Effects of grinding method and particle size of wheat grain on energy and nutrient digestibility in growing and finishing pigs

Nutritional guide to feeding wheat and wheat co-products to swine: a review

Inclusion of wheat grain can offer feeding opportunities in swine diets because of its high starch, crude protein (CP), amino acid (AA), and phosphorus (P) content. High concentrations of starch within wheat grain makes it a good energy source for swine. Mean energy content of wheat was 4,900 and 3,785 kcal/kg dry matter (DM) for digestible energy and metabolizable energy, respectively. CP concentration can vary based on the class of wheat which include hard red winter, hard red spring, soft red winter, hard white, soft white, and durum. The average CP of all wheat data collected in this review was 12.6% with a range of 8.5% to 17.6%. The AA concentration of wheat increases with increasing CP with the mean Lys content of 0.38% with a standardized ileal digestibility (SID) of 76.8%. As CP of wheat increases, the SID of AA in wheat also increases. Mean P of wheat was 0.27% and median P was 0.30%. Off-quality wheat is often associated with sprouts, low-test weight, or mycotoxin-contamination. Sprouted and low-test weight wheat are physical abnormalities associated with decreased starch within wheat kernel that leads to reductions in energy. The assumed energy value of wheat grain may need to be reduced by up to 10% when the proportion of sprouted to non-sprouted wheat is up to 40% whereas above 40%, wheat's energy may need to be reduced by 15% to 20%. Low-test weight wheat appears to not influence pig performance unless it falls below 644 kg/m3 and then energy value should be decreased by 5% compared to normal wheat. Deoxynivalenol (DON) contamination is most common with wheat grain. When content is above the guidance level of 1 mg/kg of DON in the complete diet, each 1 mg/kg increase in a DON-contaminated wheat-based diet will result in a 11% and 6% reduction in ADG and ADFI for nursery pigs, and a 2.7% and 2.6% reduction in ADG and ADFI, in finishing pigs, respectively. Wheat co-products are produced from the flour milling industry. Wheat co-products include wheat bran middlings, millrun, shorts, and red dog. Wheat co-products can be used in swine diets, but application may change because of differences in the final diet energy concentration due to changes in the starch and fiber levels of each wheat co-product. However, feeding wheat co-products are being evaluated to improve digestive health. Overall, wheat and wheat co-products can be fed in all stages of production if energy and other nutrient characteristics are considered.

Performance and nutrient digestibility of growing pigs fed highly or low fermentable coarse or finely ground fibre-rich feedstuffs

Dietary fibre is mainly classified according to its chemical characteristics but structure and particle size of fibre-rich feedstuff can also be decisive for digestion and performance. So far, only few studies investigated this in pigs. This experiment aimed to compare coarse and finely ground dried hemp plants and apple pomace regarding performance and ileal and total tract nutrient digestibility of growing pigs. Coarse or finely ground apple pomace or dried hemp plants were added to the diet of 56 nine weeks old growing pigs (DanBred x Duroc), housed in flat decks with each 2 animals. The growing pigs received the experimental diets for three weeks while performance was recorded. Eight pigs per group were sacrificed and digesta and organ tissue sampled. The stomach health was evaluated by visually scoring of the mucosa integrity. Apparent ileal (AID) and total tract digestibility (ATTD) were calculated using titanium dioxide as marker. Statistical analyses were performed using two-way ANOVA (p < 0.05). The highest feed intake (fibre particle size, p = 0.018) and bodyweight gain (fibre particle size, p = 0.018; fibre source x particle size interaction, p = 0.040), was observed in animals fed finely ground apple pomace, while the feed conversion ratio was 8-12% lower in pigs fed finely ground fibre sources (p = 0.012). No differences in stomach mucosa integrity were detected between the groups. The relative pancreas (p = 0.045), stomach (p < 0.001), and jejunum (p = 0.010) weights were higher in animals fed diets containing apple pomace. In contrast, the relative liver, caecum and colon weights were not affected by fibre source or particle size. The AID of protein and amino acids was not affected, while ATTD was increased by fibre source (hemp vs. apple pomace) reducing faecal nitrogen excretion. The AID of calcium was increased when diets contained apple pomace (p < 0.001), while zinc AID and ATTD were enhanced when diets contained dried hemp (p = 0.016; p = 0.016, respectively). Our results suggest that the structure as well as the chemical characteristics should be considered in a future fibre evaluation system in pigs.

Evaluation of Valorisation Strategies to Improve Spent Coffee Grounds' Nutritional Value as an Ingredient for Ruminants' Diets

Lignin in animal diets is a limiting factor due to its low digestibility. This study assessed the effects of thermal or mechanical pre-treatments and enzymatic hydrolysis on spent coffee grounds' (SCG) nutritional value and digestibility. A first trial studied the effect of thermal pre-treatment and hydrolysis with removal of the liquid part and a second trial studied mechanical pre-treatment and hydrolysis with and without removal of the liquid part. Autoclaving did not improve the enzymatic performance nor the nutritional value. Hydrolysis reduced the digestibility of the solid phase and impaired its ruminal fermentation efficiency. Hydrolysates without removing the liquid part improved its nutritional value, but not compared with unprocessed SCG. Grinding increased crude protein and reduced crude fibre and protein, which led to greater fermentation and in vitro digestibility. Thus, grinding emerges as the most promising valorisation strategy to improve SCG nutritional characteristics and their use for animal feed, contributing to the circular economy.

Invited review: strategic adoption of antibiotic-free pork production: the importance of a holistic approach

The discovery of the use of antibiotics to enhance growth in the 1950s proved to be one of the most dramatic and influential in the history of animal agriculture. Antibiotics have served animal agriculture, as well as human and animal medicine, well for more than seven decades, but emerging from this tremendous success has been the phenomenon of antimicrobial resistance. Consequently, human medicine and animal agriculture are being called upon, through legislation and/or marketplace demands, to reduce or eliminate antibiotics as growth promotants and even as therapeutics. As explained in this review, adoption of antibiotic-free (ABF) pork production would represent a sea change. By identifying key areas requiring attention, the clear message of this review is that success with ABF production, also referred to as "no antibiotics ever," demands a multifaceted and multidisciplinary approach. Too frequently, the topic has been approached in a piecemeal fashion by considering only one aspect of production, such as the use of certain feed additives or the adjustment in health management. Based on the literature and on practical experience, a more holistic approach is essential. It will require the modification of diet formulations to not only provide essential nutrients and energy, but to also maximize the effectiveness of normal immunological and physiological capabilities that support good health. It must also include the selection of effective non-antibiotic feed additives along with functional ingredients that have been shown to improve the utility and architecture of the gastrointestinal tract, to improve the microbiome, and to support the immune system. This holistic approach will require refining animal management strategies, including selection for more robust genetics, greater focus on care during the particularly sensitive perinatal and post-weaning periods, and practices that minimize social and environmental stressors. A clear strategy is needed to reduce pathogen load in the barn, such as greater emphasis on hygiene and biosecurity, adoption of a strategic vaccine program and the universal adoption of all-in-all-out housing. Of course, overall health management of the herd, as well as the details of animal flows, cannot be ignored. These management areas will support the basic biology of the pig in avoiding or, where necessary, overcoming pathogen challenges without the need for antibiotics, or at least with reduced usage.

Safe Fabrication, Thermal Decomposition Kinetics, and Mechanism of Nanoenergetic Composite NBC/CL-20

Benefiting from the sol-gel technology and vacuum freeze-drying technology, a novel nanoenergetic composite material nitrated bacterial cellulose (NBC)/CL-20 (hexanitrohexaazaisowurtzitane) has been fabricated. The thermal decomposition kinetic and mechanism have been studied by thermogravimetric analysis-differential scanning calorimetry (TG-DSC) under nonisothermal conditions in a nitrogen atmosphere at multiple heating rates; the process and mechanism of thermal decomposition of NBC/CL-20_1:1 have also been probed by TG-DSC-IR. The kinetic and thermodynamic parameters, such as activation energy (E _a), per-exponent factor (ln A _K), rate constant (k), activation heat (ΔH ^⧧), activation free energy (ΔG ^⧧), and activation entropy (ΔS ^⧧) are calculated. The results indicate that NBC/CL-20 presents much lower activation energy than both of raw NBC and raw NC, and NBC/CL-20_1:1 exhibits superior thermal performance of heat release and E _a. Moreover, there the existence mechanism has also been probed between NBC and CL-20 during the process of thermal decomposition. The structure and composition have been characterized by a series of characterization methods and indicate that CL-20 has been embedded homogenously in the NBC gel matrix with a prominent porous cross-linked network structure. The impact and friction sensitivities have also been decreased. The whole process effectively avoids high temperatures, and thus ensures operational safety.

Can the digestibility of corn distillers dried grains with solubles fed to pigs at two stages of growth be enhanced through management of particle size using a hammermill or a roller mill?

The objective of this study was to determine the impact of reducing the mean particle size (PS) of corn distillers dried grains with solubles (DDGS) with a hammermill (HM) or with a roller mill (RM) on the apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), N, acid hydrolyzed ether extract (AEE), and fiber components in growing and finishing pigs. Twenty-four growing barrows were housed in individual pens and were randomly assigned to a 3 × 2 factorial design (n = 8): three grinding methods [either corn DDGS ground with an HM to a PS of 450 μm; corn DDGS ground with an RM to a PS of 450 μm; and corn DDGS with a PS of 670 μm (not further ground)] and two body weight (BW) periods (growing pigs with an average initial BW of 54.7 ± 0.9 kg, and finishing pigs with an average initial BW of 107.8 ± 1.5 kg BW). Fecal samples were collected for each BW period in the last 3 d of an 11-d feeding period. Titanium dioxide was used as an indigestible marker. Digestibility data were analyzed using the MIXED procedure of SAS. Results showed that finishing pigs tended to have better ATTD of DM than growing pigs (P = 0.09) and had increased ATTD of GE and N than growing pigs (P = 0.03 and P < 0.01, respectively). On the other hand, growing pigs had better ATTD of AEE than finishing pigs (P = 0.01). Pig BW period did not affect the ATTD of neutral detergent fiber (NDF), acid detergent fiber (ADF), and hemicellulose. Reducing the mean PS of corn DDGS with either HM or RM (from 670 to 450 µm) improved the ATTD of DM and GE (P < 0.01 and P < 0.01), tended to improve the ATTD of N (P = 0.08), and improved the ATTD of AEE (P < 0.01). No effect of reducing PS was observed for the ATTD of NDF, ADF, or hemicellulose. There were no differences between HM and RM in any of the ATTD variables tested. In conclusion, reducing PS of corn DDGS from 670 to 450 μm either with an HM or with an RM improved the digestibility of DM, GE, and AEE and modestly improved the digestibility of N in growing and finishing pigs. However, reducing the PS of corn DDGS did not affect the digestibility of fiber components.