bluuebunny/crossref_metadata_2025 huggingface dataset:
PSIV-26 Extent of use of supplemental feeding in beef cattle operations across the Southeast: A report of the regional survey
Authors: Andrew Lauren M St , Dillard S Leanne , Mullenix Kimberly , Smith W Brandon
Published: September 2024

With input costs on the rise, researchers and producers, alike, are seeking alternative management strategies for profitable and sustainable beef production. Studies suggest that supplemental feed provided to grazing cattle may be used to offset some of the cost. However, there is a lack of knowledge on the extent of supplemental feeding programs in the southeastern US and which feeds may be used in these programs. Thus, the objective of this study was to better understand supplemental feeding practices and choices among beef producers in the southeastern US. To address this objective, a 24-question survey was distributed through Extension and commodity organizations to beef producers across the Southeast. This survey received 118 complete responses. The majority of respondents operated cow-calf production systems (65.6%) on either tall fescue or bermudagrass pastures (32.7 and 28.0%, respectively). Approximately 88% of these producers employed some type of supplemental feeding strategy, but there is no clear decision on whether commodity or byproduct feedstuffs were preferred. The leading commodity used was corn (61.4%), while common byproducts included whole cottonseed, corn gluten feed, and soybean hulls (17.1, 16.6, and 14.4%, respectively). At the end of the survey, the participants were asked to submit a sample of their byproduct supplements to have a nutritive analysis completed to better understand what nutritional components the products they are feeding contain and how they may vary from place to place. Some of the products that were sent in include whole cottonseed, cotton byproduct, corn gluten meal, distillers grain, chicken litter, and others. The nutritional test being run on these samples included crude protein and fiber analysis. The crude protein of the samples received ranged from 13.3% to 30.3% with an average of 21.5%. The fiber profile received ranged from 45.5% to 76.3% with an average of 59.9%. With the information recorded from these tests, recommendations can be provided on different feeding methods in both commercial settings as well as research settings.
PSIV-27 Effects of organic complexed or inorganic trace mineral supplementation on cow performance and herd longevity
Authors: Cheek Robin A , Kegley Elizabeth B , Powell Jeremy G
Published: September 2024

Records for Angus-crossbred cows (n = 219) that were born during a 3-yr project to investigate the effects of trace mineral source on beef cow performance were reviewed. For the 3-yr cow project, cows were initially assigned to 1 of 4 groups within spring and fall calving herds. Groups within each herd were assigned randomly to 1 of 2 supplemental trace mineral treatments 1) inorganic sources as Cu, Zn, and Mn in sulfate forms and Co carbonate (ING), or 2) organic sources as Cu, Zn, and Mn amino acid complexed and Co glucoheptonate (ORG). Free choice minerals were provided with appropriate mineral treatments while cattle were maintained on fescue-bermudagrass pastures that were rotated monthly. When forage or hay was limited, treatments were delivered via grain supplements. At weaning, heifer calves remained on their respective dietary treatments through their first breeding season (approximately 15 mo of age). The cow project began with pregnant cows, thus, all heifers weaned in the first year and some in other years (n = 86) were conceived before their dams received the dietary treatments. Most heifers weaned in yr 2 and 3 were conceived while their dams were on their respective dietary treatments (n = 133). After heifers were confirmed pregnant, they re-entered the cow herd. At the conclusion of this project the Cow-Calf Unit continued to keep performance records. Natural breeding occurred after artificial insemination and open cattle were culled annually. Year of performance data (calving, culling, and death records) were analyzed to determine the long-term effects of trace mineral source. MIXED procedures were used of SAS 9.4 with herd (spring/fall calving) and year weaned as random effects and individual heifer as the subject. Previously reported, heifers supplemented with organic trace mineral sources had a tendency for improved reproductive performance (P = 0.09; ING = 66%, ORG = 76.8%) and a decreased percentage of heifers culled (P = 0.07; ING = 33.7%, ORG = 22.1%) compared with heifers receiving inorganic supplementation. However, in subsequent year previous trace mineral supplementation did not influence (P = 0.65) when cows were culled (ING = 3.01 yr, ORG = 3.20 yr). The number of calves produced per cow did not differ (P = 0.45) between previous trace mineral source supplementation (ING = 2.45 calves, ORG = 2.78 calves). With heifers that were conceived on the study, there were no differences when they were culled (P = 0.25; ING = 2.83 yr, ORG = 3.51 yr) or the total calves produced (P = 0.18; ING = 2.24 calves, ORG = 2.95 calves). To conclude, supplementation of heifer calves with different sources of trace mineral did not affect their longevity in the herd, but results suggest further investigation.
PSIX-22 Maternal methane, carbon dioxide, and oxygen flux compared with progeny gas flux
Authors: Gunter Stacey A , Moffet Corey A , Friend Emalee J
Published: September 2024

Red Angus heifers [n = 19; body weight (BW) = 370 ± 8.1 kg) and their paired offspring (BW = 283 ± 4.2 kg; 18 heifers, 1 steer) were used to compare the respiration gas parameters between dams and their progeny over 2 calving cycles (8 pairs in the 1st cycle, 11 in the 2nd). The methane (CH4), carbon dioxide (CO2) emissions and oxygen (O2) consumption of the dams were measured at 14 mo of age over a 70-d period using an automated head-chamber system (AHCS) that measured the flux of these 3 gases. Dams grazed native mixed-grass prairie and were offered a daily supplement of alfalfa (Medicago sativa L.) pellets (1.0 kg) via the AHCS. Dams were artificially inseminated using sexed semen (female) from a single Black Angus sire. The gas fluxes of the progeny were measured, beginning at 11 mo of age, over a 70-d period. Like the dams, during their measurement period, the progeny grazed native mixed-grass prairie and were offered a daily supplement (1.0 kg) of alfalfa pellets via the AHCS. Pearson correlations were developed between the 70-d means of daily CH4 and CO2 emissions, O2 consumption, CH4:CO2 ratio, respiratory quotient (RQ), and heat of production estimates for the dams and their progeny by regressing maternal parameters on the parameters of the progeny, using beginning dam and progeny BW as covariates, and year as an indicator variable. A dam’s CH4 emission was very strongly correlated with that of their offspring (ρ = 0.86). The CO2 emission and O2 consumption of the dams were both also very strongly (ρ = 0.92 and ρ = 0.97, respectively) correlated, with that of their progeny. The heat production and CH4:CO2 ratio of the dams were very strongly (ρ = 0.96) and fairly (ρ = 0.50) correlated, respectively, with that of their progeny. Lastly, the RQ of the dam was also very strongly correlated (ρ = 0.87) with the RQ of the progeny. These results indicate that CH4 and CO2 emissions, O2 consumption, CH4:CO2 ratio, and heat of production of the dam are fairly to very strongly correlated to the gas flux parameters of their progeny. Hence, even with this small dataset, there is evidence that beef cattle traits related to greenhouse gas emissions are somewhat heritable and could potentially be selected in breeding animals to decrease greenhouse gas emission intensity.
PSIX-21 Can seeds rich in polyunsaturated fatty acids reduce methane emissions when substituting palm oil on dairy beef calves fed high-concentrate diets? In vitro screening
Authors: Llonch Lourdes , Marti Sonia , Verge Gerard , Riera Joan , Medinya Carles , Cucurull Jordi , Pérez Anna , Fernández Belén , Devant Maria
Published: September 2024

The aim of this study was to evaluate the rumen in vitro methane (CH4) production of concentrates feed with a different protein source (PS) replacing partially palm oil by different seeds (SE) rich in polyunsaturated fatty acids (PUFA). Concentrate PS were: T1 = 8% soybean meal; and T2 = 15% dried distillers grain. Palm oil (CTR; 4% and 3.5% for T1 and T2, respectively) was partially substituted (1%) by flax seed (FL; 2.7%), canola seed (CO; 3%) or sunflower seed (SU; 2.3%), thus 8 concentrates were tested. Samples were ground at 1-mm and used in an in vitro digestibility assay. The rumen liquid was obtained at the slaughterhouse. Two incubation sets were done; two sampling points lasted 24 and 48 h to calculate the dry matter (DM) digestibility; a third sampling point lasted 12 d to monitor the CH4 production. Data were analyzed using a mixed effects model. Net volume of CH4 per degraded DM presented a PS effect (P < 0.01); T1 produced greater net volume of CH4 per degraded DM than T2 (8.12 vs. 6.91 ± 0.330 ml/mg, respectively). Furthermore, net volume of CH4 per degraded DM presented a SE effect (P < 0.01); all concentrates with seeds tested reduced the net volume of CH4 per degraded DM compared with CTR, and specifically CO produced lower net volume of CH4 per degraded DM than FL and SU (8.91, 7.47, 6.28, 7.39 ± 0.467 ml/mg; CTR, FL, CO, SU, respectively). In conclusion, the use of flax, canola, or sunflower seeds to partially substitute palm oil in concentrate feed, regardless of its PS, can be potential strategies to reduce rumen CH4 emissions, and seems that canola seed may be the most effective one.
PSIX-19 Effect of protein and starch level on N balance and ruminal fermentation parameters in steers consuming low-quality forage: Bos taurus taurus
Authors: Cox Jodi R , Wickersham Tryon A
Published: September 2024

Globally cattle convert low-quality forage to beef and milk; therefore, understanding protein utilization in Bos taurus taurus is critical to enhancing sustainability as over and under-supplementation of protein are economically and environmentally costly. Low-quality forage lacks the N necessary for proper utilization and metabolic function. Supplemental protein improves low-quality forage utilization and is expected to increase N absorption and retention. Supplement starch can increase volatile fatty acid (VFA) production and energy supplied to the animal; however, too much starch decreases ruminally available N and pH potentially decreasing fibrolytic activity. Accordingly, our objective was to determine the effect starch supplementation on N balance and ruminal fermentation parameters in Bos taurus steers. Ruminally cannulated Angus steers [n = 5; body weight (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. Supplemental N intake decreased linearly (P < 0.01) with increasing starch as the crude protein content of the soybean was underestimated. Forage and total N intake were not affected by starch level (P ≥ 0.17). Fecal and total urinary N excretion were not different between starch levels (P ≥ 0.43). Urinary ammonia-N and urea-N averaged 6.6 and 16.8% of total urinary N excretion, respectively, but no differences between starch levels were observed (P ≥ 0.39). Level of starch supplementation had no effect on N retention and absorption (P ≥ 0.50). There was a treatment × time interaction observed for ruminal ammonia concentration (P < 0.01). All treatments, except 2% starch, peaked at 4 h post feeding, 20 and 38% treatments gradually decreased following four, but the concentration of ruminal ammonia decreased by 80% between 4 h and 8 h after feeding in the 56% starch treatment. Starch level had no effect total VFA concentration, VFA molar proportions, or ruminal pH (P ≥ 0.10). In conclusion, providing supplemental starch did not affect N balance or VFA production when fed to steers consuming low-quality forage. Nitrogen balance and VFA production likely were not affected because all supplements provided sufficient ruminally available N and, therefore, exerted minimal effects on forage utilization.
PSIX-20 Effect of protein and starch level on N balance and ruminal fermentation parameters in steers consuming low-quality forage: Bos taurus indicus
Authors: Cox Jodi R , Wickersham Tryon A
Published: September 2024

Despite the global importance of Bos taurus indicus production systems for converting low-quality forage to high-quality human consumable products, their responses to supplementation are not well characterized. Low-quality forage lacks the N necessary to support microbial activity and even correcting this deficiency may still fail to provide sufficient energy to meet animal requirements. Therefore, addition of starch may be warranted to increase animal performance and volatile fatty acid (VFA) production. Accordingly, our objective was to determine the effect starch supplementation on N balance and ruminal fermentation parameters in Bos taurus indicus steers. Accordingly, ruminally cannulated Brahman steers [n = 5; body weight (BW) = 420 ± 55 kg] were used in a 4 × 4 Latin square to evaluate the effect of increasing supplemental starch when consuming King Ranch Bluestem hay (3.5% CP, 73% NDF). Four supplements were formulated to be isonitrogenous (130 mg N/kg BW) and provide similar amounts of ruminally degradable protein while supplying 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. Supplemental N intake decreased linearly (P = 0.02) with increasing starch as the crude protein content of the soybean was underestimated. Forage and total N intake were not affected by starch level (P ≥ 0.27). Fecal and total urinary N excretion were not different between starch levels (P ≥ 0.20). Urinary ammonia-N decreased quadratically (P = 0.03) as a percentage of total N excretion, 9.5, 5.4, 5.8, and 6.9%, for 2, 20, 38, and 56% starch, respectively. In contrast, there were no significant effects of treatment (P ≥ 0.30) on urinary urea excretion. Level of starch had no effect on N retention and absorption (P ≥ 0.14). A treatment × time interaction was observed for ruminal ammonia (P < 0.01) with concentrations peaking at h 4. The greatest ruminal ammonia was observed at h 4 for 56% starch it decreased markedly between h 4 and 8 and remained low thereafter. There was a small quadratic (P = 0.04) decrease in molar proportion of acetate. No other significant effects on VFA molar proportions, total VFA concentration, or ruminal pH were observed (P ≥ 0.12). In conclusion, providing increasing levels of supplemental starch to Bos taurus indicus steers consuming low-quality forage did not significantly affect N balance or VFA concentrations.
PSV-29 In vitro digestibility and in situ degradability of lobster and mixed crab shell waste material
Authors: Stahl Tess , Valentine Lydia , Abend Alan , Islam Tamanna , Erickson Peter
Published: September 2024

The objective of this research was to determine the in situ and in vitro degradability of lobster shell waste meal (LM) and crab shell waste meal (CM). Lobster and crab harvest are major industries within the New England states and the Maritime provinces. Harvest of the American lobster amounts to 54,643 tons caught and processed in 2020 in the New England states. The Atlantic Red Crab annual quota is around 1,814 tons. The Jonah Crab amounts to 5,725 tons. Due to the significant harvest, there is a resulting increase in byproducts and wastes at processing facilities providing potential feedstuffs for cattle. For both experiments, LM and CM were compared with soybean (SBM) and blood meals (BM). In experiment 1, 0.5 g of each meal were added to an artificial rumen incubator (Daisy, Ankom technologies) and DM degradability over 48 h was measured. In experiment 2, ruminally-cannulated Holstein cows (n = 4) in a 4 × 4 Latin square, had 5 g of sample were placed in Dacron bags in the dorsal rumen. Bags were in duplicate and removed at 2, 4, 8,12, 24, and 48 h time points. Eight bags were removed at 12 h for use in the in vitro intestinal degradability measurement using the modified three-step technique. Contrasts were: SBM vs. BM+LM+CM (SBM vs others), BM vs. LM+CM, and LM vs. CM. In experiment 2, 0 h bags served as a determination of fraction A, while the 48 h bags served as fraction C. Fraction B = 100% - (fraction A + fraction C). Degradation rate (kd) was calculated by converting % CP degraded from 2 to 24 h to Ln and then calculating the slope. In experiment 1, DM degradation was 45.8, 43.8, 76.4 and 100.1 % for SBM, BM, LM, and CM respectively; SBM vs others (P < 0.01), BM vs. LM + CM (P < 0.01), and no difference between LM vs. CM. Fraction A (CP) was 9.9, 8.1, 4.2, and 4.8% respectively; with SBM vs. others (P < 0.03), BM vs. LM+CM (P < 0.01), and no difference between LM vs CM. Fraction B (CP) was 76.2, 62.2, 28.9, and 42.6% respectively; with SBM vs. others (P < 0.01), BM vs. LM + CM (P < 0.01), and LM vs. CM (P < 0.10). Fraction C (CP) was 4.41, 30.8, 46.8, and 37.5% respectively; with SBM vs. others (P < 0.01), BM vs. LM + CM (P < 0.03), and LM vs. CM (P < 0.08). Intestinal CP digestibility was 56.2, 64.7, -5.83, and 10.5% respectively, with SBM vs others (P < 0.01), BM vs LM+CM (P < 0.01), and no difference between LM and CM. Results of these studies indicated that LM and CM may have some benefits in cattle diets, but feeding studies should be conducted.
PSV-28 Liver abscess microbiota of beef cattle administered in-feed tylosin differ according to abscess size and fraction
Authors: Gruninger Robert J , O’Hara Eóin , Zaheer Rahat , Andrés-Lasheras Sara , McAllister Tim A
Published: September 2024

Liver abscesses (LA) pose a significant challenge to the Canadian beef industry as they are estimated to cost the industry ~ $61.2 million annually. This is likely an underestimate as it does not account for losses in animal productivity. Tylosin phosphate is widely used to reduce LA, but concerns over antimicrobial use selecting for antimicrobial resistance has created an urgency to explore alternative approaches. Understanding the impact of tylosin on the microbial ecology of LA is crucial to this. We hypothesized that altering the duration of in-feed administration of tylosin to feedlot cattle would alter the microbial community of LA. To investigate this, we collected abscessed livers from cattle fed a diet containing tylosin 1) throughout finishing, 2) during the first 78% of the feeding or 3) during the last 75% of the feeding period. We examined LA microbial ecology of purulent material, abscess capsule tissue, originating from abscesses of different sizes using a metataxonomic approach. Our findings revealed that shortening tylosin administration did not notably alter the alpha (P > 0.05) or beta-diversity (P > 0.05) of LA microbial communities. There was a significant difference in microbial richness associated with abscess capsule (P < 0.05) compared with bulk purulent material. Fusobacterium or Bacteroides ASVs dominated LA microbiomes, alongside probable opportunistic gut pathogens and other bacteria. Interestingly, classifying samples based on whether they originated from a liver with a single abscess, multiple abscesses or a very large abscess tended to differ in microbiome composition (P = 0.06). These insights contribute to our understanding of factors impacting liver abscess microbial ecology and will be valuable in identifying antibiotic alternatives. They underscore the importance of exploring varied approaches to address liver abscesses while reducing reliance on in-feed antibiotics.
PSVII-26 The effect of consuming red clover pasture and beneficial fatty acid supplements on ram lamb seminiferous tubule microscopic features
Authors: Morgan Staci-Ann , Barrett David , Papadopoulos Yousef , duynisveld John , Fredeen Alan , Glover Kathleen , Bidarimath Mallikarjun , Wort Jonathan
Published: September 2024

Fatty acids and phytoestrogens have been linked to short- and long-term alterations of reproductive performance in sheep. Red clover (RC) contains phytoestrogens, which have been linked to reduced reproductive performance in sheep. However, rams fed RC have increased omega-3 polyunsaturated fatty acids (n-3 PUFAs) and conjugated linoleic acid (CLA). These beneficial fatty acids may improve reproductive performance in rams. Fish oils (FO) contain significant amounts of n-3 PUFA and these improve reproductive performance. This study aimed to determine the effects of RC pasture and beneficial fatty acid supplementation on ram lamb seminiferous tubule histology. Crossbred ram lambs (n =32; 2 to 3 mo of age) were randomly divided into four groups (n = 8 per group) and balanced by body weight (BW) and dam parity. Two groups grazed tall fescue (TF)/RC, and two grazed TF pasture for 10 wk. These groups were then further randomly subdivided to receive a fat supplement [soybean oil (SBO; n = 8), SBO + CLA (n = 8), or FO (n = 8)] or no fat supplementation (CON; n = 8) during a 5-wk finishing diet. Then rams were slaughtered, and their testes were collected, fixed, and processed for histology. Testes cross sections were viewed under light microscopy and photos were taken for image analysis. Seminiferous tubule diameter, luminal diameter, cell count, and the average cell nuclear area: tubule area were determined using Image-Pro 10 software (Media Cybernetics). No significant differences were noted in tubular diameter or luminal diameter between any treatment groups. Those on TF had significantly greater cell counts (371.3 ± 39.6 vs. 305.9 ± 44.2; P < 0.05) than rams on TF/RC pasture. Soybean oil produced a significantly lower ratio than SBO + CLA (0.000324 ± 0.000190 vs. 0.000408 ± 0.000300, P < 0.05) but a greater cell count (498.2 ± 36.2) than CON, SBO + CLA, or FO (289.7 ± 52.9 vs. 282.2 ± 50.3 vs. 284.3 ± 50.9; P < 0.001). No statistical difference was noted in ratios between the two pastures. Rams on TF/RC, with no supplementation had the least cell counts (227.2 ± 58.2) of all treatment groups, with significantly fewer counts than TF/RC + SBO rams (412.4 ± 62.0 P < 0.05) and TF + SBO rams (583.9 ± 37.3; P < 0.001); the latter had the greatest cell count of all treatment groups. Results suggest that RC and oil supplementation impact cell count, and oil supplementation impacts ratios but neither factor had an impact on tubule or luminal diameter.
PSX-15 Effect of starch supplementation on rumen bacterial abundance in Bos taurus indicus steers consuming low-quality forage
Authors: Fontenot Alyson B , McCann Joshua C , Cox Jodi R , Linder Haley F , Wickersham Tryon A
Published: September 2024

Deficient ruminally available nitrogen caused by a basal diet of low-quality forage can limit microbial growth in the rumen and decrease forage utilization. Protein supplementation is well-documented to improve forage digestibility and performance. Additionally, starch has been evaluated to increase energy supply to grazing cattle when the forage cannot support adequate levels of production. However, most research in this area has been conducted in Bos taurus taurus, especially the response of the rumen microbiome to supplementation. Accordingly, the objective of this study was to evaluate the effects of increasing starch supplementation on rumen bacterial populations in Bos taurus indicus steers supplemented protein and consuming low-quality forage. Ruminal samples were collected from five ruminally-cannulated Brahman steers (BW 420 ± 55 kg) used in a 4×4 Latin square fed a basal diet of King Ranch Bluestem Hay (3.5% CP and 73% NDF) provided ad libitum, and one of four isonitrogenous (130 mg N/kg BW) supplements with increasing levels of starch (2% starch= 100% soybean meal; 20% starch= 73% soybean meal, 26.2% corn, 0.8% urea; 38% starch = 47% soybean meal, 51.6% corn, 1.4% urea; 56% starch= 19% soybean meal, 78.6% corn, 2.4% urea). Rumen content samples were collected via rumen cannula at 4h post-feeding. Microbial DNA was extracted; full length 16S rRNA amplicon libraries were prepared using Kinnex kits and then sequenced on the PacBio Revio platform. Reads were analyzed using DADA2 and QIIME2. Statistical analysis was performed with the GLIMMIX procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC). Firmicutes, Bacteroidata, Actinobacteriota, Verrucomicrobiota, and Euryarchaeota were the most abundant phyla in all treatments (83, 10, 3, 0.4, and 1%, respectively), and were not affected by treatment (P ≥ 0.10). Christensenellaceae R-7 group, Rikenellaceae RC9 gut group, Lachnospiraceae-XPB1014-group, Butyrvibrio, Lachnospiraceae-NK3A20-group, and Prevotella represented the most abundant genera for all treatments (7, 5, 11, 9, 7, and 3%, respectively). Lachnospiraceae-XPB1014-group and Lachnospiraceae-NK3A20-group responded quadratically (P ≤ 0.02) to increasing starch with decreased abundance for the 20% and 38% starch supplement. Comparatively, relative abundance of Butyrvibrio responded quadratically (P < 0.01) with increased abundance in the 20% and 38% starch supplement. Pseudobutyrvibrio increased with supplementation of 20% starch and then decreased as starch supplementation increased (quadratic, P = 0.04). In conclusion, supplementation of starch elicited changes in microbial relative abundance at the genus level with the response in Butyrivibrio suggesting greater fibrolytic activity. Forage and total digestible NDF intake in these steers decreased with increased starch supplementation; however, TDOMI was not affected by starch provision.
PSX-16 The effect of short-term heat stress on physiological, hematological, and immunological parameters of Florida Cracker Sheep
Authors: Mills-Widemon Anijia , Harrison Makenzie , Ikuejamoye-Omotore Sola , Reyes Zaira M Estrada , Terrill Thomas H , Cervantes Andres Pech
Published: September 2024

Florida Cracker sheep are a heritage sheep breed that was developed under natural selection in Florida, US. The objective of this study was to evaluate the effect of short-term heat stress on rectal temperature, respiration rate, hematological parameters, and IgA concentrations of Florida Cracker ewes (2 yr of age). A total of fourteen ewes were allocated to heat stress (HT, n = 7) or cooling (CTL, n = 7) conditions for 6 wk during the summer season. Treatment groups were grouped in covered concrete floor pens with similar dimensions and characteristics and had access to shelter, feed, and freshwater ad libitum. The HT pen was exposed to regular ambient temperatures, and for the cooling pen, an evaporative cooling fan was used. Data for ambient temperature and relative humidity of HT and CTL pens were recorded every week to estimate the temperature humidity index (THI). Blood samples were collected from each experimental ewe 1 wk before the start of the experiment (baseline) and at wk 1, wk 2, wk 3, wk 4, wk 5, and wk 6 post-treatment. Blood samples were analyzed using a hematology analyzer (Vetscan HM5, Zoetis). Plasma was extracted from the blood and was used to evaluate IgA concentrations with a commercial kit. For the statistical analysis of the physiological, hematological, and immunological parameters, a mixed model with repeated measures was used. Fixed effects included treatment (HT or CTL), wk (1 to 6), and the treatment by week interaction. Animal was fitted as a random effect and the baseline data was used as a covariate. The THI for the HT and CTL groups ranged from 81.3 to 89.5 and from 73.5 to 75.6, respectively. The HT group presented a significant (P < 0.05) increase in respiratory rate when compared with the CTL group. No significant changes were observed for rectal temperature and IgA concentrations in the experimental groups. However, for wk 3, a significant (P < 0.05) increase of neutrophils and a decrease in lymphocyte % was observed for the HT group. In conclusion, short-term heat stress increased respiratory rate and neutrophil % and decreased the lymphocyte % in Florida Cracker ewes. It is possible that heat stress could have a detrimental impact on immune mechanisms in Florida Cracker ewes. Further studies are required to investigate the effects of long-term heat stress.
PSX-19 Variation in nutritive value of whole cottonseed from the Regional Breeding Testing Network
Authors: Rigney Diva N , Rockwell Macy , Underwood Anna Grace G , Koebernick Jenny , Mullenix Kimberly , Smith W Brandon
Published: September 2024

Whole cottonseed serves as a readily accessible, nutritional, and cost-effective supplementary feed for beef cattle. Standard estimates indicate that whole cottonseed contains approximately 52% neutral detergent fiber (NDF), 24% crude protein (CP), and 18% crude fat. For more than 15 yr, the Regional Breeders Testing Network (RBTN) has conducted a multi-environment trial (MET) for breeders to evaluate germplasm to include whole cottonseed. The trial presents opportunities to analyze variations among cultivars concerning their nutritional value. Therefore, the purpose of this study was to assess the variability in nutritive value of whole cottonseed from the 2023 RBTN MET. Samples from 20 RBTN cotton varieties were obtained and assayed for NDF, ADF, ADL, and CP. Samples were also subjected for batch culture in vitro true digestibility (IVTD) and crude fat. In our study, NDF (total cell wall content) was less than previously reported book values (45.8% vs. 51.6%). Crude protein was consistent with book values (25.0% vs. 24.4%) and had the least degree of variability among the nutrients tested. However, crude fat (the primary energy source in whole cottonseed) in our samples was greater than values previously reported (20.2% vs. 17.5%) and had a greater degree of variability. Our findings indicate that the nutritional value of whole cottonseed may differ depending on the variety acquired. This research lays the groundwork for pinpointing the genetic factors responsible for regulating its nutritional value.
PSX-20 The inclusion of a tannin-based product evaluated in a typical feedlot diet under tropical conditions increases the molar proportion of propionate in a dual-flow continuous-culture system
Authors: Paula Eduardo , Dourado Stephanie , Magnani Elaine , Amancio Bruna , Loregian Kalista , Silva Thiago , Silva Melaine , Manella Marcelo Q , Arnandes Renata Branco
Published: September 2024

The objective of the present study was to evaluate increasing levels of a tannin-based product and a monensin (positive control; unique dose) using a dual-flow continuous-culture system. Diets were randomly assigned to ten fermenters in a replicated 5 x 5 Latin square with three, 10-d experimental periods consisting of 7 d for adaptation and 3 d for sample collection. Four different levels were tested independently, resulting in 5 treatments: tannin at levels of 0 (negative control), 0.07, 0.14, and 0.21 (% of DM of the total diet) and monensin as positive control at 28 mg/kg DM. The tannin-based product was a specific blend of tannin and saponins, composed of quebracho and chestnut tannin extracts, SilvaFeed-BX). Diets were prepared as concentrate mixes that were combined with sugarcane bagasse, corn grain, dry distillers grain, citrus pulp, peanut meal, and urea. Liquid and solid flow rates were adjusted to 10 and 5.0%/h, respectively. Samples were collected for digestibility, ruminal fermentation, and microbial growth. The basal diet consisted of a typical finishing diet for beef cattle (16:84 roughage:concentrate ratio). All results were assessed for residual normality and variance homogeneity. All variables were fitted through generalized mixed models (GLIMMIX procedure) and compared by using Tukey test (multiple comparison) and polynomial regressions (tannin concentrations, which were analyzed for linear and quadratic responses. Partial data were presented in the table below. Total VFA concentration, molar proportion of butyrate, and total Branched-chain VFA were not affected by treatments (P > 0.05). Molar proportion of acetate of the tannin-based product at 0.07 % of DM tended to be decreased compared with all other treatments. Molar proportion of propionate increased quadratically (P = 0.05) reaching the peak at the level of 0.07 % of DM, which were greater than monensin treatment. In conclusion, our results indicate that a smaller dose of a tannin-based product (0.07 g/kg of DM) might manipulate ruminal fermentation by increasing molar proportion of propionate in typical feedlot diet fed under tropical conditions. This is important from an energetic standpoint for the animal host, since propionate is the precursor of glucose synthesis in ruminants.
PSX-21 Supplementing essential oil blend and fumaric acid in calf feed influenced rumen fermentation and greenhouse gases emission
Authors: Alabi Joel O , Anotaenwere Chika C , Adelusi Oludotun O , Wuaku Micheal , Oderinwale Olatunde A , Enikuomehin James M , Okedoyin Deborah O , Ike Kelechi A , Anele Uchenna Y
Published: September 2024

Essential oils (EO) and fumaric acid (FA) are known for their ability to reduce greenhouse gas (GHG) emissions in ruminant animals. This study aimed to investigate the combined impact of essential oil blend (EOB) and FA (EF) on in vitro fermentation, total gas and volatile fatty acid (VFA) production and GHG emissions of a calf feed in a 24 h batch culture study. Rumen-cannulated black Angus beef cows (n = 3) served as inoculum donors. The calf feed contained 910, 5.8, 70.9, 792, 111, 72 g/kg dry matter (DM), fat, ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL), respectively. The EOB contained equal proportions of ginger, anise, peppermint, oregano and thyme. FA was added at 3% along with EOB at 10, 20, 30 and 40 µL/g calf feed. Five treatments evaluated were Control (without additives), EF10, EF20, EF30, and EF40. Results showed that pH and digestibility of DM, NDF, ADF were not significantly (P > 0.05) affected by the EF treatments (Table 1). ADL digestibility decreased linearly (P < 0.001) with increasing EF dosage. EF40 increased (P < 0.05) cellulose digestibility by approximately 11% compared with EF10. Total gas, methane and carbon dioxide production decreased (linear, quadratic, P < 0.001) with EF inclusion (Table 2). Ammonia concentration decreased linearly (P = 0.009) with increasing EF dosage, while hydrogen sulfide gas was not affected. EF inclusion reduced (P < 0.001) total VFA, acetate but increased propionate and butyrate proportion (Table 3). In conclusion, the combination of EOB and FA effectively mitigated GHG emissions without compromising nutrient digestibility in calves. Therefore, incorporating EOB at 10 µL/g and FA at 3% in calf feed is recommended as an effective nutritional strategy to reduce GHG emissions in calves.
PSX-18 Long term implanting of finished Angus Hereford steers: examining the relationship between feed and water efficiency
Authors: Franco Arturo Macias , da Silva Aghata Elins Moreira , Fonseca Mozart , da Silva Gleise Medeiros
Published: September 2024

Herein, we investigate the effects of a long-term release trenbolone acetate and estradiol implant (200 mg and 40 mg respectively, Revalor-XS; Merck Animal Health; Summit, NJ) on implanted [IMP; n = 9, body weight (BW) = 473.13 kg ± 25.22] and non-implanted (NIMP; n = 9, BW = 481.13 kg ± 21.78) finished Angus Hereford steers fed a single diet three times daily (0600, 1100, 1600 h). The objectives were to identify water and feed efficiency parameters and mechanisms of IMP and NIMP steers. Parameters evaluated included daily dry matter intake (DMI), freshwater intake (FWI), average daily gain (ADG), animal water units (AWU), drinking behavior, feed conversion (FC), feed conversion ratio (FCR), water conversion (WC), water conversion ratio (WCR), residual growth rate (RGR), and Kleiber index (KI). Linear mixed models were fitted to analyze the data under assumption of a completely randomized design, and variable relationships examined through partial correlation networks and principal component analysis. Implanted animals were more feed efficient than NIMP for FC (P < 0.001; SEM = 0.00), FCR (P < 0.001; SEM = 0.29), RGR (P < 0.001; SEM = 0.0.02), and KI (P < 0.001; SEM = 0.00). When evaluating water efficiency, IMP animals had less WCR (P < 0.001; SEM = 1.54) and greater WC (P < 0.001; SEM = 0.001). No differences were observed on marbling and carcass grades, but carcass weight, final BW, and rib eye area were greater for IMP groups (P < 0.001, P < 0.001, P = 0.004, respectively). For IMP, multivariate variable contribution (values > 10) appeared to associate FWI on the first and second eigenvectors with DMI, FC, and FCR. For NIMP, FWI was associated with WC, WCR, and AWU. The FWI of Implanted animals was associated with AWU, WCR, while NIMP was associated with AWU. Feed conversion ratio and DMI had the greatest node strength for the IMP animals, whereas for NIMP, KI was the only node with strength greater than 2. Our results indicate that feed and water efficiencies may share mechanistic pathways. We present a simple metric that accurately remains relevant in evaluating water requirements for both IMP and NIMP steers as AWU. We show how relationship strength is related to gain and efficiency for IMP animals, whereas metabolic activity, potentially in relation to body composition changes, drives the variation and relationships for NIMP animals.
PSXI-14 Effects of diets with high and low inclusion of corn with or without high concentration of amylase on in vitro fermentative parameters and gas production
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 study aimed to evaluate the effects of corn hybrids and the level of inclusion in the diet on in vitro fermentative parameters, DM disappearance, total gas and methane production. A 3 × 2 factorial design study was carried out to evaluate the Tropical Flint corn (TFC), Enogen Flint corn (EFC) and Enogen Dent corn (EDC), and the corn inclusion content in the diet (H: 71%; L: 42.5% of DM). 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 1.5 g of DM corn sample. Gas production was evaluated at the end of 24 h of incubation and a gas sample was taken for methane analysis. Furthermore, the pH of the liquid was measured at the end of 24 h and a sample was obtained for analysis of short chain fatty acids (SCFA), ammonia concentration and the final residue was used to determine de DM disappearance. The data were analyzed using Proc Mixed of SAS (9.4). There was an interaction between corn hybrid and inclusion level for the variable total SCFA (H-TFC: 70.5; H-EFC: 41.5; H-EDC: 40.7; L-TFC: 43.7; L-EFC: 38.8; L-EDC: 39.7 mM; P = 0.02) and proportion of butyrate (H-TFC: 9.25; H-EFC: 5.53; H-EDC: 6.01; L-TFC: 5.80; L-EFC: 5.41; L-EDC: 5.99 mM/100mM; P = 0.02), with greater values observed for the inclusion of TFC in relation to the other treatments. The inclusion of Enogen corn (Flint or Dent) increased propionate (TFC: 32.1; EFC: 36.3; EDC: 36.7 mM/100mM; P < 0.01) and reduced acetate (TFC: 56.7; EFC: 55.1; EDC: 54.8 mM/100mM; P = 0.02) and the acetate:propionate ratio (TFC: 1.83; EFC: 1.56; EDC: 1.53; P < 0.01). On the other hand, greater inclusion of corn in the diet increased propionate (H: 36.8; L: 33.3 mM/100mM; P < 0.01) and reduced acetate (H: 53.5; L: 57.6 mM/100mM; P < 0.01), acetate:propionate ratio (H: 1.50; L: 1.77; P < 0.01), and fluid pH (H: 6.39; L: 6.46; P < 0.01). Corn hybrids with Enogen technology increased the DM disappearance (TFC: 70.5; EFC: 73.3; EDC: 74.3%; P < 0.01), without affecting the production of gases and methane. Furthermore, greater inclusion of corn in the diet increased the DM disappearance (H: 74.1; L: 71.2%; P < 0.01) and gas production (H: 193.8; L: 160.5 mg/24 h; P < 0.01), without effect on methane production. Enogen technology and increasing corn in the diet improve fermentation and increase degradation of dry matter; however, methane production increases with greater corn inclusion in the diet.
PSXI-8 Effects of selected feed additives on feedlot cattle performance when fed diets containing rehydrated corn grain silage during adaptation period
Authors: Francischinelli André F , Gouvêa Daniel L C G , Perdigão Alexandre , Carvalho Victor , Ribeiro Vitória A M , Pereira Murilo C S , Martins Cyntia L L , Arrigoni Mário B B
Published: September 2024

The ability of some essential oils not to depress dry matter intake (DMI) is recognized, a marked effect when supplementation with sodium monensin is used; favoring DMI in wk 1 in the feedlot has a great impact on ingestive behavior in the subsequent weeks and on average daily gain (ADG) for the total period. The objective of the study was to evaluate performance and feed consumption in the first 30 d of feedlot, using different feed additives. Nelore bulls [n = 48; initial body weight (BWi) = 378.1 kg ± 8.92 kg; 20 mo of age] were used. Bulls were allocated in a collective pen, randomly distributed into two treatments, with the animal being the experimental unit. The treatments were: 1) Sodium Monensin (MON), 26 mg/kg DM; and 2) CRINA + RUMISTAR + Hy-D (CRD), blend of essential oils, 90 mg/kg DM + exogenous α-amylase, 560 mg/kg DM + 25 hydroxy-vitamin D3, 1 mgּ animal-1ּ d-1

. The animals were weighed fasting (± 16h) at the beginning of the experiment and weighed in the fed state on d 31, with 4% shrink deducted to account for the contents of the gastrointestinal tract. DMI was measured daily and individually using electronic troughs with selector doors (Intergado, PONTA, Betim, MG-Brazil), capable of identifying and allowing access to the animals through an earring with a transponder. The adaptation period lasted 15 d, with increasing levels of concentrate inclusion, being 5 d (72% concentrate), 5 d (75.8% concentrate), and 5 d (83.3% concentrate), being that between d 16 and 30 the finishing diet (89.3% concentrate) was offered, consisting of ground corn, rehydrated corn grain silage, cottonseed meal, whole cottonseed, sugarcane bagasse, urea, and vitamin-mineral supplement. The DMI was evaluated in two periods (d 0 to 15 = adaptation; d 0 to 30 = first 30 d). Data were analyzed by SAS PROC ANOVA, using BWi as a covariate when significant. Animals fed CRD had greater BW at d 30 (425 vs 417 kg, P = 0.04) and increased ADG by 0.260 kg/d (1.56 vs 1.30 kg/d, P = 0.04). The DMI at adaptation (7.96 kg/d, P = 0.90), and in the first 30 d (8.67 kg/d, P = 0.33) and in the first 30 d in relation to BW (2.18 % of BW, P = 0.46) were similar between treatments; however, CRD tended to provide a better feed efficiency (0.179 vs 0.153, P = 0.09). These findings suggest that the use of CRD may be an effective strategy to enhance feedlot cattle performance during the adaptation period, when fed diets containing rehydrated corn grain silage.
PSXI-18 Effects of different fiber levels on rumination and inflammatory markers in feedlot cattle
Authors: Souza Mailza G , Mendonça Filipe Araújo Canêdo , Ventorin João Pedro Azevedo , Garcia Matheus Copeli , Gonçalves Daniel Júdice , Guiducci Rafael Perches , Lanna Dante Pazzanese
Published: September 2024

Adding fiber to feedlot diets is essential to maximize performance, optimize feed conversion and maintain animal health. Monitoring blood inflammatory markers and rumination behavior can help to identify fiber levels that maximize performance and animal well-being. We aimed to evaluate the effect of fiber levels on inflammatory markers, lactate dehydrogenase and haptoglobin and rumination of Nellore cattle in confinement fed with diets containing 12% and 7% forage NDF, over a period of 50 d. Diets included corn silage as the source of forage fiber with 23.3% and 13.6% corn silage in the dry matter 64% and 73.5% ground corn, and 0.2 and 0.5% potassium chloride, respectively for the 12% and 7% fNDF. Soybean meal (1.5%); cottonseed (7%), urea (1.2%), and mineral mixture (2.7%) containing 25 ppm of monensin were present in both treatments. Average initial body weight (BW) was 460 ± 38 kg and average age was 20 mo. Bulls (n = 20) were randomly distributed for each treatment with animal being the experimental unit. The feeding behavior was monitored on d 21 and 42, with observations at each 10-min interval, over 24 h and data obtained were averaged for analysis and blood samples were collected immediately after behavior analysis. Blood samples were obtained by puncturing the jugular vein, centrifuged to separate the serum, stored at -20°C and subsequently analyzed. Lactate dehydrogenase was analyzed in an automatic biochemistry system using cattle specific cattle kits (LABTEST Diagnóstica SA). Haptoglobin analyses were carried out by ELISA (Vidavet-Veterinary Lab). Data were evaluated by PROC GLIMMIX from SAS. A significant interaction was observed between minutes of rumination and fNDF levels in relation to the concentration of lactate dehydrogenase (P < 0.0001), expressed by the solution: Lactate = 1,272.12 + 908.86 * (tract = 7) + 1,1427 -3.3170 * (treat = 7) * rumination. For animals receiving the 7% fNDF diet, the concentration of lactate dehydrogenase decreased as the minutes of rumination increased, with a significant linear effect (P < 0.001). On the other hand, for animals treated with 12% fNDF, no significant correlation was observed (P = 0.34) with increasing rumination time. There was also an interaction between minutes of rumination and fNDF levels for haptoglobin concentration (P < 0.01), expressed by the solution: Haptoglobin = 0.1901 + 0.4865 * (treat = 7) + 0.000828 - 0.00163 * (treat = 7) * rumination. In animals treated with 7% fNDF, haptoglobin concentration decreased with increasing minutes of rumination, with a significant linear effect (P = 0.02). Our data demonstrates that, for the low forage diet, as bulls increased rumination time there was an improvement (a decrease) in inflammatory markers concentrations.