bluuebunny/crossref_metadata_2025 huggingface dataset:
PSIX-18 Multiomic analysis to identify host and microbiome contributions to digestibility in beef cattle
Authors: O’Hara Eóin , Dubois Megan , Ribeiro Gabriel O , Gruninger Robert J
Published: September 2024

This study evaluated beef heifers selected for high (efficient) or low (inefficient) digestible fiber intake (DFI). Initial analysis showed that high DFI animals had reduced methane production versus low-DFI under a high forage diet. Using the same cohort of animals maintained on a further 4 diets of varying forage:concentrate ratios, we employed multi-kingdom amplicon sequencing and metagenome shotgun sequencing of rumen digesta and feces alongside RNA sequencing of rumen epimural samples to evaluate the compositional and functional interplay between different microbial groups, and their relationship with host gene expression in cattle divergent for DFI. Samples were collected from 16 cattle during 2 metabolism trials, comprising 5 diets. Amplicon sequencing analysis was conducted using QIIME2; 16S rRNA and 18S rRNA reads were analyzed using the SILVA database, while LSU (fungal) sequences were analyzed using a custom D1/D2 database. Additional analysis of archaeal 16S rRNA sequences was conducted using the Rumen and Intestinal Methanogens (RIM) database. Metagenome shotgun reads underwent a two-pass classification with Kraken2 using a database of prokaryotic genomes derived from the GTDB taxonomy, with the unclassified output undergoing classification using a custom database containing all NCBI protozoa, fungi, and phage genomes, enriched with selected rumen-specific ciliate and fungal genomes. Downstream analysis of taxonomic data from all microbiome work was conducted in R, and differentially abundant taxa were identified using ANCOM-BC and Aldex2. Functional analysis of metagenome contigs using the CAZY database implemented in dbCAN3 is ongoing. RNA-seq data were analyzed using the ARS-UCD reference genome, with identification of DE genes conducted using DeSeq2. Preliminary results indicate no major effect of DFI ranking on host gene expression, bacterial 16S rRNA, or metagenome compositional profiles. Several bacterial genera were differentially abundant between digestibility groups (P < 0.05), but these were all minor (< 0.01%) members of the microbiome. Fungal and methanogen communities different significantly (P < 0.05) according to DFI group, with efficient (high DFI) containing and more diverse communities under high-grain diet (P < 0.05). The same difference showed a tendency toward significance for the 18S rRNA protozoa data (P < 0.1). These preliminary data indicate that the microbial factors underpinning divergence in efficiency measured by DFI vary according to diet and may be more prominent in the non-bacterial fraction of the microbiome. Ongoing functional analysis of metagenome data as well as integration of multiomic data will provide deeper insight into these relationships and how they contribute to feed digestibility and efficiency in cattle.
PSV-26 Effect of addition of Ascophyllum nodosum and Asparagopsis taxiformis, alone or in combination, to an herbage-based diet on in vitro fermentation in continuous culture
Authors: Andreen Danielle , Billman Eric D , Brito Andre F , Soder Kathy J
Published: September 2024

This study investigated the effect of individual or simultaneous addition of two macroalgae species on in vitro fermentation in continuous culture. Four single-flow continuous culture fermentors were fed an orchardgrass herbage-based (orchardgrass; Dactylis glomerata L.) basal diet and randomly assigned one of four treatments: 1) control (CON), no macroalgae addition; 2) Ascophyllum nodosum dosed at 2.5% dry matter (DM; ASC); 3) Asparagopsis taxiformis dosed at 0.5% DM (ATX); and 4) A. nodosum (2.5% DM) + A. taxiformis (0.5% DM) dosed simultaneously (AS+AT). Four experimental periods were conducted in a randomized block design with 7 d of treatment adaptation and 3 d of sample collection. Fermentors were fed 82 g of DM per day in 4 equal feedings. In the last 3 d of each experimental period, daily samples of total effluent were taken for analyses of ammonia N and volatile fatty acids (VFA). Effluent was composited by fermentor and analyzed for DM, ash, neutral and acid detergent fiber, and crude protein. Purine concentrations of effluent and bacterial isolates were determined to estimate partitioning of N flow into feed, bacterial, and ammonia N fractions. Methane (CH4) emissions were measured in each fermentor every 15 min using a Fourier transform infrared gas analyzer, and pH was recorded every 2 min. Data were analyzed using the MIXED procedure of SAS v 9.4 with pre-planned contrasts comparing each individual macroalgae to CON (CON vs. ASC and CON vs. ATX) and comparing A. taxiformis with and without simultaneous addition of A. nodosum (ATX vs. AS+AT). Significance was declared at P ≤ 0.05 and tendencies at 0.05 < P ≤ 0.10. Nutrient digestibilities, CH4 emissions, pH, and N metabolism variables were not affected (P > 0.10) in ASC compared with CON, but total VFA concentration increased (P < 0.05) by 10%. Contrarily, the ATX diet tended (P = 0.61) to have reduced true organic matter digestibility, reduced (P < 0.05) total VFA concentration by 11%, and reduced (P < 0.05) CH4 production by 99.9% versus CON. Simultaneous the combination of microalgae (AS+AT) did not further reduce (P > 0.10) nutrient digestibility or total VFA concentration compared with ATX, and did not change (P > 0.10) the degree of CH4 inhibition. However, A. nodosum did not mitigate (P > 0.10) any of the negative effects on fermentation associated with A. taxiformis, as nutrient digestibilities and N metabolism variables in AS+AT were also not different (P > 0.10) from ATX. While the macroalgae species, A. nodosum and A. taxiformis, led to different fermentation patterns when added individually to continuous culture fermentors, no negative or positive interactions were observed from their simultaneous addition.
PSVII-25 The influence of trace mineral source on in vitro trace mineral solubility and trace mineral concentrations of rumen microorganisms in canulated steers fed a diet formulated for lactating dairy cows
Authors: Loh Huey Yi , Spears Jerry , Gibbons Ashlee , Quevedo Alejandro , Guimaraes Octavio , Miller Alexandra C , Thorndyke Meghan P , Engle Terry E
Published: September 2024

Individually fed fistulated steers [n = 8; body weight (BW) = 410 ± 10 kg] were used to investigate the effects of dietary trace mineral (TM) source on in vitro trace mineral (TM) solubility and TM concentration of rumen bacteria and protozoa. Steers were blocked by BW and sorted into two TM treatment groups. Treatments consisted of 10 mg copper (Cu), 40 mg manganese (Mn), and 60 mg zinc (Zn)/kg DM from either sulfate TM (STM) or hydroxy TM (HTM) sources (n = 4/treatment). Steers were individually housed, and dietary TM treatments were mixed with dried distillers grains and top-dressed daily. Steers were fed a diet formulated to meet the nutrient requirements for a high producing lactating dairy cow for 14 d. Strained rumen fluid (SRF) was obtained on d 15 by squeezing the rumen contents of each steer through 2 layers of cheesecloth. One-half of retained digesta was washed with pre-warmed McDougall’s buffer to remove particle-associated microorganisms (PAO). The SRF and the PAO were then filtered through 8 layers of cheesecloth, separately, and mixed at a ratio of 1:2 (SRF:PAO). The mixture of SRF-PAO from each steer was used to incubate 0.5 g of the basal diet containing either HTM or STM, respectively. The SRF-PAO fluid from each steer was incubated in triplicate with each dietary treatment at 39°C under anaerobic conditions for 24h. After incubation, abomasal digestion was stimulated by adding 1.0 M HCl and 1.5% pepsin. Tubes were then incubated for 2 h at 39°C and centrifuged at 2,000 x g for 15 minutes. Supernatant (2 mL) was removed for soluble TM determination. The pH of solution was then increased to 6.5 by the addition of 3.5% pancreatin in a 1 M NaOH solution and then incubated at 39°C for 2 h. The mixture was centrifuged at 2000 x g to separate the supernatant and digesta fractions for mineral analysis. Protozoal and bacterial fractions were also collected from SRF and PAO for TM analysis. Data were analyzed for a randomized block design using a linear mixed-effect model. There was no feeding tube interaction for all parameters measured, so only main effects are reported. Manganese and Zn concentrations in the digesta within fermentation tube containing HTM were greater (P < 0.02) than STM. Tubes containing HTM had a greater (P < 0.001) soluble Mn concentration than STM after in vitro abomasal digestion. Trace mineral concentration of bacteria and protozoa were similar across treatments. These data may indicate that the TM source may influence TM solubility in the abomasum and intestine, but has no impact on bacterial or protozoal concentrations of Cu, Mn, or Zn.
PSXI-13 Effects of corn containing gene for high concentration of alpha amylase (Enogen Feed corn) on fermentative parameters, digestibility and methane in vitro
Authors: de Oliveira Daiana Dos Santos , Brixner Bárbara Martins , Abdalla Adibe Luiz , Polizel Daniel Montanher , Drouillard James S S , Santos Flávio Augusto Portela
Published: September 2024

The objective of this study was to evaluate different corn hybrids, with (Enogen) or without high amylase concentration, on fermentative parameters, dry matter disappearance and in vitro gas production. The treatments evaluated were Tropical flint corn (TFC), Enogen flint corn (EFC) and Enogen dent corn (EDC). All corn was processed and had the same average particle size. The experiment was carried out using automatic gas pressure detection modules (ANKOM, RF). Rumen fluid was collected from two animals fitted with a rumen cannula and fed a diet containing 60% forage. The ruminal liquid was combined with buffer in a 1:4 ratio, respectively, and each bottle received 150 mL of this mixture plus 1.5g of DM corn sample. After 24 h of testing, the pH was measured in each bottle, samples were collected for analysis of short-chain fatty acids (SCFA), ammonia, gas samples for methane quantification and the final residue was taken to determine the DM disappearance. The data were analyzed using Proc Mixed from SAS (9.4), using the following contrasts: 1) TFC (without Enogen technology) vs. Enogen corn (EFC and EDC) and; 2) EFC vs. EDC. Corn with Enogen technology increased the proportion of propionate (TFC: 28.2; EFC: 29.8; EDC: 30.7 mM/100mM; P < 0.01), butyrate (TFC: 9.83; EFC: 10.8; EDC: 11.3 mM/100mM; P = 0.01), isovalerate (TFC: 1.48; EFC: 1.68; EDC: 1.61; P < 0.01) and valerate (TFC: 1.06; EFC: 1.23; EDC: 1.08 mM/100mM; P = 0.03) and decreased acetate (TFC: 58.7; EFC: 55.8; EDC: 54.6 mM/100mM; P < 0.01) and the acetate:propionate ratio (TFC: 2.09; EFC: 1.88; EDC: 1.79; P < 0.01), without affecting ruminal pH and total SCFA. The EDC reduced acetate (P < 0.01), valerate (P = 0.01) and ammonia (TFC: 0.58; EFC: 0.60; EDC: 0.40 mg/dL; P < 0.01) compared with EFC, without affecting the other fermentation variables. The Enogen technology increased the disappearance of DM (TFC: 75.6; EFC: 78.4; EDC: 82.4%; P < 0.01) and reduced the concentration of methane (TFC: 2.99 EFC: 2.09 EDC: 1.87%; P = 0.05) in relation to TFC. Furthermore, EDC corn increased the disappearance of DM (P < 0.01) without affecting gas and methane production when compared with EFC. In conclusion, Enogen technology optimizes the fermentation and DM disappearance, in addition to reducing the concentration of methane, and using the Enogen technology, dent corn is superior to flint corn.
PSXI-10 Effects of feeding doses of enzyme complex and corn ethanol coproduct on performance and carcass traits of finishing beef cattle
Authors: Brixner Bárbara M , de Dias Bruno Garcia Carvalho , Meschiatti Murillo A , De Oliveira Daiana Dos Santos , Lopes Fernanda , Polizel Daniel Montanher , Santos Flávio Augusto Portela
Published: September 2024

The use of enzyme complex and the inclusion of corn ethanol co-products are strategies that can increase feed efficiency and carcass weight of feedlot beef cattle. Crossbred bulls (n = 389) were assigned to a randomized completed block design, according to their initial shrunk body weight (BW; 314 ± 40 kg; 10 pen/treatment). The treatment arrangement was a 2 × 3 factorial, with Factor 1 defined by the inclusion of corn dried bran/fiber plus distillers solubles (15 or 45% of DFS; FS Ouro from FS Bioenergy) and factor 2 defined by the increasing doses of multicarbohydrase complex (Rovabio Advance from Adisseo Company; 0, 0.75 or 1.0 g for every 10 kg of diet DM)). The diets contained 8.5% sugar cane bagasse, 44 or 73% ground flint corn, 15 or 45% DFS, 0.5 or 1.5% urea and 2% mineral mix plus monensin (30 ppm in the diet) with the respective enzyme complex doses. On d -1 and 122, individual BW were recorded after a 16-h of fasting (feed and water). The dry matter (DM) intake (DMI) was determined by the difference of feed offer and orts samples after dried at 105°C for 24 h to determine DM. The pen average daily gain (ADG) and DMI were used to calculate feed efficiency (ADG/DMI). On d 122, subcutaneous fat thickness (FT) and the rib eye area (REA) were obtained by means of an ultrasound image, and hot carcass weight (HCW) was obtained upon slaughter on the next day. Data were analyzed using the MIXED procedure of SAS. There was no interaction between the inclusion of DFS and enzyme doses for the variables evaluated (P > 0.05). The use of enzyme complex had no effect on cattle DMI, ADG and FE (P > 0.05). No effects of DFS levels were observed on daily DMI (P ≥ 0.45) or final BW (P ≥ 0.33). Nonetheless, cattle fed 45% DFS had greater ADG (1.37 vs. 1.28 kg; P = 0.02) and FE (153 vs. 145 g/ kg; P = 0.03) than cattle fed 15% DFS. There was no effect of the inclusion of DFS or the doses of the enzyme complex on the carcass parameters evaluated. In summary, including 45% DFS in finishing diets improved feedlot cattle performance compared with 15%. The use of the enzyme complex did not affect animal performance.
PSXII-20 The effect of the partial inclusion of non-forage fiber sources (NFFS) on methane production and rumen fermentation
Authors: Grey Kayla R , Embaby Mohamed , Handlos Grace , AbuGhazaleh Amer
Published: September 2024

The study aimed to assess the impact of three different non-forage fiber sources (NFFS); soy hulls (SH), cottonseed hulls (CSH), and beet pulp (BP) on methane (CH4) production and rumen fermentation using a 24-h batch culture system. These NFFS were incorporated partially into a conventional total mixed ration (TMR) diet consisting of alfalfa (40%), cracked corn (30%), soybean meal (10%), and an individual NFFS (20%; DM basis). Methane production, total gas production, volatile fatty acids (VFA) concentration, and dry matter (DM) digestibility were measured at the end of the incubation period. One way ANOVA test was used to analyze the means and significance was declared at P < 0.05. The results of the study indicated a significant 5% reduction (P < 0.05) in CH4 production with the BP diet compared with the other treatments. However, DM digestibility was found to be significantly less (P < 0.05) with the BP diet compared with the other diets. Total gas and VFA production were greater (P < 0.05) with the BP diet compared with the other diets. Additionally, the molar proportions of acetate and propionate were greater (P < 0.05) with the BP diet and least with the SH diet. No significant differences were recorded for the ratio of acetate to propionate (C2:C3) between treatment diets. Results from this study suggest that BP is a more effective non-forage fiber source in the TMR due to its favorable effects on rumen CH4 production and rumen fermentation. However, it is important to consider the trade-off with decreased DM digestibility when selecting BP as an NFFS in TMR diets.
PSXII-28 Physiochemical and nutritional characteristics of the newly developed value-added blended fat stimulated feed product in comparison with commercial protein and energy feeds
Authors: Ihsan Umair , Prates Luciana , Lardner H (Bart) A , Newkirk Rex N , Rodríguez Espinosa María E , Yu Peiqiang
Published: September 2024

The objectives of this study were to determine physiochemical and nutritional characteristics of the newly developed value-added blended fat stimulated feed product (BFSFP) in comparison with commercial protein and energy feeds. The new value-added BFSFB with three-batch samples (BFSFP1, BFSFP2, BFSFP3) were developed. Barley grain (n = 3) and canola meal samples (n = 3) were obtained from Canadian Feed Research Center. Chemical composition and nutrient profiles were determined using standard feed analysis methods (e.g., AOAC, NRC-energy). The treatment design was a one-way structure. The experimental design was a CRD with feed treatments as a fixed effect. The data were analyzed using the Mixed model procedure of SAS. Tukey’s method was used for multi-treatment comparison. The results showed that compared with commercially available energy-rich and protein-rich feeds, the BFSFP had greater (P < 0.05) ether extract (EE) than both canola meal and barley grain [4.8 vs. 1.0, 1.6 % dry matter (DM), respectively]. It had decreased ash content than canola meal but greater than barley grain (P < 0.05). For protein chemical profiles, the BFSFP had less (P < 0.05) CP (31.0 vs. 41.6, 12.5%DM), SCP (4.9 vs. 9.1, 3.4% DM), and NPN (11.0 vs. 18.2, 9.2% CP) than canola meal but greater than barley grain. The BFSFP had greatest NDICP (2.6 vs. 0.9, 0.4%CP) and ADICP (0.14 vs. 0.30, 0.06%DM) than both canola meal and barley grain. For carbohydrate chemical profiles, the BFSFP had greater (P < 0.05) carbohydrate (58.1 vs. 50.4, 83.7%DM) and starch (4.5 vs. 1.3, 55.9%DM) than canola meal but less than barley grain. The BFSFP had greater (P < 0.05) NDF (42.9 vs. 28.6, 18.9%DM) and hemicellulose (27.7 vs. 10.5, 12.9%DM) than both canola meal and barley grain. The BFSFP had had less (P < 0.05) ADF (12.7 vs. 17.5, 5.7%DM) and ADL (3.0 vs. 8.0, 0.8%DM) than canola meal but greater barley grain. As to energy profle, the BFSFP had no significant difference in NE for lactation when compared with barley grain and canola meal (1.80 vs 1.93 vs. 1.69 Mcal/kg DM, P > 0.05). The BFSFP had similar in NE for growth (1.29 Mcal/kg DM) when compared with canola meal (1.29 vs. 1.20 Mcal/kg DM, P > 0.05) but less than barley (1.29 vs 1.42 Mcal/kg DM, P < 0.05). In conclusion, the newly developed blended fat stimulated feed product differed in physiochemical and nutritional characteristics in comparison with commercially available energy-rich and protein-rich feeds.
PSXII-17 Hydrolyzed yeast supplementation and withdrawal effect on rumen fermentation dynamics
Authors: Schulze Hagen , Francis Becca B Grimes , Johnston Jay
Published: September 2024

In vitro rumen fermentation studies have shown that hydrolyzed yeast (HY; LivaltaCell HY40, Peterborough, UK) can modify the rumen microbial composition and activity (Schulze et al 2024). The aim of this study is to investigate the effects of prolonged (10 d) feeding and withdrawal of HY (15 gּ animal-1ּ d-1) on in vitro rumen fermentation dynamics. Dry rumen-fistulated Holstein cows (n = 10) were used in this study as individual experimental units. The cows had free access to haylage and drinking water and were restricted fed a corn silage-based TMR with HY for 10 d and without HY for the following 10 d. This provided 3 treatment groups, at measure points d 0 (CTRL), 10 (HY) and 20 (-HY; withdrawal) at which duplicate samples of rumen fluid were collected at 1500 h from each cow. An automated in vitro rumen fermentation model based on infrared sensors (Fermentrics), with triplicate vessels per cow, was used to analyze gas production dynamics of total gas, CO2, CH4, H2 and NH3 during a 12 and 24 h period, and 24 h pH, aOMD and aMBP. An aliquote 20 mL sample of rumen fluid mixed with 80 mL buffer and 12 h in vitro fermentation samples were analysed for volatile fatty acids (VFA) to calculate Net vFA production per cow and treatment. Statistical analysis was performed using PROC GLIMMIX procedure of SAS (9.4, SAS Institute Inc., Cary, NC) with day as fixed effect (CTRL, HY, and -HY). LSMEANS were separated and denoted different (P ≤ 0.05) using the pairwise comparison PDIFF option of SAS. HY supplementation did not impact any of the gas parameters measured at either 12 or 24 h compared with CTRL. However, 10 d after removal of HY (-HY), 12 h total gas and CO2 as well as 12 and 24 h CH4 production increased (P < 0.05), whereas 24 h H2 was reduced (P < 0.05). The CH4 content in the 24 h total gas production was greater (P < 0.05) at -HY (15.0%), whereas no differences were observed between CTRL (13.0%) and HY (12.1%). aOMD was similar for CTRL (51.4%) and -HY (52.5%) but higher (P < 0.05) for HY (55.9%). aMBP was significantly different between all three groups, with HY showing greatest (172.8mg/g), CTRL medium (154.2mg/g) and -HY least (122.1mg/ g) microbial biomass production. Net 12 h in vitro VFA production was significantly increased with HY (29.2 mmol) compared with CTRL (16.2 mmol) and -HY (18.9mmol), mainly driven by an increase of acetic and butyric acid production. The proportion of propionic acid declined from 30% for CTRL to 20% with HY and 21% with -HY. It can be concluded that supplementing a TMR with HY can change the rumen microbiota density and composition leading to elevated VFA production and consequently energy supplies, without increasing CH4 production.
PSXIII-23 Phytogenic feed additive to improve performance by grazing Nellore growing cattle
Authors: Matos Isabelle E , Silva Aline G , Perdigão Alexandre , Carvalho Victor , Acedo Tiago S S , Silva Gislaine J , Teixeira Edvan C , Fernandes Henrique J
Published: September 2024

Our objective was to evaluate the effects of a phytogenic additive (Digestarom Prime, dsm-firmenich, Switzerland) on performance and supplement intake of growing grazing Nellore young bulls from November 2021 to April 2022. Animals [n = 120; initial body weight (BW) = 280 kg and age = 14 mo] were equally distributed in six paddocks (7.7 ha each) of B. brizantha cv. Marandu (20 animal/paddocks) equipped with electronic feeders that provided individual access (Intergado system). The experiment was conducted in a complete randomized design, with 20 replicates (animals) per treatment. Treatments consisted of a protein supplement (Fosbovi Proteico 30, DSM, Brazil), provided ad libitum, with or without the addition of Digestarom Prime, in a dose adjusted to ensure a daily intake of 0.2, 0.4, 0.6 or 0.8 gּ animal-1ּ d-1. Treatments evaluated were: 1) control (CON) with no additive; 2) monensin 15 ppm (MON); 3) Digestarom 0.2 gּ animal-1ּ d-1 (D 02); 3) Digestarom 0.4 gּ animal-1ּ d-1 (D04); Digestarom 0.6 gּ animal-1ּ d-1 (D06) and 6) Digestarom 0.8 gּ animal-1ּ d-1 (D08). The experiment lasted 150 d. Supplement intake was measured by electronic feeders, and intake as % of BW was calculated using the average of initial and final BW. Average daily gain (ADG) was measured by Intergado system, through the electronic weighing system installed underneath the drinkers. Data were analyzed by SAS PROC MIXED in DIC considering the initial BW as a covariate. Student’s t test was utilized for means comparison. Significance of 5% was adopted. Supplementation with Digestarom at the level of 0.6 gּ animal-1ּ d-1 increased ADG in approximately 0.116 kg/d (means: D06 = 1.174 kg/d vs. CON = 1.064, MON = 1.086, D02 = 1.069, D04 = 1.038 and D08 = 1.034 kg/d; P < 0.01), and final BW, in approximately 19 kg (means D06 = 459 kg vs CON = 436, MON = 439, D02 = 449, D04 = 443 and D08 = 435 kg; P < 0.05). Monensin presented the least supplement intake evaluated as either absolute or relative to BW (0.214 kg/d and 0.061% of BW, P < 0.01), followed by Digestarom levels of 0.4 and 0.8 g gּ animal-1ּ d-1 (D04 = 0.347 kg/d and 0.098% of BW and D08 = 0.367 and 0.103), that did not differ from each other (P > 0.05). Control, 0.2 and 0.6 Digestarom gּ animal-1ּ d-1 presented the greatest supplement intake (CON = 0.481 kg/d and 0.134% of BW, D02 = 0.456 and 0.123, D06 = 0.444 and 0.120, P < 0.01), that also did not differ from each other (P > 0.05). We conclude that Digestarom supplementation at 0.6 gּ animal-1ּ d-1 improves animal performance, without affecting supplement intake of grazing Nellore young bulls.
PSXIII-20 Impact of Aspergillus oryzae fermentation-derived prebiotic-like additive combined with monensin on feedlot performance in finishing steers
Authors: yraola Felipe Pereyra , Colombatto Darío , Forneris Natalia S , Bargo Fernando , Ipharraguerre Ignacio
Published: September 2024

The aim of this study was to investigate the effects of supplementing a prebiotic-like action additive product derived from the fermentation of Aspergillus oryzae (AM; 2 g Amaferm/d) in combination with monensin throughout the entire feedlot period. The primary objective was to evaluate the impact of this dietary intervention on feedlot performance, focusing on parameters such as feed intake, feed-to-gain ratio, body weight (BW), average daily gain (ADG), and carcass quality. Steers (n = 1,200), aged approximately 18 mo with an initial BW of 307.8 ± 17 kg, were randomly assigned to 8 pens (150 steers per pen) and each pen was randomly assigned to two treatments: a control diet with monensin (M; monensin supplemented at 33 mg/kg DM) and a treatment diet with the addition of AM (M+AM; monensin supplemented at 33 mg/kg DM and 2 g Amaferm/d). The feedlot period comprised three steps, with daily feed delivery adjustments using a feed bunk management system. A multilevel model using the PROC MIXED procedure of SAS with pen as experimental unit, was employed to evaluate feed intake, feed to gain ratio, BW and ADG for each period, also including effects on carcass quality and growth measured by ultrasound (random sample of 45 animals per pen; 30% of each pen). No significant differences were observed in feed intake across the three diet steps (P > 0.10). During the adaptation period, steers fed AM had greater ADG (+0.168 kg/d; P = 0.003) and increased BW at d 20 (+5.5 kg; P < 0.001). Although ADG during the finishing phase was similar for both treatments, a trend was observed for greater BW at d 108 (+4.6 kg; P = 0.095) when supplemented with AM. The inclusion of AM showed no impact on feed-to-gain ratio for the entire period (P = 0.589). In the finishing period, a positive effect on ribeye area (REA) growth rate (+0.54 cm2/mo; P = 0.016) and a trend towards greater back fat deposition rate (+0.11 mm/mo; P = 0.069) were observed with AM supplementation. At the end of the finishing period, a trend towards greater REA (+1.39 cm2; P = 0.101) was noted with no differences in back fat. Overall, this study demonstrates that the addition of AM throughout the feedlot period positively influenced the productive response during the adaptation period, leading to improvements in carcass growth during the finishing period.
PSIX-23 Evaluation of number of goats grazing grass-based pasture for estimation of methane emission using GreenFeed system
Authors: Tadesse Dereje T , Puchala Ryszard , Hirut Yirga Y , Patra Amlan K , Goetsch Arthur L
Published: September 2024

The objective of this study was to evaluate the number of goats in pasture grazing on methane (CH4) emissions estimates using the GreenFeed system (GFS). The study involved growing meat goats, approximately 1.2 yr old and body weight (BW) of 23.9 ± 0.63 kg, over seven 2-wk periods. In periods 1, 2, and 3, 24 goats were used (Treatment 1: G-24), while periods 4 and 5 involved 18 goats (Treatment 2: G-18), and periods 6 and 7 used 12 goats (Treatment 3: G-12). The pasture area was divided into three paddocks for grazing, except during gas measurements in a stationary respiration calorimetry system (SCS) room for 2 d, where goats were fed fresh forage from the same pastureland. The GFS was programmed to dispense pellets and measured gas at specific intervals of the day (i.e., at 0700-0800 h, 1300-1400 h, 1900-2000 h, and 0100-0200 h), provided 120 g/d of concentrate pellets to attract goats for gas measurements. Statistical analysis using mixed model procedures of SAS included SCS data from preceding and succeeding periods as covariates for GFS gas data analysis. Daily dry matter (DM) intake was greater (P < 0.001) in G-12 compared with G-24 and G-18, but when expressed g/kg BW, intakes were similar (P = 0.081) across treatments. Conversely, digested DM and gross energy intakes were greater (P < 0.001) in G-24 than in G-18 and G-12 (494, 509, and 577 g/d and SE = 21.3 and 7.91, 8.10, and 9.20 MJ/d and SE = 0.359 for G-24, G-18, and G-12, respectively). Daily CH4 production was unaffected (P = 0.254) by treatment (26.6, 25.2, and 26.1 g/d; SE = 0.819), despite variations in daily GFS visits by goats (3.26, 2.61, and 2.53 visits/d and SE = 0.106 for G-24, G-18, and G-12, respectively; P < 0.001). However, CH4 emissions in g/kg DM intake or digestible DM intake differed among treatments, with G-18 intermediate between G-24 and G-12 (35.6, 33.4, and 32.0 g/kg DM intake, SE = 1.02, P = 0.024; 54.1, 51.2, and 48.9 g/kg digestible DM intake, SE = 1.71, and P < 0.001 for G-24, G-18, and G-12, respectively). Carbon dioxide production, expressed in g/d and g/kg DM intake, was greater in G-12 and G-18 compared with G-24. Heat production ranked greatest in G-12, followed by G-18 and G-24. Regardless of treatment, CH4 emissions in g/d, g/kg DM intake or g/kg digestible DM intake were greater in GFS than in SCS (25.5 and 9.56 g/d, 33.8 and 14.4 g/kg DM intake, and 51.2 and 23.8 g/kg digestible DM intake for GFS and SCS, respectively; P < 0.001). In conclusion, differences in CH4 emissions in g/kg DM intake and digestible DM intake among treatments suggests that number of animals in grazing pasture may influence CH4 emission estimates in goats.
PSIX-28 Optimization of feeding trial length for evaluating feed efficiency in sheep
Authors: Lei Yaogeng , Osonowo Olufemi , Gellatly Desiree , Jawad Hamza , Thompson Sean , Manafiazar Ghader
Published: September 2024

Feed efficiency tests are well established for beef cattle, but testing for sheep remains rare due to the lack of appropriate equipment and standardized protocols. To explore the optimum trial length for evaluating feed efficiency in sheep, freshly weaned Rideau Arcott ewe lambs [n = 80; 4to 5 mo of age and body weights (BW) of 16 to 25 kg] were enrolled in a 65-d feeding trial, following a 20-d adaptation period. A mixed ration containing barley gain and protein supplement pellets were offered twice daily, and lambs had ad libitum access to feed, water and bedding straw during the trial period. Daily feed intake of individual lambs was monitored with Vytelle SENSE feed bunks, BW was recorded biweekly, as well as on two consecutive days at the start and end of the trial. Lambs that had died or had abnormal growth patterns from sickness were removed, resulting in 62 lambs remaining in the final dataset. Optimum trial length for measuring feed intake (DMI) and average daily gain (ADG) were evaluated with R Software (v. 4.3.3) via a post-hoc analysis of constructing shortened trial lengths from the regular test. The DMI and ADG values from the shortened trial datasets were compared with those from regular trial days with correlation (Pearson and Spearman tests) and linear regression analyses. There were 64 shortened trial lengths for DMI by 1 d increments, and 15 sub-datasets for ADG consisting of trial lengths between every two BW measurements. Residual feed intake (RFI), residual average daily gain (RADG), and residual intake and BW gain (RIG) were calculated for and compared between the regular trial length (65 d) and favorable shortened trial lengths based on DMI and ADG evaluations. Correlation, regression and agreement analyses were used to determine the optimum trial lengths for RFI, RADG and RIG evaluations. Results showed that DMI and ADG measurements could be shortened to 42 (r > 0.95, R2 > 0.90, β > 0.95, P < 0.001) and 56 d (r > 0.96, R2 > 0.93, β > 0.96, P < 0.001), respectively. Additionally, trial length for RFI, RADG, and RG evaluations could be reduced to 56 d (r > 0.95, R2 > 0.91, β > 0.95, CCC > 0.95, P < 0.001), primarily due to the trial length requirement for accurate ADG measurement. Reducing the duration of trials for evaluating feed efficiency in sheep not only reduces testing costs, fostering greater uptake among sheep producers, but also allows for the evaluation of more lambs annually, thereby enhancing the overall productivity and profitability of the sheep industry.
PSVII-29 Integrating hybrid rye into organic pig production to reduce feed and bedding costs
Authors: Li Yuzhi , Kavanagh Megan , Lima Gabriella , Hilbrands Adrienne , Lazarus William , DeWitte Diane , Johnston Lee J
Published: September 2024

An obstacle to profitable organic swine production is the high cost of feed and bedding. We evaluated whether growing hybrid rye for organic feed and bedding for pigs was economically viable by replacing corn with hybrid rye and evaluating pig growth performance and feed and bedding costs. Hybrid rye was grown on certified organic land at WCROC in 2022 and 2023. Rye grain and straw were used in a feeding trial with pigs raised according to the National Organic Standards. The animal trial consisted of three replicates. Each replicate included 100 pigs in two pens (Control vs. Rye, 50 pigs/pen) in a bedded hoop barn. Control pigs were fed corn soybean meal-based diets and Rye pigs were fed diets with 50% of corn in the control diets replaced by hybrid rye. Each replicate lasted for about 12 wk until pigs reached market weight (120 kg). Pigs were weighed individually at the beginning, every 4 wk thereafter, and at the conclusion of the study. Feed disappearance was recorded on a pen basis at the time of weighing pigs. Growth performance[average daily gain(ADG), average daily daily feed intake (ADFI), and Gain: Feed] was calculated for each weigh period. Carcass weight was recorded at harvest and dressing percent was calculated for each pig. Bedding usage was recorded for each pen (Control pen = wheat straw, Rye pen = rye straw) and average usage for each pig was calculated. Growth performance and bedding usage data were analyzed using the Proc Glimmix Procedures of SAS, with dietary treatment as the fixed effect, replicate as the random effect, and pen as the experimental unit. Production costs were set at $239/ha for organic rye grain and $20/ha for rye straw baling according to the FINBIN Database, and the unit costs ($/kg) were calculated based on yield for each year. Prices for organic corn, soybean meal, base mix, wheat straw, and market pigs were based on market prices (Table 1). Yield of organic hybrid rye grain at WCROC was 1,070 and 712 kg/ha in 2022 and 2023, respectively, with corresponding rye straw yield being 661 and 367 kg/ha. The reduction in rye yield in 2023 was considered due to drought. No difference was detected in growth performance, dressing percent, or bedding usage between Control and Rye pigs (all P > 0.19; Table 1). Replacing 50% of corn with hybrid rye saved $9.6/pig in 2022, but cost $7.20/pig more for feed in 2023, due to changes in hybrid rye grain yield. Savings on bedding were $15.40 and $13.20/pig for 2022 and 2023, respectively. Results indicate that replacing 50% of corn with hybrid rye in feed did not negatively affect growth performance of pigs raised organically, but the economic viability of integrating hybrid rye into organic pig production may depend on crop yield.
Effects of feeding a negative dietary cation and anion difference diet to twin-bearing Merino ewes in late gestation on parturition outcomes
Authors: Munn Amy L , van Wettere William H E J , Swinbourne Alyce M , Lean Ian J , Weaver Alice C
Published: September 2024

In Australia, dystocia is responsible for 53% of lamb mortalities, and calcium deficiencies may be a contributing factor. A negative dietary cation–anion difference (DCAD) diet can increase calcium concentrations in sheep. Therefore, this study aimed to investigate the effects of a negative DCAD diet on metabolic state, mineral status, and parturition duration in ewes compared with those fed a positive DCAD diet. At approximately day 130 of gestation (dG), 71 twin-bearing ewes were placed in the following treatment groups; ewes receiving a positive DCAD TMR (total mixed ration; DCAD of total diet = 281.8 mEq/kg DM; n = 35) and twin-bearing ewes receiving a negative DCAD TMR (DCAD of total diet = −89.0 mEq/kg DM; n = 36). Urine and blood were sampled on dG 130, 140, and 145, and blood was also sampled at the onset of parturition and 4 h postpartum. Urine was analyzed for pH and blood was analyzed for metabolites, mineral concentration, and acid–base balance. Lambs’ liveweight, rectal temperature, blood glucose and lactate, and body morphology were measured. Serum phosphate concentrations at dG 145 were significantly lower for negative DCAD ewes compared with positive DCAD ewes (1.9 ± 0.1 vs. 2.1 ± 0.1 mmol/L, P = 0.047). Ionized calcium (P = 0.09) and serum magnesium (P = 0.09) prepartum were marginally greater in the negative DCAD ewes (1.35 ± 0.06 and 1.06 ± 0.03 mmol/L, respectively) compared with the positive DCAD ewes (1.18 ± 0.08 and 0.98 ± 0.04 mmol/L, respectively). Urine pH was lower in the negative DCAD ewes compared with positive DCAD ewes at both dG 140 (7.38 ± 0.17 vs. and 8.10 ± 0.19. P = 0.01) and dG 145 (and 7.20 ± 0.19 vs. 8.25. P < 0.01). The birth interval between the first the second-born lamb was shorter in the negative DCAD ewes compared with the positive DCAD ewes (P = 0.02), but no differences in lamb survival or lamb viability (P > 0.05) were seen. The negative DCAD diet reduced parturition duration, most likely due to the marginally greater ionized calcium and magnesium concentrations. Despite this improvement, the negative DCAD ewes did not reach urinary acidification, indicating that the marginally significant greater ionized calcium and serum magnesium concentrations were due to the magnesium in the diets and not metabolic acidosis. Further research testing a negative DCAD diet that can achieve the target urine pH is required to determine whether this diet can decrease parturition duration and improve lamb viability.
Evaluation of corn fermented protein on the fecal microbiome of cats
Authors: Kilburn-Kappeler Logan R , Doerksen Tyler , Lu Andrea , Palinski Rachel M , Lu Nanyan , Aldrich Charles G
Published: September 2024

Co-products from the ethanol industry, such as distillers dried grains with solubles (DDGS), can provide alternative protein sources for pet food. Corn fermented protein (CFP) is produced using postfermentation technology to split the protein and yeast from fiber prior to drying. This results in a higher protein ingredient compared to DDGS, increasing its appeal for pet food. In addition, the substantial yeast component, at approximately 20% to 25%, may promote gut health through modulation of the microbiome and the production of short-chain fatty acids. Therefore, the objective of this study was to determine the effect of CFP on the fecal microbiome of cats. The 4 experimental diets included a control with no yeast (T1) and diets containing either 3.5% brewer’s dried yeast (T2), 2.5% brewer’s dried yeast plus 17.5% DDGS (T3), or 17.5% CFP (T4). All diets except T1 were formulated to contain 3.5% yeast. Diets were fed to adult cats (n = 11) in an incomplete 4 × 4 replicated Latin square design. Cats were adapted to diet for 9 d followed by a 5-d total fecal collection. During each collection period, fresh fecal samples from each cat were collected and stored at −80 °C until analysis. Fresh fecal samples (n = 44) were analyzed by 16S rRNA gene sequencing. Raw sequences were processed through Mothur (v.1.44.1). Community diversity was evaluated in R (v4.0.3). Relative abundance was analyzed within the 50 most abundant operational taxonomic unitsusing a mixed model of SAS (v9.4, SAS Institute, Inc., Cary, NC). Diet was the fixed effect and cat and period were random effects. Results were considered significant at P < 0.05. Alpha-diversity indices (Observed, Chao1, Shannon, Simpson) and beta-diversity metric (principal coordinate analysis) were similar for all treatments. Predominant phyla were Firmicutes (66%), Bacteroidetes (25%), Actinobacteria (8%), Proteobacteria (0.64%), and Desulfobacteria (0.54%). The relative abundance of Firmicutes and Actinobacteria was lower (P < 0.05) for T3 compared to T4 and T2, respectively. On a more specific phylogenic level, 17 genera resulted in differences (P < 0.05) among dietary treatments. Overall, this data indicates that compared to traditional yeast and distillers dried grains, CFP did not alter the overall diversity of the fecal microbiome of healthy adult cats over a 14-d period.
Four-year evaluation of drug-impaired driving drug concentrations
Authors: Cieri Grace , Mohr Amanda L.A , Fogarty Melissa , Chan-Hosokawa Aya , Logan Barry K
Published: September 2024

Drug-impaired driving is a significant public health and safety concern in the USA. To help assess current patterns of drug use in drivers, we evaluated 4 years of drug positivity in a large cohort of suspected impaired drivers. Samples collected between January 2017 and December 2020 were tested via a method compliant with the National Safety Council’s Alcohol, Drugs, and Impairment Division’s Tier I scope of recommended drugs. In 2017, NMS Labs received 17 346 driving under the influence of drugs cases, 17 471 in 2018, 19 050 in 2019, and 16 539 in 2020. The most common drug class detected was cannabinoids in ∼50% of the cases each year. The most common drugs detected over the 4 years were delta-9 tetrahydrocannabinol (delta-9 THC), ethanol, amphetamine/methamphetamine, fentanyl, and alprazolam. Delta-9 THC increased in positivity over the study, having been identified in 45% of cases in 2017, 46% in 2018, 46% in 2019, and 49% in 2020. Ethanol was found in 59% of cases in 2017, 59% in 2018, 61% in 2019, and 53% in 2020. Delta-9 THC and ethanol were the most common drug combination, found together in ∼19% of the cases every year of the study. Statistically significant increases in the average concentration of the following drugs were observed: fentanyl (5.7 ng/mL in 2017 to 9.6 ng/mL in 2020), methamphetamine (301 ng/mL in 2017 to 381 ng/mL in 2020), and delta-9-THC (6.4 ng/mL in 2017 to 7.3 ng/mL in 2020). Other findings included increases in the maximum reported concentrations between 2017 and 2020 for amphetamine (1400 to 2700 ng/mL), methamphetamine (5550 to 13 000 ng/mL), and fentanyl (56 to 310 ng/mL). Statistically significant concentration decreases were noted for several central nervous system depressants, notably prescription benzodiazepines, and several prescription narcotic analgesics.
The rise of bromazolam in postmortem cases from Travis County, TX, and surrounding areas: 2021 to 2023
Authors: Ellefsen Kayla N , Smith Christina R , Simmons Paul D , Edelman Lauren A , Hall Brad J
Published: September 2024

As novel psychoactive substances (NPSs) have continued to emerge over the past decade, NPS benzodiazepines have likewise increased in prevalence. They pose an evolving threat to public health and safety with regard to postmortem cases, particularly when used in combination with opioids. Bromazolam was first detected in Travis County, Texas, in April 2021. Given the recent onset of the fentanyl epidemic in this region, the international rise of bromazolam, and increased reports of “benzo-dope,” a retrospective study was conducted to characterize bromazolam-positive deaths in Travis County and surrounding counties from 2021 to 2023. Bromazolam was identified in 112 deaths from 2021 to 2023, accounting for 1.57% of cases submitted for toxicology testing (n = 7129). During that interval, a 7.5-fold increase in postmortem bromazolam-related drug toxicities from 2021 (n = 7) to 2023 (n = 53) was observed. Fatalities primarily occurred in men in their early 30s. Postmortem concentrations ranged from 21 to 220 ng/mL, with mean (median) concentrations of 69.4 ± 48.4 (53.5) ng/mL. Polydrug use was present in 99% of bromazolam-positive deaths with co-occurrence with other drugs and drug classes widely varying over time. Bromazolam was attributed as the sole cause of death in one case with a postmortem blood concentration of 23 ng/mL. Polydrug use in bromazolam-related drug toxicities commonly involved fentanyl (82%), methamphetamine (41%), and cocaine (28%). Similarly, cases where bromazolam was an incidental finding and noncontributory to the cause of death often involved methamphetamine (38%), alprazolam (33%), and cocaine (33%). In light of the significant increase in fentanyl-related deaths in Travis County, the increasing prevalence of bromazolam accompanying fentanyl was particularly alarming due to the heightened risk of toxicity when used in combination. Identifying and evaluating bromazolam-related deaths clarify the impact of bromazolam on this population, promote awareness, and aid in identifying meaningful harm reduction strategies to decrease bromazolam-related morbidity and mortality.
The Fractured Insurance Landscape of Laser Therapy for Scar Revision
Authors: Heron Matthew J , Reinoso Tyler R , Dane Julia M , Rezwan Siam K , Mack Sylvia , Broderick Kristen P , Cooney Carisa M , Caffrey Julie A
Published: September 2024

Fractional laser therapy improves skin texture, range of motion, and quality of life for patients with traumatic scars. Nevertheless, anecdotal evidence suggests declining insurance coverage for laser therapy. We aimed to characterize the landscape of insurance coverage for fractional laser therapy present our 6 year reimbursement trends. We cross-sectionally analyzed the 60 largest American health insurers by enrollee size and market share. For each, we identified their laser therapy policy for scar revision and extracted their documentation, prior and continuing authorization requirements and treatment guidelines. We also collected retrospective institutional claims data from 2017 to 2022 to investigate trends in reimbursement. Of the 60 largest health insurers, we identified 11 (18.3%) policies on scar revision and 40 policies (66.7%) on reconstructive surgery, including scar revision. Nineteen policies considered laser therapy medically necessary with evidence of functional impairment refractory to prior treatment. Three insurers denied laser coverage under any circumstance. Of the 1,531 claims submitted by our institution for burn scar laser therapy, 13.8% were denied. Patients with Medicare (ORadj, 3.78) or Medicaid (ORadj, 2.80) had significantly greater odds of coverage than privately insured patients (P < .01). There was a 14.5% annual reduction in the odds of reimbursement during the study period (ORadj, 0.86, P < .01). Laser therapy is a powerful treatment that is not widely available to patients with traumatic scars. Our institutional data suggest this access may be further eclipsed by decreasing trends in coverage since 2017. Strategies are needed to protect patient access to this life-changing treatment.