sustainable livestock consumption

The need for more sustainable production and consumption of animal source food (ASF) is central to the achievement of the sustainable development goals: within this context, wise use of land is a core challenge and concern. A key question in feeding the future world is: how much ASF should we eat? We demonstrate that livestock raised under the circular economy concept could provide a significant, nonnegligible part (9-23 g/per capita) of our daily protein needs (~50-60 g/per capita). This livestock then would not consume human-edible biomass, such as grains, but mainly convert leftovers from arable land and grass resources into valuable food, implying that production of livestock feed is largely decoupled from arable land. The availability of these biomass streams for livestock then determines the boundaries for livestock production and consumption. Under this concept, the competition for land for feed or food would be minimized and compared to no ASF, including some ASF in the human diet could free up about one quarter of global arable land. Our results also demonstrate that restricted growth in consumption of ASF in Africa and Asia would be feasible under these boundary conditions, while reductions in the rest of the world would be necessary to meet land use sustainability criteria. Managing this expansion and contraction of future consumption of ASF is essential for achieving sustainable nutrition security.

Castor bean cake detoxified with calcium hydroxide in diets for pigs at growing and finishing phases

The present study was aimed to evaluate the use of increasing levels of castor bean cake detoxified with calcium hydroxide in diets for pigs at growing and finishing phases on performance, diet digestibility, weight of digestive organs, carcass traits, and economic evaluation. A total of 40 barrows with 44.59 ± 5.16 kg initial weight were fed diets with 0%, 7%, 14%, and 21% detoxified castor bean cake. Increasing levels of detoxified castor bean cake in diets resulted in linear worsening in the average daily gain of the pigs. Dry matter, crude protein, and gross energy digestibilities were adversely affected by the levels of detoxified castor bean cake. A linear decrease in loin eye area and ham yield was detected depending on detoxified castor bean cake inclusion levels. Although the detoxified castor bean cake had no effect on the assessed economic variables, its use in diets for growing and finishing pigs is not recommended.

Fecal microbial composition associated with variation in feed efficiency in pigs depends on diet and sex

Dietary fiber content and composition affect microbial composition and activity in the gut, which in turn influence energetic contribution of fermentation products to the metabolic energy supply in pigs. This may affect feed efficiency (FE) in pigs. The present study investigated the relationship between the fecal microbial composition and FE in individual growing-finishing pigs. In addition, the effects of diet composition and sex on the fecal microbiome were studied. Fecal samples were collected of 154 grower-finisher pigs (3-way crossbreeds) the day before slaughter. Pigs were either fed a diet based on corn/soybean meal (CS) or a diet based on wheat/barley/by-products (WB). Fecal microbiome was characterized by 16S ribosomal DNA sequencing, clustered by operational taxonomic unit (OTU), and results were subjected to a discriminant approach combined with principal component analysis to discriminate diets, sexes, and FE extreme groups (10 high and 10 low FE pigs for each diet by sex-combination). Pigs on different diets and males vs. females had a very distinct fecal microbiome, needing only 2 OTU for diet (P = 0.020) and 18 OTU for sex (P = 0.040) to separate the groups. The 2 most important OTU for diet, and the most important OTU for sex, were taxonomically classified as the same bacterium. In pigs fed the CS diet, there was no significant association between FE and fecal microbiota composition based on OTU (P > 0.05), but in pigs fed the WB diet differences in FE were associated with 17 OTU in males (P = 0.018) and to 7 OTU in females (P = 0.010), with 3 OTU in common for both sexes. In conclusion, our results showed a diet and sex-dependent relationship between FE and the fecal microbial composition at slaughter weight in grower-finisher pigs.

Nutrient composition and digestibility of energy and nutrients in wheat middlings and red dog fed to growing pigs

This experiment was designed to determine nutrient composition and apparent total tract digestibility (ATTD) of GE, DM, OM, and NDF and the concentration of DE and ME in 10 sources of wheat middlings and in 1 source of red dog that were obtained from different flour mills in the United States. Twelve growing pigs (initial BW: 31.0 ± 1.0 kg) were randomly allotted to a 12 × 8 Youden square design with 12 dietary treatments and eight 14 d periods. Pigs were individually housed in metabolism crates for total collection of feces and urine. A basal diet based on corn and soybean meal, and 11 diets containing corn, soybean meal, and 39.4% of one of the 10 sources of wheat middlings or of red dog were formulated. The ATTD of GE, DM, OM, and NDF in all diets was calculated using the direct procedure, and the ATTD of GE, DM, OM, and NDF in each source of wheat middlings or red dog was calculated by difference. Values for DE and ME were calculated as well. The average concentration of CP was 17.67% in wheat midlings and 17.0% in red dog, and the concentration of acid hydrolyzed ether extract (AEE) and total dietary fiber (TDF) was 2.44 and 13.90% in red dog, but 4.07 and 36.45% in wheat middlings. Red dog also contained more starch (42.98%) than wheat middlings (20.28%). Red dog had greater bulk density (498.5 g/L) and smaller particle size (146 µm) compared with wheat middlings (315.1 g/L and 783 µm). The average ATTD of GE, DM, OM, and NDF in wheat middlings (67.2%, 71.2%, 72.9%, and 53.0%, respectively) was less (P < 0.05) than in red dog (79.35%, 82.9%, 86.6%, and 58.7%, respectively). The average concentrations of DE and ME in wheat middlings were 2,990 and 2,893 kcal/kg DM, and these values were less (P < 0.05) than the DE and ME in red dog (3,408 and 3,292 kcal/kg DM). In conclusion, wheat middlings contains more fiber and less starch than red dog and the ATTD of GE and nutrients is greater in red dog than in wheat middlings. As a consequence, concentrations of DE and ME are greater in red dog than in wheat middlings.

Modulation of intestinal cell differentiation in growing pigs is dependent on the fiber source in the diet

Feeding high-fiber diets decreases cost, but also caloric and nutritional efficiency by modifying intestinal morphology and function. We analyzed the changes in intestinal cell composition, nutrient transporters and receptors, and cell differentiation induced by fibers from different sources. Forty-six finishing pigs (BW 84 ± 7 kg) were fed 1 of 4 diets: corn-soybean (Control; = 12), 23% wheat straw (WS; = 11), 55% corn distillers dried grains with solubles (DDGS; = 11), and 30% soybean hulls (SBH; = 12). Pigs were fed 2 meals daily to an amount equivalent to 2.5% of initial BW for 14 d in metabolism cages. Ilea were collected for histological and gene expression analysis after euthanasia. Data were analyzed using the Kruskal-Wallis test followed by Dunn's multiple comparisons and differences considered significant when < 0.05. The enterocyte marker was increased ( < 0.03) by feeding SBH compared with Control and WS diets. Goblet cells presence was greater ( < 0.01) in pigs fed WS and DDGS compared with Control, and in pigs fed WS compared with SBH ( = 0.02). expression was greater ( < 0.05) in pigs fed DDGS and SBH compared with Control diet. No changes were observed for endocrine and Paneth cells markers, villus and crypt length, or proliferation index. Compared with the Control, gene expression of receptors for oligopeptides, calcium, glucose, fructose, , and and was increased ( < 0.05) by feeding WS and DDGS diets. Feeding SBH diet repressed ( < 0.005) the compared with WS and DDGS diets, while DDGS repressed ( = 0.02) its expression compared with Control. Pigs fed DDGS had reduced ( < 0.001) , and those fed SBH showed increased ( < 0.05) expression compared with WS and DDGS pigs. Feeding WS and DDGS diets induced ( < 0.01) the expression of stem cell marker r-spondin receptor (, while was reduced ( < 0.02) by feeding DDGS compared with Control. The expression of was induced ( < 0.05) by all fibers compared with Control. Transcription factors and were suppressed ( < 0.001) by WS and DDGS compared with Control. In conclusion, feeding diets containing WS and DDGS modulated intestinal differentiation by promoting goblet cells and altered expression of nutrient receptors and transporters in growing pigs, while feeding SBH had less effect.

Effect of including sweet potato (Ipomoea batatas Lam) meal in finishing pig diets on growth performance, carcass traits and pork quality

The partial replacement of a commercial concentrate at 10-20% and 15-30% (the first percentage of each dietary treatment corresponded to weeks 1-3 and the second to weeks 4-7 of the experiment, respectively) by sweet potato meal (SPM; 70% foliage: 30% roots) was evaluated for growth performance, carcass yield, instrumental and sensory pork quality using 36 commercial crossbred pigs (56.8 ± 1.3 kg initial body weight). Three dietary treatments were compared in a randomized complete block design. Most growth, carcass traits and pork quality variables were not affected by the SPM inclusion. Growth performance averaged 868 g/day and feed efficiency 0.24 kg/kg. However, feed intake increased 2.2% (P = 0.04) in pigs fed the 10-20% SPM diets, in a similar order of magnitude as the decrease in dietary energy. Despite an increase in gastrointestinal tract as a percent of hot carcass weight (+14.7%) (P = 0.03) with SPM inclusion, carcass yield averaged 69.4%. Conversely, decreases in loin yield (-4.2%) (P = 0.05), backfat thickness (-6.0%) (P < 0.01) and pork tenderness (-13%) (P = 0.02) were observed with 15-30% SPM inclusion. Results suggest that up to 20% SPM inclusion is a viable feed strategy for finishing pigs, easily replicable in small farm settings. © 2016 Japanese Society of Animal Science.

Empiric narrowing of the net energy value of reduced-oil corn distillers’ dried grain with solubles for growing-finishing pigs

Smit, M. N., Zamora, V., Young, M. G., Campbell, N., Uttaro, B. and Beltranena, E. 2015. Empiric narrowing of the net energy value of reduced-oil corn distillers’ dried grain with solubles for growing-finishing pigs. Can. J. Anim. Sci. 95: 225–241. This study attempted to empirically narrow down the net energy (NE) value of reduced-oil corn distillers’ dried grains and solubles (RO-cDDGS) by evaluating the response in pig growth performance, live backfat and loin depth, carcass traits, and primal pork cuts tissue composition to feeding diets formulated increasing the assumed NE value of RO-cDDGS, expecting a brisk change in slope of the response at the point at which the NE value of RO-cDDGS would be identified. In total, 1056 cross-bred pigs (31.7 kg) housed in 48 pens by gender were fed dietary regimens including 30% RO-cDDGS (6.7% ether extract) with assumed NE values of 1.7, 1.85, 2.0, 2.15, 2.3, or 2.45 Mcal kg−1over five growth periods (Grower 1: days 0–21, Grower 2: days 22–42, Grower 3: days 43–63, Finisher 1: days 64–76, Finisher 2: day 77 to market weight). Pig body weights were measured and feed disappearance (ADFI) was calculated by pen on days 0, 21, 42, 63, 76 and weekly thereafter until target slaughter weight (120 kg). For the entire trial (days 0–76), increasing the assumed NE value of RO-cDDGS linearly increased (P<0.01) ADFI and total lysine intake, did not affect NE intake and daily weight gain (ADG), quadratically decreased (P<0.05) feed efficiency, linearly decreased (P<0.05) live backfat depth and backfat:loin depth ratio, and did not affect carcass characteristics or pork primal cut tissue composition. Segmented regression only identified a change in slope for carcass ADG and lean ADG at 1.85 Mcal kg−1. These results indicate that the experimental approach taken was not reliable in narrowing down the NE value of RO-cDDGS because the decrease in dietary NE was too small (0.03 Mcal kg−1d), which limited the change in dietary Lys:NE ratio with increasing assumed NE value of RO-cDDGS. The approach resulted in progressive, but small changes in slope rather than a clearly identifiable point where one could conclude that the incremental dietary energy contribution from RO-cDDGS changed the response in a given variable.

Nutritional value of full-fat green canola seed fed to growing-finishing pigs

Immature green canola seed (full-fat green canola seed [FFGC]) is rejected by canola crushing plants due to chlorophyll staining of oil destined for human consumption. With >35% oil, FFGC can contribute energy to pig diets. The nutritive value of FFGC for growing-finishing pigs was determined in 2 studies. In Exp. 1, 6 ileal-cannulated barrows (46.5 kg BW) were fed 3 diets as a replicated 3 × 3 Latin square to determine standardized ileal digestible (SID) coefficients of AA and calculate DE and NE values for FFGC. A diet including 40% FFGC replaced wheat in a basal diet and a cornstarch-based N-free diet were fed to determine energy and nutrient digestibility by difference and to estimate basal endogenous AA losses to calculate SID of AA. In Exp. 2, 1,100 pigs (32.9 kg BW), housed in 50 pens of 22 barrows or gilts per pen, were fed 5 diets including 0, 5, 10, and 15% constant or declining amounts (15, 10, 5, 0, and 0%, respectively) of FFGC over 5 phases to determine effects of feeding FFGC on growth performance and carcass characteristics. Phase diets were formulated to provide 4.00, 3.60, 3.25, 2.90, and 2.65 g SID Lys/Mcal NE for d 0 to 21, d 22 to 42, d 43 to 62, d 63 to 74, and d 75 to 123 kg market weight. Carcass characteristics were measured using the Destron grading system. On DM basis, FFGC contained 43% ether extract, 25% CP, 22% NDF, 10 μmol/g glucosinolates, 1.35% Lys, 0.5% Met, 0.9% Thr, and 0.27% Trp. In FFGC, SID coefficients of Lys, Met, Thr, and Trp were 86.9, 87.3, 76.9, and 84.3%, respectively, and calculated DE and NE values were 4.92 and 3.50 Mcal/kg of DM, respectively. Overall, increasing dietary FFGC inclusion from 0 to 15% linearly decreased (P < 0.05) G:F, carcass weight, and dressing percentage (0.392 to 0.381 kg/kg, 96.7 to 95.7 kg, and 78.4 to 77.8%, respectively) and tended to decrease (P = 0.078) ADG. Pigs fed decreasing amounts of FFGC by growth phase compared with controls (0% FFGC) had lower (P = 0.011) overall G:F (0.392 vs. 0.372 kg/kg). Increasing dietary FFGC inclusion did not affect carcass backfat thickness and loin depth. The FFGC was a good source of dietary energy and AA. However, increasing dietary FFGC inclusion for pigs reduced G:F and dressing percentage likely because of the increased dietary fiber content, resulting from increasing FFGC and barley and reducing wheat, soybean meal, and tallow in diets. Inclusion of FFGC in swine diets should, therefore, be based on targeted G:F and relative cost to other feedstuffs.

Nonruminant Nutrition Symposium: Controlling feed cost by including alternative ingredients into pig diets: a review

Sustained price increases for traditional cereal grain and protein meal feed commodities have forced the pork industry to consider the dietary inclusion of alternative feedstuffs. Crop seed may serve as feedstuffs but their demand as feedstock for human food, biofuel, and bioindustrial products has increased. Together with these products, coproducts such as distillers dried grains with solubles, wheat millrun, and canola meal are produced. As omnivores, pigs are ideally suited to convert these non-human-edible coproducts into high-quality food animal protein. Therefore, coproducts and other low-cost alternative feedstuffs such as pulses and oilseeds can be included in pig diets to reduce feed cost per metric ton of feed. However, inclusion of alternative feedstuffs in pig diets does not necessarily reduce feed cost per kilogram of gain. Therefore, the use of novel and existing feedstuffs in pig diets must be optimized following their characterization for energy and AA profile. Alternative feedstuffs generally have a high content of at least 1 of the following antinutritional factors (ANF): fiber, tannins, glucosinolates, and heat-labile trypsin inhibitors. Several methods can optimize nutrient use of pigs fed alternative feedstuffs by reducing effects of their ANF. These methods include 1) particle size reduction to increase nutrient digestibility, 2) dehulling or scarification to reduce tannin and fiber content of pulses and oilseeds, 3) air classification to create fractions that have a greater content of nutrients and lower content of ANF than the feedstock, 4) heat treatments such as extrusion, toasting, roasting, and micronization to reduce heat-labile ANF, 5) dietary supplementation with fiber-degrading enzymes or predigestion of fibrous feedstuffs or diets with fiber-degrading enzymes to increase dietary nutrient availability, and 6) formulation of diets based on bioavailable AA coefficients. In conclusion, the feeding of alternative ingredients may reduce feed cost per unit of pork produced provided that their price per unit NE or digestible lysine is less than that of the traditional feedstuffs and that negative effects of their ANF are controlled.

Effects of increasing co-product inclusion and reducing dietary protein on growth performance, carcass characteristics, and jowl fatty acid profile of growing-finishing pigs

Dietary inclusion of co-products (Co-P) provides opportunities for diversifying the feedstuff matrix by using local feedstuffs, reducing feed costs, and producing value-added pork. In 2 studies, we determined effects of Co-P (canola meal, distillers dried grains with solubles, and co-extruded oil seed and field pea) inclusion level and reduced dietary CP concentration on growth performance, carcass characteristics, and jowl fatty acid profiles of growing-finishing pigs. Pigs were fed isoenergetic and isolysinic diets over 4 growth phases with 8 pen observations per dietary regimen. At slaughter, carcasses were characterized for all pigs and jowl fat was collected from 2 pigs per pen. In Exp. 1, 1,056 pigs (initial BW, 35.3 ± 0.4 kg) were fed 3 levels of dietary Co-P (low, mid, and high) and 2 CP concentrations (low and normal). Overall (d 0 to 86), increasing Co-P inclusion from low to mid or high decreased (P < 0.001) ADFI and ADG of pigs. Low CP concentration increased (P < 0.05) ADFI and ADG compared with normal CP concentration. An interaction (P = 0.026) occurred between dietary Co-P inclusion and CP concentration for G:F; low CP reduced (P < 0.05) G:F compared with normal CP for pig fed low Co-P, but G:F did not differ between CP concentrations for pigs fed mid and high Co-P. Increasing dietary Co-P inclusion from low to high increased (P < 0.001) α-linolenic acid (ALA) in jowl fat but decreased (P < 0.001) carcass weight and loin depth. In Exp. 2, 1,008 pigs (initial BW, 30.3 ± 0.4 kg) were assigned to 5 dietary regimens with Co-P increasing from 2.0 to 50.0% or a sixth regimen with 10% extra supplemental AA for the 37.5% Co-P diet. Overall (d 0 to 97), increasing Co-P inclusion did not affect ADFI, ADG, and G:F. Increasing dietary Co-P inclusion linearly decreased (P < 0.01) carcass weight, dressing percentage, backfat thickness, and loin depth but linearly increased (P < 0.001) jowl ALA. Supplementing 10% extra AA to the 37.5% Co-P diet did not affect growth performance or dressing percentage but increased (P = 0.014) carcass leanness and decreased (P = 0.023) backfat thickness compared with the 37.5% Co-P diet, indicating that dietary AA supply did not limit BW gain. In conclusion, Co-P can be included by up to 50% in diets for growing-finishing pigs without affecting G:F. However, increasing dietary Co-P may reduce ADG, ADFI, and carcass weight even if diets are balanced for dietary NE and standardized ileal digestible AA content.