bluuebunny/crossref_metadata_2025 huggingface dataset:
327 A Novel, in Vivo Model to Increase Endogenous Pancreatic and Small Intestinal Carbohydrase Activity to Evaluate Limitations of Small Intestinal Starch Digestion in Cattle
Authors: Trotta Ronald J , Swanson Kendall C , Klotz James L , Harmon David L
Published: November 2023

Consumption of high-grain diets by cattle can result in large quantities of starch that flow to the small intestine for potential enzymatic digestion. However, small intestinal starch digestion is potentially limited because of insufficient activity of pancreatic and/or small intestinal carbohydrases. Studies suggest regulation of carbohydrase activity is complex in cattle and perhaps uncoordinated in response to luminal carbohydrate flow. The objective of this experiment was to use postruminal casein infusion and exogenous glucagon-like peptide 2 (GLP-2) administration, known stimulators of pancreatic and small intestinal function, to evaluate their effects on pancreatic and small intestinal carbohydrase activities. Twenty-four Holstein steers [250 ± 23 kg body weight (BW)] were used in a randomized complete block design with a 2 × 2 factorial arrangement of treatments. Steers were fed an alfalfa cube-based diet to limit dietary starch intake. Steers received a continuous abomasal infusion of 4 g/kg of BW of raw corn starch combined with either 0 or 1.33 g/kg of BW of casein for 7 d. Steers received subcutaneous injections in two portions daily of excipient (0.5% bovine serum albumin) or 100 µg/kg of BW GLP-2. This resulted in four treatments: control, casein, GLP-2, and casein + GLP-2. At the end of the 7-d treatment period, steers were slaughtered for pancreatic and small intestinal tissue collection. Data were analyzed using the GLM procedure of SAS. Postruminal casein infusion increased (P ≤ 0.03) pancreatic mass by 12.6%, total pancreatic α-amylase activity by 50%, and postruminal starch disappearance from 96.7% to 99.3%. Exogenous GLP-2 increased (P < 0.01) total small intestinal mass and small intestinal mucosal mass by 1.2 kg and 896 g, respectively. Relative to control, GLP-2 and casein + GLP-2 treatments increased (P = 0.04) total small intestinal α-glucosidase activity (sum of maltase, isomaltase, glucoamylase) by 83.5%. Total small intestinal maltase, isomaltase, and glucoamylase activity was 90%, 100%, and 66.7% greater for GLP-2 and casein + GLP-2 steers compared with control. The use of postruminal casein infusion and exogenous GLP-2 administration resulted in four distinct carbohydrase activity phenotypes. Relative to control, casein increased pancreatic α-amylase activity, GLP-2 increased small intestinal α-glucosidase activity, and the combination of casein and GLP-2 increased both pancreatic α-amylase activity and small intestinal α-glucosidase activity. This approach provides a novel in vivo animal model to selectively increase endogenous carbohydrase activity to overcome complications of coordinating carbohydrase activity with luminal nutrient flows. This model could be useful to understand physiological mechanisms that might improve small intestinal starch assimilation and efficiency of cattle consuming high-grain diets.
361 The Effects of Feeding Sprouted Barley on Cow Calf Pairs Health and Performance
Authors: Crump Zachary C , Alberto Anthony F , Brown Bailee , Roholt Bryce W , Okamoto Lillian , Sego Mia , Ward Robert , Blackett Brady , Harding Rob , Ranathunga Sanjeewa , Thornton Kara J , Spurling Ryan A
Published: November 2023

Currently the world population is growing exponentially, which increases the demand to produce high-quality protein. Changes in weather patterns, such as drought, and decreased land resources due to urbanization, increase the strain on the agriculture sector to meet world demands. An alternative method to remedy these issues and still produce high quality livestock feed is through controlled environment vertical farming systems. Sprouted grains are one feed these systems can produce. However, there is little information on the effects of feeding sprouted grains to cattle. Angus cows with a steer calf were fed either feeder quality alfalfa (n =10 pairs) or the same alfalfa and sprouted barley (12.5% DM; n = 10 pairs) for 90 days. On days 0 and 90, body weight, milk, rumen fluid and BCS were collected from cows and hip height and weight were recorded for calves. On day 10, weight was recorded for cows and calves and rumen fluid and milk were obtained from cows. On day 45, rumen fluid and milk were collected from cows. On day 55, body weights were collected for both cows and calves and milk from cows. Intake was recorded throughout the trial via bunks with Vytelle technology. PROC MIXED procedure of SAS was used to analyze all data with day as a repeated measure to determine the main effect of treatment. Individual volatile fatty acids (VFA) were measured as a percent of total VFA present. No differences (P ≥ 0.16) were observed in calf weight, hip height, milk protein, fat, lactose, calf DM intake, or cow DM intake. Cows fed barley sprouts tended (P = 0.08) to have a decreased somatic cell count compared with alfalfa fed cows. There was a treatmentxday effect (P = 0.004) for isobutyrate, such that the treatment and control decreased over time, but the control remained consistent the last 45 days. A treatmentxday effect (P = 0.02) was also observed for butyrate indicating that both remained consistent over the first 45 days and then treatment increased over the last 45 days. Additionally, treatmentxday effect (P = 0.001) for rumen pH demonstrated that both groups stayed consistent until day 45 and then treatment pH decreased the last 45 days. There was a day affect for total VFA (P = 0.0009), acetate:propionate (P < 0.0001), acetate (P < 0.0001), and propionate (P < 0.0001) demonstrating that total VFA and acetate increased throughout the duration of the trial and acetate:propionate and propionate decreased throughout the trial, while the acetate:propionate ratio increased (P < 0.0001) the duration of the trial. Cows receiving sprouted barley produced more (P = 0.02) capronate than control. These results indicate that sprouted barley can be an alternative feed at this stage in production without having a negative impact on health or production but does change the rumen pH and proportion of some VFA.
362 The Influence of Supplemental Protein Level on the Intake, Digestion, and Metabolism of Beef Cattle Consuming Low-Quality, High-Fiber Roughages
Authors: Peterson Jeremiah , Kluth Janessa A , Hamilton Thomas , Sitz Taylre , Pondolfino Jackie , Wyffels Sam , Van Emon Megan L , Eberly Jed , DelCurto Timothy
Published: November 2023

Two studies were conducted to evaluate the influence of graded levels of supplemental protein on the intake, digestion, ruminal fermentation, and metabolism of beef cows consuming low-quality forage base diets (6% CP and 74% NDF). For both studies, 15 ruminally cannulated cows (4/5 yrs age, 803 and 757 kg = avg BW for study 1 and 2, respectively) were stratified by BW and, within stratum, randomly assigned to three supplemental treatment groups (n = 5). In study 1, cows were assigned to the following treatments: 1) control, no supplement; 2) 0.25 % BW of a 20% CP supplement; and 3) 0.25 % BW of a 40% supplement. Both supplements were composed of soybean meal and ground corn with the composition adjusted to hit the target CP level. In study 2, cows were assigned to the following alfalfa pellet supplement treatments: 1) control, no supplement; 2) 0.20 % BW of alfalfa pellets, and 3) 0.40 % BW of alfalfa pellets. In study 1, forage intake, DM fill, liquid fill and total tract digestibility were not influenced by supplemental treatment (P ≥ 0.49). However, total DM intake increased linearly (P = 0.02) with increasing supplemental protein, with the 40% CP supplemented cows consuming 39% more DM than control cows. No treatment differences (P ≥ 0.97) were observed for heart rate or surface temperature just before feeding (hour 0) nor 5 hours post-feeding averaging 46.0 bpm, 15.3°C, and 35.2°C, respectively. In study 2, both forage intake and total intake increased linearly (P ≤ 0.02) with increasing amounts of supplemental alfalfa. Cattle supplemented alfalfa pellets at 0.4% of BW had 33 and 71% greater forage and total DM intake compared with non-supplemented control cows, respectively. In contrast, there were no treatment effects (P ≥ 0.11) on DM fill and total tract digestibility averaging 15.73 kg and 44.99%, respectively. In contrast, liquid fill tended to increase (P = 0.08) linearly with increasing levels of supplemental alfalfa. Heart rate nor surface temperature prior to feeding and 5-hours post feeding were influenced (P ≥ 0.83) by the addition of supplemental alfalfa averaging 51.91 bpm, 15.05°C and 31.75°C, respectively. In summary, overall total DM intake was enhanced with the addition of supplemental protein, however, only modest effects were observed in ruminal fill and total tract digestion. Additionally, heart rate and surface body temperatures were not influenced by supplemental treatments under the conditions of these studies.
357 The Influence of Supplemental Protein Levels on Beef Cattle Grazing Winter Foothill Rangelands: Cow and Subsequent Calf Performance
Authors: Hamilton Thomas , Wyffels Sam , Nack Makae , Kluth Janessa A , Peterson Jeremiah , DelCurto Timothy , Carlisle T J
Published: November 2023

Angus based bred cows [n = 150; initial shrunk body weight (BW) = 615 ± 6.61 kg; initial body condition score (BCS) = 5.2] were used in an 84-d winter grazing experiment that took place over two consecutive years. Cattle were stratified by age and body condition and, within stratum, randomly assigned to one of three protein supplementation treatments: 1) no supplement, 2) cows fed 0.20% BW· d-1 of a 30% protein supplement, and 3) cows fed 0.40% BW · d-1 of a 30% protein supplement. Protein supplement was a 30% CP canola-based pelleted supplement with 9 units protein from urea. Cows were gathered three-times weekly and provided supplement on a replicated pen basis. Performance data were analyzed as a completely randomized design with linear and quadratic contrasts used for mean separation (reps = 5; n = 7). Body weights and BCS were recorded every 28-d period throughout the study and calf BW were obtained at birth and weaning. A treatment × period interaction was detected for body weight change (P < 0.01) where a linear response (P < 0.01) where increasing protein status resulted in modest weight gains relative to the control treatment. BCS also exhibited a linear response for two of the three weight periods (P < 0.01) where level of BCS lost was least in cows with the higher supplemental protein levels. A year × period interaction was detected where cows from year two exhibited less BW change on days 28, 56, and 84 of the study (P < 0.01) and had greater BCS (P < 0.01) than those from year one during these periods. In addition, we observed a treatment × year interaction where cows from year two experienced less BW change and had greater BCS than cows from year one (P < 0.01). No treatment × year interactions were detected for birth weight, average daily gain (ADG), or adjusted 205-d weight in calves. A tendency was noted for cows offered 0.4% BW· d-1 supplement to have heavier calves at birth than their counterparts (P = 0.09) over both years. A year effect was detected where calves born in year two had increased ADG and adjusted 205-d weights compared with those from year one. A tendency (P = 0.09) for the calves in year two of the study to have heavier weights at birth compared with those from year one was also noted. In summary, increasing levels of supplemental protein resulted in linear improvements of BW and BCS of grazing beef cattle during the winter. While birth weights of calves tended to differ due to the gestational nutrition of the dam, calf growth and weaning weights were not affected.
363 Effect of Protein and Starch Supplementation Level on Intake and Digestibility By Steers Consuming Low-Quality Forage: I. Bos Taurus Taurus
Authors: Cox Jodi R , Wickersham Tryon A
Published: November 2023

A deficiency of ruminally available N (RAN) caused by a basal diet of low-quality forage depresses forage utilization. Supplemental protein improves forage utilization by increasing RAN, resulting in increased intake and potentially improving digestion. Addition of starch to a supplement can increase total digestible OM intake (TDOMI); however, too much starch decreases RAN creating competition between fiber and starch fermenting bacteria potentially decreasing forage utilization. Our objective was to determine the effect of starch supplementation on intake and digestion in Bos taurus taurus steers. Accordingly, five ruminally cannulated Angus steers (BW 375 ± 45 kg) were used in a 4 × 4 Latin square to evaluate the effect of decreasing supplemental starch when consuming King Ranch Bluestem hay (3.5% CP, 73% NDF). Steers received four isonitrogenous (130 mg N/ kg BW) supplements providing increasing levels of starch (2% starch = 100% soybean meal; 20% starch = 26.3% corn, 73% soybean meal, 0.7% urea; 38% starch = 51.6% corn, 47% soybean meal, 1.4% urea; 56% starch = 78.6% corn, 19% soybean meal, 2.4% urea). Five 14-d periods were conducted, consisting of 9 d adaptation and 4 d to measure intake and digestion, and 1 d for ruminal fermentation. As designed, supplement OM intake (SOMI) increased linearly (P < 0.01) as starch level increased. Forage OM intake (FOMI) decreased linearly with increasing starch (P < 0.01). Increases in SOMI and decreases in FOMI combined to result in no significant (P ≥ 0.14) differences in total OMI (TOMI) between starch levels. Total digestible OMI (TDOMI) responded quadratically (P = 0.05) to increasing starch and was 45.8, 49.4, 48.4 and 41.9 g TDOMI/kg BW0.75 for 2, 20, 38, and 56% starch, respectfully. Total DOMI was 18% greater when steers were provided 20% starch supplement compared with 56% starch. Similarly, total digestible NDF intake responded quadratically (P = 0.05) and was maximized with 20% starch. Total tract OM digestion and NDF digestion were not significantly affected (P ≥ 0.15) by starch level in the supplement. In conclusion, providing supplemental starch over 20% decrease forage utilization. Decreases in FOMI with starch inclusion may be attributed to competition for RAN between fiber fermenting and starch fermenting bacteria.
370 Evaluation of Nutrient Digestibility By Calves Born from Early and Late Shedding Angus Dams
Authors: Keele Jennifer , Rude Brian , Smith Trent , Karisch Brandi B , Masaitis Malori
Published: November 2023

Researchers have investigated several factors that could alter fetal growth, including nutrient restriction (Valiente et al., 2021), hair shedding (Gray et al., 2011), and extreme hot and cold temperatures (Davidson et al., 2022). Hot temperatures and increased humidity percentages in the southeast United States caused researchers to investigate the hair coats of Angus cattle in the commercial production setting. An improvement in fiber digestibility and calf birth and weaning weights has been observed in Angus dams that shed 50% of the winter hair coat by May (Gray et al., 2011; Burnett et al., 2021). Our objective of this experiment was to investigate the nutrient digestibility of Angus calves born to cows that on average, shed early compared with calves from cows that shed later. Newly weaned, purebred Angus bull calves (early; n = 6, late; n = 6) were housed in metabolism crates for 10 d. Before the trial, calves had a 14-d adaption period to a 14% CP textured feed (CPC 14% Developer, CPC Commodities, Fountain Run, KY) and offered ad libitum Cynodon dactlyon hay and water. After 3 d crate acclimation period, urine, feces, orts, and hay samples were collected for 7 d. Concentrate was offered at 0.25% of average BW. Approximately 5% samples were taken of feces, and urine samples had 1 to 1.5% of 25% metaphosphoric acid added to prevent ammonia volatilization, and both collections were composited by animal. Orts were collected at 0600 h daily, dried, and composited by animal. Laboratory analysis included dry matter (DM), organic matter (OM), ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), Kjeldahl N (CP), and fat. Data were analyzed using the GLM procedure of SAS 9.4 in a completely randomized design with calf as the experimental unit. Significant (P ≤ 0.05) means were separated using Fischer’s protected LSD. The model for intake included average daily DM and OM (kg) and adjusted by body weight (BW%). For digestibility analysis, the model included: DM, OM, ash, NDF, ADF, hemi-cellulose (HC), CP, and fat. The N retention model included: N retained (g/d), N retained/consumed (%), and N retained/DM intake (%). There were no differences between early or late calves for DM intake (5.502 ± 0.2774 kg/d; 2.251 ± 0.1247 %BW), or OM intake (5.199 ± 0.2591 kg/d; 2.128 ± 0.1166 %BW). There were no differences in digestibility for either group for DM, OM, Ash, NDF, ADF, HC, CP, or fat (Table 1.). There were also no differences in N retention in either group of calves (3.686 ± 2.0242 g/d; 4.366 ± 2.3964 %; 0.064 ± 0.0355 %). Further research is needed in this area to adequately understand factors influencing nutrient digestibility in calves born from early and late shedding dams.
439 Identifying Forage Efficient Cows
Authors: Lalman David
Published: November 2023

In recent years, substantial progress has been made in understanding the sources of biological variation and genetic components of feed efficiency in growing animals consuming energy-dense mixed diets during the post-weaning phase. Much less is known about within-animal variation of feed efficiency for beef cows consuming moderate to low-quality forage diets common to most cow/calf production systems and where > 74% of the total feed energy required to produce beef is consumed. Considerable evidence indicates the existence of a genetic by environment interaction for feed efficiency. Therefore, more rapid progress in forage utilization efficiency and reduction in greenhouse gas emissions in the cow herd could be made by studying feed efficiency when cattle consume moderate quality, unprocessed forage diets. Phenotype for feed intake and feed efficiency are most practically and cost effectively determined during the post-weaning growing stage. However, due to the additional nutrient sinks associated with gestation and lactation, little is known about the repeatability of forage utilization efficiency between growing heifers and beef cows. An update of recent advancements to identify forage-efficient cows will be provided during the presentation.
38 Application of Real-Time Location Systems for Automated Behavioral Monitoring in Sheep
Authors: Adcock Sarah J J , Woods Jocelyn M , Peckler Gretchen
Published: November 2023

Evaluating how, when, and where an animal moves in their environment can provide insights into their health and welfare states. Spatial tracking systems for monitoring sheep are less well developed than accelerometer-based systems, but have the potential to add important behavioral information to Precision Livestock Farming (PLF) applications. Global Positioning Systems (GPS) can be used to track pasture-based animals, but are not suitable to establish indoor locations. Real-Time Location Systems (RTLS) are a recent development that use radio-frequency signals emitted by tags to track the indoor location of an animal online and continuously. Raw RTLS data in the form of x, y coordinates can be used to calculate multiple spatial metrics, including velocity, acceleration, distance moved, the proportion of time an animal spends in different functional areas, social network attributes, and range size. RTLS can also be integrated with accelerometers to potentially improve predictive accuracy of behavioral algorithms. RTLS have been primarily tested and validated for indoor tracking of dairy cattle and have been used to assess behavioral time budgets and to detect space-use changes related to estrus or health status. For on-farm applications, these data must be transformed into threshold-based algorithms to generate notifications on changes in the health or welfare status of an animal. Algorithm development needs to account for confounding factors such as breed, sex, age, parity, and stage of lactation, as well as environmental variability that can influence the performance of decision-making tools under real-life conditions. In addition, independent validation studies of commercial systems are lacking, and many calculate positioning error with stationary objects rather than moving animals, potentially inflating accuracy estimates. In conclusion, there is growing empirical support for the use of RTLS as a PLF technology for on-farm animal health and welfare assessment. However, research is needed to validate these systems in sheep and identify spatial metrics that are accurate and robust predictors of health and welfare states for commercial applications.
380 The Sow Milk Microbiome and Resistome
Authors: Holman Devin B , Gzyl Katherine E , Kommadath Arun
Published: November 2023

In addition to oligosaccharides, proteins (e.g., immunoglobulins), lipids, vitamins, and other nutrients vital for piglet health, sow’s milk contains bacteria believed to be important in gut health. Therefore, certain sow milk isolates with potentially beneficial properties may be of interest for use as probiotic strains. Furthermore, given the relatively large reservoir of antimicrobial-resistant bacteria carried by commercial pigs even in the absence of direct antimicrobial exposure, it is possible that sow’s milk may also transfer antimicrobial-resistant bacteria to their piglets. The objective of this study was to characterize the bacterial microbiome of sow’s milk using both culturing and shotgun metagenomics. To do this, colostrum (within 24 h of farrowing) and milk samples (n = 42) were collected from 14 sows at d 0, 7, and 21 during the suckling phase. We recovered 323 isolates on four different culture media, and 135 of these were chosen for whole-genome sequencing based on their 16S rRNA gene sequence identity to maximize isolate diversity. The majority (n = 90) of the sequenced isolates belonged to either the Staphylococcus or Streptococcus genera. Twelve isolates (Lactiplantibacillus plantarum, Lactobacillus amylovorus, Ligilactobacillus salivarius, Limosilactobacillus reuteri, and Weissella paramesenteroides) were members of lactic acid-producing bacterial species noted for their beneficial properties in mammals. Several potentially pathogenic bacterial species were also isolated including Clostridium perfringens, Escherichia coli, Klebsiella pneumonia, Streptococcus dysgalactiae, Staphylococcus hyicus, and Streptococcus suis. In addition, seven isolates could not be assigned to a specific species (< 95% average nucleotide identity) and thus may represent potentially novel bacterial species. We also mapped the shotgun metagenomic reads back to the sequenced isolate genomes and found Rothia spp. and L. amylovorus to be relatively most abundant ( > 0.25%). Nearly all of the isolates (n = 130) carried at least one antimicrobial resistance gene and many strains, including S. suis and S. dysgalactiae isolates, encoded genes conferring resistance to more than three antimicrobial classes. The tetracycline resistance genes tet(W), tet(Q), tet(W/N/W), tet(K), and tet(O) were the relatively most abundant antimicrobial resistance genes in the colostrum and milk metagenomes. These results show that sow’s milk may be a source of both beneficial and potentially pathogenic bacteria as well as a significant source of antimicrobial-resistant bacteria.
396 Implications of Repeated Subacute Lipopolysaccharide Exposure During Synchronized Estrous
Authors: Austin Molly , Castro Briza , Dominguez- Areallnes Jeffery , Luna Karime , Duran Kenneth , Gutierrez Michelle , Ochoa Luis , Gifford Craig A , Hernandez Gifford Jennifer A
Published: November 2023

Acute inflammation induced by chronic infection or a single intravenous administration of the bacterial endotoxin, lipopolysaccharide (LPS) induces immune responses capable of depressing female fertility. However, the effect of dose and repeated endotoxin exposure during the estrous cycle on immune response and reproductive performance has yet to be investigated. To investigate the effects of varying doses of LPS delivered at distinct stages of follicular maturation, thirty-six Ramboulliet ewes (68.2 ± 1.1 kg; age 3 to 7 yr) were stratified by weight and age and randomly assigned to vehicle (n = 12), low (n = 12) or high (n = 12) LPS-treated groups to evaluate febrile response, serum progesterone and cortisol concentrations, and reproductive performance. Ewes received subcutaneous injections of saline (CON), 1.5 µg/kg BW LPS (LOW), or 3.0 µg/kg BW LPS (HIGH) on d 5, 10, and 15 after onset of synchronized estrus. Estrous synchronization was determined by serum progesterone (P4) analysis. All ewes demonstrated similar P4 profiles, but HIGH-LPS ewes tended to have elevated values (P = 0.1). On treatment d 5 and 15, blood samples and rectal temperature were collected before and intermittently throughout the duration of the trial. Lipopolysaccharide increased rectal temperature of LOW and HIGH groups at 2, 3, and 6 h, respectively after initial LPS challenge (d 5) when compared with vehicle-treated controls (0.67, and 0.70 °C, P < 0.05), but no significance was observed at d 10 or 15. Serum concentrations of cortisol were similar among treatment groups at 0 h (P > 0.05). However, a rapid and sustained cortisol increase was demonstrated within 1 h of LPS exposure in both LPS-treatment groups compared with controls (P = 0.001). A similar pattern of cortisol release among treatment groups was demonstrated on d 15 (P < 0.05). While there was no significant difference in services per cycle by treatment, there was a marked difference (16.67%) in remarks during the second cycle for HIGH and LOW groups (P = 0.23) as compared with controls. Control ewes had d 100 pregnancy rate of 90.91%, while low and high LPS-treated groups had pregnancy rates of 91.67% (P = 0.96) and 83.33% (P = 0.59) respectively. The administration of LPS resulted in significant increases in serum cortisol in treated ewes, and serum progesterone was significantly increased in LOW LPS-treated ewes compared with CON or HIGH LPS-treated ewes. Thus, alterations of temperature, steroid hormone concentration, and time to estrus in response to LPS may ultimately implicate female fertility and prevent economic losses for producers.
PSVII-4 Genetic Parameters for Various Semen Quality and Reproductive Performance Traits in Nellore Cattle Including X Chromosome Markers
Authors: de Carvalho Felipe E , Ferraz José Bento S , Pedrosa Victor B , Eler Joanir P , de Mattos Elisangela C , Silva Marcio R , Guimaraes José Domingos , Bussiman Fernando , da Silva Barbara Conceição A , Araujo Andre C , Wen Hui , Mulim Henrique A , Rocha Artur Oliveira , Brito Luiz F F
Published: November 2023

Estimating genetic parameters of male and female fertility and reproduction traits is essential for optimizing beef cattle breeding programs. In general, only markers located on autosomal chromosomes are used for genetic evaluations. Sex chromosomes tend to be excluded due to the compensation mechanism of dosage of genes linked to the X chromosome, which is the second largest chromosome in the cattle genome and harbors many genes potentially influencing these traits. Therefore, we estimated genomic-based variance components, including the X chromosome in the variance components analysis for female precocity, fertility, and andrological traits based on the single-step GBLUP procedure and Bayesian inference. The dataset consisted of ~120,000 records for the probability of pregnancy at 14 months (PP14), early rebreeding (REBA), and stability (STAY). From the breeding soundness exam (BSE) of bulls, 20,000 records were obtained for semen quality, andrological biometry, semen defects, and bull fitness (BULL_FIT). The pedigree contained 660,608 animals, where 11,012 animals were genotyped for 770,111 SNPs. All traits have reasonable additive genetic variation and are heritable, with a substantial contribution from the X chromosome, indicating that genetic progress for these traits is feasible. The heritability estimates (h2) explained by autosomal and X chromosome SNPs was low and low-to-moderate, respectively, for female reproductive performance traits, such as REBA [0.17 (auto); 0.07 (sex chr)], PP14 (0.42;0.05), and STAY (0.32;0.01). For male traits, the heritability estimates based on the autosomes and X chromosome, respectively, ranged from 0.02 to 0.04 and from 0.01 to 0.03 for semen quality traits; from 0.10 to 0.68 and from 0.02 to 0.07 for morphological traits; from 0.10 to 0.12 and from 0.01 to 0.02 for semen defects traits; for bull evaluation (BULL_FIT) were observed h2 for autosomes 0.18 and 0.10 for sexual chromosome X. The results observed in this study indicate a substantial contribution of the X chromosome on fertility and reproductive performance traits. These findings will serve as background information for designing breeding programs for genetically improving semen production and quality and reproductive performance in Nellore cattle.
PSXII-10 Development of a 70k Snp Genotyping Array for American Mink (Neogale vison)
Authors: Do Duy Ngoc , Karimi Karim , Sargolzaei Mehdi , Plastow Graham , Wang Zhiquan , Miar Younes
Published: November 2023

Mink is an important fur animal species; however, little is known about the genomics of complex traits in mink. The development of single nucleotide polymorphism (SNP) array has accelerated genomics application in animal breeding by facilitating genotyping and associated analyses. The current project aimed to design a medium-density SNP array in American mink for genomic studies and selection in this species. For this purpose, whole genome sequence with 30x coverage was generated for 100 individuals from the Canadian Centre for Fur Animal Research (CCFAR) at the Dalhousie Faculty of Agriculture (Truro, NS, Canada) and Millbank Fur Farm (Rockwood, ON, Canada). Variant calling was done using Samtools and GATK pipelines. A total of 8,373,854 bi-allelic SNPs identified by both pipelines were used for an initial selection of 91K SNPs for submission to the Affymetrix scoring system. After filtering, 62,375 SNPs were selected for probe design and production of an Axiom Mink Genotyping Array 70K. This 70K SNP array was used to genotype 2,973 mink for validation. After quality control of genotypes, 47,159 SNPs were classified as high-resolution SNPs, and among them 24,237 were polymorphic. A preliminary genome-wide association study of 1,356 mink for body length at harvest identified a SNP (AX-647623051) significantly associated (P < 1.26 × 10-5) with the trait. In conclusion, this 70K mink SNP array could be used for genomic studies and potentially as a starting point for genomic selection programs in American mink.
PSV-19 Supplementation of a Multi-Strain Probiotic Increases the Expression of Biomarkers of Immunity in Savannah X Spanish Goat Blood
Authors: Asiamah Emmanuel K , Mkunga Maxwell , Lohakare Jayant
Published: November 2023

Probiotics are considered a safe, non-chemical alternative to antibiotics and have been shown to boost the host immune response of livestock. The present study investigated the effect of Gut Candy (GC), a multi-strain probiotic supplementation, on immune gene expression in Spanish X Savannah goats. Seven adult female Spanish X Savannah goats (n = 7) received a daily dose (28 g) of a GC (containing Lactobacillus acidophilus, Enterococcus faecium, Bacillus subtilis, Propioni bacterium freudenreichii, and Aspergillus oryza) for 60 days. The control group received no probiotics (n = 7). Blood (10 mL) was collected aseptically from the jugular vein on days 0 and 60. Total RNA was extracted from whole blood, reverse transcribed to cDNA, and quantitative real-time PCR (RT-PCR) was performed using specific primers for TLR2, TLR4, TNF-α, IL1B, IL10, and MPO. The fold changes (FC) in relative gene abundance were analyzed using Livak's method. β-actin and GAPDH were used as internal controls and for normalization. Fold changes (FC) were considered significant at -2 ≥ FC ≥ 2. After 60 days of GC supplementation, there was an increase in fold change in relative gene abundance in IL10 (FC = 3.66), TNF-α (FC = 11.7), IL1β (FC = 19.59), TLR4 (FC = 5.09), and MPO (FC = 2.05). GC also tended to increase the FC of TLR 2(FC = 1.86). The results from the study demonstrate that probiotic supplementation modulates the expression of immune genes in goats. Incorporating probiotics supplementation into the feed regimen of livestock could be beneficial to the animals' health and overall performance.
PSI-8 Effect of Monensin Withdrawal on the Rumen Prokaryote Microbiome in Bos Indicus and Bos Taurus Steers Consuming Bermudagrass Hay
Authors: Giesey Jennifer , Brady Jeff A , Obayomi Olabiyi , Wickersham Tryon A , Mast Natasha L
Published: November 2023

Monensin, a carboxylic polyether ionophore, is commonly added to ruminant diets as a strategy for improving animal production by altering ruminal fermentation. However, research concerning the effect of monensin withdrawal is limited. Therefore, the effect of monensin withdrawal and the subspecies of cattle on the rumen prokaryote microbiome was evaluated using ruminally cannulated steers (5 Bos indicus, BI and 5 Bos taurus, BT; 398 kg BW) consuming bermudagrass hay (13.7% CP). Subspecies were concurrently subjected to a two period, two treatment crossover design. Each 70-d period consisted of a 42 d adaptation phase with treatments including 0 (CON) or 200 (MON) mg·animal-1 monensin (Rumensin 90; Elanco Animal Health, Greenfield, IN) fed in 0.91 kg dried distillers grains with solubles daily. Withdrawal of monensin was then evaluated for a 28-d phase following adaptation. Rumen fluid was collected via suction strainer from the dorsal and ventral sacs of the rumen at feeding on d 1, 7, 14, 21, and 28 of the withdrawal phase and frozen until further analysis. Upon completion of the trial, samples were thawed and analyzed for microbial populations using massively parallel sequencing. The V4 region of the 16S rRNA gene was sequenced to analyze and compare rumen prokaryotic microbes within treatment groups and subspecies. Sequences were processed using QIIME 2 (q2) version 2021.2 and imported into R v4.1 for statistical analysis and graphical displays. Bray Curtis-based principle coordinate analysis (PCoA) provided visualization of microbial community clustering by monensin treatment and subspecies, facilitating identification of microbial community shifts resulting from treatments or subspecies. No monensin×subspecies×day interaction (P = 0.96) was observed. However, an effect of monensin (P = 0.01), subspecies (P ≤ 0.01), and day (P = 0.017) on the microbiome was present. The changes in microbial density that were observed with monensin withdrawal help to provide insight into the mode of action of monensin and its impact on potential methane mitigation in cattle.
PSXII-19 Effects of Feeding Hybrid Rye Grain as a Replacement for Barley Grain on Feed Intake, Growth Performance and Carcass Characteristics of Finishing Beef Cattle
Authors: Zhang Fuquan , Carey Rachel E , Brattain Rebecca S , Wehrle Herman , Penner Greg B
Published: November 2023

The objective of this study was to evaluate effects of increasing hybrid rye as a replacement for barley grain on feed intake, growth performance, and carcass characteristics for growing and finishing cattle. Commercial steers (n = 360) with an initial body weight (BW) of 348 ± 6.6 kg were stratified by BW and randomly assigned to 1 of 24 pens (15 steers/pen) for growing (n = 8; 65 d) phase and re-randomized for the finishing (n = 6; 118 d) phase. The control diet (BCON) for the growing phase included 60.2% barley grain, 28.0% barley silage, 7.0% corn silage, 3.4% oat hulls, with the remainder as mineral, vitamins, and urea. Hybrid rye was then included by replacing 50 or 100% of the barley grain (DM basis). Treatments for the finishing phase included a control containing 10% hay, 85.2% barley grain, with the remainder coming from mineral and vitamins (FCON). Hybrid rye grain was included by replacing 33 (33R), 67 (67R), and 100% (100R) of the barley grain (DM basis). Data were analyzed using the MIXED procedure for each phase independently with carcass data analyzed using the GLIMMIX procedure of SAS (SAS version 9.4; SAS Institute, Inc. Cary, NC). There was no effect of hybrid rye inclusion on DMI or G:F during the growing phase, but ADG increased quadratically (P = 0.04) with 50% rye having the greatest value. During finishing, DMI decreased linearly as hybrid rye inclusion increased (P = 0.03). Average daily gain was quadratically affected (P = 0.03) with an initial increase from FCON to 33% rye followed by a decrease with increasing rye grain inclusion, but G:F was not affected (0.148 kg BW/kg DMI). There was no effect of hybrid rye inclusion on hot carcass weight, dressing percentage, back-fat thickness, ribeye area, marbling score, and yield score. Increasing the inclusion of hybrid rye quadratically (P < 0.01) increased the proportion of severe liver abscesses with an average of 34.6% severely abscessed livers when hybrid rye grain was included compared with 11.1% for FCON. Partial replacement of barley grain with hybrid rye may improve ADG without affecting DMI or G:F during the growing phase. However, replacing barley grain in finishing diets with hybrid rye decreases DMI, increases risk for severe liver abscesses, but does not affect feed conversion suggesting hybrid rye could replace up to 33% of the barley grain.
PSIX-10 Influence of Graded Levels of Microbially Enhanced Protein on Nutrient Digestibility of Extruded Cat Foods
Authors: Chen Youhan , Aldrich Charles G G
Published: November 2023

Pet food ingredients that bring extra nutrition and health benefits are much better accepted than being simply an economic choice by the manufacturer. Microbially enhanced protein (MEP) from soybeans is a fermented ingredient that is believed to promote nutrient utilization. The objective of this study was to determine the effect of increasing levels of MEP on nutrient digestibility of extruded cat food. Four extruded dietary treatments differing by level of MEP in exchange for soybean meal (15%; SBM) at 5, 10 and 15% (5MEP, 10MEP and 15MEP, respectively) were randomly assigned to 12 individually housed adult domestic shorthair cats (6 castrated males and 6 spayed females) of similar age (0.9 ± 0.23 months) and body weight (4.35 ± 0.87). The study was designed as a 4 × 4 replicated Latin square with 9-day adaptation followed by 5-day total fecal collection for each period. Data were analyzed using a mixed model through SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and square (i.e., replicate), period, and cat(square) as random effects. Treatment means were separated by Tukey’s test. The 15MEP increased fecal moisture content (P<0.05) while 5MEP and 10MEP made no difference compared with SBM. No differences were observed for food intake, fecal dry matter output, fecal score, fecal pH or apparent total tract digestibility of dry matter, organic matter, crude protein or gross energy for MEPs compared with SBM. However, crude fat digestibility of cats fed 5MEP was lower (P<0.05) than cats fed with10MEP and 15MEP but not different from cats fed with SBM. These results suggest that MEP did not have adverse effects on nutrient digestibility when added to extruded diets at up to 15% in healthy adult cats.
PSVIII-16 Saccharomyces Cerevisiae Fermentation Product Promotes Improved Preference and Consumption in Adult Cats Fed an Extruded Diet
Authors: Norton Sharon A , Lin Ching-Yen , Franz Nolan
Published: November 2023

Dietary Saccharomyces cerevisiae fermentation product (SCFP) has been previously demonstrated to improve palatability when included in extruded dog food. The objective of this study was to quantify key indicators of palatability of a SCFP (TruMune, Cargill, Inc.) formulated at two levels versus a control in an extruded, complete and balanced adult cat maintenance cat food. The base diet (CON) was a chicken-based formula (32% crude protein;16% crude fat) and did not contain SCFP. The SCFP was added to the base diet to deliver 150 mg/kg BW SCFP (TRUL) or 300 mg/kg BW SCFP (TRUH). Three, 2-d studies were conducted each using 20 healthy adult cats (mean age = 8.4±4.3 yr; mean BW = 5.1±1.3 kg) to compare all diet combinations (CON vs TRUL, CON vs TRUH and TRUL vs TRUH). Five analyses were employed to describe differences between each of the dietary comparisons including an intake ratio of consumption using a Wilcox Signed Rank test and 2-way ANOVA to validate and test the assumption of a difference; overall and daily preference by first choice using X2 probability to determine significance and average daily consumption using a paired t-test. Differences P < 0.05 were considered significant and P < 0.10 as trends. Preference scoring by intake ratio to determine differences between preferences were assessed using a standard 2:1 consumption criteria that is an accepted indicator of a clear preference. Compared with CON, total food consumed was greater for TRUL (P = 0.016) and TRULH (P = 0.001), and greater for TRUL vs TRUH (P = 0.011). No difference in overall preference by first choice or daily preference by first choice were observed for TRUL vs CON, but a daily preference by first choice was exhibited for TRUH vs CON on d2 (P = 0.0.043). Daily preference by first choice did not differ between the two SCFP treatments, but overall preference by first choice was greater for TRUL vs TRUH (P = 0.005). Average daily consumption was higher on d1 for both TRUL (P = 0.006) and TRUH (P < 0.0001) versus control but similar between treatments on d 2. Average daily consumption was not different between TRUL and TRUH on d1 but was greater for TRUL vs TRUH on d 2 (P = 0.028). Preference scoring by intake ratio revealed a 4:1 preference for TRUL vs CON, 10:1 for TRUH vs CON and an inestimable difference for TRUL vs TRUH with 5 cats preferring TRUL and no cats preferring TRUH. These studies show SCFP increases the palatability of an extruded cat food and that inclusion of 150 mg/kg BW may yield optimal palatability and preference outcomes.
PSVIII-24 Dietary Vitamin D Was Associated with Increased Circulating Vitamin D in Dogs with No Observable Adverse Effect Up to 9,992 Iu/Kg Dry Matter
Authors: Jewell Dennis E , Panickar Kiran S
Published: November 2023

Adult dogs have been reported to benefit from circulating 25 (OH) vitamin D above 100 ng/mL to support optimal health. Although there is no consensus for optimum concentrations of circulating vitamin D it has been reported that circulating vitamin D is positively related to a reduced severity of disease, decreased disease risk, enhanced efficacy of treatment and overall positive disease outcome. This association does not prove causality. However, the positive effect of circulating vitamin D suggests that this relationship is not simply an association or a response to disease but reflects a causal supporting function of increased circulating vitamin D above that required for bone health. Understanding the relationship between dietary vitamin D and circulating vitamin D status is essential to progress in using dietary vitamin D to influence health and disease in the dog. Five groups of 8 adult dogs each were fed for 6 months according to AAFCO maintenance protocols to evaluate the influence of dietary vitamin D on circulating vitamin D concentrations and indices of health. Body weight was recorded, and blood samples taken before being fed treatment foods. After initiation of treatment foods, intake was measured daily, body weight was measured weekly, and blood samples were taken initially, after 85 days of feeding, and at the end of the study. The dry matter concentrations of vitamin D (IU/kg) were 796, 3,087, 5,511, 7,314, and 9,992 in approximately 4,000 kcal/kg foods. There were no clinical signs of either deficiency or excess vitamin D. Normal circulating concentrations of hemoglobin, packed cell volume, albumin, total calcium, phosphorus and alkaline phosphatase were maintained in all groups. Circulating vitamin D increased in all groups except those consuming 796 IU/kg. All dogs consuming increased dietary vitamin D had increased concentrations of 25 (OH) D compared with the control group consuming 796 IU/kg. Concentration of calcium increased in all groups with no difference in calcium increase associated with dietary vitamin D. There was no difference in the change in concentration of parathyroid hormone or ionized calcium in response to treatment. Vitamin D increased in a linear and quadratic fashion in response to dietary vitamin D concentration. This resulted in all the dogs fed 5,511 IU/kg and above exceeding 100 ng/mL circulating 25 (OH) D. Dietary vitamin D was positively associated with increased circulating concentrations with no observable adverse effects in dietary concentrations up to 9,992 IU/kg dry matter. This allowed all dogs consuming 5,511 IU/kg and above to exceed the circulating concentration previously recommended for optimal health in dogs.
PSVIII-20 A Premium Dry Cat Food Enhances Digestibility and Gut Health in Cats Compared with a Grocery Dry Cat Food
Authors: Lin Ching-Yen , Daristotle Leighann , Franz Nolan
Published: November 2023

As the awareness of pet owners to the benefits of nutrition on pet health and wellness increases, pet owners are looking for foods that include high-quality ingredients and functional benefits. However, little research is available on cats comparing health measures when feeding premium foods vs basic cat foods. This study aimed to compare the effects of feeding a premium cat kibble diet (Blue Buffalo Tastefuls; BB) and a basic grocery cat kibble diet on digestibility, blood biomarkers, and fecal microbiome in healthy adult cats. Sixty cats (mean BW = 4.2 ± 0.8 kg; mean age = 4.3 ± 3.2 yr) were randomly selected to consume BB (n = 30) or grocery diet (n = 30) for 180 days. On days 0, 90, and 180, fresh fecal samples were collected for fecal microbiome and dysbiosis index analysis and blood samples were collected for measurements of complete blood count, serum chemistry, and serum biomarkers. A separate 10-day digestibility study was conducted using 14 cats (BB n = 7, grocery diet n = 7; mean BW = 3.8 ± 0.7 kg). Total fecal samples were collected from day 6 to day 10 for nutrient digestibility analysis. Protocols were approved by the facility’s Institutional Animal Care and Use Committee before the study. All data were analyzed using the Mixed Models procedure of SAS. Fecal scores were not changed (P > 0.05) by diet. Greater (P < 0.05) digestibility of protein, fat, and energy were observed in cats consuming BB. Although all blood cell count and blood chemistry values were within the reference ranges, measurements such as total protein, aspartate transaminase, alkaline phosphatase, cholesterol, and triglycerides were significantly different (P < 0.05) between diet groups. Greater (P < 0.05) insulin-like growth factor-1 was observed in cats fed BB. Cats consuming BB had a lower (P < 0.05) dysbiosis index (less dysbiotic microbiome) and a greater (P < 0.05) bacterial species richness. Relative abundances of 28 bacterial genera were altered (P < 0.05) by the diets, with greater abundances of Faecalibacterium, Megamonas, and Ruminococcus observed in cats fed BB. The data suggest that a premium dry cat food may elicit beneficial effects on digestibility and the GI microbiome of healthy adult cats.