bluuebunny/crossref_metadata_2025 huggingface dataset:
PSVII-30 Winter-feeding high concentrate diets reduces enteric methane emissions pre-calving in beef cows
Authors: Wehrbein Megan A , Moreno Elias Velasquez , Menendez Hector M , Rusche Warren C , Smith Zachary K , Menezes Ana Clara B
Published: September 2024

Objectives were to evaluate the effects of winter-feeding forage (2.02 Mcal/kg dietary ME) vs. concentrate (2.84 Mcal/kg of dietary ME) diets pre- and post- calving on enteric methane emissions, dry matter intake (DMI), and performance of beef cows. Forty-six pregnant (210 ± 10 d of gestation) Angus and Simmental-Angus cows [n = 46; body weight (BW) = 630 ± 12.0 kg) were blocked by breed, age, and BW and assigned to one of two treatments: 1) Ad-libitum feeding of forage-based diet (HFOR; n = 23); or 2) a concentrate corn-based diet with a restricted intake of 1.2% BW (HCON; n = 23). Cows were housed in a group-pen at the South Dakota State University Cow-Calf Education and Research Facility (Brookings, SD). Feed consumption was tracked using an electronic feeder (Insentec, The Hague, Netherlands) and enteric methane emissions were monitored using the GreenFeed trailer system (C-Lock Inc., Rapid City, SD). Body weight measurements were taken bi-weekly. Treatments started being applied on d 50 (± 10) pre-calving and will continue to be applied up to d 84 post-calving. Preliminary data reported herein was collected from d 42 pre-calving up to d 42 post-calving. Performance and dry matter intake data were analyzed as repeated measures using the MIXED procedure of SAS with treatment, period, and their interaction as fixed effects and animal as a random effect. Enteric emissions were analyzed using a linear mixed effects model with animal as a random effect in R, with a post-hoc contrast among treatments. Pre-calving, HFOR had greater (P < 0.01) CH4 emissions than HCON (264 ± 9.19 g/d and 246 ± 9 g/d for HFOR and HCON, respectively). Both groups presented dynamic changes in CH4 emissions over time (P < 0.01). Post-calving, no differences were observed between treatments (P = 0.55); however, temporal changes (P < 0.01) and treatment × d interaction (P < 0.01) persisted, indicating ongoing diet-temporal interplay. No treatment × period interactions (P ≥ 0.16) were observed for DMI and performance. As designed, dry matter intake was less (P < 0.01) for HCON (8.66 ± 0.45 kg) than HFOR (17.3 ± 0.45 kg) cows. Further, dry matter intake was less (P < 0.01) pre-calving (11.11 ± 0.28 kg) than post-calving (14.85 ± 0.48 kg). Cows in the HFOR group were heavier (P = 0.01) than HCON (646.22 ± 14 kg vs. 593.43 ± 14 kg, respectively) likely due to ruminal fill; and as expected cows were heavier (P < 0.01) pre- than post-calving, with the greatest BW observed on d 14 pre-calving (639.52 ± 9.92 kg). These data indicate that high concentrate corn-based diets may be used in dry-lot settings to optimize nutritional management and reduce methane emissions when compared with conventional high forage winter-feeding strategies.
PSVII-24 Effectiveness of hot water knife sanitation practices during beef dressing processes
Authors: Yang Xianqin , Tran Frances , Chhabra Prakriti , Platter Zane , Tennant Travis C , Brown Tyson , Lawrence Ty E
Published: September 2024

Our objective was to assess whether the harvest processing equipment sanitation practices in beef processing plants are sufficient to mitigate pathogen transfer. Multiple regulatory agencies across the globe require that harvest equipment be sanitized using hot water at a minimum of 82°C, with a momentary dip when a time is specified. Consequently, hot water sanitizers have been widely implemented at meat processing facilities, in particular, for knife sanitation throughout the dressing process. However, there is no standard time requirement for hot water immersion and, as such, the effectiveness of hot water sanitization is uncertain. The practice for knife sanitation at a large beef processing facility was audited and the microbial reduction that simulated the audited practice was assessed along with a momentary dip at 82°C. A five-strain cocktail of Escherichia coli and 11 knives of differing degree of usage obtained from the beef plant were used in the study. An area of 50 cm2 of the upper surface of each knife was spread-inoculated with the five-strain E. coli cocktail and the knife was subsequently submerged in a water bath coupled to a water circulator for immersion at 82°C. Exposures times tested were those derived from the in-plant audit for each knife type. A knife that was similarly inoculated, but was not treated with hot water, served as a positive control. E. coli surviving the treatment were enumerated by plating. In addition, two knives that had most and least reduction of E. coli were artificially contaminated with meat prior to inoculation, by passing the knife through meat multiple times. For each condition, three independent trials were conducted. Least-squares means for log counts were separated by a post-hoc Tukey test. Mean immersion times for different knives audited ranged from 1 to 9.8 s. Immersing knives in water at 82°C significantly reduced the number of E. coli (P < 0.05; Table 1), ranging from 2.3 (air knife)-5.5 (skinning knife 2) log units. Variation among the same knife type was observed. Momentary dip at 82°C reduced E. coli on de-boning, hook, air knife and wizard knife by 1-1.2 log (P < 0.05) and < 1 log for the other six knives (P ≥ 0.05). Treatment at 82°C for the duration of average exposure time observed during the in-plant audit of knives that had been contaminated with meat debris showed lower reductions of E. coli, compared with clean knives. Those reductions (>1.5 log units) were significant (P < 0.05). In conclusion, the duration for hot water sanitation of knives at beef processing plants achieves significant reduction of E. coli if temperature is maintained at 82°C and a momentary dip at the same temperature would be less likely to be effective.
PSI-30 Effects of high canola meal diet with acidifiers supplementation on cecal microbiota of nursery pigs
Authors: McClellan Katlyn A , Fowler Emily , Perez-Palencia Jorge Y , St-Pierre Benoit , Levesque Crystal L , Hong Jinsu
Published: September 2024

Inclusion of canola meal (CM) in swine diets is typically limited stemming from the presence of glucosinolates (Gls), which can reduce growth performance and cause thyroid dysfunction in nursery pigs. While certain members of hindgut bacterial communities are capable of degrading dietary Gls, which would mitigate their detrimental effects, they have yet to be identified. Moreover, lowering the pH in the hindgut of the pig can break down Gls into less toxic compounds, potentially reducing harm. Thus, this study aimed to characterize major bacterial species populating the hindgut of nursery pigs fed a high CM diet supplemented with acidifier and encapsulated butyrate. A total of 315 nursery pigs weaned at 21 d old, average body weight (BW) 6.0 ± 1.2 kg, were assigned to one of five dietary treatments with 9 replicate pens (7 pigs/pen) in a randomized complete block design. The dietary treatments included PC: a corn-soybean meal-based diet with 20% CM, NC: a corn-soybean meal-based diet with 40% CM, NC+A: NC diet supplemented with an acidifier at 1,500 ppm, NC+B: NC diet supplemented with encapsulated butyrate at 500 ppm, and NC+A+B: NC diet supplemented with both an acidifier and encapsulated butyrate. All diets were formulated to meet or exceed the nutrient requirements of NRC (2012). At the end of the feeding trial (6 wk), one pig from each pen was euthanized to collect fresh cecal digesta. Samples were analyzed using the 16S rRNA gene through PCR-amplification of the V1-V3 regions from microbial genomic DNA, followed by Illumina MiSeq 2X300 sequencing. A comparative analysis of the highly represented taxonomic groups and operational taxonomic units (OTU) using non-parametric Kruskal-Wallis sum-rank test and Wilcoxon pairwise test identified candidate bacterial groups or species enriched across different diets. Bacillota was the predominant phylum across all diets, ranging from 83.2% to 86.3%. At the genus level, Lachnospiracea incertae sedis was less abundant in the NC diets with acidifier (Acidifier effect, P < 0.05), whereas Dialister was less in the NC diets with encapsulated butyrate (Butyrate effect, P < 0.05). The OTU Ssd-00001 (Lactobacillus amylovorus, 99.6%) tended to be greater in the cecal microbiota of pigs fed the NC diets with acidifier (Acidifier effect, P = 0.09). Interestingly, OTU Ssd-00188 (Agathobacter rectalis, 99.2%) tended to be higher in PC diet than in NC diet (P = 0.06), while its abundance was less in the cecal microbiota of pigs fed the NC diets with acidifier (Acidifier effect, P = 0.09). In conclusion, these results provide valuable insights into the microbiome of pigs fed high CM diets. Understanding the interplay between microbial communities and high CM diet with acidifier supplementation is crucial for optimizing swine diets and mitigating challenges associated with the antinutritional effects of dietary Gls from CM.
PSII-23 Egg production and quality in older Lohmann LSL lite hens in response to rearing space allowance and provision of omega-3 fatty acids and yeast bioactives from placement through to 17 wk of age
Authors: Lee Junhyung , Cheng Veronica , Kiarie Elijah
Published: September 2024

Rearing practices prior to sexual maturity have implications on hen performance. The objective of the current study was to evaluate egg production and quality in Lohmann LSL lite hens reared on low or high spacing allowances (SA) in enriched cages and fed diets with a source of omega-3 fatty acids (n-3 FA) or yeast bioactives (YB) from placement to 17 wk of age (woa). The high and low SA were: 348 cm2/bird; ~50 birds/cage) and 284 cm2/bird; ~68 birds/cage, respectively. The diets provided were control (C), C + 3% co-extruded full fat flaxseed and pulse mixture (FFF; 1:1 wt/wt) for n-3 FA and C + YB, yeast cell walls processed with β-1,3-glucan hydrolase (Tables 1-3). At the beginning of 18 woa, a total of 288 hens were placed in 72 enriched cages (4 hens/cage) based on rearing treatments (n = 12). The hens had ad libitum access to commercial layer diet and water. From 52 to 72 woa, eggs were recorded daily for calculation of hen day egg production (HDEP). Egg weight (EW), shell thickness (EST), shell breaking strength (ESBS), yolk color (YC), and Haugh unit (HU) were analyzed on bi-weekly basis. Egg mass was calculated based on EW and HDEP. Data were subjected to PROC GLIMMIX procedure of SAS with rearing SA, diets, and associated interactions as fixed effects. The cumulative impact of the diets on HDEP did not exhibit significant differences (Table 4). However, the space allowance (SA) demonstrated an effect (P < 0.05) with hens reared in increased SA yielding greater HDEP (98.2 to 94.5%) compared with hens reared in decreased SA (94.0 to 90.8%) at 56, 58, 60, 63 and 71 woa. Furthermore, hens reared in SA exhibited greater HU values (P < 0.05) throughout, although egg weight and mass were not affected (P > 0.05; Table 5-8) by SA. In conclusion, under the conditions of the study, provision of n-3 FA and YB did not present noticeable carryover impact on egg production and quality during the mid to late laying cycle. However, rearing spacing allowance influenced egg production and quality. Suggesting, reducing rearing stress through the provision of higher space allowance prior to sexual maturity had carryover effects on hen productivity in late lay cycle.
PSII-28 Comparative analysis on dietary Quillaja Saponin and/or phytase additive on growth performance, nutrient digestibility, fecal gas emission, and carcass grade in growing- finishing pigs
Authors: Li Tian Xiang , Lee Kye Jin , Kim In Ho
Published: September 2024

Quillaja saponin (QS) is a substitute for antibiotics which is obtained from the wood and bark of the soap tree and contains a triterpenoid structural component. It has been demonstrated that QS can increase productivity, boost the immune system, promote intestinal health, and improve meat quality in monogastric animals without changing production costs. On the other hand, phytase (PHY), an enzyme that catalyzes the release of phosphorus from phytate has been used in swine diet for many decades. To date, there are no studies on the analysis of the comparative effect of QS and PHY supplementation in swine. Therefore, this study aimed to examine the comparative effects of low doses of QS and/or PHY on growth performance, nutrient digestibility, fecal gas emissions, and carcass grade in growing-finishing pigs. A total of 72 [(Landrace×Yorkshire) ×Duroc] pigs [initial body weight (BW) = 25.82 ± 1.68kg] were selected and randomly allocated to 3 dietary treatments with 6 replicates of 4 pigs/pen for 110 d. The test treatments were CON-basal diet, and the basal diet supplemented with 0.02% of PHY and 0.01% of QS. Experimental data were analyzed using GLM procedure of SAS and the difference between the treatments was determined using contrast. P < 0.05 denotes significance. During the overall experimental period pigs fed a diet supplemented with 0.01% QS supplement showed increased (P < 0.05) BW, daily feed intake (ADFI), and reduced (P < 0.05) gain to feed ratio (G: F) compared with those fed CON and PHY. While pigs fed a diet supplemented with 0.02% PHY had only improved (P < 0.05) average daily gain (ADG) with no adverse effect on BW, ADFI, and G:F. The results of nutrient digestibility, fecal gas emission, and carcass grade were similar between the test treatments, and no significant effects were found until d 110. In conclusion, instead of adding 0.02% of PHY, adding 0.01% of QS to growing-finishing pig diets would be more beneficial to enhance their growth rate.
PSII-24 Effect of supplemental guanidinoacetic acid in low energy diets with different forms of pellet and mash on growth performance, intestinal morphology and some blood attributes in broiler chickens
Authors: Toghyani Majid , Hossein Teysir Ali , shahsavan Mehdi
Published: September 2024

The present experiment was designed to investigate effects of supplemental guanidinoacetic acid in standard or low energy diets with mash or pelleted form on growth performance, intestinal morphology and blood attributes of broiler chickens. A total of 360 one-day-old broiler chickens (Ross 308) were assigned to 6 treatments and 5 replicates of 12 chicks each, based on a completely randomized design during the starter (1 to 14), growing (15 to 28), and finisher (29 to 42) periods. Experimental treatments were pelleted or mash diets with standard or 150 kilocalories deficient in energy contents. A 1.2 g/kg guanidinoacetic acid was supplemented to low energy diets (Table 1). All chickens were evaluated for growth performance [body weight (BW), daily weight gain (DWG), daily feed intake (DFI), and feed conversion ratio (FCR)], carcass traits (carcass yield, abdominal fat, heart, liver, pancreas, proventriculus, gizzard, and small intestine), intestinal morphology (villus height, crypt depth, and villus height to crypt depth ratio), and serum biochemical parameters (uric acid, creatinine, total protein, homocysteine). Results indicated that chickens received pelleted diets had improved DWG and (FCR) compared with broilers fed on mash diets (P < 0.05; Table 2). Broilers received mash diets with low energy contents had compromised DWG and FCR which ameliorated after dietary guanidinoacetic acid supplementation equal to standard energy diets (P < 0.05). Furthermore, supplementation of guanidinoacetic acid in pelleted diets deficient in energy content could compensate growth only during the entire rearing period (P < 0.05). Supplemental guanidinoacetic acid decreased liver weight (P < 0.05) and decreased heart weight when supplemented in mash diets (P < 0.05; Table 3). Reduction in dietary energy content increased villus height to crypt depth ratio in all 3 intestinal sections of dedunum, jejunum and ileum (P < 0.05) but supplementation of guanidinoacetic acid did not change the noted intestinal morphology. Reduction in dietary energy content of mash or pelleted diets increased serum acid uric concentration (P < 0.05) while decreased when diet of broilers added with guanidinoacetic acid (P < 0.05). Serum creatinine concentrations increased following dietary guanidinoacetic acid supplementation (P < 0.05; Table 4). Overall, supplementation of 1.2 g/kg guanidinoacetic acid improved growth performance of broiler chickens fed on energy deficient diets with more pronounced effects in mash diets. Moreover, supplemental guanidinoacetic acid affected blood attributes but failed to influence the effect of dietary energy variations on the intestinal morphology of broiler chickens.
PSVI-28 Interactive effects of different fiber and lipid sources on amino acid digestibility in growing pigs
Authors: Hong Jinsu , Ndou Saymore , Woyengo Tofuko A
Published: September 2024

A study was conducted to determine the effects of different fiber and lipid sources on the digestibility of amino acids (AA) in growing pigs. Five diets were fed in this study. The diets were corn-soybean meal-based diet with either soybean hulls (SBH) or sugar beet pulp (SBP) as fiber source and either soybean oil (SBO) or choice white grease (CWG) as lipid source in a 2 × 2 factorial arrangement; and a N-free diet. The diets were formulated to be similar in content of AA, calcium, available phosphorus, and total dietary fiber. The SBH and SBP were each included in their respective diets at 15%, whereas the SBO and CWG were each included in their respective diets at 4.5%. The 5 diets were fed to 10 ileal-cannulated pigs [5 barrows and 5 gilts; initial average body weight (BW) = 54.8 ± 5.6 kg)]in a 5 × 5 Latin square design to give 10 replicates per diet. On an as fed basis, SBH and SBP contained 11.3 and 8.8% crude protein, 66.1 and 49.8% total non-starch-polysaccharides (NSP), 54.3 and 29.5% insoluble NSP, and 11.8 and 20.3% soluble NSP, respectively. The SBO and CWG contained >98.5 and >98.5% crude fat, 14.7 and 35.6% saturated fatty acids, and 76.6 and 62.5% unsaturated fatty acids, respectively. Dietary fiber source and lipid sources did not interact on standardized ileal digestibility (SID) of AA. The SBH- and SBP-containing diets did not differ regarding SID of all AA except Met and Trp. Pigs fed SBP-containing diets had lower (P < 0.05) SID of Met and greater (P < 0.05) SID of Trp than those fed SBH-containing diets by 2.5 and 4.7%, respectively. The SBO- and CWG-containing diets did not differ regarding SID of all AA except Trp. The SID of Trp for SBO-containing diets was greater (P < 0.05) than that for CWG-containing diets by 2.6%. In conclusion, the lack of interaction between dietary fiber and lipid sources on the SID of AA implies that these two factors (fiber and lipid sources) may exert their effects on ileal digestibility of AA independently if the fiber and lipid sources are included in diets for growing pigs at same levels included in the diets fed in the current study. The dietary fiber source and dietary lipid source had limited effects on the digestibility of most AA, implying that replacement of one fiber source with one another fiber source or of one lipid source with another lipid source in diets for growing pigs may have limited effect on digestibility of AA if the fiber and lipid sources are included in diets for growing pigs at same levels included in the diets fed in the current study.
PSVI-27 Syntheses of guanidinoacetate and creatine in maternal tissues and placentae of gestating gilts fed diets with or without supplemental creatine
Authors: Connolly Erin D , He Wenliang , Lopez Arianna , Olivarez Maddison , Cain Joseph , Lefevre Carli , Ross Alex , Johnson Gregory , Bazer Fuller , Wu Guoyao
Published: September 2024

This study determined the effects of dietary supplementation with creatine to gestating gilts (n = 6) on their ability to form guanidinoacetate (GA) and creatine in placentae and maternal tissues. Gilts were assigned randomly to one of two dietary groups: control and creatine supplementation (Cr; n = 12 gilts/diet). Once estrus was detected (d 0), gilts were artificially inseminated 12 h and 24 h later. All gilts were individually housed and fed 0.9 kg of a corn- and soybean-based diet containing 14% crude protein (but no creatine or GA) twice daily. Gilts in the control and Cr groups received daily top dressing of 0 or 2 × 15 g Cr either between d 10 and 60 or between d 10 and 90 of gestation. There were 6 gilts per dietary treatment per gestational stage. On either d 60 or 90 of gestation, gilts were euthanized to collect maternal tissues and placentae. Each tissue (~150 mg) was incubated at 37 ℃ for 2 h in 2 mL of oxygenated (95% O2/5% CO2) Krebs bicarbonate buffer with or without a) 2 mM glycine plus 2 mM L-arginine or b) 0.2 mM GA plus 0.5 mM L-methionine (the source of S-adenosylmethionine). After the 2-h period of incubation, 0.2 mL of 1.5 M HClO4 was added to the medium. The acidified medium plus tissue was homogenized and the homogenizer rinsed with 1 mL water, followed by the addition of 0.1 mLl of 2 M K2CO3. The extract was analyzed for GA, creatine, and amino acids using HPLC. Results indicated that on both d 60 and 90 of gestation, a) GA was formed from glycine plus L-arginine by maternal kidneys and pancreas of all gilts, but not maternal liver, placentae, or endometria; b) GA was converted into Cr by both maternal liver and pancreas, but not maternal kidneys, endometria, or placentae; c) dietary supplementation with Cr did not affect (P > 0.05) either the formation of GA from glycine plus L-arginine in maternal kidneys and pancreas or the conversion of GA into creatine in maternal liver and pancreas (Tables 1 and 2). Collectively, these results indicate interorgan cooperation to form creatine in pregnant gilts to support fetal growth and development, as well as the lack of inhibition of this metabolic pathway by dietary supplementation with creatine. (Supported by USDA/NIFA grant No. 2022-67015-36376)
PSXII-11 Impact of pre-breeding and breeding supplementation in May-born range heifers on growth rates and reproductive performance
Authors: Crouch Josie , Mulliniks Travis , Musgrave Jacki A , McCarthy Kacie L
Published: September 2024

Our objectives were to determine the impact rumen undegradable protein (RUP) supplementation prior to and during the breeding season had on growth rates and reproductive performance in May-born yearling range heifers. This study was conducted over a 3-yr period at the University of Nebraska, Gudmundsen Sandhills Laboratory (GSL) near Whitman, NE and utilized May-born Red Angus x Simmental crossbred heifers [n = 192; weaning body weight (BW) = 200 kg ± 28 kg]. Heifers were randomly assigned by pre-breeding BW to one of two treatments: 1) received 0.908 kg of a dried distillers grain supplement (DDGS; Supp, n = 66) pre-breeding through the breeding season or 2) received no supplement (NoSupp, n = 138). Each year, treatments were initiated in July and ended in August (55 ± 3 d). Using a C-Lock Smart Feeder (Rapid City, SD) heifers had individual access to their allotted DDGS supplementation. On average, NoSupp heifers consumed 0.09 kg/d (yr 1) and 0.02 kg/d (yr 2 and 3); whereas, Supp heifers averaged 0.59, 0.74, and 0.76 kg/d in yr 1, 2, and 3, respectively. Heifer BW was collected pre-trial (May), pre-breeding (July), breeding (August), pregnancy diagnosis (October), and pre-calving (April). Body condition score (BCS) was collected at pregnancy diagnosis (October) and pre-calving (April; Yr 1 and 2). Before each breeding season, two blood samples were collected 10 d apart to determine pubertal status. Heifers were synchronized with a single 5 mL intramuscular injection of prostaglandin F2 alpha (Lutalyse, Zoetis, Parsippany, NJ) 5 d after bull turnout during a 30 d natural service breeding season. Pregnancy diagnosis was determined via rectal ultrasound in October. No differences (P > 0.12) in BW were noted among treatments for all measurement timepoints. Moreover, SUPP heifers had greater (P < 0.02) average daily gain (ADG) from pre- trial to pregnancy diagnosis compared with NoSUPP heifers. However, there was no differences (P = 0.11) in ADG from pregnancy diagnosis to pre- calving. At pregnancy diagnosis (October), a treatment x year interaction (P = 0.02) for BCS was present where Supp heifers had a greater BCS than NoSupp heifers in yr 3. Heifer BCS pre-calving was not affected (P = 0.12) by treatment. There was a greater percentage (P < 0.01) of SUPP heifers cycling compared with NoSUPP heifers. However, there were no differences (P > 0.24) in pregnancy rates, the percentage that calved in the first 21 d, calf birth BW, or subsequent calving date. Ultimately, this study implies that providing a RUP supplement prior to and during the breeding season will increase the percentage of heifers that are cycling before breeding and have a greater ADG through pregnancy diagnosis; however, supplementation will not impact other reproductive parameters or BW gains.
PSXII-12 Effects of compost environment on bone degradation of livestock mortality compost
Authors: Vigil Justin M , DeAtley Kasey L
Published: September 2024

Livestock mortality composting is an effective carcass disposal option for many producers. One issue that arises once the compost has gone through its curing process is that large, dense bone is present in the compost. Producers are forced to sift out the bone and dispose of it in alternative ways. Objectives of this study were to determine weight degradation of post-composted bone when subjected to re-composting using either manure-only (i.e., control; n = 3) or offal and flaked hay (i.e., treatment; n = 3) as additional nitrogen and carbon sources, respectively. All materials used for the 125-d study were sourced from the CSU, Chico University Farm. Control compost mounds were constructed in three layers (i.e., manure-bedding mix, bone, and manure-bedding mix) whereas the treatment compost mounds were constructed using the layering method consisting of a flaked hay base, manure-bedding mix, bone, boneless offal treatment, manure-bedding mix, and flaked hay cap. Offal compost mounds used boneless butcher waste (i.e., bovine, ovine, and porcine digestive tracts). Each compost mound included 1 skull, 2 pubis, 2 mandibles, 3 scapulas, 3 vertebrae, 4 femurs, 8 metacarpus or metatarsus, and 10 ribs. Bones were weighed and recorded on d 0 and d 125. Temperature was monitored weekly. Data were analyzed as a completely randomized design using a single factor analysis of variance. There was no difference (P > 0.05) between control and treatment compost mounds for total bone weight at d 0. Results also showed that there was no difference between the control and the treatment on d 125 (17.86 ± 1.31 kg vs. 15.76 ± 0.88 kg; P = 0.26). These results suggest longer composting periods may be necessary to see degradation of bone by weight loss.
PSXII-13 Heavy metal and nutrient concentration in non- and livestock-mortality compost
Authors: DeAtley Kasey L , Vigil Justin M , Yount Dana
Published: September 2024

Composting is a viable disposal option for livestock-mortalities and offal; however, is illegal in California due to the perceived risk of disease transfer, heavy metal and nutrient leaching into ground water. Objectives were to determine heavy metal and nutrient concentration in non- and livestock-mortality compost. The trial was conducted at the CSU, Chico composting facility where treatments included: 1) non-mortality (i.e., control; n = 3), 2) whole carcass (n = 3), 3) bone-in offal (n = 3) and 4) boneless offal compost (n = 3). Carcass and offal materials were bovine, porcine, and ovine. Carbon, nitrogen, and stock materials were similarly sourced. Control compost was produced using dairy manure and bedding materials in the windrow method while carcass and offal treatments were produced using the mounding method. Decomposition of soft tissue occurred from d 1 to 45 for bone-in and boneless offal mounds and from d 1 to 90 for the whole carcass mounds. Each decomposition period was followed by a 15-d pathogen reduction period where temperatures were maintained at or above 55°C. Compost samples (n = 3 per treatment) were collected on d 15 of the pathogen reduction period for heavy metal and nutrient analysis. All heavy metal concentrations were below regulatory limits. Data were analyzed as a completely randomized design with analysis of variance and Tukey mean separation tests. Results indicate no difference (P > 0.05) among treatments for arsenic, cadmium, chromium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc. No difference was detected among treatments for phosphorus, nitrogen, or pH (P > 0.05). Percent organic matter was greater in conventional vs. bone-in and boneless offal (31.42 ± 2.05 % vs. 25.00 ± 2.10 % and 26.17 ± 2.30 %; P = 0.009). Similarly, potassium was greater in conventional vs. bone-in and boneless offal (4.25 ± 1.4 mg/kg vs. 2.5 ± 1.2 mg/kg and 2.0 ± 1.0 mg/kg; P < 0.0001). Results suggest minimal heavy metal accumulation in non- and livestock-mortality compost and indicate that bone-in and boneless compost may contribute less organic matter and potassium compared with non-mortality compost.
PSIV-25 Utilization of rumen protected lysine and methionine in beef feedlot diets: Impacts on steer performance
Authors: Neville Bryan W , Oliver William T , Wells Jim E , Crouse Matt S , Lindholm-Perry Amanda K , Thorson Jennifer F , Kuehn Larry A , Freetly Harvey C
Published: September 2024

Our objective was to compare intake, gain, and feed efficiency of steers fed rumen protected lysine and/or methionine in 10% crude protein diet relative to performance of steers fed a diet with 13% crude protein without added amino acids. Beef steers [n = 161; body weight (BW) = 429.7 ± 44.5kg] were used in this experiment. Calves were randomly assigned to treatments consisting of 1) positive control diet (POS), formulated to contain 13.0 to 13.5% CP, 2) negative control (NEG) diet containing 10.2% CP, which also forms the basal diet for the remaining treatments, 3) rumen protected methionine (RPMet) 10.2% CP basal diet and 7.2 g/d supplemental methionine, 4) rumen protected lysine (RPLys) 10.2% CP basal diet and 18.5 g/d supplemental lysine, and 5) the combination of rumen protected lysine and methionine (RPMet+Lys) 10.2% basal diet with 7.2 and 18.5 g/d supplemental methionine and lysine, respectively. Initial and final BW were unaffected by treatment (P ≥ 0.24). Average daily gain for POS (1.93 kg/d P ≤ 0.02) was greater than those of NEG, RPLYS, and RPMET+LYS, but was similar to RPMET (1.86 kg/d; P = 0.17). Dry matter intake was greater in RPMET (12.1kg/d; P ≤ 0.10) compared with all other treatments. Gain-to-feed ratio was greatest in POS (0.170 kg gain:kg DMI; P ≤ 0.04). The impacts of rumen-protected amino acids on performance (intake, gain, and efficiency) of beef steers fed high-concentrate diets were inconsistent. Evaluating both lysine and methionine supplied independent of each other in various concentrations is critical before moving forward with recommendations for beef cattle. USDA is an equal opportunity provider and employer.
PSV-30 Effects of divergent residual feed intake on performance, feed efficiency, feeding behavior and gaseous exchange in replacement beef heifers
Authors: Adcock Zoe , O’Reilly Keara , Carstens Gordon E , Tedeschi Luis O , Pinchak William E , Walker Ryon S
Published: September 2024

The objective of this study was to examine the differences in performance, feed efficiency, feeding behavior and gaseous exchange (methane, carbon dioxide and oxygen) in replacement beef heifers with divergent phenotypes for residual feed intake (RFI). Crossbred beef replacement heifers [n = 63; initial body weight (BW) = 277 ± 21 kg] were blocked by BW and assigned to 1 of 2 pens each equipped with electronic feed bunks (GrowSafe Systems) and GreenFeed gaseous-exchange measurement systems (GEM; C-Lock). Heifers were fed a corn-silage based ration twice daily. Individual dry matter intake (DMI), feeding behavior, and gas flux data were collected for 70 d and BW measured weekly. Carcass ultrasound data were collected at the beginning and end of the study. Residual feed intake was calculated as the residual from the regression of DMI on ADG and mid-test BW0.75 and heifers assigned to low-, medium-, and high-RFI classes (± 0.5 SD from the mean RFI). A mixed model with RFI class as fixed effect and pen as a random effect was used for data analysis. There were no differences due to RFI class in BW and ADG. However, low-RFI heifers consumed 16% less (P < 0.001) DMI and had more favorable gain to feed (G:F) then high-RFI heifers. High-RFI heifers had a greater (P < 0.05) backfat gain during the 70-d study, with backfat gain accounting for an additional 4.2% of the variation in DMI. Low-RFI heifers exhibited more favorable feeding behavior, with 10.4% fewer (P = 0.057) bunk visit events and spent numerically less time at the feed bunk (103 vs 122 min/d) compared with high-RFI heifers. Methane emissions (g/d) did not differ between heifers with divergent RFI (P = 0.138; 129 vs 140 g/d in low- and high RFI heifers respectively), however, methane yield (g/kg DMI) was 9% greater (P < 0.05) in low- compared with high-RFI heifers. Additionally, low-RFI heifers produced 7.9% less (P < 0.05) carbon dioxide (g/d) and consumed 6.9% less (P < 0.05) oxygen than high RFI heifers. Further research is warranted to investigate the biological mechanisms influencing RFI and the effects of selection for RFI as a strategy to mitigate reduce greenhouse gas emissions from cattle production systems.
PSVII-24 Backgrounding carryover nutritional effects on nitrogen metabolism and water requirements onto grain or forage-fed finished cattle
Authors: da Silva Aghata Elins Moreira , Franco Arturo Macias , da Silva Gleise Medeiros , Fonseca Mozart A
Published: September 2024

The objective of this study was to examine how different backgrounding and finishing systems might affect nitrogen (N) metabolism, and consequently water requirements of cattle. Further, we investigated if the previous plane of nutrition might affect the results obtained in the subsequent phase. Cattle (n = 24) were randomly distributed into either a moderate (MP; crude protein (CP): 9.10%) or high (HP; CP: 12.62%) plane of nutrition during the background phase for 85 d. Animals were then blocked by their previous plane of nutrition and were moved onto a 105-d finishing phase. The forage-finished group received only high-quality alfalfa hay (CP: 21.3%), whereas the grain-finished group received a high grain diet (80% whole corn and 20% alfalfa hay; CP: 10.8%). Animals on MP diets excreted less N through urine (P < 0.01) and feces (P < 0.01), while retaining more N (P < 0.01), which resulted in an increased N efficiency (P < 0.01) when compared with HP animals. No differences were observed for water intake or microbial N being observed (P > 0.05). Grain-fed animals consumed less N and water (P < 0.01), but still had a greater amount of N being digested when compared with forage-fed animals (P < 0.01), as well as the least excretion of N through feces (P < 0.01) and urine (P < 0.01), and consequently a greater rate of N being retained (P < 0.01) and a greater efficiency on utilizing the ingested N (P < 0.05). Further interaction was also observed between treatment and previous plane of nutrition, where animals coming from a MP had the least dry matter intake, greatest amount of N being digested and least N excretion, fecal output, and excretion of N through the feces (P < 0.05). These results indicate that animals receiving MP will reduce their excretion of N without modifying the required amount of water while producing the same amount of microbial N due to more efficient N recycling. Extremely important is the fact that efficiency is carried over after these animals are transitioned to grain-fed finishing systems.
PSX-17 Effects of Saccharomyces cerevisiae fermentation product on methane production of steers fed a finishing diet
Authors: Dhungana Anjan , Odunfa Oluwaseun , Blair Jansen , Yoon Ilkyu , Ogunade Ibukun M , Altman Alexander , McLeod Kyle R , Harmon David L , Jiang Yun
Published: September 2024

Saccharomyces cerevisiae fermentation product (SCFP), a postbiotic feed additive, has been reported to improve ruminal pH in cattle fed a high-starch diet. Given that higher ruminal pH was associated with greater methane production, SCFP may affect enteric methane production. However, no research has investigated the effect of SCFP on methane production in finishing cattle. This study assessed the effects of SCFP on enteric methane production of steers fed a high-concentrate finishing diet. Holstein steers (n = 12) were blocked based on their initial body weight (BW; 294 ± 12.7 kg) to 3 groups and enrolled in a randomized block design study. The 4 steers in each block were randomly assigned to two treatments and fed ad libitum a finishing diet consisting of 20% corn silage and 80% concentrate on a DM basis. The treatments were CON (Control, basal diet only) and SCFP (basal diet, top dressed with 12 gּ animal-1ּ d-1 SCFP, NaturSafe, Diamond V, Cedar Rapids, IA). After 29 d, steers were transferred to head-boxes for respiratory measurement for 72 h. The first 24 h was used as adaptation. During the last 48 h, respiratory samples were collected every 21 min and analyzed with gas sensors to determine O2 consumption and CO2 and CH4 production. Data were analyzed with the GLIMMIX procedure of SAS 9.4. The BW of steers was similar (342.5 vs. 338.8 kg for SCFP and CON respectively, P = 0.65) between two treatments before the respiratory measurement. Steers fed SCFP tended to have an overall greater dry matter intake (DMI; 7.26 vs. 6.76 kg/d, P = 0.10) and had graeter DMI during the 48-h respiratory measurement (6.58 vs. 5.45 kg/d, P = 0.03). The amount of O2 consumed was not affected by SCFP (35.6 vs. 34.4 Lּ kg BW.75/d, P = 0.45). Similarly, CO2 production was not affected by SCFP (36.5 vs. 34.8 Lּ kg BW.75/d, P = 0.36). Supplementing SCFP did not affect daily CH4 production per unit of metabolic BW (1.82 vs 1.80 Lּkg BW.75/d, P = 0.94), but it numerically reduced hourly methane emissions per unit of DMI (1.00 vs. 1.29 L/kg DMI, P = 0.39, Figure 1). Our results suggest that SCFP did not lead to greater methane production but instead showed a trend toward reduced methane emission per kilogram of DMI. This is likely driven by greater DMI by feeding SCFP during the respiratory chamber measurements. Further studies using larger experimental units are needed to confirm this observation.
PSX-22 Boosting techniques for prediction of dry matter intake of cattle in confinement settings and SHAP analysis on the models’ output
Authors: ArunKumar K E , Blake Nathan , Walker Matthew , Holaskova Ida , Mata-Padrino Domingo , Wilson Matthew E
Published: September 2024

Measurement of individual dry matter intake (DMI) is critical to improving the management of the beef herd and is necessary to determine the feed efficiency of individual cattle. Combining machine learning models and proxies for DMI (e.g., water intake, body weight, climatic variables) has the potential to replace the need for dedicated feed intake equipment. It would also open the possibility of measuring DMI in situations like grazing where quantifying DMI directly is not possible. In this study, we examined the relationship between DMI, animal variables and environmental variables. In this study, we developed and tested machine learning models based boosting techniques to develop approaches to predict DMI in cattle, using the same data we have previously published results from Random Forest techniques in the past. The dataset included both bulls and steers. The developed models include both regular boosting regression models and random effects boosting models. The regular boosting technique models such as gradient boosting regression, light gradient boosting regression, extreme gradient boosting regression. Similarly, random effects boosting machine learning model Gaussian process boosting (GPBoost) was developed to consider the random effects associated with the intake behavior of the animals. The extreme gradient boosting model outperformed other regular boosting regression models with a r2 of 0.81 and 0.48 on training and testing datasets respectively. However, it does not consider the random effects associated with the longitudinal nature of the animal intake and weather variables and prone to overfitting. GPBoost model variants were tested and developed to avoid overfitting and to incorporate a random effects model, which we propose as the overall best performing model. The GPBoost generalized well on the training and testing datasets with r2 scores of 0.55 and 0.54 respectively. To further understand the model’s performance on the unseen dataset, we used SHAP analysis on the GPBoost. The SHAP analysis revealed that water intake, full body weight and age of the animals contributed significantly to predicting unseen data.
PSXI-16 Increased copper concentrations in liver and duodenum tissues in Rambouillet-crossbred sheep receiving copper supplementation
Authors: Loh Huey Yi , Thorndyke Meghan P , Quevedo Alejandro , Gibbons Ashlee , Baer Brecken , Gleckler Leala , Engle Terry E
Published: September 2024

Rambouillet-crossbred wethers (n = 8; approximately 7 mo of age) were stratified by body weight (BW) into 4 BW blocks to examine the impact of copper (Cu) supplementation on plasma, bile, liver, duodenum, jejunum, and ileum tissue Cu concentrations. On d 0 of the experiment, liver biopsies and plasma samples were collected from each animal and analyzed for Cu concentrations. Animals were housed in individual pens and received a total mixed ration (dry matter basis: 30.0% cracked corn, 33.3% grass hay, 33.3% alfalfa hay, 3.4% soybean meal) once daily in amounts to allow ad libitum access to feed over a 24 h period. Wethers were paired by BW and assigned to 1 of two treatments (n = 4 wethers/treatment). Treatments consisted of 1) no supplemental Cu (control), and 2) +Cu: 12 mg of supplemental Cu/kg DM from CuSO4∙5H2O. Ground corn was used as a carrier for each treatment and fed in a separate feed container daily. On d 28 of the experiment, all wethers were transported to an USDA inspected abattoir and harvested. Following harvest, blood, bile, liver, duodenum, jejunum, and ileum samples were collected. Digestive tract samples were thoroughly washed with phosphate-buffered saline to remove all feed particles. Blood samples were collected in heparinized trace mineral free vacutainer tubes and centrifuged at 2,000 x g for 15 min at room temperature. Plasma, bile, and gastrointestinal tissue samples were stored in acid-washed storage vials at -20 ºC until analyzed for Cu concentrations. Data were analyzed as a randomized block design using the MIXED procedure in SAS with individual animal as the experimental unit. Liver (P < 0.05) and duodenum (P < 0.04) Cu concentrations were greater and ileum Cu concentrations were less (P < 0.04) in sheep receiving supplemental Cu compared with controls. Plasma, bile, and jejunum Cu concentrations were similar across treatments. These data suggest that Cu absorption takes place primarily in the duodenum and accumulates in the liver in sheep fed a diet containing 18 mg Cu/kg dry matter. Although total bile production was not measured in this experiment, the accumulation of Cu in the liver in +Cu sheep coupled with no treatment effect on bile Cu concentrations suggests an inability of sheep to excrete excess Cu from the liver via bile. Future research examining the impact of Cu supplementation on the molecular mechanisms associated with Cu absorption from each segment of the small intestine and storage and excretion mechanisms in the liver is warranted.
PSXI-23 Development of sub-models to estimate protein requirements and supply of lactating dairy cows using machine learning algorithms
Authors: Lee Mingyung , Seo Seongwon , Tedeschi Luis O
Published: September 2024

The objectives of this study were to develop sub-models for predicting protein requirements and supply, encompassing 1) net protein for maintenance (NPm), 2) lactation (NPl), 3) rumen undegradable protein (RUP), and 4) duodenal microbial nitrogen (MicN) from the feed protein. The dataset used in this study was constructed by integrating in vivo experimental data collected from open databases (the National Animal Nutrition Program) and articles (Journal of Dairy Science), which includes a total of 1,779 observations from 436 publications. In the development of the model, animal information and feed chemical components were used as candidate variables, and two types of machine learning algorithms, Random Forest Regression (RFR) and Support Vector Regression (SVR) were employed. After testing, the following predictors were selected for predicting: 1) NPm: body weight (BW) and dry matter intake (DMI), 2) NPl: BW, DMI, days in milk (DIM), and dietary organic matter (OM) and crude protein (CP) contents, 3) RUP: DIM, DMI, dietary DM content, and CP fraction intake (B and C), and 4) MicN: DIM, DMI, DM, dietary neutral detergent fiber (NDF) content, CP fraction intake (A, B, and C). The selected models were assessed using a cross-validation method with the following statistical metrics including the coefficient of determination (R2), root-mean-square error of prediction (RMSEP), residual analyses, and concordance correlation coefficient (CCC). For the RUP and MicN models, they were compared with the NASEM (2021) model. In predicting NPm, both SVR and RFR algorithms demonstrated increased precision (R2 = 0.965 vs. 0.969) and accuracy (RMSEP = 9.7 vs. 9.2 g/d); however, during residual analysis, the RFR model showed a statistically significant slope bias (P < 0.05). In the NPl prediction, the RFR algorithm showed slightly greater performance compared with SVR (R2 = 0.864 vs. 0.814 and RMSEP = 86.7 vs. 98.5 g/d). However, similar to the NPm prediction, the RFR model displayed a statistically significant slope bias (P < 0.05). In the supply model, the RFR model exhibited the greatest precision and accuracy in predicting RUP (R2 = 0.60, RMSEP = 0.326 kg/d, and CCC = 0.71) without any biases. This model achieved a 2.37-fold increase in R2 and a decrease of 0.111 kg/d in RMSEP compared with the NASEM model. As for MicN prediction, the SVR model performed the best (R2 = 0.76, RMSEP = 42.4 g/d, and CCC = 0.86) without biases. This model attained a 19-times improvement in R2 and a reduction of 38.7 g/d in RMSEP when compared with the NASEM model. In conclusion, the models developed using machine learning algorithms can be helpful for accurately and precisely predicting protein requirements and supply based on animal information and the chemical composition of feed.