Effects of moisture and temperature on Salmonella survivability in beef tallow, white grease and chicken rendered fat

High moisture levels introduced to fats after the rendering process can lead to Salmonella presence and growth. Limited research on strategies to eliminate pathogens in these environments are available. Rendered fat characteristics, such as water activity and fatty acids composition, may contribute to Salmonella survivability. The purpose of this research was to evaluate the effects of moisture levels (0%, 0.5%, 1%, and 3%), storage temperatures (48˚C and 76˚C), and fat characteristics on the growth and survival of Salmonella in beef tallow, white grease and poultry fat samples. Samples were inoculated with a high (~10⁸ CFU/mL) and a low (~10⁵ CFU/mL) Salmonella cocktail (S. Sentfenberg, S. Newport, S. Thompson and S. Infantis). Samples were stored for up to 5 days at 48 and 76 ºC. Remaining population was evaluated daily with and without enrichment step. Death rates were calculated using Weibull model for each temperature and moisture level. Only temperature had an effect (P < 0.05) on Salmonella inactivation, while no effect between moisture and/or inoculum level were observed. When all products were challenged at 76 ˚C, counts were below detectable limits after 6 hours. At 48˚C a progressive decline in Salmonella population was observed within 3 days for both beef tallow and white grease when high inoculum was used for the challenge study. Salmonella was below detectable limit within 4 days for both fat types when a low inoculum was instead applied. This research identified the effect of moisture and temperature in rendered fat samples contaminated with Salmonella and underlined the need to use time-moisture-temperature data to minimize microbial growth during transportation and storage.

167 Effects of L-lys Hcl and Distillers Dried Grains Inclusion Rate on Growth Performance of Finishing Pigs

An experiment was conducted to determine the effects of L-Lys HCl inclusion in diets with or without distillers dried grains with solubles (DDGS) on growth performance of finishing pigs. A total of 2,414 pigs (initial BW = 92.7 kg) were used in a 34-d trial. Treatments were arranged as a 2 × 3 factorial treatment structure with two levels of DDGS (0 or 10%) and three levels of L-Lys HCl (0.2, 0.3, or 0.4%). Diets were corn and soybean meal-based and were formulated to be isocaloric (NE = 2,668 kcal/kg) and isolysinic (0.75% SID Lys) by adjusting the inclusion of soybean meal, crystalline amino acids, and choice white grease. All other nutrient levels met or exceeded the NRC (2012) requirement estimates. There were 16 replicates per treatment. Pigs were weighed and feed disappearance measured to calculate ADG, ADFI, and G:F. Data was analyzed with SAS MIXED procedure. There was no evidence (P > 0.10) for interactive effects between L-Lys HCl and DDGS inclusion rate. Pigs fed diets with 10% DDGS had improved (P = 0.002) G:F, but there was no evidence (P > 0.10) for differences in ADG or ADFI. Pigs fed increasing levels of L-Lys HCl had higher (linear, P = 0.026) ADFI, decreased (quadratic, P = 0.013) G:F, and a tendency for quadratic response (P = 0.063) in ADG, overall with the poorest performance observed for pigs fed the diet with 0.4% L-Lys HCl. In conclusion, pigs fed 0 or 10% DDGS presented similar performance; however, pigs fed the high level of L-Lys HCl presented decreased performance.

123 President Oral Presentation Pick: Identification of correlated metabolomic and microbiomic responses that connect dietary energy level with pig growth

Corn, soybean meal, DDGS and extracted lipids are common staple ingredients in swine feed. Purpose-based proportioning of these ingredients in the formulation can achieve distinct levels of net energy (NE) and amino acids (AA), as well as fiber and micronutrients, in feed. In this study, diets were formulated using a 2 × 2 factorial design on NE and AA, in which the diet with high AA (HAA) had more soybean meal than the diet with low AA (LAA), while the diet with high NE (HNE) had more choice white grease and less DDGS than the diet with low net energy (LNE). Total 160 pigs (4 pigs/pen) were fed for 90 days under a three-phase feeding program. In each phase, 4 groups of pigs (10 pens/group) were fed four respective diets of HNE+HAA, HNE+LAA, LNE+HAA, and LNE+LAA. On day 90, body weights were recorded to calculate ADG, and cecal digesta were collected for LC-MS-based metabolomic analysis and 16S RNA sequencing-based microbiomic analysis. The one-way ANOWA of ADG data showed that ADG was increased by NE (p < 0.05), but not by AA. Multivariate analysis (MVA) of metabolomics and microbiomics data also showed that NE, but not AA, caused apparent changes in the metabolome and microbiome of cecal digesta. The metabolites and microbes connecting NE level with ADG, including citrulline, hexadecenoic acid, Bacteroides stercoris, and Ruminococcus bromii, were identified through examining the markers that separate HNE and LNE feedings in the MVA models of cecal metabolome and microbiome as well as the markers that were significantly correlated with ADG in the Pearson correlation analysis. Overall, the results from this study revealed specific metabolomic and microbiomic changes associated with dietary NE level and growth performance, which could serve as a foundation for further analysis on the metabolic and prebiotic functions of feed ingredients.

Analysis of anisotropy in the upsetting process of AA2014 cast alloy embedded with fly ash

Developing new metal matrix composites for a wide variety of applications and analyzing the formability aspects are challenging in the area of manufacturing. In the current study, solid cylindrical samples with AA2014 as matrix material and fly ash as reinforcement were used for the investigation. AA2014 was heated to a pouring temperature of 750 ℃ and the preheated fly ash was added to the molten AA2014 in different compositions. The whole mixture was stirred to prepare composite rods of AA2014, AA2014 + 3% fly ash and AA2014 + 6% fly ash. Each set of cylindrical samples were compressed between a set of dies till fracture by employing grease, white grease and no lubrication conditions. The varying friction conditions and composition influence the anisotropy of the billets at fracture. Empirical equations were modeled to investigate the effect of anisotropy on the stress trixiality and fracture strain at the onset of fracture. The developed equation is useful in estimating critical damage constants for any material and for any lubrication condition. A correlation between damage anisotropy factor, damage constant and fracture strain was established to understand the formability limits for different anisotropy coefficients.

PSVII-24 Growth performance and organ weight of weaned pigs fed diets with different fiber and fat sources

The objective of this study was to determine the interactive effects of dietary fiber source and lipid source on growth performance and visceral organ weights of weaned pigs. Two hundred and eighty 21 days old pigs [initial body weight (BW) = 6.84 kg] were housed in 40 pens (7 pigs/pen). The pigs were fed 4 diets (10 pens/diet) in a randomized complete block design in 2 phases, Phase 1 from day 0 to 14 and Phase 2 from day 14 to 35. The diets were corn-soybean meal-based with either sugar beet pulp (SBP) or soybean hulls (SBH) as fiber source and either soybean oil (SBO) or choice white grease (CWG) as fat source in 2 × 2 factorial arrangement. The BW and feed intake were determined by phase, whereas visceral organ weights were determined on day 35. Fiber source and fat source did not interact on growth performance and organ weights relative to BW. Pigs fed CWG-containing diets had lower (P < 0.05) gain to feed ratio than those fed SBO-containing diets by 7.95% during Phase 1 of feeding. Pigs fed SBP-containing diets had lower (P < 0.05) gain to feed ratio than those fed SBH-containing diets by 7.94% during Phase 1 of feeding. However, pigs fed SBP-containing diets had greater (P < 0.05) stomach weight, and tended to have greater (P < 0.1) heart, small intestine and large intestine weights relative to BW than those fed SBO-containing diets. In conclusion, replacement of SBH with SBP in diets for weaned pigs reduced feed efficiency and increased visceral organ weights relative to BW, implying that the replacement of SBH with SBP in diets of weaned pigs increased energy expenditure in visceral organs. Inclusion of SBO (at the expense of CWG) in diets for weaned pigs can improve feed efficiency.

Effects of added fat on growth performance of finishing pigs sorted by initial weight1

Two studies were conducted to determine whether dietary fat fed to pigs of different weight categories differentially influences growth performance. Both experiments were conducted in a 2 × 3 factorial arrangement with main effects of dietary fat addition (0 or 6% choice white grease) and sort weight category (HEAVY, LIGHT, or MIXED). In experiment 1, 1,032 pigs (initially 30.7 kg) were individually weighed and sorted into two body weight (BW) groups with one group consisting of pigs greater than median BW and the other group less than median BW. Pens were then formed by randomly selecting pigs: 1) only from heavy group (HEAVY), 2) only from light group (LIGHT), or 3) from both heavy and light groups to create a normal distribution around barn BW mean (simulation of unsorted pigs; MIXED). In experiment 2, 1,176 pigs (initially 35.1 kg) were visually sorted into BW groups and assigned to HEAVY, LIGHT, and MIXED pen weight categories. Overall in experiment 1, adding 6% dietary fat increased average daily gain (ADG) of LIGHT pigs, but not HEAVY pigs (HEAVY vs. LIGHT × fat interaction, P = 0.03), but increased (P < 0.05) ADG regardless of sort category in experiment 2. In both experiments, HEAVY pigs had greater (P < 0.05) overall ADG and average daily feed intake (ADFI), but decreased (P < 0.05) G:F compared with LIGHT pigs. However, when HEAVY and LIGHT treatment groups were combined, growth performance and carcass characteristics were similar to MIXED pigs. Sorting decreased coefficient of variation (CV) of final BW but did not affect CV of ADG. In conclusion, because adding fat to the diets of lightweight pigs improved ADG in both experiments, dietary fat could be used selectively in the barn to increase the weight of the lightest 50% of the pigs. However, the sorting pigs into light and heavy weight groups did not improve growth performance or carcass characteristics.

Diet formulation method influences the response to increasing net energy in finishing pigs1

An experiment was conducted to compare the effects of increasing dietary net energy (NE) in finishing pig diets while either maintaining a standardized ileal digestible lysine:NE ratio (SID Lys:NE) or maintaining SID Lys as a constant percentage of the diet across increasing energy densities. A total of 150 pigs (Line 600 × 241; DNA, Columbus, NE; initially 35.7 kg) were used in a 91-d study. Pigs were blocked by sex and weight and randomly assigned to 1 of 5 treatments with 2 pigs per pen and 15 pens per treatment. Treatments included a low-energy control diet that was corn-soybean meal-based with added soybean hulls, and a 2 × 2 factorial arrangement of treatments with main effects of increasing dietary NE (medium or high by adding choice white grease) and formulation method (with a SID Lys:NE ratio or maintaining the same percentage SID Lys). Linear and quadratic contrasts were made using the control diet and the medium- and high-energy diets within each formulation method. Pigs and feeders were weighed approximately every 30 d to calculate average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F). At the end of the experiment, pigs were sent to a commercial processing facility for carcass data collection. From days 0 to 34 and 34 to 61, ADG and SID Lys intake increased as NE increased (linear, P < 0.05) in pigs fed diets with a Lys:NE ratio, but not for those fed the same percentage Lys. As NE increased, NE intake and G:F increased (P < 0.01) in pigs fed diets with either formulation method. From days 61 to 91, increasing NE had no effect (P > 0.10) on ADG. There was no change in G:F in pigs fed diets with the same percentage Lys (P > 0.10), but G:F decreased then increased (quadratic, P < 0.01) in response to increasing NE in pigs fed diets with a SID Lys:NE ratio. Overall, increasing dietary NE increased (linear, P < 0.001) daily NE intake and G:F (linear, P < 0.018) with either formulation method. However, SID Lys intake, ADG, and hot carcass weight only increased (linear, P < 0.01) when a SID Lys:NE ratio was maintained. Increasing NE without maintaining a constant SID Lys:NE ratio increased backfat depth (quadratic, P = 0.01), whereas it did not in pigs fed diets with a SID Lys:NE ratio. In conclusion, increasing dietary energy density increased NE intake and G:F regardless of formulation method. However, a SID Lys:NE ratio must be maintained to achieve increased ADG and minimize fat deposition.

125 Effects of copper hydroxychloride and increasing concentrations of dietary fat on growth performance, total tract endogenous loss of fat, and apparent total tract digestibility of fat by growing pigs

Two experiments were conducted to test the hypothesis that Cu hydroxychloride (IntelliBond C, Micronutrients, LLC, Indianapolis, IN) improves gain:feed of pigs by increasing apparent total tract digestibility (ATTD) of fat. In experiment 1, 144 pigs (15.40 ± 2.39 kg) were allotted to 1 of 6 treatments. Four diets contained 0, 2, 4, or 6% choice white grease (CWG) and 2 diets contained 150 mg/kg Cu from Cu hydroxychloride and 0 or 2% CWG. Data for growth performance were analyzed by contrast statements, and Cu equivalency of CWG was determined using prediction equations derived from regression procedures using SAS. Results indicated that gain:feed linearly increased (P ≤ 0.05) as CWG concentration increased in diets (Table 1). Supplementation of Cu hydroxychloride to diets improved (P ≤ 0.05) gain:feed of pigs, which resulted in a CWG equivalence of 2.8 to 3.8% for 150 mg/kg Cu hydroxychloride. In experiment 2, 80 pigs (18.24 ± 1.81 kg) were housed individually in metabolism crates and randomly allotted to 1 of 10 diets. Eight diets contained 0, 15, 30, or 45% distillers dried grains with solubles (DDGS) and 0 or 150 mg/kg Cu hydroxychloride. Two additional diets contained 2% CWG and 15% DDGS and 0 or 150 mg/kg Cu hydroxychloride. Feces were collected for 4 d after 5 d adaptation. Data were analyzed by contrast statements and regression procedures using SAS. Supplementation of Cu to diets improved (P ≤ 0.05) ATTD of fat by 20% due to reduced (P ≤ 0.05) endogenous loss of fat (from 11.23 to 7.14 g/kg dry matter intake), but did not affect energy digestibility or true total tract digestibility of fat. In conclusion, supplementation of 150 mg/kg Cu hydroxychloride to diets improved gain:feed of pigs with a CWG equivalence of 2.8 to 3.8%, but this was not due to improved energy digestibility.

Utilization of Ring Compression Test to Investigate the Mushroom Effect and Adhesive Nature of AA2014 Billets

In the cold forging of AA2014, friction at the die/billet interface plays a significant role. AA2014 metallic rings of height 8 mm with an outer diameter of 24 mm and inner diameter of 12 mm was upset between H13 steel dies to different levels of deformation. Different types of lubricants namely, grease, molybdenum disulphide, white grease, palm oil were employed at the die/ring interface and ring compression test was also conducted for un lubricated condition. The values based on the changes in the geometry after different levels of deformation were fit into Male and Cockroft calibration curves to estimate the friction factor (m). The values of friction factors determined from the experiments were given as input to the finite element package, Deform 2D. The results obtained from the finite element studies were compared with the experimental results. After validation, the research was extended by considering ring geometries of different sizes. The effect of the friction between the die/billet interface and geometry were studied on the flow of metal. The zone of minimum velocity of particles, defined as neutral plane was analyzed for different friction conditions and different geometries of the ring.