bluuebunny/crossref_metadata_2025 huggingface dataset:
512 Divergence of the sow vaginal microbiome based on fertility status
Authors: Fletcher Lauren A , Zhan Xiaoshu , Song Yashu , Li Julang
Published: September 2024

The need for alternative biomarkers of reproductive potential in the pork industry is apparent as the current selection approach for sow fertility is not keeping up with the improvement of other production-related traits. To date, the vaginal microbiome has been overlooked as a source of potential biomarkers of sow fertility status. We aimed to elucidate a possible divergence of the vaginal microbiome between sows of differing fertility status and identify possible microbial biomarkers that classify the fertility potential of a sow. Microbial DNA was extracted from vaginal microbiome samples originating from highly reproductive sows (HRP, n = 41) with the number of piglets born alive ≥ 13 or infertile sows (INF, n = 22), that failed to become pregnant after two rounds of consecutive artificial insemination. Our 16S rRNA sequencing results revealed significant (P < 0.05) beta diversity divergence at the family and genus taxonomic levels between HRP and INF vaginal communities. INF vaginal communities displayed significantly greater (P < 0.05) alpha diversity at both the family and genus levels and had a significantly (P < 0.05) greater number of unique OTUs identified at the genus level. The composition of the vaginal microbiome diverges between HRP and INF sows, with INF sows experiencing a disruption of their communities via the colonization of opportunistic pathogens reducing the abundance of normal microbiota seen in HRP. The genera Streptococcus, Lachnospiraceae XPB1014 group, Staphylococcus and Treponema were selected to test as potential biomarkers due to their univariate significance, contribution to partial least squares discriminant analysis (PLS-DA) and selection in a recursive feature elimination model (RFE). The resultant support-vector machine model was diagnostic (achieving an ROC-AUC = 0.86), supporting the selected biomarkers as diagnostic markers for sow fertility status. Overall, there was an apparent shift from a normal vaginal microbiota in HRP sows to a dysbiotic vaginal microbiota in INF sows dominated by potentially pathogenic, more anaerobic and short-chain fatty acid (SCFA)-producing microbiota that may play damaging and pro-inflammatory roles in the vaginal canal. Lactobacillus, known to be the dominant genus in a majority of healthy human vaginal microbiomes, was not the dominating genus in either INF or HRP vaginal microbiomes, suggesting the uniqueness of pig vaginal microbiomes. This also emphasizes the need for pig-specific vaginal microbiome research. Investigations regarding the application of the potential vaginal microbial biomarkers identified in this study to a large, novel population of sow and gilt vaginal microbiome samples to test their on-farm accuracy are underway. In addition, the mechanistic and physiologic role of SCFAs and the bacteria that produce them in the sow vaginal microbiome should be further investigated to understand how they may influence or be a product of fertility status.
493 Predicting pellet quality using multiple linear regression with Principal Component Analysis (PCA)
Authors: You Jihao , Tulpan Dan , Ellis Jennifer L
Published: September 2024

Pellet quality is a crucial key performance indicator (KPI) for commercial feed manufacturing, which influences both the efficiency of the feed mill and downstream performance of animals fed these diets. However, due to the complexity of feed manufacturing and the large number of factors involved in the manufacturing process, controlling pellet quality is an ongoing challenge for the feed industry. Previous studies have mainly explored the impact of a few factors on pellet quality under experimental settings, and empirical equations have been seldomly developed to reflect the relationship between the factors and pellet quality under the commercial feed mill settings. This study aimed to establish a relationship between pellet quality and factors collected under the settings of a commercial feed mill. The data were collected from Trouw Nutrition Canada’s feed mill located in St. Marys, Ontario (Plant 2), between December 15, 2021, and December 6, 2022. During this period, 2,691 observations were collected, with each observation representing an individual batch of pelleted feed. A total of 75 factors were recorded, including 4 factors associated with the general information of each batch, 10 manufacturing parameters, 41 feed ingredients, 8 factors regarding the nutrient composition of each diet, and 12 environmental factors. Pellet Durability Index (PDI), which was the response variable, was determined for each batch using the Holmen method. The data were randomly split into an 80% subset for training and a 20% subset for testing. The training subset was used to construct the model via a 5-fold cross-validation, while the testing subset was withheld as an independent dataset to evaluate the generalization performance of the model. The response variable (PDI) was transformed (tPDI) using the Box-Cox method to meet a normal distribution assumption. To avoid multicollinearity, Principal Component Analysis (PCA) was used to reduce the dimensionality of the numeric factors before building the multiple linear regression model. The model prediction performance was evaluated on both the training subset (using 5-fold cross-validation) and the testing subset, and the prediction performance metrics were consistent between the two subsets (Mean Absolute Error = 1.94 ± 0.102 vs. 2.02; Root Mean Square Prediction Error = 2.47 ± 0.111 vs. 2.58; Mean Square Prediction Error = 6.12 ± 0.538 vs. 6.68; Concordance Correlation Coefficient = 0.538 ± 0.0231 vs. 0.490; Pearson Correlation Coefficient = 0.606 ± 0.0247 vs. 0.553, respectively). Most feed ingredients and nutrient compositions showed either positive or negative loadings on Component 1 (17.87% of total variance), and outdoor/indoor environmental factors were positively loaded on Component 2 (14.21% of total variance). The model developed in this study could help commercial feed mills better understand how various factors impact pellet quality and optimize the manufacturing processes of pelleted feeds.
489 Antibiotic Resistance of cecal Escherichia coli isolates from Lohmann LSL lite pullets and laying hens fed omega-3 fatty acids or yeast bioactives, reared at different spacing allowance
Authors: Waliaula Paul Kibaba , Kiarie Elijah , Diarra Moussa
Published: September 2024

Poultry diets provide components that alter gut microbiota composition. We investigated antimicrobial resistance (AMR) phenotypes of E. coli isolates from ceca digesta of pullets and hens reared at different spacing allowance (SA) and dietary source of omega-3 fatty acids (N-3 FA) and yeast bioactives (YB) from placement to 17 wk of age (woa). A total of 2,632-day old chicks were placed in cages at two SA (24 cages each): High SA (HSA, 348 cm2/bird; ~50 birds/cage) and Low SA (LSA, 284 cm2/bird; ~68 birds/cage). Birds were fed corn and soybean-based diets (C), C + 3% co-extruded full fat flaxseed and pulse mixture (N-3 FA) and C + 0.05% YB processed with β-1,3-glucan hydrolase. At 4, 16 and 35 woa, ceca samples were collected to isolate E. coli using Chromocult agar. Their susceptibility to 14 antibiotics were determined by automated Sensititre system according to CLSI and CIPARS guidelines to determine their antimicrobial susceptibility profile. Number of antibiotics resistant E. coli isolates were analyzed using general linear mixed model procedure of SAS with diets, SA, sampling age and associated interactions as fixed factors. Cochran-Mantel-Haenszel test was used to determine the relationship between these treatments, and differences between treatments were considered significant at P < 0.05. Out of 428 presumptive E. coli isolated, 153 of 428 isolates (35.7%) were resistant to one antimicrobial class but no resistance against ciprofloxacin, azithromycin and nalidixic acid were detected. The prevalence of antimicrobial resistant E. coli decreased as the birds aged from wk 4–35 (P < 0.05). At wk 4 (P = 0.002) and 16 (P = 0.011), the least prevalence of ampicillin (AMP) resistance was in ceca digesta from N-3 FA-fed birds. At 35 woa, no AMP and cefoxitin (FOX) resistance were detected in birds fed YB (Table 2). At 16 woa, the prevalence of streptomycin resistance was greater in N-3 FA-fed than in YB-fed birds (P = 0.02), which was less than control-fed birds. Of the 428 isolates, 59 (13.8%) were resistant to more than two antimicrobial classes, with most from TIO-FOX-AMP-TET and STR-SULF-TET. At wk-4, SA had a significant effect on multiple resistance spectrum with LSA having the lowest MDR E. coli (P = 0.02) mainly from N-3 FA-fed pullets. This study showed an overall low AMR prevalence which decreases with age of the bird. This study is the first to report that feed additives (N-3 FA or YB) influence the AMR profile of cecal E. coli in pullets and layers. Prevalence of AMP resistance was least in N-3 FA-fed birds, whereas least STEP- and SULF resistance was observed in YB-fed birds. Our next study would help understand the molecular and evolutionary aspect of this resistant E. coli and their potential to cause colibacillosis.
315 A 99-year journey on the evolution of food safety in Canadian livestock production
Authors: Yang Xianqin , Stanford Kim
Published: September 2024

Almost 100 yr ago, food safety concerns in Canadian livestock were very different than they are today. In the 1920s Brucella spp. which causes ‘undulant fever’ in humans was a major zoonotic pathogen. The main route of transmission of Brucella spp. was through consumption of unpasteurized milk, often from the family milk cow. By the 1940s transmission was more by slaughter-house workers and others handling cattle as Canada started a brucellosis eradication program which led to Canadian cattle being declared brucellosis-free in 1985. Another major zoonotic disease in the 1920s was bovine tuberculosis (TB) which was also transmitted by unpasteurized milk or through meat and was often fatal to the young children consuming the milk. Testing of cattle TB was spear-headed by the province of Manitoba, with the first general TB testing occurring in that province in 1923. The first Canada-wide TB test of cattle was not completed until 1961, with 400,000 reactors identified. By 1974 TB-infected herds were required to be quarantined and by 1997 after some years of depopulation of TB-positive animals, Canada was recognized by the USDA as having TB-free status. In the 1980s as brucellosis and tuberculosis no longer were food safety concerns, they were replaced by Salmonella spp., Campylobacter spp. and pathogenic strains of E. coli. These remain organisms of food safety concern in livestock production today. As livestock are often intermittently colonized with these pathogens and only neonates exhibit signs of infection, the cull positive animals plan which worked for brucellosis and TB is not an effective strategy. Instead, the focus has been on improving antimicrobial hurdles in Canadian slaughter plants and improving detection of these organisms to prevent the release of contaminated food to consumers. Physical and chemical antimicrobial interventions such as washing hide-on carcasses with caustic soda and spraying carcasses with organic acid or hot water are widely implemented at processing facilities. Improved detection has included incorporation of molecular methods such as PCR and whole genome sequencing (WGS), with WGS becoming in 2018 the standard technology for identification of and traceback of sources of food-borne disease by the Public Health Agency of Canada. With these improvements, we are better able to prevent outbreaks of human disease than at any time in the past. Accordingly, cases of Salmonellosis, the leading food-borne illness in Canada and a major concern in poultry products, have declined by approximately one-third since 2019. It is the collaboration of a huge team of researchers, regulatory bodies, food processors, and farmers across Canada that have led to the improvements in food safety in Canada over the past 99 yr. Challenges still remain, but work continues to ensure that Canadian food is among the safest in the world.
314 A 99 Year Journey on the evolution of health and welfare in Canadian livestock
Authors: Schwartzkopf-Genswein Karen S , Meléndez Daniela M
Published: September 2024

The symbiotic relationship between humans and animals is so intwined that it can be considered a primary factor in the shaping of modern-day societies, including our current livestock production systems. This relationship is complex and involves the use of animals for food, labor, materials as well as companionship, entertainment and even religious practices. There is no question that significant changes in the care, understanding and acknowledgement of animals as sentient beings have evolved over the past 100 yr. Early misunderstandings of the differences between those advocating for animal rights (any use of animals is unacceptable) versus those advocating for animal welfare (humane use of animals is acceptable) resulted in push back and mistrust by industry stakeholders. Initially, animal welfare advocates promoted basic aspects of animal care such as being treated humanely and ensuring that animals were not subjected to unnecessary suffering. However, current ideology includes the ability of an animal to lead a natural life, taking their feelings and needs into consideration. Advances in veterinary and animal welfare science have been key factors in improving our understanding of optimal animal welfare and its close association with animal health. Examples from Canadian beef cattle production will be used to show how cattle health and welfare have evolved in the past century and will cover painful management procedures, transport, handling, as well as the management of vulnerable and ill cattle. Livestock health and welfare in Canada will continue to evolve and will be shaped by factors including societal views, food safety, production costs, environmental impacts, new technologies and continued research.
219 Winter nutritional dynamics of Idaho fescue and bluebunch wheatgrass on a Montana foothill rangeland
Authors: Davis Noah G , Wyffels Sam , DelCurto Timothy
Published: September 2024

The objectives of this study were to quantify the change and variation in forage quality of Idaho fescue (Festuca idahoensis) and bluebunch wheatgrass (Pseudoroegneria spicata) over the course of two consecutive winters. Five sites were selected from within a 1064-ha, foothill grassland management unit at Red Bluff Research Ranch in Norris, MT. Beginning mid-October and ending early February, a minimum of seven ungrazed individuals of Idaho fescue and bluebunch wheatgrass were clipped at each site every 14 d, for a total of nine sampling dates. This was repeated for two consecutive winters. Samples were analyzed for crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF). Data were analyzed as a repeated measures completely randomized design. Idaho fescue had greater CP than bluebunch wheatgrass across all sampling dates and both years (P < 0.01); however, at each sampling date, Idaho fescue also had a greater variation in CP than bluebunch wheatgrass (P = 0.02). Across species, there was no difference in CP between sampling dates in yr 1 (P ≥ 0.1); however, in yr 2, there was a tendency for a positive linear contrast (P = 0.05). In yr 1, ADF was greater in Idaho fescue than bluebunch wheatgrass; however, in yr 2, ADF was greater in bluebunch wheatgrass than Idaho fescue (P < 0.05). In yr 1, there was a positive cubic contrast for ADF between sampling dates (P < 0.05), and in yr 2 there was a tendency for a negative quadratic contrast between sampling dates (P = 0.06). There was no difference in NDF between sampling dates (P = 0.27); however, NDF was greater in yr 2 than yr 1 (P < 0.01). There was a tendency for greater NDF in bluebunch wheatgrass than Idaho fescue (P = 0.06). The forage quality of Idaho fescue and bluebunch wheatgrass is relatively stable during the dormant season compared with the growing season. The differences between species are greater and more consistent in CP. The differences between years are greater in ADF and NDF. If forage quality is temporally uniform during the winter, then the diet quality of livestock must therefore be controlled by other factors such as stocking rate, selectivity, and spatial use of the pasture. Under moderate stocking rates, livestock may be able to select a greater quality diet than is presented here.
395 The effect of forage allocation on steer performance when grazing cereal rye
Authors: Davies-Jenkins Shelby L , Sartin Abigail M , Calus Kallie J , Drewnoski Mary E
Published: September 2024

With good winter tolerance and rapid spring growth, cereal rye can fill the early spring grazing gap in pasture productivity. However, there are little data regarding how to best use these acres in the Midwest. Thus, the objective was to study the effect of forage allowance on steer performance when rotationally grazing fall-planted cereal rye in the spring. Over 3 yr, steers (n = 170) were stratified by initial body weight (BW; yr 1 = 338 kg, yr 2 = 375 kg, yr 3 = 347 kg) and assigned to treatment groups of 5 to 30 depending on the year and desired stocking rate (range = 1.98 to 7.41 steers/ha) then assigned to a pasture. Experimental unit (EU) was pasture (n = 14), with three EU per year in yr 1 and 2 and eight EU in yr 3. Pasture size ranged from 0.81 ha to 6.1 ha. Pastures were divided into 2 paddocks for rotational grazing in yr 1 and 2, while pastures in yr 3 were divided into 4 paddocks. Grazing was initiated when average pasture height reached 12.7 cm and groups were rotated when paddock height reached 5 cm. Just before initiation of grazing in a paddock, forage mass and nutritive value were measured. The weighted average nutritive value of the cereal rye across the 3 yr was 69 ± 2.5% digestible organic matter (DOM) and 22.9 ± 5.1% CP. Data were analyzed using the regression procedure of SAS to test for a linear relationship between stocking rate and either forage offered or forage mass to determine if stocking rate effectively changed forage availability. Forage offered averaged 4.62 (SD ± 1.80) kg DM·100 kg BW-1·d-1 and had a moderate (R2 = 0.51) negative linear relationship (P < 0.01) to stocking rate. Mean forage mass was 947 (SD ± 301) kg DM·ha-1 was negatively linearly related (P < 0.01) to stocking rate with a moderate correlation of (R2 = 0.39). Additionally, a linear regression was used to analyze the relationship between average daily gain (ADG) and forage offered, forage mass, DOM offered, and CP offered. There was no correlation (P ≥ 0.75) between ADG (0.91 kg/d; SD ± 0.15) and the parameters of interest. The average DOM offered was 3.18 (SD ± 1.18) kg DOM·100 kg BW-1·d-1 and the average CP offered was 1.13 (SD ± 0.62) kg. When rotational grazing immature cereal rye, stocking rate did influence the amount of forage offered; however, ADG was not influenced by forage offered when it ranged from 1.4 to 8.5 kg DM·100 kg BW-1·d and there was no relationship between ADG and forage mass or nutrients offered. Lack of observed differences is likely due to the high nutritive value of the forage coupled with the close monitoring of forage height in the rotationally grazed system.
278 Awardee Talk: A multi-perspective approach to understanding fundamental mechanisms that regulate growth and nutrient utilization in pigs
Authors: Ajuwon Kolapo M
Published: September 2024

Pigs raised in commercial production settings often do not grow and utilize nutrients to their genetic potential due to a myriad of factors that negatively affect their performance. Understanding the underpinnings of growth and nutrient use by pigs is fundamental to optimizing their growth. The overall objective of research in my laboratory is to investigate mechanisms that guide growth and nutrient use in pigs. We use approaches that involve whole-animal systems and cellular models that query physiological processes in pigs during normal and stressful conditions. To understand the effect of heat stress on adipose tissue development and function in pigs, multiple experiments were conducted using in vitro and in vivo methodologies. First, using in vitro adipocyte differentiation model to characterize cellular responses that occur during differentiation of pig adipocytes, HS was found to increase (P < 0.05) adipogenesis in adipocytes, and this was accompanied by increased (P < 0.05) expression of C/EBPα and HSP 70. Heat stress also increased (P < 0.05) expression of genes involved in fatty acid uptake and TAG synthesis (FAS, aP2, CD36, FATP4, FATP6, LPL, GLUT4, PCK1, and GK). This is supported by increased (P < 0.05) cellular triacylglycerol under HS. In pigs exposed to HS (35°C) vs. Control (20°C), HS resulted in increased (P < 0.05) expression of PCK1, suggesting that increased glyceroneogenesis might be involved in the increased fat storage in pigs under HS. Additionally, experiments conducted to investigate effects of live yeast (LY), fiber and fiber-derived microbial products have shown that maternal fiber type consumed during gestation affects adiposity in the offspring. Experiments have also elucidated the mechanisms by which fiber-derived products such as butyrate affect intestinal epithelial cell function. This work has shown that butyrate increased (P < 0.05) activation of the AKT signaling pathway in epithelial cells to promote tight junction integrity and mitigate effect of inflammation. Using metabolomics analysis, it was also shown that dietary fiber regulates 97 different metabolites in the fecal content of pigs. These metabolites include amino acids and known PPAR gamma ligands, demonstrating a potential role for microbial derived products to regulate intestinal cell metabolism through the PPAR signaling pathway. Feeding LY to sows during gestation and lactation was also accompanied by increased (P < 0.05) growth and nutrient utilization in piglets after weaning, underlying a potential for postweaning growth modulation in piglets with maternal LY supplementation during gestation and lactation. Additional work using proteomics has revealed the potential importance of immune stimulating proteins in the milk of LY fed sows in the growth response of piglets. Knowledge gained from this research would be useful for developing new strategies for optimizing animal growth.
430 Spent hemp biomass increases bone mineral density in broilers
Authors: Pearce Carolyn , Bionaz Massimo
Published: September 2024

Spent hemp biomass (SHB) is a byproduct of CBD oil production, which has been used in multiple trials recently as an alternative feed for livestock, but it has not been approved as a feed ingredient by the FDA-CVM. This is due in part to the lack of information on the potential effects on animal health. Recent studies have shown possible effects of cannabinoids on bone healing, though the effects on bone growth and calcification are not well established. The objective of the study was to investigate the effects of varying levels of SHB on bone growth, calcification, and strength. A total of two hundred birds (5-d-old Cobb 500 Cornish Cross chicks) were randomly assigned to five different rooms with 4 pens per room and 10 animals/pen. Birds received isonitrogenous, isocaloric diets with either 0, 5, 10, or 20% SHB until euthanasia at 42 d. The tibiotarsus, femur, and humerus were collected from 2 males and 2 females per pen for 80 birds (20 per treatment group). The tibiotarsus bending strength was measured with an Instron 5969 using a three-point bending testing fixture set at 10 mm/min for 19 parameters of the bending and breaking properties. The humerus and femur were scanned with a Hologic Discovery A (S/N 84870) DEXA for mineral content (BMC) and density (BMD). Statistical significance was set at P ≤ 0.05 and analyzed using a generalized linear mixed model. BMD and BMC were not affected by treatments in the humerus, a pneumatic bone, but in the weight bearing femur bones, a significant effect on both BMD (P = 0.0078) and BMC (P = 0.0069) was observed. The change in BMC was quadratic, with a peak in animals receiving 10% SHB in the diet, but the BMD effect was linear with the increased dose of SHB in the diet. In the tibiotarsus three-point bending analysis, no significant changes were found in any of the strength and bending parameters measured, except a tendency (P = 0.07) for a greater work-to-fracture adjusted by bone diameter in 5% vs. 0% SHB group. These data indicate some interaction of SHB on the mineralization of bone; however, the level causes less than significant changes to the overall strength of the bone.
431 Evaluating a foundation model for animal body segmentation based on few-shot learning against a domain-specific deep neural network
Authors: Casella Enrico , Dórea Joao R R
Published: September 2024

Computer vision (CV) has been proposed as a powerful technology to collect individual measurements of livestock animals, such as body weight or body condition score, to name a few. In all these tasks, the first step of image processing is semantic segmentation (SS), which represents the use of deep neural networks to locate pixels that belong to the animal body, while removing the background which may add noise and other information that are not needed to compute body biometrics. Despite the generalization abilities of CV, oftentimes SS models need to be re-trained on the specific dataset at hand in order to maximize performance, and thus require labor-intensive annotations. With the rise of foundation models like GPT-4, LLaMA, DALL-E, among others, we aim to explore whether a foundation model for SS called SegGPT performs well in a highly specific agricultural scenario, in comparison with a model trained using domain-specific data, i.e., a U-net model trained on our datasets. Our evaluation is carried out over 9 different datasets of top-down depth images over bodies of calves and cows. The combined datasets amount to a total of 4,328 images (average count = 541) from 485 animals (average count = 54) from 2 wk to 7 yr of age, and it was collected with a mix of RealSense D435 and Kinect V2 sensors at several farm settings (entering/exiting the milking parlor, in a chute, or during weighing on a scale or weighing cart). We investigated the performance of these two models under several scenarios: training on a single dataset and validating within the same dataset (Same Dataset Internal Validation; SDIV), training on a single dataset and validating on an external dataset (Same Dataset External Validation; SDEV), and training on multiple datasets and validating on an external dataset (Multiple Datasets External Validation; MDEV). For the U-net trained in the SDIV approach, we used a 70/30 train/test split over 100 epochs. SegGPT and U-net presented intersection over union of 0.84 and 0.95, 0.73 and 0.59, 0.84 and 0.91, for SDIV, SDEV, and MDEV, respectively. U-net was not able to segment the animal body with performance similar to SegGPT in a new dataset when trained with a single dataset, but it outperformed SegGPT when trained with multiple datasets. Although U-net performed slightly better on these scenarios, it’s important to highlight that SegGPT only received one prompt (one depth image with its annotation) per dataset and performed reasonably well on unseen (validation) datasets. In conclusion, foundation models for image processing tasks can be an alternative for training domain-specific deep neural networks, which demands labor, annotation, and large datasets to present satisfactory results. However, high performance still requires domain-specific models in similar agricultural scenarios.
55 Establishing grain-based modified protocols for re-feeding malnourished horses
Authors: Bardassi Ariane Tabari , Boyd Jamie A , Santos Hugo , Dodson Zach A , Rosa Laura Patterson
Published: September 2024

Increased feed costs, forage availability, and the increasing number of malnourished horses present major challenges to the equine industry. The goal of this project was to test an adapted refeeding protocol using Bermuda hay and two commercial grain products in severely malnourished horses. So, an 8-wk study from January to March 2023 was conducted to evaluate the effects of Total Equine in the refeeding of 10 emaciated horses. Horses were previously destined for slaughter and purchased from an auction with an average body condition score (BCS) of 2.01 (S.D. ± 0.69), then quarantined for 30 d before starting the study following recommended biosecurity protocols. During quarantine, horses were evaluated by a veterinarian and received treatment as needed, vaccinations, deworming, and mares were pregnancy checked. All horses were provided with ad libitum Bermuda hay and water. Upon completion of the quarantine period, horses were blocked into two groups based on age, BCS, pregnancy status, and gender and randomly assigned to a diet. The Control (Ctrl) diet consisted of a commercial grain diet recommended and used by five local West Texas horse rescue groups and the Treatment (Trt) diet consisted of Total Equine. Both diets included ad libitum access to water and Bermuda hay (TDN 56.5) offered twice daily in port-a-grazer tubs to control waste and the amount was adjusted daily to maintain a 3% refusal rate. Grain was offered at a rate of 0.005% BW + 227 kg per the manufacturer’s suggestion, divided into 2 equal feedings with amounts adjusted weekly. Individual horses were weighed weekly using an electronic scale and BCS was evaluated at wk 0, 4, and 8. All horses were allowed a 1-h turnout in a dry-pen per day for 6 d each week. Blood samples were collected at wk 0, 4, and 8 for analysis. Health parameters were measured weekly throughout the study. Samples (grain, hay, hay orts) were collected twice weekly for DM, NDF, ADF, EE, CP, and Ash analysis. Data was analyzed using Proc Mixed in SAS. Overall, there was no significant difference between DMI by diet (Ctrl 8.74 kg/d and Trt 9.44 kg/d). However, a tendency for increased ADG (P = 0.06) for the Trt diet (Ctrl 0.20 kg/d & Trt 1.34 kg/d) was noted. Efficiency calculated as (ADG/DMI) was significantly improved (P = 0.04) indicating an improvement in the efficiency of BW gain for the Trt diet compared with the Ctrl. Improved BW gain and efficiency of gain are of interest when rehabilitating malnourished horses. The establishment of accessible modified feeding protocols may improve efficiency and reduce the cost involved in the rehabilitation of malnourished horses and would be a step forward for the equine industry.
82 Impact of visual dark-cutting severity and wet aging on the bloom and retail color stability of beef longissimus lumborum steaks
Authors: Harr Keayla M , Scott Madelyn , More Sunil , Mafi Gretchen G , Pfeiffer Morgan , Ramanathan Ranjith
Published: September 2024

A dark red to coffee bean color present within the ribeye between the 12th and 13th rib of a beef carcass at the time of grading is the hallmarking characteristic of dark-cutting (DC) beef. However, the degree of darkness within the ribeye can vary. Limited studies have evaluated DC beef of varying visual severity throughout aging and retail display. Therefore, the objective was to evaluate the impact of varying degrees of dark-cutting severity on the bloom and retail color of beef longissimus lumborum subjected to 0, 21, or 39 d of aging. Beef strip loins (IMPS #180; n = 8/treatment) were collected from commercial beef processors based on the visual degree of SC at the time of grading. Strip loins represented one-half dark, two-thirds dark, full dark, and a normal, cherry-red colored control. At 48 to 60 h postmortem, loins were fabricated by slicing two 2.54 cm steaks from the anterior end of each loin for retail display (unaged) or biochemical analysis. The remaining portion of the strip loin was segmented into two sections and assigned to 21 or 39 d of wet aging. Following aging, one 2.54 cm steak from the anterior end of each loin was cut for retail display. All steaks designated for retail display were placed into Styrofoam trays and overwrapped with polyvinyl chloride film and placed into retail display following aging. Bloom, metmyoglobin reducing activity, and pH were evaluated for biochemical analysis. Color measurements were taken each day of display using a HunterLab MiniScan EZ spectrophotometer. The data were analyzed using the Glimmix procedure of SAS. One-half and normal steaks had a lower (P < 0.05) initial pH than two-thirds and full steaks. Unaged full steaks had greater (P < 0.05) metmyoglobin reducing activity than unaged normal and half steaks. Steaks aged for 21 and 39 d were more (P < 0.05) red initially following bloom than unaged steaks. Full and two-thirds steaks aged for 0 d had a decreased (P < 0.05) a* value on d 0 of display than normal and half steaks aged for 0 d. Similarly, following 21 and 39 d of aging full and two-thirds dark steaks had a lower (P < 0.05) a* value and were less red in color than normal and half steaks on the initial day of retail display. By d 4 of display, normal and one-half steaks aged for 21 d had a greater (P < 0.05) a* value than two-thirds steaks aged for 21 d. When aged for 39 d, all treatments were similar (P < 0.05) in redness by the end of display. Results from this study indicate that the visual severity of dark-cutting can impact color throughout aging and retail display.
239 Growth performance and gut health indicators of Escherichia coli-challenged weaned pigs fed diets supplemented with Bacillus subtilis or Enterococcus faecium
Authors: Woyengo Tofuko A , Canibe Nuria , Jayaraman Balachandar , Htoo John K
Published: September 2024

A study evaluated the effects of adding B. subtilis or E. faecium based probiotics in diets for weaned pigs challenged with E. coli on growth performance and indicators of gut health. Pigs [n = 64; initial body weight (BW) = 6.95 kg] weaned at 22 d of age were obtained in 2 batches of 32 pigs each. The pigs were from sows that were homozygous susceptible to infection by F4 strain of E. coli. Pigs in each batch were housed in 16 pens in 2 rooms: first room with 4 pens and second room with 12 pens. Pigs were fed 3 diets for 14 d. The diets were control or control plus B. subtilis (1×10E6 CFU/kg) or E. faecium (1×10E6 CFU/kg). On d 7 and 8 of the experiment, all pigs in the second room were orally challenged with F4 strain of E. coli (5 mL with ~109 CFUּ mL-1ּ d-1) to create the following 4 treatments with 4 pensּ traetment-1ּ batch-1) (8 pens/treatment for the study): unchallenged pigs fed control diet, challenged pigs fed control diet, challenged pigs fed control diet plus E. faecium, and challenged pigs fed control diet plus B. subtilis. Challenging pigs with E. coli F4 reduced (P < 0.05) average daily gain (ADG) for d 7 to 11 and d 11 to 14 of the study from 81 to -67 g and 460 to 259 g, respectively; increased (P < 0.05) plasma haptoglobin concentration (PHC) on d 9 from 1.10 to 1.69 mg/mL and fecal E. coli F4 content (FEC) on d 11 from 4.92 to 7.86 log copies/g; and decreased (P < 0.05) volatile fatty acids (VFA) concentration in the cecum and colon on d 14 from 89.5 to 52.3 mmol/kg and 88.1 to 63.9 mmol/kg, respectively. The E. faecium supplementation did not affect ADG for d 0 to 7 of the study but increased (P < 0.05) ADG for d 7 to 11 by 161%. The E. faecium supplementation did not affect FEC, PHC, and VFA concentration in the cecum and colon. The B. subtilis supplementation did not affect ADG and ADFI, FEC, PHC, but tended to increase (P < 0.10) VFA concentration in the cecum and colon by 32 and 20%, respectively. In conclusion, challenging weaned pigs with the E. coli F4 reduced growth performance and microbial fermentation in the hindgut and increased fecal E. coli shedding. Supplemental E. faecium probiotic improved ADG of weaned pigs after their challenge with E. coli, implying that it can be included in diets for weaned pigs raised under commercial conditions to improve their performance. The B. subtilis probiotic can be included in diets for weaned pigs to counteract the reducing impact of E. coli infection on microbial fermentation in the hindgut.
378 Growth responses and antioxidant status of finishing pigs fed low-energy, low-phosphorus, low-calcium and low-trace mineral diets added with exogenous enzymes
Authors: Gomez-Rosales Sergio , de Angeles Maria Lourdes , Perez-Alvarado Alejandra , Lopez-Hernandez Luis Humberto
Published: September 2024

The objective of the study was to evaluate the productivity parameters and the antioxidant responses in the meat in finishing pigs fed diets reduced in metabolizable energy (ME), Ca, P and trace minerals added with the exogenous enzymes phytase, xylanase and pectinase. Pigs (n = 48) were randomly distributed into 4 treatments: 1) A Sorghum/soybean meal diet formulated to meet all the nutrient requirements, with a mineral premix based on sulfates (Control); 2) Same as 1) but reduced in ME, Ca and P, added with phytase, xylanase and pectinase, the same mineral premix; 3) Same as 2) but with reduction of 33.3 % of the mineral premix; or 4) Same as 2) but reduction of 66.6% of the mineral premix. Pigs were housed in an open building, with natural ventilation in individual pens with solid concrete floor. The feeding program consisted of 2 phases, the first for 28 d and the second for 25 d. All diets were offered in meal form. Pigs were weighed individually at the beginning and end of the experiment, to estimate daily body weight gain. The daily feed consumption was registered. Feed efficiency was estimated as body weight gain based on feed consumption. At the end of the study, the depth of fat and loin muscle were measured at the 10th and the last rib. Pigs were transported to a slaughter facility. Samples of the loin and psoas major muscle were taken to determine the antioxidant status. Data were analyzed for a completely randomized design using the GLM, MEANS, MIXED, and UNIVARIATE procedures of SAS. No statistical differences were found on the productive responses, the depth of fat and loin muscle, fat-free lean tissue and carcass yield. The luminosity in the loin muscle increased (58.89 vs 59.85; P < 0.042), the antioxidant power of ferric radicals tended to be less (3.25 vs 2.90 mg Eq. Trolox/g; P < 0.052) and the thiobarbituric acid reactive substances tended to be greater (0.15 vs 0.21 mg MDA/kg; P < 0.063) in the loin muscle of pigs fed diet 4) reduced by 66.6% in mineral premix compared with that of pigs fed the control diet (1). The thiobarbituric acid reactive substances were greater (0.18 vs 0.25 mg MDA/kg; P < 0.023) and the drip loss tended to be greater (1.1 vs 1.4%; P < 0.056) in the psoas major muscle of pigs fed diet 4) reduced by 66.6% in mineral premix compared with that of pigs fed the control diet 1). Finishing pigs fed diets reduced in ME, Ca, P and trace minerals by 66.6% and added with exogenous enzymes did not show detrimental effects on productivity, but it reduced the antioxidant capacity of the loin and psoas major muscles.
444 The effects of increasing standardized ileal digestible lysine-to-net energy ratio during at 24-day lactation period on primiparous sow nitrogen utilization and lactation performance
Authors: Gregory Nicole , Huber Lee-Anne
Published: September 2024

Primiparous sows (n = 50) were used to evaluate the impacts of increasing standardized ileal digestible (SID) Lys-to-net energy (NE) ratios on sow performance and nitrogen utilization during a 24-d lactation period. Sows were assigned to one of five diets with equally spaced and increasing SID Lys-to-NE ratios between 2.85 and 5.51 g SID Lys/Mcal NE. Desired ratios were achieved by blending the two extreme diets in varying proportions using a feeding system with feed blending capabilities and were provided to sows immediately after farrowing until weaning (d 24 ± 0.3). Litters were standardized to 13 ± 1 piglets within 24 h after birth and were not provided creep feed. Nitrogen balances were conducted between d 4 and 7 (NB1), 12 and 15 (NB2), and 20 and 23 (NB3) of lactation, with total urine collection and fecal grab sampling. Contrast statements were used to assess linear and quadratic effects of increasing the SID Lys-to-NE ratio. Linear (LBL) and quadratic broken-line and polynomial quadratic models were used to determine the optimum dietary Lys-to-NE ratios for maternal nitrogen retention. The Bayesian information criterion was used to assess best fit. Sow body weight (BW) and backfat depth losses over lactation decreased with increasing dietary SID Lys-to-NE ratio (linear; -19.0 to -5.9 ± 3.7 kg, P = 0.001 and -3.9 to -2.0 ± 0.7 mm, P = 0.003, respectively). No differences were observed for milk nitrogen output (69.3 ± 4.5, 74.2 ± 6.6, 85.6 ± 6.8 g/day for NB1, NB2, and NB3, respectively), overall piglet average daily gain (219 ± 10 g), and piglet BW at weaning (6.33 ± 0.24 kg). Sow average daily feed intake was not influenced by SID Lys-to-NE ratio (5.3 ± 0.2 kg/day) but sow nitrogen intake (linear; P < 0.001) and total nitrogen excretion (urine + feces; linear; P < 0.001) increased with dietary SID Lys-to-NE ratio in all NB periods. Nitrogen retention (linear; P < 0.001) and maternal nitrogen retention (nitrogen intake – nitrogen excretion – milk nitrogen output; P < 0.05) increased with dietary SID Lys-to-NE ratio in all NB periods (-22.8 to -2.7 ± 6.7, 3.6 to 36.3 ± 8.4, and 9.0 to 34.8 ± 6.8 g/d for maternal nitrogen retention in NB1, NB2, and NB3, respectively). The LBL model showed that maternal nitrogen retention was optimized beyond the SID Lys-to-NE ratio limits in NB1 but breakpoints were observed for maternal nitrogen retention at 4.74 and 4.85 g SID Lys/Mcal NE in NB2 and NB3, respectively. Therefore, optimizing the SID Lys-to-NE ratio during specific weeks of lactation could minimize maternal nitrogen losses of primiparous sows.
449 Comparative study on performance, carcass traits and meat quality of different varieties of guinea fowl
Authors: Sarker Md Sazedul Karim , Lisa N N , Faruque S , Rashid M A , Sharmin Farhana
Published: September 2024

The purpose of this study was to evaluate productive, reproductive performance, carcass characteristics, chemical composition and meat quality of four varieties of guinea fowl. A total of 200 guinea fowls from White, Pearl, Lavender and Mixed varieties were reared in an intensive production system from 0 to 20 wk of age. Guinea fowl keets were reared provided with balanced recommended ration (Starter diet: ME 2,950 kcal/kg, CP 23% for initial 8 wk; Grower diet: ME 2,950 kcal/kg, CP 16% for 9 to 16 wk and Layer diet: ME 2,900 kcal/kg, CP 17% from 17 wk till the end of the laying period). There was no significant (P < 0.05) difference found in body weight (BW) from 0 to 20 wk old guinea fowl. However, BW of Pearl variety was greater than other varieties numerically (Table 1). At adult age, a total of 40 birds (10 from each variety) were slaughtered according to standard method and carcasses were cut into parts. Weights were taken for all carcass parts. Proximate analysis and meat quality were performed on breast and thigh meat, as well as on abdominal fat of the studied guinea fowls. Carcass weight (930.33 ± 27.37 g), dressing percentage (67.6 ± 0.013%), breast weight (228.33 ± 13.68 g) and thigh weight (166.33 ± 6.69 g) of Pearl variety was significantly (P < 0.001) greatest (Table 2). Measured abdominal fat (23 ± 0.13) was found to be significantly (P < 0.001) greatest in Pearl variety. Furthermore, there was no significant difference found in crude protein among breast and thigh meat of different varieties. The ether extract (EE) and crude fiber (CF) of breast (EE: 0.27, CF:0.33) and thigh meat (EE: 0.20, CF:0.33) of Lavender variety was significantly (P < 0.05) less than other varieties (Table 3). In case of reproductive parameters, Pearl variety exhibited better egg fertility (65.72 ± 6.10) numerically and significantly greater (P < 0.001) hatchability percentage (76.75 ± 3.88) than other varieties. Meat color values of all the varieties of guinea fowl found in this study are in line with the demands of poultry consumers (Table 4). Regarding water holding capacity (WHC) and drip loss (DL), there was no discernible difference (P > 0.05). Considering all the parameters especially cooking loss (CL) and pH, there was a noticeable difference (P < 0.05) in which the Lavender (CL: 24.81 ± 0.69, pH:6.12 ± 0.05) and White variety (CL: 25.35 ± 0.69, pH: 6.11 ± 0.05) performed better than the other varieties.
103 Integration of omics studies identifies molecular signatures associated with uterine function in beef cattle
Authors: Kertz Nicholas C , Banerjee Priyanka , Afonso Juliana , Dyce Paul W W , Da Diniz Wellison Jarles Silva
Published: September 2024

Reproductive inefficiency is a major cause for economic loss in cattle operations. However, the mechanisms underlying their ethology are still unknown. Herein, we aimed to identify genes and genetic variants underlying the uterine function and their role in female fertility. To this end, we performed a multi-tiered approach to identify endometrial differentially expressed genes (DEGs) from beef heifers classified as fertile (n = 7) or sub-fertile (n = 5). Further, we used public RNA-Seq data from uterine luminal epithelial cells from beef cows (n = 43) to identify genetic variants affecting the expression of genes (expression quantitative trait loci - eQTLs) involved with pregnancy outcomes. We identified 798 DEGs underlying pathways important for pregnancy establishment, including inflammatory response and G-protein coupled receptor (GPCR) signaling (P-value ≤ 0.01). Based on the eQTL mapping analysis, we identified 4,676 cis and 7,682 trans eQTLs (FDR ≤ 0.05). Interestingly, some of the eQTLs overlapped with 13 reproduction-related traits from the CattleQTLdb (FDR ≤ 0.05), including daughter pregnancy rate and non-return rate. Additionally, these eQTLs were modulating the expression of transcription factors and DEGs previously associated with pregnancy outcomes in beef cows. The integration of gene lists from both studies resulted in 16 common genes, including F2 and P2RX5. The F2 gene encodes for a coagulation factor that plays a role in smooth muscle contraction and is modulated by a unique family of GPCRs. The expression of purinergic receptors, such as P2RX5, have been proposed to be major facilitators of attachment and implantation through calcium ions. Functional over-representation analysis highlighted metabolism, immune response, and hormone (estrogen and GnRH) signaling pathways affected by eQTL-regulated genes (P-value < 0.01). Immune cells and regulatory pregnancy hormones, such as interferon tau and progesterone, are tightly regulated by each other and work cooperatively. GPCR signaling involves key regulatory hormones of the estrous cycle, specifically GnRH, LH, and FSH. Improper immune cell signaling, cyclicity, hormonal signaling, and smooth muscle contractions all affect the endometrium function, with potential downstream effects on pregnancy establishment and fertility. Dysregulation of these signaling pathways due to genetic variants could have detrimental effects, ultimately leading to failed pregnancy. Our findings provide novel insights into the genetic basis of reproductive processes in beef cattle. The molecular features and over-represented pathways could be used for identification of potential biomarkers for predicting pregnancy success. However, the underlying causal mechanisms modulating the expression of uterine genes warrant further investigation.