Abstract The role of animal-sourced foods (ASF) in healthy human diets is increasingly scrutinized. The objective of this study was to explore how diets varying in protein content and protein source (ASF vs substitutes) varied in their ability to support balanced dietary nutrient profiles. Data on nutritional composition of foods were obtained from USDA FoodData Central. Foods were categorized as meats and meat substitutes (types included: Lamb, veal, and game products; finfish and shellfish products; pork products; legumes and legume products; nuts and seed products; beef products) or other dietary components (types included: vegetables and vegetable products; fruits and fruit juices; cereal grains and pasta; dairy and egg products). A total of 3,855 foods were considered. From these foods, 500,000 dietary scenarios were generated. Adapted from the Dietary Guidelines for Americans serving recommendations, each scenario consisted of 3 servings of vegetables, 2 servings of fruits, 2 servings of meats or meat substitutes, 2 servings of grains, and 2 servings of dairy/eggs. The specific food items to meet these serving targets were randomly selected in each scenario from the full set of foods within each respective category. In each scenario, the expected food intake and dietary composition of energy and nutrients was calculated and evaluated relative to the nutrient requirements of an adult human. Data were analyzed using Bayesian networks trained for each nutrient of interest based on the simulated scenario results. Nodes included binary categorical variables reflecting the inclusion of different meat or meat substitute types, continuous variables reflecting the amount of food consumed, the protein as a percent of energy intake, and a binary response variable reflecting the adequacy of diet for the nutrient of interest. For each network, the conditional probabilities of the diet being adequate given use of each meat or meat substitute type and low (protein < 18.5% of energy intake), moderate (protein 18.5 to 26.6% of energy intake) or high (protein >26.6% of energy intake) protein levels were calculated. The inclusion of meats in the diet increased the probability of adequate intake of essential amino acids, iron, zinc, vitamin B12 and B6, particularly in diets with low protein as a percent of energy. The inclusion of meat substitutes supported adequate intake of fiber, linoleic acid, magnesium, potassium, and folate, showing high complementarity with meats. These data reinforce the nutritional complementarity of meat and meat substitutes, and suggest that protein source is less impactful on nutrient adequacy when diets are high in protein.

Abstract Weaning stress in piglets poses a significant challenge to the swine industry, often leading to compromised intestinal health, reduced feed intake, diarrhea, and increased mortality. Although antibiotics and pharmacological doses of zinc oxide have traditionally been used to alleviate these issues, rising concerns over antimicrobial resistance and environmental sustainability have driven the search for effective alternatives. The purpose of this study was to evaluate the effects of plant essential oils (PEO) as dietary supplements in a low-zinc, antibiotic-free diet on the growth performance, blood parameters, and intestinal health of weaned piglets. A total of 100 weaned piglets (7.90 ± 0.2 kg) were randomly assigned to five dietary treatments: ZnO, 0PEO, 30PEO, 60PEO, and 120PEO. Each treatment included four replicates of five piglets. The ZnO group received a basal diet (65 mg/kg Zn) supplemented with 1600 mg/kg zinc oxide from d 1 to 14 post-weaning. The 0PEO, 30PEO, 60PEO, and 120PEO groups received the basal diet with 0, 30, 60, and 120 mg/kg PEO, respectively. On d 28, one piglet per replicate with a body weight (BW) closest to the treatment average was selected and euthanized for sampling of duodenum, jejunum, and ileum tissue and colonic digesta (n = 4). Parameters included growth, serum indices, intestinal morphology, colonic volatile fatty acid (VFA), and colonic microbiota. Data were analyzed using SAS 9.4 (Cary, NC, USA). Polynomial contrasts were used to test the linear and quadratic effects of increasing PEO levels. A pre-planned contrast was used to compare the ZnO and 0PEO groups. Results showed a quadratic effect (P < 0.05) of PEO supplementation on hemoglobin concentration, with the predicted peak at 53 mg/kg. Villus height and the villus-to-crypt ratio in the duodenum, jejunum, and ileum increased linearly (P < 0.05) with PEO levels. Colonic VFA concentrations, including total VFAs, acetic, propionic, butyric, and valeric acids, were significantly affected by PEO in both linear and quadratic (P < 0.05) manners, with 52 mg/kg achieving total VFAs levels equivalent to the ZnO group. Additionally, colonic microbiota alpha diversity responded quadratically (P < 0.05) to PEO concentrations. In terms of growth performance, piglets in the 0PEO group had lower (P < 0.05) BW than those in the ZnO group by d 28. PEO supplementation showed a quadratic tendency (P = 0.055) on BW, with the highest estimated value at 69 mg/kg, comparable to that of the ZnO group. Although regression analyses identified slightly varying optimal PEO concentrations for different parameters, the 60 mg/kg level consistently improved multiple indicators. In conclusion, dietary supplementation with 60 mg/kg of PEO improved intestinal morphology, microbial fermentation, and growth performance, suggesting its potential as a natural alternative to pharmacological ZnO in antibiotic-free diets for weaned piglets.

Abstract Breeding for improved sow longevity will contribute to directly improving animal welfare, production efficiency, and environmental sustainability in the swine industry. Sow longevity is a complex trait that can be defined by different indicators, including length of productive life (LPL), removal age (RA), and removal parity (RP). Genetic selection for improved sow longevity is also more challenging due to the time taken for obtaining the phenotypic measurements for each animal, censored nature of the records due to voluntary culling, and potential genotype-by-environment interactions between nucleus and commercial farm conditions. Therefore, the primary objectives of this study were to estimate variance components and genetic parameters for LPL, RA, and RP in purebred and crossbred pig populations incorporating genomic information in the analyses. Data from 26,441 sows were analyzed, including 14,787 Landrace and 11,654 Landrace x Large White crossbreed sows. Pedigree and genotype data were incorporated into the analyses, including information from 5,378,363 animals in the pedigree and 22,925 genotyped animals. Variance components and genetic parameters were estimated using the Restricted Maximum Likelihood (REML) method implemented in the BLUPF90+ software. The fixed effects included in the models were contemporary group (concatenation of herd, season, and year of birth) and age at first parity as a linear covariate. For the analyses combining purebred and crossbred animals, line was also added as a fixed effect. The average (SD) LPL was 242.10 (242.22) days for Landrace and 352.56 (289.29) days for the crossbred sows, with maximum values of 1,592 and 1,258 days, respectively. The average (SD) RA was 587.50 (241.89) days for Landrace and 674.60 (291.78) days for the crossbred sows. A total of 81.32% of the sows, considering both purebred and crossbred animals, were removed by the fourth parity. The heritability estimates for the Landrace sows were 0.20 (0.02) for LPL and RA, and 0.22 (0.02) for RP. For the crossbred population, the heritability estimates were 0.11 (0.02) for all three traits. For the complete dataset (i.e., combining both lines), the heritability (SE) estimates were 0.28 (0.02) for LPL and RA, and 0.30 (0.02) for RP and the genetic correlation between LPL and RP, as well as between RA and RP, was 0.99 (0.0003). The observed heritability estimates suggest that genetic selection can effectively improve sow longevity. Additionally, the high genetic correlation (0.99) between them indicates that these traits are essentially the same from a genetic perspective. This suggests that only one of them may be needed as selection criteria.

Abstract The United Nations defines a circular economy as one where markets encourage the reuse of products instead of discarding them and sourcing new materials. As a result, assessing waste by-products (‘opportunity feeds’) as part of beef cattle diets become an essential strategy to achieve sustainability in the global beef chain. In this context, we examined the incorporation of various by-products commonly utilized in Brazilian beef production by replacing high moisture corn (high and low energy diets). A total of 1,781 24-month-old Nellore bulls [382.3 ± 22.6 kg of body weight (BW; mean ± SD)] were assigned to 32 open dry lot pens (n=55/pen; 16 pens/treatment) in a complete block design (4 blocks set by initial BW) with ad libitum access to feed and water. The experimental feeding program consisted of adaptation (16 d), growing (27 d), and finishing phases (66 to 76 d). The treatments consisted of 2 levels of energy: Normal and Low energy (reduction of 18.4, 16.7, and 15.1 %, for adaptation, growing, and finishing diets, respectively). Diets were formulated to provide nutrients for an ADG of at least 1.5 kg, according to the LRNS. The energy level was modulated by replacing high moisture corn by sugar cane bagasse, citrus pulp, and soybean hulls. Dry matter intake was evaluated in a pen approach (considering 1-2% of feed refusals) as well as BW and all derivations index created by combining these variables. Initial carcass weight (used in the carcass gain and carcass feed conversion), was estimated by considering 50% of dressing. All statistical analyses were performed using SAS version 9.4 (SAS Institute Inc.) considering pen as experimental unit. Low energy diets reduced final BW (574.6 vs. 571.3 kg; P = 0.03) and ADG (1.517 vs. 1.491 kg/d; P = 0.03) while increased dry matter intake during the finishing phase (12.09 vs. 10.76 kg/d; P< 0.0001). This finding was reflected in lower feed efficiency of LE diets compared to NE diets (0.137 vs. 0.125; P< 0.0001) throughout the entire feedlot period. In addition, as expected, hot carcass weight (P < 0.0001), carcass feed conversion (P < 0.0001), and dressing percentage (P < 0.0001) were compromised in LE diets compared to NE diets. In conclusion, reducing the energy provided by starch feedstuffs, as seen in this study by replacing high-moisture corn with sugar cane bagasse, citrus pulp, and soybean hulls, should be approached carefully, as it may lead to decreased performance and feed efficiency. However, it depends on the input costs and market conditions of each operation.

Abstract Real-time detection of calving is critical for proper reproduction management, as it may allow for assistance with dystocia and/or prevention of peripartum mortality. GNSS tracking has been used to monitor the ethological changes associated with calving in free-ranging cows, allowing its automatic detection (García García et al., 2023). A complementary approach to GNSS tracking is to identify patterns of calving site selection, which may allow the identification of areas where calving cows are most likely to be found. The aim of this study was to identify common patterns in the characteristics of the sites selected by cows during calving in relation to the sites selected by non-calving herdmates. Thirty-four cows from three farms were fitted with commercial GNSS collars (Digitanimal Ltd.) during the peripartum period. Calving sites were defined as the GNSS coordinates of cows on the day of calving while isolated from herdmates. Grazing land within each paddock was classified according to distance to water (< 25 m, 25-100 m, and >100 m), geomorphology (Jasiewicz and Stepinski, 2013) and canopy cover (< 10%, 10-20%, 20-40% and >40%) using digital elevation models and orthophotographs. For each land category, Jacobs’ selection indices (JSI) were calculated from the GNSS positions. The difference between the JSI of the calving cow and the JSI of her herdmates during the same period was used as an indicator of site preference (positive values) or rejection (negative values). Data processing and calculations were carried out using the open-source software R. Calving cows showed a greater preference for areas further away from water sources (> 100 m) than their herdmates on the three farms (JSI difference between +0.24 and +0.77). Conversely, they rejected areas close to water (25 to 100 m), with JSI differences ranging from -0.24 to -0.98. Regarding geomorphology, differences between calving cows and their herdmates were not consistent between farms for most geomorphons. On all farms, cows selected gentle slopes (5 - 10%) for calving, but herdmates also preferred this geomorphon in two farms and rejected it on one farm, resulting in JSI differences between -0.19 and +0.25. Systematic differences were only observed for flat areas (JSI differences between -0.07 and -0.33). In terms of tree cover, calving cows showed a relative preference for areas with more than 40% canopy, with JSI differences ranging from + 0.04 to +1.04. Despite the differences between farms, which may be due to paddock size and spatial configuration, some common behavioral patterns were observed. Calving cows avoided areas close to water, flat areas, and areas with little or no canopy cover, which can be interpreted as an avoidance of cattle concentrations and exposed areas. These results may facilitate the location of calving cows on heterogeneous pastures.

Abstract The objective of this survey was to establish current adoption rates of common management practices on beef cattle operations throughout Kentucky to assist in development of effective extension education programs. These programs aim to increase knowledge, awareness, and adoption of management practices among beef cattle producers. This survey was distributed through email listservs and social media, yielding responses from 700 Kentucky producers representing 96 of 120 counties. It included questions to identify basic characteristics of each operation such as type, herd size, and farming status (full-time vs. part-time), followed by a series of questions regarding use of specific management practices (n = 73). These practices were grouped into six categories: business planning, general management, nutrition, forages, breeding and genetics, and animal health. To assist in development of targeted educational programming, adoption rates were analyzed by production system, herd size, farming status, and producer age. Respondents could select multiple types of operations including commercial cow-calf (60.8%), seedstock (11.8%), stocker/backgrounder (13.4%), and finishing (13.8%). Among stocker/backgrounder operations, 49% reported having more than 50 growing calves, while 61% of finishing operations fed fewer than 10 head per year. Part-time producers made up the majority (60.6%) of respondents. Adoption rates were analyzed using chi-square tests to evaluate associations between management practice adoption and operation characteristics. For commercial cow-calf producers, herd size, and farming status had the greatest influence on adoption of individual practices. Herd size significantly impacted (P £ 0.05) adoption of 33 practices and tended to impact (P £ 0.10) an additional 7 practices, with larger herds (³ 101 cows) more likely to adopt recommended management practices compared to medium (50-100 cows) and small (£ 49 cows). Full-time producers were significantly (P £ 0.05) more likely to adopt 25 additional management practices and tended (P £ 0.10) to adopt 10 more compared to part-time producers. Producer age (£ 39, 40-59, ³ 60) impacted adoption of 12 practices (P £ 0.05) and tended (P £0.10) to impact adoption of 5 additional practices, with younger producers more likely to utilize written farm goals, routinely monitor and record body condition scores, and deworm and vaccinate calves for respiratory diseases. Older producers were more likely to have an estate plan or will, use certified varieties of seed, and seed legumes into pastures, and tend to store hay indoors. Survey results were used to develop extension programs focused on increasing knowledge, awareness, and adoption of specific management practices that had low overall adoption rates, including hay testing (34.9%), implant use (21.5%), and pregnancy diagnosis (52.8%), regardless of farming status, herd size, and producer age. These efforts aim to improve productivity, profitability, and sustainability of Kentucky beef cattle operations.

Abstract This study investigated the effect of silage additives on a) silage composition and fermentation characteristics, and b) bacterial and fungal communities during ensiling and aerobic exposure. Whole plant corn was harvested at 33% DM and ensiled in vacuum-sealed laboratory silos following treatment with a) deionized water (control; CON), b) a bacterial inoculant, LB+ Supersile® (Strong Microbials Inc., Milwaukee WI; INOC), applied to supply 1 x 105 cfu/g of fresh forage, c) a propionic acid-based additive, Silage SAVOR® Plus (KEMIN Industries, Des Moines, Iowa; PRE), applied at 0.1% of fresh forage, and d) additive plus inoculant (PRE+INOC) applied at the same rates as INOC and PRE. Silage was sampled twice; at silo opening after 180 d of ensiling and 21 d after silo opening. Silage composition and fermentation characteristics were measured at silo opening. For bacterial and fungal communities, we considered the effect of silage additives on two sampling dates in a 4 x 2 factorial arrangement. Bacterial and fungal communities were characterized using 16S rRNA gene amplicon and ITS sequencing, respectively. Treatment of silage with PRE and PRE+INOC increased CP, WSC, and lignin concentration relative to INOC. Main differences in fermentation characteristics among treatments were a greater pH, greater ammonia-N concentration, and lower total acids concentration in PRE and PRE+INOC-treated silages. Firmicutes and Proteobacteria were predominant bacterial phyla during ensiling and aerobic exposure. Firmicutes abundance was not impacted by silage additives but Proteobacteria abundance was reduced (P = 0.057) by PRE and PRE+INOC treatment.

Abstract The objective of this study was to identify when and where tail-biting occurs and analyze pig postures to inform management strategies that reduce tail-biting and improve pig welfare. Pigs (N = 315; initial weight = 22.07 ± 3.76 kg) with intact tails were assigned to small (SG, 9 pigs/pen, 4.80 x 1.55 m) or large (LG, 18 pigs/pen, 4.80 x 3.10 m) pens, with SG having 4 feeder spaces and LG having 8 feeder spaces. Pig behavior was recorded continuously for 14 weeks using the NUtrack Livestock Monitoring System. Videos were manually viewed from 0800 to 1500 h on the day before the first tail-biting outbreak in each pen to register behavior when tail-biting occurred. Data were analyzed using the FREQ procedure in SAS. Standardized residuals (> 2 or < -2) were used to identify significant deviations in temporal distribution and feeder occupancy. Residuals of hourly tail-biting events indicated a higher-than-expected occurrence between 0800 – 0900 h (r = 3.21) and 1400 – 1500 h (r = 3.72), whereas lower-than-expected occurrences were observed between 0900 – 1000 h (r = -3.26) and 1000 – 1100 h (r = -4.36). Victimized pigs were primarily lying sternal (χ2 = 1818.06, df = 5; P < 0.0001), while pigs engaging in tail-biting were more likely to be standing compared to non-biting pigs (χ2 = 1008.6, df = 3; P < 0.0001) during tail-biting events. Tail-biting predominantly occurred in the middle of the pen rather than near the front or rear of the pen (χ2 = 24.41, df = 2; P < 0.0001). Tail-biting was more likely to occur when feeder occupancy was low, specifically when 50% or fewer of the feeder spaces were occupied, in both SG (χ² = 362.55, df = 4; P < 0.0001) and LG (χ² = 224.86, df = 8; P < 0.0001). In SG, biting was significantly overrepresented when 0 or 1 pigs were at the feeder (r = 9.70, 9.34). Pigs in LG exhibited a similar trend, with tail-biting overrepresented when 0, 1, 2, or 3 pigs were at the feeder (r = 3.0, 2.04, 6.35, 7.62). These results indicate that tail-biting occurred more frequently when victimized pigs were lying sternally in the middle of the pen during the morning and late afternoon, particularly when most feeder spaces were unoccupied. Further research is needed to validate these findings for the development of management strategies to minimize tail-biting and improve pig welfare.

Abstract The thermal efficiency Index (TEI) generated through infrared thermography is associated with the growth efficiency in pigs. It is hypothesized that pigs with high TEI are energetically less efficient and produce more radiant heat to the environment, whereas those with low TEI are more efficient with greater ability to conserve energy for growth and production while minimizing energy loss to the environment. This study evaluated the growth performance and carcass quality of grow-finish pigs selected based on low and high TEI categories. A total of 176 eight-week-old pigs were enrolled in a 16-week experiment, with 88 pigs per batch (replicated once over time) in a randomized complete block design. At nursery exit, pigs were scanned using an infrared camera to determine TEI (mean dorsal temperature/body weight0.75). In each replicate, 44 pigs with high TEI (“HIGH”: 4.29 ±0.39; body weight 15.62 ±1.43kg) and 44 with low TEI (“LOW”: 3.48 ±035; body weight 20.28 ±1.82kg) were selected and housed at 11 pigs/pen. The study was partitioned into the grower (8-12 weeks of age), Finisher1 (12-16 weeks) and Finisher2 (16-20 weeks) phases. TEI and body weight were recorded at the end of each phase to determine average daily gain (ADG). Individual feed intake was recorded daily using automated feeders (IVOG pro) to determine average daily feed intake (ADFI) and Gain: Feed (G: F). Pigs were marketed at 20 weeks of age and carcass grading data were obtained. Mixed model was used for data analysis with TEI category as main effect and replication as random effect. Spearman’s Rho correlation was used to explore the relationship between TEI and feed efficiency. In the grower phase, LOW pigs tended to gain more weight (p=0.06), but there was no difference in ADFI or G:F. During Finisher1, LOW pigs consumed more feed (p=0.02) and had greater ADG (p=0.01) with no difference in G:F. During Finisher2, there was no difference in ADFI, ADG or G:F between TEI categories. The overall ADG throughout grower-finisher stage was greater for LOW than HIGH pigs (p=0.01). LOW pigs had greater net weight at slaughter (p< 0.01), and fat content (p=0.03). There was no effect of TEI on loin depth. The lean yield percentage tended to be lower in LOW than HIGH pigs (p=0.05). The results of this study showed a decreasing correlation between TEI and G:F overtime from 12-20 weeks of age. At week 12, there was a moderate positive correlation (r= 0.38, p< 0.01). By week 16, the correlation weakened (r=0.25, p< 0.01). At week 20, the correlation was further reduced and not significant (r=0.15, p=0.06). In conclusion, this study reveals that TEI can be used to identify pigs with better performance in terms of weight gain and carcass yield.

Abstract A published peer-reviewed manuscript is often viewed as the end of a research project and is considered tangible evidence of sound science. Publishing a manuscript requires entering a relationship with unknown reviewers, but because reviewers are usually anonymous, clear communication is imperative. The peer-review process actually begins long before the submit button is pressed. Perhaps the most important steps for creating credibility for the science presented in a manuscript are the objective statement and materials and methods. A successful peer-review outcome requires a research trial with a clearly stated objective to directly communicate to the reviewers the information they can expect in the manuscript. It also provides an explanation why data are presented in a certain way and just as important why data were not presented in a certain way. The objective is the first impression of your work and sets the tone for the rest of the document. It should be clear, concise, and near the beginning of the introduction. Materials and methods should be thorough, detailed, and adequate for any scientist to replicate. Materials and methods should address each table or figure. Most journals provide instructions to authors on what is required in the Materials and Methods section. The objective and the materials and methods section provide credibility to a manuscript and allow a reviewer to comprehensively evaluate the merit of the work. It is important to consult instructions to authors prior to submission to ensure all required sections have been included and to avoid immediate rejection. A cover letter and suggested reviewers are often required during the submission process. The cover letter should be short and professional and, in a sentence or two, describe the scope of the work. Careful consideration should be given when suggesting reviewers- they should be an expert in the field but not pose a direct or implied conflict of interest. Quality suggested reviewers can substantially expedite the review process. Once a manuscript has been evaluated by peer-reviewers a recommendation will be made to the editorial board. Recommendations may be accept, reject, or revisions are required. Rarely are manuscripts accepted after the first submission. If revisions are required, a report of the editorial suggestions will be provided. Authors should address each point by providing context for the original statement and highlighted revisions are required. Providing line numbers where the original statement and revised statement is greatly appreciated because it allows for quick evaluation of each revision. Multiple revisions using the same process may be necessary. Overall, a clearly defined objective and detailed materials and methods are necessary for successful publication of a manuscript. Remaining polite and professional throughout the process will provide a more enjoyable experience for both the author and editorial group.