bluuebunny/crossref_metadata_2025 huggingface dataset:
241 Impact of benzoic acid supplementation in low-protein diets for starter pigs
Authors: Azevedo Paulo , Urzua Jose Rodrigo Wever , Crosby Mary A , Outlaw Alex , Kim Haejin , Rudar Marko
Published: September 2024

Utilizing low crude protein (CP) diets represents a potential avenue for reducing both feed costs and nitrogen excretion in swine production. However, dietary non-essential amino acid content must be considered in addition to essential amino acid content in the context of low CP diet formulations. Dietary glycine content may become limiting in such diets because this glycine in corn and soybean meal is low relative to glycine utilization in the pig. The objective of this study was to evaluate the effect of adding benzoic acid, which is excreted in urine as its glycine conjugate hippuric acid, to low CP diets on growth performance of starter pigs. At 28 d age, pigs were weaned and divided into nursery room pens according to body weight (BW) and sex 5 mixed-sex pigs per pen). Pigs were fed a commercial nursery diet for 4 d; at 32 d age, pigs were weighed, and pens were assigned to one of three dietary treatments: 1) high crude protein (HCP; n = 12 pens); 2) low crude protein (LCP; n = 11 pens) and 3) low crude protein + benzoic acid (LCP+BA; n = 12 pens). Pigs were fed for 4 wk and pig BW and feed disappearance were measured weekly to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (FE; gain-to-feed ratio). At d 0, 14 and 28, blood was collected from one pig/pen by jugular venipuncture. Serum was analyzed for amino acid concentrations with HPLC. The ADG of HCP group (0.58 ± 0.01 kg/d) was greater than LCP (0.54 ± 0.01 kg/d) and LCP+BA (0.51 ± 0.01 kg/d; P < 0.05); ADG of LCP was also greater than LCP+BA (P < 0.05). There was no difference in ADFI among groups (P > 0.05). However, FE of LCP+BA was less than both HCP (0.536 vs 0.579 ± 0.006 kg/kg; P < 0.05) and LCP (0.536 vs 0.576 ± 0.006 kg/kg; P < 0.05); there was no difference in FE between HCP and LCP (P > 0.10). Glycine concentration of LCP+BA (513 ± 32 µmol/L) was less than LCP (630 ± 32 µmol/L; P < 0.05), whereas glycine concentration of HCP (578 ± 32 µmol/L) was intermediate. Lysine concentrations were least in HCP (105 ± 9 µmol/L), intermediate in LCP (138 ± 9 µmol/L), and greatest in LCP+BA (167 ± 9 µmol/L; P < 0.01). The observed reduction in growth performance with benzoic acid exceeds that achieved by feeding low CP diets alone. Greater lysine concentrations in pigs supplemented benzoic acid suggests that lysine was used less efficiently for growth. These findings also caution against supplementing low CP diets with benzoic acid without supplementing additional protein.
240 Feed preference of weanling pigs fed diets containing extruded corn ground to different particle sizes
Authors: Marshall Caleb M , Lee Su A , Stein Hans H
Published: September 2024

The objective was to test the null hypothesis that there were no effects of reducing particle size of extruded corn on feed preference by weanling pigs. Three corn-based diets containing extruded corn ground to 700, 500, or 300 μm were prepared. An 8-d feed preference test was conducted with all possible combinations of the three diets. Each pair of diets constituted a treatment group (i.e., 700 vs. 500 μm; 700 vs. 300 μm; 500 vs. 300 μm). A total of 48 growing pigs [initial body weight (BW) = 12.1 ± 1.34 kg] were allotted to the three preference test combinations using a randomized complete block design with initial BW group as the blocking factor, resulting in eight replicate pens per treatment group. Two pigs were housed in each pen. Pigs had ad libitum access to feed and water. For each preference test, each pen contained two feeders with two of the three diets. Feeder positions within each pen were switched daily to minimize positional preference. Feed allotments and feed disappearances were recorded daily. Feed preference (%) was calculated by dividing the amount of feed disappeared for each diet by the total amount of two diets consumed by pigs. Three statistical models for each preference test included particle size of corn as fixed effect and block as random effect. Results indicated that pigs had greater (P < 0.05) daily feed disappearance and preference for corn with 700 µm on d 1, 4, 5, 7, and 8 when pigs had a choice between 700 µm vs. 500 µm (Table 1). For the other two preference tests, which were 700 µm vs. 300 µm and 500 µm vs. 300 µm, pigs had a greater (P < 0.05) preference for the larger particle size corn (700 and 500 µm, respectively) for d 3 to 8. In conclusion, it was demonstrated that pigs have a preference for larger particle sizes of extruded corn when given the choice. This may be a result of better texture of feed, a satisfying chewing experience, and the perception of greater bulkiness provided by greater particle sizes. However, further research with longer-term feeding trials is needed because pigs may have already adapted to consuming diets with 700 µm particle size prior to the experiment, which is similar to commercial diets.
235 Impact of yeast cell wall and probiotics on gut microbiota, immunity, and growth in weaned piglets
Authors: Souza Fernando Augusto , Bonato Melina A , Huamán Soimer Omar Baldera , Dias Cleandro A , Callegari Marco Antonio , Carvalho Rafael Humberto , Silva Caio Abercio
Published: September 2024

This study investigates the effect of yeast cell wall (YCW) supplementation and multispecies probiotics as alternatives to antibiotic growth promoters (AGPs) on the gut microbiota, immune function, and growth performance in weaned piglets. We utilized a randomized complete block design involving 160 piglets across four treatments during the nursery phase. The treatments administered throughout the experimental period were as follows: CONT+ = basal diet with Halquinol (AGP); YCW = basal diet with Saccharomyces cerevisiae yeast cell wall at 1 kg/MT; SIM+ = basal diet with YCW at 0.5 kg/MT + multispecies probiotic (Bacillus subtilis 2.0 x 10^9 CFU/g, Bacillus coagulans 5.0 x 10^8 CFU/g, Clostridium butyricum 5.0 x 10^7 CFU/g, and Bacillus licheniformis 2.0 x 10^9 CFU/g) at 0.6 kg/MT; SIM- = basal diet with YCW at 0.5 kg/MT + multispecies probiotic at 0.3 kg/MT. Methodologies include daily feed intake, body weight gain measurement, feed conversion ratio (FCR), diarrhea scoring, serum cytokine and chemokine concentration, and microbiome analysis. Throughout the study period (21 to 63 d), only FCR showed differences (P = 0.0076). CONT+ and YCW demonstrated better FCRs, at 1.543 and 1.585 respectively, without significant variation between them, while SIM- lagged with the least favorable outcome at 1.654 (Table 1). At 35 d, IL-10 concentrations were greatest in the SIM- group, showing a 271.25% increase compared with other treatments (Figure 2). At 49 d, IL-8 was least in the YCW group, with a 247% reduction compared with CONT+, while SIM+ and SIM- showed no significant differences compared with other treatments (Figure 1). The Firmicutes/Bacteroidota (F/B) ratio shows that the CONT+ treatment was inferior compared with the YCW, SIM+, and SIM- treatments (Figure 3). The Lactobacillaceae family differed between CONT+ and the YCW, SIM+, and SIM- treatments, with the greatest abundance in the SIM+ treatment, followed by SIM- and YCW (Figure 4). The genera Lactobacillus differed between the CONT+ treatment compared with the YCW, SIM+, and SIM- treatments. Prebiotics, whether used alone or combined with probiotics, serve as effective substitutes for AGPs, boosting the health and performance of piglets throughout the nursery phase.
238 Boosting post-weaning performance of piglets and uniformity with yeast extract supplementation
Authors: Souza Fernando Augusto , Bonato Melina A
Published: September 2024

The yeast extract, derived from 100% natural and pure Saccharomyces cerevisiae, boasts a high digestibility coefficient (> 95%). It is an excellent source of vitamins, minerals, and amino acids, particularly aspartic and glutamic acids, and is noted for its exceptional palatability (Figure 1). This study aimed to assess the impact of dietary yeast extract supplementation on the performance of nursery-phase piglets. Mixed-sex piglets (n = 1,360) were allocated across 18 pens, with 75 animals per pen, and subjected to two treatments (9 replicates each) on a commercial farm in Minas Gerais, Brazil. The treatment groups included a positive control (PC) group, receiving a phase-specific standard diet, and a yeast extract (YE) group, supplemented with 1% yeast extract on top. Initially, all piglets were fed a commercial diet for the first 7 d (from 21 to 27 d old), followed by a farm-specific diet (PC and YE). The YE was administered as a liquid via an oil-injection system at the feed mill. Performance metrics evaluated included body weight gain (BWG) and feed conversion ratio (FCR), with feed intake (FI) being constant due to automated feeding. Data analysis employed ANOVA at a 90% confidence level, with mean differences assessed using the F-test. Piglets in the YE group demonstrated significantly greater BWG from wk 1 post-supplementation, maintaining statistical differences throughout the study (Table 1). The final BWG difference favored the YE group by 1.560 kg (PC = 15.106 kg; YE = 16.666 kg; P-value = 0.05). Notably, animal uniformity within each treatment was superior in the YE group, exhibiting a 49% reduction in variance across the study period compared with the PC group (Figure 2). This improvement in BWG was accompanied by enhanced batch uniformity relative to the PC group. FCR differences were statistically significant from wk 1 of supplementation, concluding with a final FCR of 1.49 for the PC group and 1.39 for the YE group (P-value = 0.02; Table 2). Given the fixed FI across phases, this FCR improvement primarily reflects the observed weight gain differences. These findings indicate that YE supplementation can enhance performance parameters and piglet uniformity in the nursery phase, offering nutritional benefits throughout this critical growth stage.
376 Effects of multi-carbohydrase and protease supplementation on ileal digestibility of amino acids in expeller-pressed canola meal fed to growing pigs
Authors: Lee Jinyoung , Olivo Alicia , Patterson Rob , Nyachoti C Martin
Published: September 2024

Expeller-pressed canola meal (ECM) is a co-product obtained from expeller-pressing canola seeds to obtain canola oil, and it has potential as a cost-effective feedstuff in swine diets. Also, ECM may be a superior protein source compared with solvent-extracted canola meal due to its greater digestible amino acid (AA) contents. However, limited information is available on the effects of enzyme supplementation on AA digestibility in ECM for pigs. Therefore, the objective of this study was to determine the effects of multi-carbohydrase (MC) and protease supplementation on the apparent (AID) and standardized ileal digestibility (SID) of AA in ECM when fed to growing pigs. A total of 12 barrows (65.9 ± 5.0 kg initial body weight), each fitted with a T-cannula in the distal ileum, were allocated for 2 studies: the current study (4 treatments) and another study with 8 treatments. Pigs were arranged in a 12 × 6 incomplete Latin square design with 12 diets and 6 periods, resulting in 6 observations per dietary treatment. Four dietary treatments were: 1) basal ECM diet; 2) ECM diet with MC supplementation (1 kg/tonne); 3) ECM diet with protease supplementation (250 g/tonne); and 4) ECM diet with both MC and protease supplementation. A casein diet was fed to all 12 pigs for 1 wk after feeding experimental treatments to quantify endogenous losses of AA. All diets contained 0.3% titanium dioxide as an indigestible marker. Pigs were fed 1 of the 4 diets during each of the 7-d periods, and ileal digesta were collected on d 6 and 7 from 0800 to 1700 h. Pigs were fed the diets at 2.8 times maintenance energy requirement based on their body weight at the beginning of each period. Data were analyzed using the PROC MIXED of SAS. The statistical model included MC, protease, and their interaction as fixed effects, and replication, animal within replication, and period within replication as random effects. Protease supplementation did not affect AID or SID of AA in ECM. Similarly, no significant differences were observed in MC supplementation on AID and SID of AA, except for a significant increase (P < 0.05) in the AID of Gly with MC supplementation compared with the non-supplemented diet. No interactive effects were found between MC and protease supplementation on the AID and SID of AA in growing pigs. In conclusion, the digestibility of AA in ECM fed to growing pigs with and without enzyme supplementation did not differ, and no interactive effects were observed. Future studies will aim to investigate the dose-effect to accurately determine whether the absence of an effect was attributable to improper enzyme-to-substrate ratio.
375 The effects of protease supplementation on weaned piglet performance and intestinal function fed greater amounts of lower digestible protein sources
Authors: Tactacan Glenmer B , Babatunde Olufemi O , Lahaye Ludovic
Published: September 2024

The present study investigated the impact of dietary protease supplementation on the growth performance and intestinal function of weaned piglets when fed a diet comprising high levels of low digestible protein sources, in comparison with a standard commercially representative piglet diet. A total of 180 weaned piglets, 21 d old, of Duroc × Large White × Landrace crossbreeds, with an initial body weight (BW) of 6.27 ± 0.45 kg, were randomly assigned to three dietary treatments: 1) a standard commercial positive control (PC) diet comprising 22.2% soy protein, 5% whey protein, and 3% fish meal, 2) a negative control (NC) diet comprising 30.1% soy protein without whey protein and fish meal, and 3) a NC diet supplemented with 0.02% protease (NC + PROT). The diets were formulated to be iso-nitrogenous and iso-caloric and were pelleted at conditions of 0.4 MPa and 75°C. The experimental design employed a completely randomized design with 6 replicate pens per treatment, each pen containing 10 piglets. Statistical analysis was conducted using one-way ANOVA, with differences between means assessed using Duncan’s Multiple Range Test (P < 0.05). In terms of piglet performance, feeding the NC diet, containing high levels of low digestible protein sources, resulted in a significant decrease (P < 0.05) in final BW, average daily gain (ADG), and average daily feed intake (ADFI) by 3.1%, 8.2%, and 5.2%, respectively, compared with piglets fed the PC diet. Conversely, the NC diet significantly increased (P < 0.05) the feed-to-gain ratio and incidence of diarrhea by 3.4% and 88.3%, respectively, relative to PC. However, the supplementation of protease in the NC + PROT diet restored final BW, feed-to-gain ratio, and incidence of diarrhea to the same level as PC, while ADG and ADFI were increased (P < 0.05) by 4.6% and 4.3%, respectively. Regarding intestinal function, relative to PC, piglets fed the NC diet exhibited significantly less (P < 0.05) duodenal villus height, crude protein digestibility, and gene expressions of duodenal peptide transporter PepT1 and jejunal amino acid transporter b0,+AT, while blood urea nitrogen and diamine oxidase concentrations were greater (P < 0.05). However, the addition of protease in the NC diet reinstated measures of intestinal function, as NC + PROT-fed piglets showed similar duodenal villus height, crude protein digestibility, gene expressions of duodenal peptide transporter PepT1 and jejunal amino acid transporter b0,+AT, as well as blood urea nitrogen and diamine oxidase concentrations to PC. In conclusion, dietary supplementation of protease in weaned piglets fed higher levels of lower digestible protein sources mitigated losses in growth performance and intestinal functionality by enhancing intestinal development, protein digestibility, nutrient transport efficiency, and overall health status of piglets.
384 Synthesis of glycine from trans-4-hydroxy-L-proline by placentae but not endometria of gestating gilts
Authors: Connolly Erin D , He Wenliang , Lopez Arianna , Olivarez Maddison , Cain Joseph , Lefevre Carli , Ross Alex , Johnson Gregory , Bazer Fuller , Wu Guoyao
Published: September 2024

Trans-4-hydroxy-L-proline (Hyp) is an abundant amino acid in the collagen of pigs. The turnover of this protein releases a large amount of Hyp, traditionally considered a metabolic waste. However, results of recent studies documented the conversion of Hyp into glycine in young pigs. Because pregnant gilts are typically fed a soybean meal-based diet that contains insufficient glycine and provides only 35% of the total glycine needed by pregnant gilts, it is possible that the conceptus can form glycine from Hyp. This hypothesis was tested in the present study. Gilts were fed a 1.8-kg corn- and soybean meal-based diet containing 14% crude protein. On d 90 of gestation, gilts (n = 5) were hysterectomized after euthanasia. Slices (~ 100 mg) of placentae or endometria were incubated at 37 °C for 2 h in oxygenated (95% O2/5% CO2) Krebs-Henseleit bicarbonate buffer (pH 7.4, with 5 mM D-glucose) containing 0 or 2 mM Hyp. After a period of 2 h incubation, 200 μL of 1.5 M HClO4 was added into the incubation medium to stop the reaction. The tissues were homogenized and rinsed with 1 mL water, followed by the addition of 100 μL of 2 M K2CO3. The neutralized extract was analyzed for amino acids using HPLC involving derivatization with o-phthaldialdehyde. Tissues that received no incubation time were determined as well. Data were analyzed by the paired t-test. Results indicated that glycine was produced from 2 mM Hyp by the placenta (Table 1). Glycine was subsequently converted into serine by the placenta. The formation of glycine and serine from Hyp was not due to protein breakdown because there were no differences (P > 0.05) in concentrations of tyrosine (an amino acid that is neither synthesized nor degraded by porcine placentae) in the incubation medium plus tissue at the end of a 2-h incubation period. In contrast to placentae, endometria did not form glycine or serine from Hyp. These findings indicate an important role for Hyp in the provision of both glycine and serine in the conceptus, which may be nutritionally and physiologically significant to compensate for a deficiency of glycine in maternal diets for gestating gilts. (Supported by a USDA/NIFA grant # 2022-67015-36376 and USDA multistate Hatch project #7752: S1081)
381 Effects of L-glutamate and L-aspartate supplementation on intestinal immunity and intestinal barrier integrity of weaned piglets challenged with F18 ETEC
Authors: Wongchanla Supatirada , Park Sangwoo , Kim Kwangwook , Sun Shuhan , Li Xunde , Liu Yanhong
Published: September 2024

L-glutamate (Glu) and L-aspartate (Asp) are pivotal components in the cellular metabolic pathways and immune regulation of pigs. This study aimed to investigate the effects of Glu and Asp on systemic and intestinal immune responses of weaned piglets challenged with an enterotoxigenic Escherichia coli (ETEC) F18. Weaned pigs [n = 49; 8.18 ± 1.54 kg body weight (BW)] were randomly assigned to one of seven treatments, with seven piglets per treatment. The treatments included negative control (NC) and positive control (PC) that were fed with control diet without or with ETEC challenge, respectively. The other five dietary treatments were supplemented with either 1% or 2% Glu or Asp, or 50 mg/kg of Carbadox, and were challenged with ETEC. All pigs except for NC were challenged with F18 ETEC orally for three consecutive days at the dose of 1010 CFUּ dose-1ּ d-1. The study period lasted for 3 wk, with a 7-d adaptation period and 14 d post-inoculation (PI). On d 14 PI, jejunal and ileal mucosa were collected to analyze the mRNA expression of inflammatory cytokines and tight junction proteins by quantitative polymerase chain reaction. All data were analyzed with ANOVA using the PROC MIXED of SAS with pig as the experimental unit. Among all treatments, pigs fed with carbadox showed greatest (P < 0.05) mRNA expression of interleukin (IL)10 in jejunal mucosa. Supplementing 2% Asp or carbadox had less (P < 0.05) expression of IL6 than PC in jejunal mucosa, while supplementing 1% Asp had lowest (P < 0.05) expression of IL6 in ileal mucosa. Pigs fed with 1% Glu had greatest (P < 0.05) expression of IL17A and IL22, while pigs fed with 2% Glu had greatest (P < 0.05) expression of IL23 among all treatments in jejunal mucosa. However, dietary treatments did not affect mRNA expression of IL17A, IL22, and IL23 among all treatments in ileal mucosa. Compared with PC, supplementing 1% Asp had greater (P < 0.05) expression of MUC2, OCDN, and ZO1 in ileal mucosa. Supplementation of 2% Glu or 1% Asp had greater (P < 0.05) expression of MUC2 in jejunal mucosa than NC. Among all treatments, pigs fed with 2% Asp showed greatest (P < 0.05) expression of CLDN1 in ileal mucosa, while showed least (P < 0.05) expression of CLDN1 in jejunal mucosa. However, no difference was observed in expression of OCDN and ZO1 in jejunal mucosa. In conclusion, results of the present study indicate that dietary supplementation of Glu or Asp affected both intestinal immunity and integrity of ETEC-challenged weaned pigs with similar trends as the supplementation of carbadox.
441 Development of a multi-objective feed formulation to improve sustainability of swine production
Authors: De Quelen Francine , Labussiere Etienne , Wilfart Aurélie , Dourmad Jean-Yves , Garcia-Launay Florence
Published: September 2024

Traditional feed formulation focuses on minimizing cost while meeting nutritional requirements and does not consider the environmental impacts associated with producing feed ingredients. Incorporating the impacts of feed ingredients into the formulation process has been proposed as a way to mitigate the impacts of pig production. Garcia-Launay et al. (2018) developed a multi-objective (MO) formulation method based on the environmental impacts of feed ingredients calculated by Life Cycle Assessment (LCA). The objective of this study was to quantify the effects of such eco-friendly pig diets on nitrogen (N) and energy (E) balances, the components of heat production (HP) and the performance of finishing pigs. We compared two different diets: a control diet in accordance with practices in French commercial farms (Control-diet) and an eco-diet formulated with the MO method (Eco-diet). The Eco-diet contained reduced proportion of cereals (50% vs 70%), no oil meals (0% vs 8%) and greater proportions of coproducts (19.5% vs 5%) and protein crops (26% vs 10%) in comparison with the Control-diet. Pietrain x (Large White x Landrace) entire males [n = 12; mean body weight (BW) = 81 kg] were used in this study (n = 6 per experimental diet). Animals were housed individually in digestible cages equipped for measurement of individual feed and water intake, feeding behavior, and separate collection of feces and urine. All animals were adapted to experimental conditions, diets, and digestible cages during 14 d. After the adaptation period, pigs were housed in climate respiration chambers (one pig in an individual cage per chamber) for 6 d to measure digestibility of nutrients, energy and nitrogen balance, and heat production components calculated according to Labussière et al. (2013). We did not observe any significant effect of the dietary treatment on growth performance of pigs (feed intake, average daily gain, feed conversion ratio or water consumption). The digestibility coefficients of dry matter (DM) and N were not different between the two groups. N excreted in urine was significantly greater for the group of pigs fed the Control-diet than for the group fed the Eco-friendly diet (13.5 vs 11 gּ pig-1ּ d-1, respectively, P = 0.03) with no difference for N excreted in feces between the two groups. N retention was less in the Control-diet group in comparison with the Eco-diet group (28.3 vs 30.4 gּ pig-1ּ d-1, respectively; P = 0.05). The E balance was similar between the two groups. The protein deposition was less in the Control-diet group than the Eco-diet group (177 vs 190 g/d, respectively, P = 0.05). Formulating feeds with adequate net energy, SID amino-acids and protein levels while choosing feed ingredients with least environmental impacts, such as co-products, can be an effective way to decrease environmental impacts of pig production without consequences on animal performances.
31 Sustainable livestock, sustainable future: Why we need a toolkit of solutions to improve sustainability in animal agriculture
Authors: Mitloehner Frank
Published: September 2024

Meat and dairy will continue to be an essential part of diets around the world, but as demand increases so does pressure to reduce the environmental impact of farming. There is no single solution that will allow the global community to meet demand and improve sustainability in our food system. We will need a toolkit of solutions to meet the needs of producers in various regions and production systems.
105 Fetal hypothyroidism dysregulates local hepatic and renal renin-angiotensin systems in a temporal manner
Authors: Smith Alyssa A , Rudy Kaylyn , Pasternak J Alex
Published: September 2024

The renin-angiotensin system (RAS) is an essential endocrine system with roles in electrolyte balance, blood volume, and blood pressure. While the canonical RAS exerts systemic vasoregulatory effects through steps involving hepatic, renal, and pulmonary-derived compounds, there is also evidence of localized, independently acting RAS in organs such as the liver and kidney. Further, modulations in RAS resulting from fetal hypothyroidism have previously been documented, although the temporal specificity of this endocrine interaction is not well-characterized. Thus, the objective of the current study was to examine the time-dependency of modulations in local hepatic and renal RAS in a porcine model of fetal hypothyroidism. To achieve this, pregnant gilts (n = 24) were divided evenly into either a control (CON) or methimazole (MMI) treatment group, with the MMI group receiving 5 mgּ kg-1ּ d-1 of oral MMI treatment and the CON group receiving an equivalent sham carrier. Each group was further divided into four timepoints (n = 3/treatment at each timepoint), with treatment beginning on d 34, 45, 55, or 65 of gestation. After 21 d of treatment, and at d 55, 66, 76, and 86, respectively, the gilts were humanely euthanized, blood samples taken from all fetuses (n = 340), and thyroid, liver (LVR), and kidney (KID) collected from a subset of four fetuses per litter (n = 96). Confirmation of fetal hypothyroidism in the MMI group was accomplished via histological assessment of the thyroid and measurement of circulating thyroxine (T4) concentrations. Each MMI-treated fetus (n = 96) subset showed evidence of goitrous thyroid histology, with the absence of healthy eosinophilic colloid indicating successful disruption of the fetal hypothalamic-pituitary-thyroid axis. T4 assays performed on a similar subset of n = 96 fetuses showed that MMI treatment significantly reduced T4 concentrations within each timepoint relative to CON (P < 0.001 at all timepoints). Following confirmation of hypothyroidism, RNA was extracted from the fetal LVR and KID samples to allow for gene expression analysis by qPCR. Ct values were normalized, fold changes calculated using the 2-∆∆Ct method, and differences within timepoint determined using a Wilcoxon signed-rank test. AGT, the precursor to all bioactive RAS peptides, was significantly downregulated in LVR at d 66 (P = 0.014) and 76 (P < 0.001). ACE was significantly upregulated at d 76 in both LVR (P = 0.037) and KID (P = 0.005). No significant changes were observed for ACE2 in either tissue, or for renal REN. Finally, AGTR1, the receptor that mediates RAS effects, was significantly downregulated at d 55 in KID (P < 0.001) and d 76 in LVR (P = 0.023), while also being upregulated at d 86 in LVR (P = 0.033). Collectively, these results show that fetal hypothyroidism modulates RAS function in a gestational age-dependent manner, which may alter fetal development and subsequent postnatal physiology.
109 Dam and calf influences on colostrum yield and quality in beef cattle
Authors: Meyer Allison M , Redifer Colby A , Rathert-Williams Abigail R
Published: September 2024

To determine factors affecting colostrum yield and quality, data from 148 cow-calf pairs over 6 experiments were combined. In each experiment, single rear quarter colostrum yield was obtained post-calving but pre-suckling. Colostrum IgG was determined by ELISA, and colostrum lactose, triglycerides (as a measure of total fat), and protein were determined by colorimetric analyses. Total IgG and nutrients were calculated as the concentration multiplied by single-quarter yield. Calf birth weight and expelled placental dry weight were also collected post-calving. Mixed linear models (experiment as a random effect) were used to determine the effects of dam age (primiparous: 2 yr, young: 3 to 4 yr, mature: ≥ 5 yr), dam peripartum body condition score (BCS; thin: < 5, moderate: 5 to 5.99, fleshy: ≥ 6), and calf sex on colostrum yield (single-quarter colostrum weight) and quality. Pearson correlation coefficients were also determined for colostrum yield with dam pre-calving body weight (BW), calf birth weight, calf birth weight relative to dam BW, whole placental dry weight, and gestation length. Mature dams had the greatest (P ≤ 0.03) and primiparous dams had the least (P ≤ 0.001) colostrum yield and total lactose. Colostrum from primiparous dams had greater (P = 0.03) IgG concentration than mature and greater (P ≤ 0.001) protein concentration than young and mature. Mature dams had greater (P ≤ 0.02) total IgG, total protein, and total triglycerides compared with both primiparous and young. Colostrum yield was less (P ≤ 0.04) for thin than moderate and fleshy dams. Total IgG was unaffected (P = 0.11) by dam BCS; however, thin dams had greater (P ≤ 0.04) IgG concentration than moderate and fleshy. Lactose concentration and total lactose were less (P ≤ 0.02) in colostrum from thin compared with moderate dams. Protein concentration was greater (P = 0.001) in thin than moderate dams, but thin dams had less (P ≤ 0.02) total protein compared with moderate and fleshy. Dam BCS did not affect (P ≥ 0.59) colostrum triglyceride concentration or total triglycerides. Colostrum yield and quality were not affected (P ≥ 0.22) by calf sex. Pre-calving dam BW was positively correlated with colostrum yield (r = 0.46, P < 0.001). Colostrum yield was also positively correlated with calf birth weight (r = 0.31, P < 0.001) and whole placental dry weight (r = 0.26, P = 0.007), but tended to be negatively correlated with calf birth weight relative to dam BW (r = -0.14, P = 0.09). Gestation length had no relationship (P = 0.31) with colostrum yield. Overall, colostrum yield and quality are negatively affected in young and thin beef dams. In addition, both dam and calf weight have positive relationships with colostrum yield, likely mediated by endocrine action associated with placental size.
112 Effects of maternal body condition on colostrum, foal weight, and foal IgG concentration
Authors: Summers Cheyenne S , Tillquist Nicole M , Engle Terry E , Barnello Nicholas M , Voggu Santhi Priya , Reiter Amanda S , Govoni Kristen E , Zinn Steven A , Reed Sarah A
Published: September 2024

Foals are born with little to no immunity and rely on maternal colostrum to develop adequate circulating immunoglobulin G (IgG) concentrations in the periparturient period. Colostrum directly impacts the health of the foal, and there are limited data assessing how maternal metabolism and body condition impacts IgG in colostrum and in the foal postnatally. To determine the influence of maternal body condition score (BCS) and cresty neck score (CNS) on glucose and insulin metabolism in the pregnant mare, colostrum composition, and colostrum and foal IgG concentrations, light breed mares (n = 6) were divided into two groups based on BCS and CNS at 315 ± 0.45 d of gestation. The groups were identified as moderately obese (MO; n = 3, BCS) and lean (LN; n = 3). Mares were fasted overnight and then underwent an intravenous (iv) glucose tolerance test at 315 ± 0.45 d gestation. Blood samples were collected at -30, -15 and 0 min and mares were administered dextrose iv [0.3 g/kg body weight (BW)] over 3.7 ± 0.17 min followed by an intravenous infusion of insulin (0.3 mU/kg BW) 20-min later. Additional blood samples were collected 2, 5, 10, 15, 20, 25, 30, 45, 60, and 120 min after initiation of dextrose infusion. At parturition, a colostrum sample was collected before foals nursed and analyzed for protein and fat, and IgG concentration. A foal blood sample was collected 18 h after birth to determine passive transfer of IgG. Placental, mare, and foal weights were measured at birth. Data were analyzed using a t-test with significance at P ≤ 0.05 and a tendency at 0.05 < P ≤ 0.10. The MO group had greater BCS (P = 0.01) and CNS (P = 0.01) than the LN group. Moderately obese mares tended to have 9% greater glucose area under the curve (AUC) after dextrose (P = 0.10) and a 9% greater glucose AUC after insulin infusion (P = 0.10) than LN mares. Colostrum IgG concentrations, and protein and fat content (P ≥ 0.3) did not differ between groups. Foal serum IgG concentrations, foal BW, and placental weights were similar between groups (P ≥ 0.8). The ratios between foal BW and placenta weight, and between foal BW and mare BW were similar between groups (P ≥ 0.3). Moderately obese maternal BCS and CNS scores may decrease maternal glucose clearance during late gestation but did not impact colostrum quality or foal IgG concentrations within 24 h postpartum. As the equine fetus matures later in gestation than other livestock species and relies heavily on glucose uptake from the placenta, it is critical to increase our understanding of the impacts of maternal obesity and glucose clearance on foal development and pre- and post-natal health.
228 Evaluation of sire vs. dam influences on age at first parturition in Brahman heifers
Authors: Willis Caleta , Earnhardt-San Audrey , Carson Chloey P , Long Charles R , Welsh Thomas H , Randel Ronald D , Perry George A
Published: September 2024

The objective of this study was to determine if sire or dam had a stronger impact on age at first parturition of Brahman heifers (n = 833) born between 2000-2021. Typically, in Bos taurus heifers, puberty occurs between 10 to 12 mo of age leading to parturition of the first calf occurring around 24 mo of age. However, in Bos indicus cattle, puberty is achieved between 15 to 17 mo of age leading to a first calf around 36 mo of age. The ability of heifers to achieve pubertal status earlier plays a vital role in reproductive success. For selection purposes, knowing if early pubertal attainment is influenced more by the sire or dam is important for herd management. For this study, to minimize any epigenetic and environmental changes, all heifers originated and were developed at the Texas A&M AgriLife Research Center at Overton. Sire groups (SG) and dam groups (DG) were established based on the number of offspring used in the study. Sire groups were comprised of SG-1 (1+ calves sired; n = 58 sires), SG-2 (5+ calves sired; n = 44 sires), SG-3 (10+ calves sired; n = 31 sires), SG-4 (15+ calves sired; n = 23 sires), SG-5 (20+ calves sired; n = 17 sires), and SG-6 (25+ calves sired; n = 12 sires). Dam groups consisted of DG-1 (1+ calves; n = 489 dams), DG-2 (2+ calves; n = 215 dams), DG-3 (3+ calves; n = 81 dams), DG-4 (4+ calves; n = 38 dams), and DG-5 (5+ calves; n = 9 dams). Statistical analysis (PROC GLM; SAS 9.4) included the fixed effect of sire group (dam group) and all dams (sires) utilized in that grouping. Significance for age at first calving was considered at P < 0.05. Mean separation for age was performed using LSmeans. Sire significantly impacted age at first calving in SG-1 (P = 0.0173) vs dam effect (P = 0.3993; n = 489 dams), SG-2 (P = 0.0159) vs dam effect (P = 0.5476; n = 481 dams), SG-3 (P = 0.0023) vs dam effect (P = 0.2532; n = 439 dams), SG-4 (P = 0.0022) vs dam effect (P = 0.3997; n = 400 dams), SG-5 (P = 0.0002) vs dam effect (P = 0.0602; n = 361 dams), and SG-6 (P = 0.0005) vs dam effect (P = 0.1058; n = 305 dams). The dam impact on age at first calving was never significant in the dam groupings but sires did impact age at first calving in two groups: DG-1 (P = 0.3993) vs sire effect (P = 0.0173; n = 58 sires), DG-2 (P = 0.4823) vs sire effect (P = 0.0173; n = 56 sires), DG-3 (P = 0.3011) vs sire effect (P = 0.3420; n = 49 sires), DG-4 (P = 0.3911) vs sire effect (P = 0.6278; n = 40 sires), and DG-5 (P = 0.3042) vs sire effect (P = 0.9159; n = 23 sires). In summary, evaluation of sire and dam influences on age at first parturition for female offspring demonstrates that the ability to calve at an earlier age is influenced by the sire but not the dam. Further studies into the mechanisms for the transmission of this trait are warranted.
226 Serotonin stimulates relaxation in ovine saphenous vein precontracted with ergovaline
Authors: Klotz James L , Duckett Susan K , Checura Celina M
Published: September 2024

The predominant ergot alkaloid found in wild type endophyte-infected tall fescue grass is ergovaline. Ergovaline is a potent vasoconstrictor in livestock that consume it. Previous research has shown that ergovaline can bind serotonin (5-HT) receptors and blood vessels exposed to ergovaline become unresponsive to subsequent 5-HT exposure. Serotonin can stimulate vascular contraction or relaxation depending on the receptor subtype targeted. The objective of this experiment was to evaluate 5HT as vasorelaxant in the ovine saphenous artery and vein that were precontracted with ergovaline. Blood vessels were collected from mixed breed market rams (n = 7) at slaughter, cleaned of surrounding adipose and connective tissue, sliced into 2-mm cross-sections, and mounted in a multimyograph. Artery and vein cross-sections were equilibrated to 1 g tension in continuously gassed (95% O2/5% CO2) Krebs-Henseleit buffer (pH 7.4; 37.5 °C) for 90 min, precontracted with 1.0 μM ergovaline (in a tall fescue seed extract) for 30 min, exposed to increasing concentrations of 5-HT that ranged from 1 x 10-9 to 1 x 10-4 M for a 5-min interval. Response data were normalized to the 1.0 μM ergovaline response and were analyzed as a completely randomized design in SAS. The saphenous vein was larger in diameter blood vessel than the saphenous artery. Both vessel types contracted in response to exposure to 1 μM ergovaline. The saphenous artery had a much lower maximal response to ergovaline than did the vein (P < 0.05) that could be attributed to the size difference. The lateral saphenous vein relaxed to increasing concentrations of 5-HT (P < 0.05) with 87 % relaxation occurring by 1 x 10-6 M 5-HT. Conversely, the lateral saphenous artery contracted in response to increasing concentrations of 5-HT (P < 0.05) resulting in a 43% increase from the ergovaline response by the 1 x 10-4 M addition. This response did not become significant in the artery until 1 x 10-5 M 5-HT compared with 1 x 10-8 M for the vein. This resulted in a 50% effective concentration for 5-HT in the artery of 4.5 compared with 8.1 M for the vein (P < 0.05). The differing responses across vessels are likely a result of different receptor populations and this should be verified in future research. This is the first reported observation of stimulated relaxation of a blood vessel constricted ergovaline. Additional research is needed to understand the mechanism of how 5HT can be used to stimulate vasorelaxation in livestock suffering from ergot alkaloid-induced vasoconstriction.
232 Influence of melatonin supplementation on uterine and coccygeal artery hemodynamics of pregnant multiparous crossbred beef cows grazing endophyte-infected tall fescue
Authors: Snider Miriam A , Culp Timothy C , Hopkins Carson R , Moss Nathaniel T , Edwards J Lannett , Looney Charles R , Powell Jeremy G , Kegley Elizabeth B , Coffey Ken P , Gadberry M Shane , Lemley Caleb O , Littlejohn Brittni P
Published: September 2024

The objective was to determine the influence of melatonin supplementation on uterine and coccygeal artery hemodynamics of pregnant beef cattle grazing toxic, endophyte-infected (E+) tall fescue during mid-late gestation. Multiparous crossbred cows were artificially inseminated with sex-sorted semen (Y chromosome-bearing sperm) from a single Red Angus sire and maintained on pastures free from E+ fescue prior to the start of the treatment period. Pregnant cows (n = 50) were assigned to one of three treatment groups with two replications per treatment: non-toxic, novel endophyte-infected (NE+) fescue without melatonin supplementation (NE+/NM; n = 16), E+ fescue with melatonin supplementation (E+/M; n = 16), and E+ fescue without melatonin supplementation (E+/NM; n = 18). Treatments were administered over a 70-d period between May and July (d 147 ± 1 to 217 ± 1 of gestation). A commercially available feed was mixed with or without melatonin [100 µg/kg body weight (BW)] and hand-fed daily. Cows were weighed at d 0, 14, 28, 42, 56, and 70 relative to the start of the treatment period. Measures of uterine and coccygeal artery hemodynamics included artery diameter, pulsatility index (PI), resistance index (RI), blood flow (BF), and blood flow as a proportion of BW (BF/BW) and were determined by color Doppler ultrasonography at the conclusion of the 70-d treatment period. Plasma prolactin was determined at the end of the 70-d treatment by radioimmunoassay. After the treatment period, cattle were maintained together as a single group on pastures that were free from E+ fescue. Body weights were analyzed using the MIXED procedure of SAS specific for repeated measures with treatment, time, and the interaction as fixed effects and replicate as random. Prolactin and arterial hemodynamics were analyzed using the MIXED procedure of SAS with treatment as a fixed effect and replicate as random. There was an effect of time and a treatment by time interaction on cow BW (P < 0.01). Prolactin was decreased (P = 0.02) in E+/NM (71.8 ± 14.0 ng/mL) and E+/M (86.9 ± 14.9 ng/mL) relative to NE+/NM (128.9 ± 14.9 ng/mL) cows. Coccygeal artery PI was decreased (P < 0.02) in E+/M (0.86 ± 0.1) relative to NE+/NM (1.06 ± 0.1) cows. Coccygeal artery RI was decreased (P < 0.01) in E+/M (0.53 ± 0.02) relative to NE+/NM (0.62 ± 0.02) cows. There were no other effects of treatment (P > 0.05). Preliminary results suggest limited effects of melatonin on uterine and coccygeal artery hemodynamics in pregnant multiparous crossbred beef cows grazing endophyte-infected tall fescue.
231 Ovarian follicle diameter and corpus luteum volume of beef cows enrolled in fixed-time artificial insemination while receiving chromium propionate supplementation
Authors: Vidlund Trinity , Currin John , Clark Sherrie , Stewart Jamie L , Craun Hannah , Mitchell Camille , Wolpert Bailey , Redifer Tracey , Mercadante Vitor R G
Published: September 2024

We investigated the effects of chromium propionate (CrP) supplementation on reproductive performance of beef cows during the pre-partum and breeding periods. Angus-based commercial suckled beef cows were stratified by predicted calving date, body weight (BW) and randomly assigned to one of two treatments: 1) Control, (n = 30) supplementation of a corn gluten, soy hull pellet feed (50:50) with a mineral pack at 1 kg ּ cows-1 d-1; or 2) CrP, (n = 32) supplementation at 1 kgּ cow-1ּּ d-1 of a corn gluten, soy hull pellet feed (50:50) with a mineral pack containing 1.4 g of CrP (KemTRACE chromium 0.4%, Kemin Industries, Inc., Des Moines, IA). Cows remained on a single pasture equipped with feed bunks capable of monitoring individual supplement intake (SmartFeed, C-lock Inc., Rapid City, SD). Treatments were initiated at 92 d prepartum and ended on d 35 post fixed-time artificial insemination (TAI), for a total of 127 d. Cows were enrolled in the 7-d CO-Synch+CIDR TAI protocol. Ovarian ultrasonography was performed to determine diameter of the largest follicle, and the volume of a corpus luteum (CL) on d -10, -3, 0 (TAI day), and 7. Pregnancy diagnosis was performed by ultrasonography on d 35. Cow BW was recorded on d -92, 0, and 35. Data were analyzed using the GLIMMIX and MIXED procedures of SAS with cow as the experimental and fixed effect of treatment. Age, days postpartum, and initial BW were similar (P > 0.05) between treatments (7.4 and 7.2 ± 0.61 yr, 81.3 and 80.8 ± 4.61 d, 526.2 and 528.6 ± 16.21 kg for Control and CrP, respectively). Supplement intake was similar (P = 0.534) between treatments (1.22 and 1.03 gּ cow-1ּּ d-1, for Control and CrP, respectively). Cow BW was similar (P > 0.05) between treatments on d 0 and 35 (548.5 and 551.4 ± 13.50 kg, 562.8 and 574.6 ± 11.41 kg, for Control and CrP, respectively). Furthermore, estrus expression and TAI pregnancy rate was similar (P > 0.05) between treatments (62.1 and 61.1 ± 1.2% estrus, 55.1 and 81.2 ± 20.1% TAI pregnancy rate, for Control and CrP, respectively). However, CrP cows had a larger follicle (P = 0.028) on d 0 (13.79 and 15.56 ± 0.58 mm, for Control and CrP, respectively). Additionally, on d 7, CrP cows had an increased (P = 0.038) CL volume (15.24 and 17.55 ± 0.68 mm3, for Control and CrP, respectively). Supplementation of CrP to beef cows from the pre-partum until breeding did not change cow BW, but increased follicle diameter at TAI and subsequent CL volume.