bluuebunny/crossref_metadata_2025 huggingface dataset:
41 Genetic Selection for Improved Profit Conditioned on Enterprise-Specific Circumstances
Authors: Spangler Matthew L , Golden Bruce L , Newman Scott
Published: November 2023

Circumstances of producers relative to objectives, economic constraints, and production environments differ substantially. Consequently, the specific path of sustainability differs among beef enterprises. Such a path must take a supply-chain approach, contemplating market (consumer) demands, and firm-level economic costs and returns in both the short- and long- term. Long-term economic returns imply longer-term stewardship of natural resources. Genetic selection is uniquely poised to aid in the pursuit of greater economic and biological efficiency, given it represents a cumulative and permanent source of change. However, it is critical that such change be consistent with the producer-specific sustainability path. Given there are multiple traits that impact economic outcomes economic selection indexes are the appropriate tool. The general form of such indexes has been around for about 80 years, albeit with a less than desirable adoption rate in beef selection decisions. The process of index development can account for known sensitivities to differences in marketing endpoints and current levels of phenotypic performance. Moreover, the time horizon used to determine the economic consequences of a selection decision could differ among enterprises. The choice of planning horizon (PH) is an important, yet often overlooked component of breeding objective and index construction. Shorter PH inherently emphasizes traits that can be fully expressed in the near term whilst longer PH allow more substantial weighting of traits expressed later in life. Misalignment of breeding objectives and selection indexes, as might be the case in using a terminal index to choose sires in a self-replacing herd, or incorrect choice of PH could lead to less profitable genetic selection decisions by increasing mature cow weight and/or de-emphasizing reproductive longevity. Consequently, our objective was to provide examples of how trait emphasis might be altered under different assumptions during selection index development using the web-based tool iGENDEC. Indexes assumed replacement females were retained and terminal animals were retained through harvest. We then compared changes in PH, annual cow variable costs, and phenotypic means of hot carcass weight (HCW). The combined relative emphasis (RE) of mature cow weight (MWT) and stayability (STAY) in the breeding objective was 0, 10, and 22% when planning horizon was 2, 10, and 20 years, respectively. As HCW increased from 318 to 408 kg the RE of STAY increased from 10.9% to 18.7% while the RE of HCW decreased from 43.8% to 28.9%. When annual cow variable costs were $250, $500, and $750 the RE of MWT was 6, 14.9, and 22.5%, respectively, assuming the value of calves sold stayed the same. Collectively, these examples illustrate that incorrect definition of breeding objectives and parametrization of indexes can lead to inappropriate weighting of traits that are drivers of long-term resource use (i.e., MWT and STAY).
42 Environmental Impacts of Improving Forage Use Efficiency in Beef Cattle
Authors: DiLorenzo Nicolas
Published: November 2023

As population grows, so does the demand for high quality protein, and beef ranks among the greatest in terms of nutrient density per caloric intake. Maintaining the sustainability of beef cattle production systems has been one of the main priorities of researchers worldwide. Because the global demand for beef production is projected to increase, the contribution of beef production to greenhouse gas emissions will increase. One of the most useful tools available to researchers to reduce the carbon footprint of beef production is the selection for more feed efficient cattle. The use of residual feed intake as a criterion for selection has been demonstrated to have potential impact on the carbon footprint of beef systems, by reducing emissions intensity. Greenhouse gas emissions intensity involves the carbon footprint per unit of product (e.g., beef or milk produced) and it is the main metric to be considered when assessing the environmental impact of production systems. Great advances have been made in terms of improving the digestibility of forage resources. However, because of the impact that fiber digestion has on enteric methane production, these improvements in forage digestibility need to be considered in the context of emissions intensity. Advances in forage breeding such as the incorporation of brown mid-rib traits, have undoubtedly led to improvements in fiber digestion and animal productivity. Fewer studies have examined the impact of this technology on greenhouse gas emissions. A great opportunity exists to begin assessing the impact of new technologies such as the use or fibrolytic enzymes and prebiotics, with the potential of enhancing fiber digestibility. Global beef production will continue to rely heavily on high-forage diets for at least some segments of the production system. Assessing the impact of new technologies to enhance fiber digestion in the context of greenhouse gas emissions per unit of product will be essential to maintain the sustainability of beef production systems.
197 Trace Mineral Source Affects Haircoat Characteristics and Shedding in Cats
Authors: Amundson Laura , Kirn Brent , Millican Allison , Matti Taryn
Published: November 2023

Trace minerals have a pivotal role in maintaining skin health and haircoat characteristics in companion animals. The objective of the current study was to evaluate the effects of inorganic versus amino acid complexed sources of trace minerals on feline skin and haircoat characteristics as well as hair growth. A total of 40 cats (age 5 – 12 years; 22 female, 18 male) were used in this 105-d (15-d acclimation; 90-d test period) trial at Summit Ridge Farms (Susquehanna, PA) from January to April 2022. All cats were fed a basal diet that contained sulfate sources of trace minerals formulated to meet AAFCO (2021) recommendations for 15 d before being randomly assigned (blocked by haircoat color, age, sex, and weight) to 1 of 2 treatments. Dietary treatments included sulfate sources (CON; n = 20) and amino acid complexed (Zinpro ProPath, Zinpro Corp. Eden Prairie, MN) sources (ZPM; n = 20) of supplemental trace minerals. Both treatments were formulated to provide equal amounts of supplemental trace minerals (DM basis), differing only in source (100 ppm Zn, 15 ppm Mn, 12 ppm Cu, 80 ppm Fe). On d 15, a side patch was shaved just below the back (3” x 4”) to evaluate hair growth on d 60 and 105 (average of 3 measurements). Additionally, visual haircoat evaluations and shed hair amount were evaluated at d 60 and 105. All research personnel were blinded to treatments. Statistical analyses were completed using GLIMMIX procedure of SAS 9.4 with d 15 as a covariate and cat as the experimental unit. Trace mineral source did not affect body condition score at either time point. There was no treatment or treatment x day interaction for hair length. A trend (p = 0.13) for a 3-way interaction between treatment, sex, and day was detected due to male cats having longer hair at d 105. Shed hair was evaluated by brushing (20 strokes) and weighing collected hair. No overall treatment effect was detected for shed hair; although, a treatment x day interaction (P = 0.02) for shed hair was observed. At d 60, ZPM cats had 23 mg less shed hair compared with CON cats (P = 0.08). Haircoat scores for shine, scale, and overall quality were assessed by a veterinarian. There were no treatment or treatment x day interactions for shine or overall scores. A treatment x day interaction was detected (P = 0.02) for scale (dander). At d 60, ZPM cats had a reduced average scale score compared with CON cats (0.66 vs 1.05, respectively; P = 0.03). Overall, our data suggests trace mineral source may influence shed hair amount and dander production in cats. Further research to evaluate the influence of season and sex is warranted.
61 Life Stage Feeding: Is There Path Forward for Senior/Geriatric Nutrient recommendations?
Authors: Laflamme Dottie
Published: November 2023

Complete and balanced foods for “all life stages”, according to the Association of American Feed Control Officials (AAFCO), meet the needs for reproduction and growth. While these are recognized as the most nutritionally demanding stages, they are relatively short time periods in the life of a pet. Unique to companion animals, and humans, is the prolonged “senior” life stage. Although this stage is not well defined, it has become evident that energy, protein and other nutrient requirements may change with age in seniors. To establish guidelines for a lifestage, that lifestage must be defined (Table 1). Species and breed differences exist in terms of aging, in that small breed dogs have longer lifespans versus large breed dogs, and cats differ from dogs, with cats showing a definable fourth lifestage of “geriatric” that differs from a “senior” lifestage. A major challenge to defining senior or geriatric nutritional needs is the fact that animals “age” at different rates, causing senior/geriatric to be the most physiologically diverse lifestage. In nutritionally complete and balanced foods, nutrients are provided in proportion to the energy content of the diet and to the expected energy intake of the pet. Regardless of lifestage, energy requirements can differ significantly among dog breeds and among individuals. Added to this is evidence that energy requirements in dogs decrease with age, such that senior dogs need about 25% fewer calories, on average, than young adult dogs. Likewise, senior cats show a decrease in energy requirements, but geriatric cats display an increase in energy needs. Thus, even if the absolute requirement for nutrients did not change with age, the content needed on an energy basis will change. One of the challenges to establishing protein requirements for senior and geriatric pets is age-related loss of lean body mass (LBM), or sarcopenia. LBM serves as a protein reservoir and provides the amino acids used on a 24/7 basis for endogenous protein synthesis, while dietary protein maintains or restores this reservoir. It has become evident that nitrogen balance studies, long used to determine protein requirements for adults, are not sufficient in that they do not account for contributions from LBM. Maintenance of LBM may be a better assay for defining protein requirements. However, LBM is lost with age in all species studied, including humans, dogs and cats. Geriatric cats lose approximately one third of their LBM, while senior dogs lose about 10%. Loss of LBM is associated with greater morbidity and mortality, thus, preservation of LBM is an important goal. While increasing protein intake can slow the loss, and vice versa, increasing protein intake alone cannot prevent loss of LBM. Therefore, an important challenge is to determine how to measure protein requirements in aging pets.
15 Effects of the Maternal Gut and Reproductive Microbiome on Postnatal Development in Ruminants
Authors: Amat Samat , Luecke Sarah M , Swanson Kendall C , Dahlen Carl R
Published: November 2023

The microbial communities residing within the gastrointestinal and reproductive tracts are vital to cattle health; not only for their involvement in nutrient metabolism, but also for their ability to influence infectious and metabolic diseases as well as reproductive efficiency. Therefore, harnessing the ruminal and vagino-uterine microbiomes for improved cattle health and productivity have recently become an active area of research in an era where microbiome manipulation holds as much potential as genetic selection and management refinement for enhancing herd productivity. New developments highlight that the maternal gut and reproductive microbiome extend their impact to offspring development and health. These developments include the demonstrations of maternal gut microbiota involvement in developmental programming in murine models, and increased evidence supporting the existence of in utero microbial colonization and the role of maternal nutrition on fetal programming in cattle. Our recent work has focused on understanding the role of the maternal microbiota and feto-maternal microbial crosstalk in fetal programming and offspring microbiome development. Our lab has investigated the impacts of maternal dietary restriction, supplementation of one carbon metabolites or vitamins and minerals during gestation on maternal ruminal and vaginal microbiota; as well as pre- and postnatal microbial colonization in offspring calves. Our results indicate that maternal dietary alterations during pregnancy may influence ruminal and vaginal microbiota of dams, which may subsequently impact early life microbial colonization in calves being gestated. Our findings call for further research in the area of maternal gut and reproductive microbiome alterations and their impacts on fetal programming and offspring development in ruminants.
17 The Rumen Microbiome: Realizing the Potential for Mediating Host Performance
Authors: Cunningham-Hollinger Hannah C
Published: November 2023

The rumen microbiome has a critical role in multiple facets of ruminant livestock production. It is well known that the rumen microbiome is integral to animal performance through impacts on feed efficiency, greenhouse gas production, volatile fatty acid production, and numerous aspects of animal health. Therefore, understanding factors that influence the rumen microbiome at various stages of the production cycle and the interactions with other microbial niches and physiological processes is a critical area of research to aid in the goal of improving livestock performance. Our research objectives have focused on 3 primary general areas including 1) to characterize and understand the potential pathways of early gut colonization from conception throughout gestation, 2) implications of varying gestational perturbations on rumen microbiome development and calf performance post-weaning, and 3) understand the connections between the rumen microbiome and the microbiomes of the reproductive tract, blood, and respiratory tract. We hypothesize that strategies to program the rumen microbiome early in life may have lasting impacts on host performance specific to feed efficiency, reproductive fitness, and have implications on high altitude disease. These effects may not be a direct relationship between the rumen microbiome and host response, but rather through a total system level response that has the rumen microbiome as a key player in that cascade. The rumen microbiome has the potential to impact numerous aspects of host performance, as such, it is imperative that research continues to elucidate its role in host physiology and the development of intervention mechanisms to initiate specific responses in the rumen microbiome to improve downstream host response.
205 Level of Supplemental Fat in the Diet of Gestating Beef Cows: Effects on Cow and Calf Performance
Authors: Cornand Erika E , Larson Kathy A , Fitzsimmons Carolyn J , McKinnon John J , Lardner Herbert A
Published: November 2023

This study evaluated the effects of feeding a canola seed-based (7.2% ether extract) pellet to gestating cows on cow performance, reproductive efficiency, milk yield and composition, and calf birth weight. Seventy-two pregnant, multiparous cows were allocated to 12 pens in a completely randomized block design. Body weight (BW; 605 ± 35 kg) was utilized as the blocking criteria. Diets were formulated to be isonitrogenous (CP: 8.20 ± 0.24% and 9.07 ± 0.05% second and third trimesters, respectively) and isocaloric (TDN: 58.29 ± 0.24% and 60.50 ± 0.04% second and third trimesters, respectively), and to meet NASEM (2016) nutrient requirements for pregnant beef cattle. Pens were randomly assigned to three replicated (n = 4) dietary treatments: 0 (CON), 150 (LOW), and 300 (HIGH) g of fat/d (DM basis). Dietary treatments were fed from 148 ± 8 d prepartum until at least 50% of all cows had calved, then switched to a common lactation diet. Body condition score (BCS), BW and subcutaneous fat thickness were measured at the start (SOT) and end of trial (EOT), and at 21 and 42 d postpartum. Orthogonal contrasts were used to assess linear and quadratic relationships between fat inclusion and dependent variables. At SOT, there were no differences (P ≥ 0.73) in conceptus corrected BW (597 ± 34 kg) or (P ≥ 0.13) BCS (2.85 ± 0.12, Canadian System: 1 to 5). After 84 d on trial (64 ± 8 d prepartum), conceptus corrected average daily gain (ADG) increased linearly (P = 0.04) as fat inclusion increased. After 151 d of supplementation (EOT), conceptus corrected ADG and subcutaneous fat thickness did not differ (P ≥ 0.71 and 0.63, respectively). BCS change from SOT to EOT increased, while EOT to 21 d postpartum decreased quadratically as fat inclusion increased (P = 0.02 and 0.01, respectively). Female calf birth weight decreased quadratically (P = 0.01) as fat inclusion increased, but there was no effect (P ≥ 0.75) on male calf birth weight. As fat inclusion increased, lactose concentration in milk decreased linearly (P = 0.04). As days in milk (DIM) increased, milk protein, total solids, and milk energy yield decreased (P ≤ 0.05). Milk urea-N tended to increase (P = 0.07), while 12 h milk yield (P = 0.05) tended to decrease as DIM increased. Milk fat and energy were not affected by fat inclusion, day, or the interaction between fat inclusion and day (P ≥ 0.16). There was a quadratic tendency for fat inclusion to affect pregnancy rate (P = 0.09), being maximized on LOW treatment. These results suggest that increasing fat inclusion during mid-to-late gestation tended to improve cow reproductive efficiency. Further investigation is required to determine the optimal level of fat inclusion from canola seed.
204 Evaluation of the Chemical Composition and Animal Performance of Intermediate Wheatgrass (Thinopyrum intermedium) Regrowth for Potential Fall Grazing of Beef Cattle
Authors: Chan Ekoria , Ominski Kim H , Cattani Douglas J , Crow Gary , McGeough Emma J J
Published: November 2023

This study assessed forage yield and chemical composition, feed intake, and performance of beef heifers grazing intermediate wheatgrass (IWG) regrowth post-grain harvest compared with a stockpiled grass/legume control in the late fall. Pastures were established in 2020 at Glenlea, MB, Canada and treatments were: 1) Courtenay tall fescue/Algonquin alfalfa/Oxley II cicer milkvetch (50:25:25; FORCON); 2) IWG, pure stand, no fertilizer post establishment (NFERT); 3) IWG, pure stand+50 kg N· ha-1 post-grain harvest (FERT); 4) IWG with Alsike clover (50:50; AL). The FORCON and IWG treatments were harvested in June (hay) and August (grain) 2021, respectively. Thirty-two beef heifers were assigned to eight paddocks, four heifers per paddock in a randomized complete block design with two blocks. Each block had four paddocks, each paddock receiving one of the four treatments. Heifers began grazing on Oct 6 for a 14-d adaptation period and a 22-d experimental period. Forage samples were obtained once every 2 weeks and analyzed for CP and TDN. Individual feed intake was estimated using the titanium oxide method with fecal samples collected on d 21 and 22 and pooled. Bodyweight and blood samples (blood urea nitrogen, BUN) were obtained on d 1 and d 22. Data were analyzed using a mixed model in R studio, with the fixed effect of forage treatment and the random effects of block and paddock. Forage yield and CP were greater for FORCON (3,515 kg· ha-1 and 14.9% DM, respectively) than the IWG treatments (mean 2778 kg· ha-1 and 12.83% DM, respectively), which did not differ (P < 0.0001 and P = 0.150, respectively). The TDN was less for FORCON (60.6% DM) than IWG treatments (mean 61.5% DM), which did not differ (P = 0.394). Dry matter, CP and TDN intake were lower for FORCON (7.91 kg· DM d-1, 1.15 kg· DM d-1, 4.98 kg· DM d-1, respectively) than IWG treatments (mean 8.54 kg· DM d-1, 1.16 kg· DM d-1, 5.44 kg DM d-1), which did not differ (P = 0.237, P = 0.218, P = 0.137, respectively). The ADG was less for FORCON (0.53 kg· d-1) than IWG treatments (mean 0.77 kg· d-1), with the greatest gains observed in IWG AL (0.90 kg d-1; P = 0.046). Blood urea nitrogen was greater for FORCON (3.95 mmol· L-1) than IWG treatments (mean 3.78 mmol· L-1), which did not differ (P = 0.203) on d 1. However, on d 22 the opposite response was observed with decreased BUN in FORCON (2.97 mmol ·L-1) than in IWG treatments (mean 3.51 mmol· L-1), which did not differ (P = 0.350). In conclusion, IWG offered comparable performance as a feed alternative to the conventional perennial grass/legume mix commonly used for extended grazing. However, the effects of fertilizer or legume on IWG may differ under different soil conditions due to high fertility at the experimental site.
211 Evaluation of Beef Heifer Variability in the Ability to Eat and Digest a High Forage Diet
Authors: Payne Nikita A , Penner Greg B , Lardner Herbert A , Abbott Wade , Gruninger Robert J , Ribeiro Gabriel O
Published: November 2023

This study evaluated beef heifers selected for high or low digestible fiber intake (DFI) and investigated its relationship with methane production, residual feed intake (RFI), and total tract digestibility. Sixteen recently weaned black Angus beef heifers (n = 8/treatment) were selected from a group 64 heifers (224 ± 17.2 kg) fed a high forage-based diet [70% barley silage:30% pelleted concentrate (DM basis)]. The 64 heifers were fed in 6 outdoor pens equipped with GrowSafe bunks to monitor feed intake for 60 d (14 d adaptation + 46 d for data collection). Individual fecal samples and BW, and feed samples were taken once weekly. Fecal samples were pooled by animal. Feed and fecal samples were analyzed for dry matter (DM), neutral detergent fibre (NDF), and undigested neutral detergent fiber (uNDF) content. The internal marker uNDF was used to estimate total tract diet DM and NDF digestibility. The 8 heifers with the greatest and the 8 with the least digestible NDF intake (g/kg BW0.75) were selected and used for methane measurements using the GreenFeed system (42 d) and in a total-tract digestibility trial with total fecal and urine collection using the same high forage based diet. Results from the GrowSafe selection trial indicated no differences between the average BW of low and high DFI heifers (264 vs. 274 kg, P = 0.20). Heifers selected for high DFI had greater (P < 0.01) DM and NDF intake (kg/d or % of BW), and digestibility (49.6 vs. 42.1% NDF digestibility). The heifer groups differed in RFI (P < 0.01), with high DFI categorized as inefficient (+0.84 RFI) and low DFI as efficient (-0.34 RFI). No differences in ADG were observed between low and high DFI heifers during this short 46 d study period (0.614 vs 0.773, P = 0.16). High DFI heifers had lower methane production than low DFI heifers (15.9 vs. 19.0 g/kg of DMI, P = 0.02). The results of the total-tract digestibility trial showed that the high DFI heifers had a greater DMI compared with the low DFI heifers (10.9 vs. 10.2 kg/d; P = 0.04). The DMI intake was not different between groups when expressed as a % of BW (2.06 vs 2.04, P = 0.65). There was also no difference observed for DM digestibility (73.0 vs 73.1%) between the two groups. It is important to note that in the digestibility study, the DMI was less than in the GrowSafe selection trial (2.5 vs 3.2% BW) and this may have influenced results. Heifers with high DFI were heavier than low DFI heifers (533 vs. 505, P = 0.02) during the digestibility trial. Results suggest that selecting heifers for high DFI may increase growth rate and reduce methane production.
213 Effect of Continuous Or Intermittent Feeding of Ergot Contaminated Grain in a Mash Or Pelleted Form on the Performance and Health Parameters of Finishing Beef Steers
Authors: Reynolds Matthew R , Stanford Kim , Meléndez Daniela M , Schwartzkopf-Genswein Karen S , McAllister Tim A , Blakley Barry R , McKinnon John J , Ribeiro Gabriel O
Published: November 2023

This study evaluated the effect of feeding pelleted or mash ergot contaminated grain fed continuously or intermittently on the growth performance, blood serum variables, and carcass quality of finishing beef steers. Sixty black angus steers (442 ± 36.7 kg) were used in a complete randomized finishing (90% concentrate:10% barley silage DM basis) 126-d study. Steers were randomly assigned to 4 different treatments and individually housed. Treatments included: 1) control ration [CON; no added ergot alkaloids (EA)], 2) continuous ergot mash (CEM; fed continuously at 2 ppm total EA), 3) intermittent ergot mash (IEM; fed at 2 ppm EA during the first week of each 21-d period and control diet for the remaining 2 weeks), and 4) intermittent ergot pellet (IEP; fed at 2 ppm EA incorporated into a pelleted supplement during the first week of each 21-d period and control diet for the other 2 weeks). Steers were weighed every 21 d and blood samples were collected on day 0, 42, 84, and 126. Steer DMI (P < 0.01, 9.95 vs. 11.05 kg/day) and ADG (P = 0.04) decreased for all EA treatments compared with the CON. Total shrunk BW gain (P = 0.03, 202.5 vs. 225.2 kg), final BW (P = 0.03, 617.9 vs. 662.2 kg), and carcass weight (P = 0.06) decreased for all EA steers compared with the CON steers. No treatment effects (P > 0.05) were observed for carcass dressing percentage, ribeye area, marbling score, or liver abscess. The percent of carcasses graded AAA decreased for all EA steers compared CON steers (P < 0.01, 46.7 vs. 93.3%). Steers fed EA had increased rectal temperature compared with CON steers (P < 0.01, 39.8 vs. 39.4 °C). Hair cortisol concentrations were less in steers fed IEP (P = 0.05, 1.23 vs. 1.76 pg/mg) than CON. No treatment effects (P > 0.05) were observed for complete blood count, and serum prolactin, haptoglobin, albumin, alkaline phosphatase, alanine transaminase, amylase, calcium, creatine, glucose, lipase, total bilirubin, total protein, or globulin. Blood urea nitrogen was less for EA steers compared with CON (P = 0.01, 3.48 vs. 4.10 mmol/L). The IEM steers had decreased concentrations of serum gamma-glutamyl transferase compared with IEP steers (P = 0.04, 23.4 vs. 28.5 IU). Pelleting ergot contaminated grain did not reduce the impact of ergot alkaloids on any of the measured parameters. Results suggest that continuously or intermittently feeding an ergot contaminated diet (2 ppm EA) can significantly reduce intake, growth performance, and carcass weight, with minimal impact on blood serum variables in finishing steers. Pelleting was not an effective method of reducing ergot toxicity.
221 Increasing Functional Amino Acid Ratios Does Not Improve Growth Performance in Pigs Raised Under Poor Sanitary Conditions When Fed with Individual Precision Feeding Or Conventional Feeding Systems
Authors: Arnaut Pedro Righetti , Hauschild Luciano , Remus Aline , Pomar Candido , Gastman Brand Henrique G , Khun Kyaw Htoo John K
Published: November 2023

Immune system activation redirects dietary nutrients to defense mechanisms, thereby impairing growth performance of pigs. Supplementing pigs with functional amino acids (AA) such as Met, Thr and Trp was shown to support the immune system and reduce the negative effects on growth. However, pigs respond differently to immune stressors which increase herd variability. In this context, individual precision feeding (IPF) might be an alternative approach to reduce herd variability and increase nutrient efficiency in immune challenged pigs. This study aimed to evaluate growth performance, body composition, nitrogen (N) efficiency and haptoglobin and triglycerides serum concentration in growing pigs raised in poor sanitary conditions (PoorSC). The PoorSC was characterized by oral inoculation with 2 × 109 cfu of Salmonella typhimurium and manure spreading on the pen floor. Sixty gilts (23 ± 2.8 kg BW) were distributed in BW blocks according to a 2 dietary (D) × 2 feeding system (FS) factorial arrangement composed of to 2 diets [control (CN): INRA ideal AA ratio or supplemented (AA+) 120% of the ideal ratio for Met, Thr and Trp] and 2 feeding systems [conventional (GP) or IPF]. GP pigs were fed with a unique diet that matched the SID Lys requirement of the 80th-percentile pig at the beginning of the trial whereas the IPF pigs received a diet tailored daily to each pig requirement. All pigs were housed in the same pen and fed ad libitum during 28 experimental days with automatic feeding stations able to provide to each pig the assigned diet. Body composition was obtained by dual X-ray absorptiometry at days 0 and 28 and blood samples were collected at d 28. Data were analyzed with D and FS and their interaction as main fixed factors and body weight (BW) blocks as a random effect (Table 1). Haptoglobin serum concentration increased from d 0 to 28 regardless of FS and D (P < 0.10). IPF pigs fed with CN diet had the lightest BW at the end of the trial (P ≤ 0.10; FS × D), whereas BW was similar for the other treatments. However, across diets, IPF pigs had final BW, and protein, ADG, G:F, protein and lipid deposition, N intake and excretion and circulating triglycerides that were less than GP pigs. N utilization efficiency was similar across treatments. Additionally, increasing the provision of the studied functional AA did not improve pig performance. Thus, showing no benefits in increasing AA ratios for growth and immune response. The increased triglycerides concentration and low protein and lipid deposition suggests that IPF pigs prioritized the immune system to the expense of protein and lipid accretion. In conclusion, AA supplementation and IPF do not improve growth performance and N efficiency of pigs raised in poor sanitary conditions.
223 Impacts of Active Dry Yeast (Saccharomyces cerevisiae) on Gut Permeability in Finishing Beef Cattle
Authors: Williams Melissa S , AlZahal Ousama , Steele Michael A , Wood Katharine M , Penner Greg B
Published: November 2023

The objectives of this study were to examine the impacts of active live yeast (Saccharomyces cerevisiae) as a dietary feed additive on dry matter intake, feed sorting, gut permeability, ruminal pH and volatile fatty acids (VFA) concentration, as well as fecal pH and VFA concentration in cattle fed a high-grain finishing diet and subjected to a ruminal acidotic challenge. Fifteen Hereford X Charolais heifers were blocked by BW into three blocks. Heifers were randomly assigned within block to one of two dietary treatments; CON (no additive), or YST (3 g· animal-1· day-1 of active live S. cerevisiae) added to a steam-flaked corn diet (83% steam-flaked corn, 8% wheat straw, 5% soybean meal protein mix, 4% vitamin and minerals on a DM basis). The experimental timeline was as follows: 30 d adaptation (ADPT), 5 d baseline (BASE), 5 d ruminal acidosis challenge (CHAL), and three subsequent 5 d recovery phases (REC1, REC2, and REC3). On day 2 of each phase and days 2 and 4 of CHAL, 179 mM Cr-EDTA and 360 mM Co-EDTA were infused into the omasum and rumen, respectively, as gut permeability markers. Within each phase, in-dwelling pH probes were used to capture reticulo-ruminal pH every 5min for 96 consecutive hours, rumen fluid and fecal grab samples were collected once for every 3 h in a 24 h period, and blood was collected at 2, 4, 12, and 24 h after each Co and Cr infusion. Dry matter intake and feed sorting were measured daily for each animal. Statistical analysis was conducted using PROC GLIMMIX in SAS as a randomized complete block design with block, treatment, and phase as fixed effects and animal as a random effect. Ruminal acidosis was successfully induced using this method, as suggested by the statistically significant reduction in minimum pH and increase in pH range in the CHAL phase compared with other phases of the experiment (P ≤ 0.02). Recovery from the ruminal acidosis challenge was detected within the REC1 phase when comparing minimum pH (CHAL 5.25 vs. REC1 5.54; P = 0.001). Additionally, the sorting behavior of some particle sizes was significantly impacted by phase (P ≤ 0.01). Overall, the addition of yeast to the diet did not impact feed intake, sorting behavior, spot ruminal and fecal pH, volatile fatty acid concentrations in ruminal fluid or feces, or the uptake of Cr-EDTA and Co-EDTA. These results suggest that adding live S. cerevisiae yeast at this dose in a high-grain finishing diet does not impact feed intake, gut permeability, or the production of VFA when ruminal acidosis is induced.
64 Digital Technologies and Machine Learning: a New Way to Look at Novel Traits at Spatial and Temporal Dimensions
Authors: Rosa Guilherme J M , Dorea Joao R R , Hernandez Laura
Published: November 2023

Accurate measurement of target traits in individual animals or groups of animals under different environmental conditions, such as varying diets, disease treatments, and management practices, is crucial for the progress of livestock research. While experimental studies on research farms ensure internal validity of results, observational studies on commercial farms provide external validity, i.e. how such results generalize to commercial settings. Both types of studies require longitudinal follow-up of animals and individual identification for monitoring their well-being, as well as their performance in terms of production, reproduction, and disease traits. Advances in digital technologies, including wearables and remote sensors, coupled with efficient data management and data mining techniques, now allow for accurate monitoring of animals and their environment in both spatial and temporal dimensions. These technologies enable investigations of novel traits such as traits related to product quality, animal behavior and welfare, individual feed intake, and gas emissions. This presentation will highlight our research efforts in developing and adapting tools and methods for livestock applications, including specific research projects that implement such tools. For instance, we will discuss a case study aiming to predict dairy cows’ future performance based on their growth and mammary gland development during calf-heifer stages.
226 Measuring Agricultural Means of Influence on Young Adults Via Instagram in the United States
Authors: Coursen Madison , Corbitt Katie , Bennett Samantha , Martin David , Sawyer Jason T , Mulvaney Donald
Published: November 2023

The way society consumes information has changed drastically, and the agricultural industry is fighting to remain a part of the media landscape. With the gradual death of print news and the rise of social media (SM) consumption by young adults (Twenge et al., 2019), this leaves the questions of where do young consumers get new information and how do pro-agriculture voices successfully communicate scientific agricultural topics with them? With extremist activist voices on Instagram gripping the attentions of young adult SM users, opposing voices of influence sharing scientific and pro-agriculture messages seem to be missing. Social media influencers (SMIs), of which can be found on the SM platform Instagram, serve as “third party endorsers” who impact the feelings and opinions of audiences such as young consumers or SM users through content shared on SM. We sought to perform an evaluation of the impact established agricultural SMIs on Instagram can have on changing the perceived knowledge of participants regarding several different agricultural topics. Participants were recruited through the platform ProlificTM and were asked to complete an anonymous survey. Survey questions were asked both prior to participants being shown example images of agricultural SMIs and afterwards. Data collected were analyzed utilizing SPSS to compare pre-image and post-image results to determine the impact of contents on perceived knowledge participants on subjects relating to agriculture. Results indicated significant differences (P < .05) between the pre-image and post-image perceived knowledge results, as well as between different forms of reported engagement willingness. Future research should be conducted to determine what forms of content best reach nonagricultural target audience members and best practices for interacting on SM with those users.
424 Botanical Composition and Quality of Beef Cattle Diets on a Burned Versus Unburned Foothills Rangeland
Authors: Kluth Janessa A , Davis Noah , Wyffels Sam , Marlow Clayton , Vermeire Lance , Van Emon Megan L , Nack Makae , Sitz Taylre , Hamilton Thomas , Peterson Jeremiah , DelCurto Timothy
Published: November 2023

Current management paradigms suggest deferring grazing rangeland for two years after a wildfire to avoid additional stress on native plant species, but there is limited research supporting these recommendations. Therefore, this experiment was conducted within and adjacent to a burn area of an August 2020 wildfire to evaluate the differences in diet quality, botanical composition, and foraging efficiency of beef cattle grazing both burned and unburned rangelands. A randomized complete block design with a 2×2 factorial arrangement of treatments contrasting burn versus unburned and June versus September grazing periods were used. Pastures (4 ha) within the burn area were grazed in either June 2021 or deferred to September 2021. Grazing occurred for two days with 20 cow/calf pairs in June and 16 cow/calf pairs in September. Cattle diet composition and masticate samples were collected during 20-minute bite-count periods using six ruminally cannulated cows in each pasture prior to and after the two-day grazing periods. Cannulated cows grazed a pasture adjacent to the burn area to compare diet quality and composition between burned and unburned rangeland. Diet composition displayed a burn treatment by season of use interaction (P < 0.01) with greater forb consumption in burned than unburned in June (P < 0.01), but not different in September (P = 0.58). Additionally, both bites per minute and grams per minute displayed a treatment by season of use interaction (P < 0.01). Specifically, cattle grazing unburned pastures in June tended to take more bites per minute (P = 0.07) than in burned pastures. In contrast, the opposite was observed with September diets where cattle took more bites per minute in burned pastures than unburned pastures (P < 0.01). Grams per minute did not differ between September treatments (P = 0.26), but cattle did consume more grams per minute in unburned pastures in June (P < 0.01). The ash content of diets tended to display a treatment by season of use interaction (P = 0.09) with dietary ash tending to be greater in burned pastures in June (P = 0.07), but not differing in September (P = 0.54). Both dietary NDF and CP displayed a treatment by season interaction (P < 0.01), where crude protein was greater and NDF was lower for June burned pastures than unburned pastures (P < 0.01) but did not differ in September (P ≥ 0.27). In summary, diet quality was improved for grazing during the growing season after wildfire. The differences in diet quality may be related to the increase in forb consumption in post-fire vegetation communities.
421 Inherent Livestock Feed Production: Abundance of Non-Edible Biomass in the Agricultural and Processing Sector in Germany
Authors: Vorndran Anton M , Steinhoff-Wagner Julia , Windisch Wilhelm
Published: November 2023

Livestock have a central role in food production as extractors and concentrators of nutrients from non-edible biomass [neB] producing high value foodstuff for human nutrition [1]. Agricultural production aims for maximizing edible biomass [eB] production whereby, neB production is inevitably coupled to it. The goal of this study was to determine how much neB and eB is produced annually in agricultural and processing sector in Germany. Literature research has been conducted (26 peer-reviewed publications, 15 books, 26 reports, 15 other grey literature) to identify the amount of eB and neB along the agricultural production chain in Germany. Therefore, conversion efficiencies of biomass from field to fork have been calculated on a dry matter basis by considering main- to by-product ratios on the field as well as processing efficiencies for food and renewable energy industry branches (e.g., milling, ethanol production, brewing, oil extraction, starch extraction, sugar extraction). Based upon these calculations, the human edible fraction (HeF) [2] was used together with mean agricultural production data (2012-17) in Germany to determine the abundance of eB and neB for two scenarios: low vs. high edibility of biomass. Since HeF factors denote theoretical margins of edibility of biomass, additional scenarios were calculated assuming current processing efficiencies as well as silage maize being completely inedible. Furthermore, changes in biomass production in scenarios of complete substitution of land used for silage maize production and cultivation of human edible foods have been analysed.115 to 134 million tons of neB and 38 to 57 million tons of eB were produced annually during the observation period. This equals 2-3.5 kg of neB per kg of eB. When silage maize was considered as neB, numbers increased to 2.5 to -4.8 kg of neB per kg of eB. When current processing efficiencies in Germany and grain usage were used for calculations instead of the two HeF scenarios, and silage maize was considered not edible, then 1kg of eB produced 4kg of neB. When the used area for silage maize cultivation would in future be substituted for food crop cultivation then 1kg of eB yielded 2.8kg of neB. The scenarios suggest that the amount of eB per acre of agricultural land changes dramatically once the whole agricultural system including grassland, green plants for feed production, straw, and by-products is adapted to future scenarios. The future challenge will be to improve current processing efficiencies of the food and renewable energy industry to approach the upper limits of edibility given by the HeF fractions. In any case, feed production is inherent.[1] Bradford et al. (1999) Ames, IA (Task force report / Council for Agricultural Science and Technology, 135) ISBN 1-887383-17-4[2] Ertl et al. (2015) In: Agricultural Systems 137, S. 119–125. DOI: 10.1016/j.agsy.2015.04.004.
235 Effects of Curing Extent on the Phytoestrogen Concentrations of Red Clover Hay and Silage Across Storage Phases
Authors: Ayala Diego Zamudio , Lima Marta , De Castro Raphaella Alexandra , Jimenez Ana Paula , Cardoso Marcus , Knight Colt W , Romero Juan Jose J
Published: November 2023

Our objective was to assess the effects of insufficient (WET) or ample (CUR) curing on the phytoestrogen concentrations of red clover silage (29.4 and 45.3% DM) and hay (65.1 and 89.1, respectively). Measurements were taken at the start of storage (STRT), after 14 d (MicA), and once storage processes had stabilized for hay and silage (50 and 78 d, respectively; LATE). Hay was packed into mini-bales (~500 fresh g; ~232 kg DM/m3) and silage into mini-silos (19.5 L; ~214 kg DM/m3). Data were analyzed as a randomized complete block design (5 blocks) with a 2 (curing extents) x 2 (storage methods) x 3 (storage phases) factorial. Differences were declared at P ≤ 0.05. The concentration of formononetin was greater in silage vs. hay at STRT (4,624 vs. 2,893 ± 175 mg/kg of DM, respectively), MicA (5,383 vs. 2,110), and LATE (5,666 vs. 2,569). Also, more formononetin was found in WET vs. CUR silage (5,841 vs. 4,608.1± 154 mg/kg of DM, respectively). However, no differences were observed between WET vs. CUR hay (x̅ = 2,524). At STRT, biochanin A was greater in silage vs. hay (3,105 vs. 2,012 ± 139 mg/kg of DM, respectively). A similar trend was observed at MicA (3,233 vs. 1,057), and LATE (3,295 vs. 1,228). In addition, more biochanin A was observed in WET vs. CUR silage (3,793 vs. 2,628.9 ± 127 mg/kg of DM, respectively). The opposite was observed in WET vs. CUR hay (1,219.5 vs. 1,644.9). The genistein concentration was greater in silage vs. hay at STRT (149 vs. 120 ± 8.36 mg/kg of DM, respectively), MicA (246 vs. 62.6), and LATE (264 vs. 72.9). Also, the concentration of genistein was greater in WET vs. CUR silage (236 vs. 202.3 ± 7.21 mg/kg of DM, respectively) but the opposite was observed in WET vs. CUR hay (72.8 vs. 97.3). In the case of daidzein, hay had a greater concentration of this phytoestrogen than silage (12.8 vs. 6.67 ± 0.43 mg/kg of DM, respectively). In conclusion, red clover silage maintains greater concentrations of formononetin, biochanin A, and genistein than hay during curing period and across the storage phase. Also, adequate curing is more beneficial for silage than hay in terms of decreasing the phytoestrogen concentrations.
241 Increased Inflammatory Tone and Impaired Skeletal Muscle Growth in Intrauterine Growth-Restricted Neonatal Lambs Is Improved By Daily Supplementation of ω-3 Polyunsaturated Fatty Acid Ca2+ Salts
Authors: White Melanie R , Gibbs Rachel L , Grijalva Pablo Cesar C , Hicks Zena M , Beer Haley N , Most Micah S , Schmidt Ty B B , Peterson Jessica L L , Yates Dustin T
Published: November 2023

Low birthweight due to fetal intrauterine growth restriction (IUGR) often results from maternofetal heat stress. IUGR fetuses exhibit enhanced inflammatory tone, which persists after birth and impacts body composition, skeletal muscle growth, and metabolic function. Therefore, our objective was to determine whether daily oral supplementation of Ca2+ salts of ω-3 polyunsaturated fatty acids (ω-3 PUFA) to IUGR-born neonatal lambs improved inflammatory tone, body composition, and growth metrics. Pregnant ewes were exposed to heat stress (40°C, 35% humidity, THI = 85) from d 40 to 95 of gestation to induce IUGR. Lambs were weaned at birth and hand-reared on milk replacer. Daily oral boluses of 0.5 mL molasses containing 0 or 0.42 g/kg bodyweight of ω-3 PUFA (Virtus Nutrition) were administered. Femoral catheters were placed at d 24 and lambs were necropsied at d 30. At birth, IUGR lambs (n = 8; 3.12 ± 0.34 kg) and IUGR+ω-3 lambs (n = 7; 3.67 ± 0.32 kg) were lighter (P < 0.05) than controls (n = 12; 4.28 ± 0.15 kg). Plasma TNFα concentrations were greater (P < 0.05) at birth for IUGR (557 ± 121 pg/mL) and IUGR+ω-3 lambs (437 ± 82 pg/mL) than for controls (213 ± 78 pg/mL). Plasma TNFα concentrations remained increased (P < 0.05) for IUGR lambs but not for IUGR+ω-3 compared with controls at 2, 3, and 4 wk of age. Adjusted 30-d bodyweights were lighter (P < 0.05) for IUGR lambs (9.83 ± 0.6 kg) but not for IUGR+ω-3 lambs (11.59 ± 0.4 kg) than for controls (12.35 ± 0.2 kg). Heart and brain weights were 17% and 6% lighter (P < 0.05), respectively, for IUGR lambs than for controls. Brain weight deficits were resolved in IUGR+ω3 lambs, but heart weights did not differ between IUGR and IUGR+ω-3 IUGR lambs. Crown circumference/ bodyweight, abdominal circumference/ bodyweight, and cannon bone length/ bodyweight (indicators of asymmetric body composition) were 11% to 15% greater (P < 0.05) for IUGR lambs than for IUGR+ω-3 lambs or controls. At necropsy, IUGR lambs had lighter (P < 0.05) whole hindlimbs (29%) and flexor digitorum superficialis (24%), soleus (36%), biceps femoris (25%), semitendinosus (24%), gastrocnemius (29%), and longissimus dorsi (26%) muscles compared with controls. Weight deficits were partially or fully resolved in IUGR+ω-3 lambs for whole hindlimbs and for all muscles but the soleus, which did not differ from IUGR lambs. These findings demonstrate that daily oral supplementation of Ca2+ salts of ω-3 PUFA reduced the enhanced inflammatory tone observed in IUGR-born offspring, which coincided with improved skeletal muscle growth and indicators of symmetrical body composition.