bluuebunny/crossref_metadata_2025_split huggingface dataset:
322 Nutrient transport across gastrointestinal tissues using Ussing chambers
Authors: Laarman Anne H , Penner Gregory 
Published: September 2024

Abstract
One of the principal roles of the gut is the absorption of nutrients to meet animal needs. While in vivo measures such as total tract digestibility indicate the totality of the nutrients that disappear, these methods provide no information on the digestion, site, flux, and mechanism of nutrient absorption. Nutrient absorption is a complex set of transport pathways including passive diffusion, facilitated transport, ion exchange, active transport, and secondary active transport that is driven by electrochemical gradients. To tease apart the complexities of nutrient transport at different sites along the gastrointestinal tract, Ussing chambers have been a useful tool. Two ex vivo chambers, filled with oxygenated physiological buffer, and separated by epithelial tissue allow for the detection of nutrient flux, transepithelial currents, and/or membrane permeability. Historically, detection of the nutrient of interest was achieved using radio-labelled or fluorescent tracers. Beyond detecting flux (uptake, efflux, net flux), Ussing chambers can also tease apart the complex network of transport pathways that govern nutrient absorption. Isolating specific transport pathways can be broad spectrum inhibitors, and alterations to the physiological buffers to target transport pathways of interest. Altering the electrical gradient using a voltage clamp for instance, can be used to neutralize, inhibit, or promote, the electrical gradient; such alterations can be especially useful for charged nutrients. Inhibitors, meanwhile, inhibit the activity of entire families of proteins, useful for when the role of specific protein transporters is of interest. Alterations to buffer composition, such as bicarbonate-free buffer solutions or the inclusion and exclusion of compounds with similar size and charge, can isolate transport solely dependent on that solute or provide knowledge on the solutes that may share a common transport mechanism. Together, these modulations allow for a powerful tool to study the presence or absence of nutrient transport and has been crucial in establishing absorption kinetics of ionic nutrients (e.g., Na+, Cl-), small organic nutrients (e.g., short chain fatty acids, glucose), and macromolecules (e.g., immunoglobulins). Done in conjunction with other techniques, Ussing chambers can offer strong insight to improve our understanding of nutrient absorption and epithelial physiology of the gut. This presentation will discuss the methods key to successful use of Ussing chambers, alongside with their limitations and ways to augment data generated by Ussing chambers.
175 Corporate drivers of sustainability and implications for the business case to make changes based on sustainability opportunities
Authors: Dayhoff David 
Published: September 2024

Abstract
Frequently NGOs, policy organizations, academics and others outside corporate decision-making structures, promote fact-based analyses with the intent of driving change in operations, products and services of businesses. However, there are many other considerations that business leaders weigh before implementing any changes in the name of sustainability. While cost often comes to mind first, fundamentally customer behavior, investor expectations and the ambiguity of potential future risks versus rewards, are crucial. The world of animal agriculture and animal proteins is no exception. While advancing the science of animal protein sustainability is very necessary, practitioners need to have realistic expectations of how, and how quickly, businesses will make changes consistent with science-based arguments. In some extreme cases, companies even take positive actions that they intentionally downplay. Using examples from published analyses, corporate statements and first-hand experience, this presentation will provide insights about the competing influences on food businesses to implement changes intended to improve sustainability of animal agriculture.
512 Divergence of the sow vaginal microbiome based on fertility status
Authors: Fletcher Lauren A , Zhan Xiaoshu , Song Yashu , Li Julang 
Published: September 2024

Abstract
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 &lt; 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 &lt; 0.05) alpha diversity at both the family and genus levels and had a significantly (P &lt; 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

Abstract
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

Abstract
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 &lt; 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 &lt; 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

Abstract
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

Abstract
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

Abstract
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 &lt; 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 &lt; 0.05). In yr 1, there was a positive cubic contrast for ADF between sampling dates (P &lt; 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 &lt; 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

Abstract
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 &lt; 0.01) to stocking rate. Mean forage mass was 947 (SD ± 301) kg DM·ha-1 was negatively linearly related (P &lt; 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.