bluuebunny/crossref_metadata_2025_split huggingface dataset:
42 Environmental Impacts of Improving Forage Use Efficiency in Beef Cattle
Authors: DiLorenzo Nicolas 
Published: November 2023

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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 &lt; 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

Abstract
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 &lt; 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 &lt; 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

Abstract
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 &lt; 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 &gt; 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 &lt; 0.01, 46.7 vs. 93.3%). Steers fed EA had increased rectal temperature compared with CON steers (P &lt; 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 &gt; 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.