bluuebunny/crossref_metadata_2025_split huggingface dataset:
56 Metabolic status of respiratory disease challenged beef steers altered by intranasal Zn and vitamin A treatments
Authors: Rients Emma L , Franco Carlos , McGill Jodi , Hansen Stephanie L 
Published: May 2024

Abstract
Bovine respiratory disease (BRD) is a major cause of morbidity and mortality in the cattle industry. Increasing the ability of a calf to respond to disease is of interest due to the loss of production during disease. Zinc and vitamin A (VA) are key micronutrients involved in many immunologic processes such as cell signaling and mucosal immunity. Angus crossbred steers [n = 48; body weight (BW) = 333 ± 4.2 kg] were utilized in this 14-d BRD challenge investigating intranasal (IN) treatments of Zn and VA. Steers were split into two groups (n = 24) with identical disease challenge and sample collection schedules. Before disease challenge, steers were housed at the Iowa State University Beef Nutrition farm (BNF). Steers were weighed on d -2 and -1 of viral challenge and trucked for 6 h before delivery to the Iowa State University Animal Resource Station. On d 0, steers were challenged with an aerosol inoculation with 104 TCID50 BRSV followed by 5x108 CFU of Mannheimia haemolytica on d 5. On d 4, steers received IN treatments of Zn (ZN; ZnO nanoparticles), VA (VA), Zn and VA (VA+ZN), or control with no IN treatment (CON). For trace mineral and VA analysis, liver biopsies were collected on d -9 and 20 and plasma collected on d 0, 4 (trace mineral only), 5, 7 and 14. Steers were tested for viral shedding on d 0, 4, 5, 7, 10 and 14. RNA was isolated from bronchioalveolar lavage (BAL) cells (d 0 and 7) for gene expression related to inflammation, VA and trace mineral metabolism. Statistical analysis was completed using the GLIMMIX and MIXED procedures in SAS 9.4. Throughout the study, viral shedding was not affected by intranasal treatment (P ≥ 0.59). There were no group × TRT × day effects for plasma trace minerals (Cu, Zn, Fe) or VA concentrations (P ≥ 0.18). Intranasal VA prevented a decrease in plasma VA on d 5, after which all treatments were similar (P &lt; 0.01). There were no TRT × day effects for plasma Zn and Cu (P ≥ 0.50). Post challenge, liver VA was increased in VA treated steers compared with steers not treated with VA (P = 0.04). Liver Mn tended to be increased post challenge in IN ZN treated steers (P = 0.08). IN Zn treated steers tended to have lesser expression of IL-10 in BAL cells on d 7 post infection (P = 0.07). Local IN supplementation of Zn and VA can have systemic and local affects on respiratory disease challenged steers and may support increased response to disease.
57 Effect of diet mixing strategies on growth performance and carcass characteristic in feedlot steer
Authors: Waldon Naomi , Garcia Lyda , Clevenger Doug , Relling Alejandro E 
Published: May 2024

Abstract
Our objective was to determine the effects of a feeding management strategy on growth and carcass quality and characteristics on finishing feedlot beef cattle. Angus-Simmental steers (n = 60), blocked by body weight (BW), were housed in individual pens and randomly assigned to treatments. Treatments were total mixed ration (TMR) or a non-mixed diet (Split). The diet contained 67.5% of dry rolled corn, 18% of distiller grains with soluble, 2.5% soybean meal, 7% hay, and 5% of mineral and vitamin mixed. The diet composition for both treatments was similar, the only difference was the use of a TMR or that the concentrate was fed separately from the hay on the Split treated calves. Feed intake was monitored through slick bunk management in both treatments. For the Split assigned calves, if any hay or concentrate was left in the bunk on two consecutive days, the total feed was decreased by 5%; maintaining always the 93% concentrate and 7% forage ratio. Steers were weighed monthly and feed samples were collected for nutrient composition analysis semimonthly. Monthly weights and intakes were used to calculate average daily gain (ADG) and gain to feed ratio (G:F). Steers were slaughtered per block when the average weight of the block reached 555 kg. Carcasses were evaluated 48 h post slaughter. Carcass yield and quality factors were evaluated at the 12th/13th rib interface. Data were analyzed as randomized complete block design. Considering the fixed effect of the feeding strategy and the random effect of block. We did not observe differences (P &gt; 0.17) in growth performance or carcass characteristics variables due to management strategy (Table 1). The lack of observed differences due to treatment might be because the ratio of concentrate and forage intake was similar for both groups, in addition to the slick bunk management in both treatments, which forced steers to eat all their ration, independent of the treatment, to continue to receive the same amount of feed.
164 Impact of varying dietary inclusion of modified distiller’s grains plus solubles weekly compared with constant inclusion on feedlot cattle performance and carcass characteristics
Authors: Sousa Debora Gomes , McDermott Rebecca L , Norman Mitch M , MacDonald James C , Stock Rick A , Erickson Galen E 
Published: May 2024

Abstract
The use of distiller’s grains in feedlot diets was abundant due to supply and price, but the availability to feedlots and greater prices of distiller’s grains has led to reduced inclusion and more variation in supply, and thus, inclusion within the feeding period for cattle. The hypothesis was that varying inclusion of modified wet distiller’s grains plus solubles (MDGS) in the diet would negatively impact cattle performance due to changing dietary starch concentration and risk of acidosis. One solution to help with ruminal acidosis concerns with variable MDGS inclusion would be increasing roughage inclusion. Therefore, our objective was to evaluate if varying the inclusion of MDGS at normal and 2X normal roughage inclusion influences performance of finishing cattle. In this study, crossbred steers (n = 576) with an initial body weight (BW) = 379 kg (SD= 11 kg) were evaluated for performance and carcass traits over the 143 d on study. Two inclusions of grass hay (6% and 12%) and three treatments related to MDGS (no inclusion, constant inclusion at 25% MDGS, and varying inclusion between 15 and 35% MDGS) were tested in a 2 × 3 factorial. Variable inclusion was accomplished by randomly selecting inclusions of 15, 20, 25, 30, or 35% each week with inclusion averaging 25% over the entire feeding period. There was no interaction between grass hay inclusion and MDGS inclusion (P ≥ 0.67) for performance data except a tendency (P = 0.09) for a gain to feed (G:F) interaction. In treatments fed 12% hay, G:F increased for cattle fed either MDGS inclusion (25% constant or varying inclusion) compared with 0% MDGS. In cattle fed 6% hay, G:F was similar between 0, 25 constant or variable 25% MDGS treatments. There was not an interaction due to a different response of variable versus constant inclusion of MDGS when more hay was included, as hypothesized. The 25% constant MDGS and 25% variable MDGS treatments did not differ (P ≥ 0.22) in average daily gain (ADG), hot carcass weight, or G:F. There was a tendency for cattle fed varying inclusion of MDGS to eat less (P = 0.10), but this difference was small (0.1 kg/d). In general, cattle fed MDGS (constant or varying) had greater dry matter intake and ADG, with greater fatness and marbling compared with cattle fed without MDGS (P ≤ 0.01). As for the degree of liver abscess severity, there was no interaction between treatments. Our results show that although varying supply of MDGS in diets is not recommended or desired, if it occurs and inclusions vary from 15 to 35%, these weekly adjustments did not negatively affect gain or feed efficiency in this study.
297 Effects of plasma zinc concentration on longissimus thoracis metabolic status of beef steers
Authors: Ortner Brock M , Smerchek Dathan T , Hansen Stephanie L 
Published: May 2024

Abstract
The objective of this study was to examine the role of Zn status on muscle glucose and other metabolites. Angus steers [n = 144; body weight (BW) = 525 ± 30 kg] with varying plasma Zn concentration and implant status served as the initial pool for this secondary experiment. Steers were assigned to one of two implant (IMP) treatments: no implant (NO) or Component TE-200 (TE-200; Elanco, Greenfield, IN) on d 0. Zinc was supplemented as ZnSO4 at 0 mg Zn/kg dry matter (DM; analyzed 54 mg Zn/kg DM), 30 mg Zn/kg DM, or 100 mg Zn/kg DM, starting 60 d before implant day. Steers were fed via GrowSafe bunks (GrowSafe Systems Ltd., Airdie, AB, Canada), and steer was experimental unit. Steers were fed in two blocks with a 14-d stagger for sample logistics. Blood and muscle biopsies of the longissimus thoracis were collected on d 40 after implant, a minimum of 2 h post-feed delivery. Plasma Zn was quantified via ICP-OES and 144 samples were stratified into quantiles by plasma Zn concentration. Samples (n = 12 low and 12 high from NO and TE-200 groups) were identified and designated as low plasma Zn (LOW, 1.1 mg Zn/L average) and high plasma Zn (HI, 1.6 mg Zn/L average) treatments (TRT). Muscle samples from these 48 steers were homogenized and derivatized for subsequent analysis via gas chromatography-mass spectrometry (GCMS) for non-targeted metabolomic analysis. Data were analyzed as a complete randomized design using the MIXED procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC) with fixed effects of TRT, IMP, BLOCK, and TRT×IMP. A TRT×IMP effect was observed for muscle glycine (P = 0.02) where LOW/IMP was similar to HI/NO but had greater glycine concentrations than LOW/NO and HI/IMP. There was a tendency for a TRT×IMP (P = 0.07) effect where LOW/IMP and HI/NO tended to have greater concentrations of hydroxyisovaleric acid. Given the role of glycine in protein synthesis and hydroxyisovaleric acid in leucine metabolism these data suggest differential protein responses to implants in cattle of lesser vs. greater plasma Zn concentrations. Hydroxybutyric acid, a ketone body which can be utilized for energy, tended to be greater in muscle of steers receiving an IMP (P = 0.09). Contrary to our hypothesis that greater plasma Zn would support differential muscle glucose metabolism, no effects of plasma Zn TRT or IMP were noted for glucose, lactate, and other detected metabolites. Both LOW and HI plasma Zn concentrations were still considered adequate, and future research should explore the impact of distinctly deficient and adequate plasma Zn concentration on glucose metabolism pathways in muscle.
298 Impact of ruminal acidosis on cattle energy metabolism
Authors: Linder Haley F , Li Jiangong , Berger Larry L , Green-Miller Angela R , McCann Joshua C 
Published: May 2024

Abstract
The objective of this study was to determine the impact of a bout of ruminal acidosis on energy metabolism of cattle unadapted to a high concentrate diet. Eleven ruminally cannulated steers [body weight (BW) = 352 kg ± 27] were blocked into 3 groups based on initial BW. Before the start of the experiment, animals were consuming a forage-based diet as well as adapted to the headbox style respiration chambers. Additionally, before the experiment, gas emission data were collected over a 24-h period when cattle received an ad libitum forage-based diet for use as a covariate in the statistical analysis. For the experiment, steers were moved into headboxes at the conclusion of a 24-h fast and subsequently received 1 of 2 treatment diets: control (CON), forage-based diet or acidosis (AC), concentrate-based diet. Steers remained in the headboxes for 48 h. Gas concentrations from each headbox were collected hourly and analyzed with an infrared photoacoustic gas analyzer. Ruminal pH, fecal pH, volatile fatty acids, and lactate were also measured during the acidosis challenge. Data were analyzed with the MIXED procedure of SAS 9.4. A treatment × day effect (P = 0.03) was observed for dry matter intake with intake being similar for both CON and AC steers on d 1 but AC steers consuming 2.02 kg less on d 2. Treatment affected ruminal pH (P &lt; 0.01) as CON steers had a greater ruminal pH than AC steers. Greater total volatile fatty acids (P &lt; 0.01) were observed for steers on AC treatment compared with CON. A treatment × time interaction (P &lt; 0.01) was observed for ruminal lactate concentration with AC steers having greater concentrations from h 16 to 36. Fecal pH was affected by a treatment × time interaction (P = 0.05) as AC steers had lower fecal pH from h 24 to h 32. Over the 48-h observation period, there was a treatment × time interaction (P = 0.04) for carbon dioxide production as AC steers produced less CO2 after h 24. No treatment × time interaction was detected for oxygen consumption. However, there was a time effect (P &lt; 0.01). Respiratory quotient was not affected by treatment, day, or their interaction (P ≥ 0.19). Heat production tended (P = 0.06) to be different between treatments, with AC having less heat production than CON. Thus, the effects of ruminal acidosis on gas emissions and energetics may be more transient during the time course of an acidotic bout or have a longer duration even after ruminal pH has recovered.
217 Weaning weight associated with improved nursery pig growth rate
Authors: McCallum Michelle , Krahn Gregory , Mahoney Julie , Hinson Rodney , Eden Chris L 
Published: May 2024

Abstract
Heavier body weight (BW) at weaning is associated not only with heavier birth weight, but also with heavier downstream BW at nursery exit and at fixed-time marketing. To further address management implications of wean weight (WW), this study evaluated WW impact on nursery pig start-up, gain to feed ratio (G:F), and performance variation from 6 to 20 kg BW. Individual BW were collected at the time of weaning using the LeeO individual animal identification system. Pigs (n = 1,054; PIC 800 x DNA 241 F1) were blocked by wean age (20.1 ± 0.8 d) and sex, ranked in order of individual WW (5.94 ± 1.35 kg), and split into eight WW groups each representing 12.5% of the weaning population (P &lt; 0.05; Table 1). Similar sized pigs were housed together (12 pigs/pen, 11 replicate pens/WW group) and fed a common 4-phase nursery diet for 42 d post-wean. Pen weights and feed disappearance were recorded at d 7, 14, 21, and 42, and individual BW were collected at d 42. Data were analyzed using linear mixed effects models in the lme4 package of R. Body weight differences (P &lt; 0.05) between each WW group were evident on d 0 and through d 7 post-weaning. The lightest 12.5% of the weaning population had the greatest (P &lt; 0.001) individual pig BW coefficient of variation (CV) at weaning and d 42 whereas no differences (P &gt; 0.05) in d 42 BW CV were evident among the other WW groups. During the first week post-weaning, average daily feed intake (ADFI) diverged (P &lt; 0.05) between the lightest 12.5% (113 g/d) and the heaviest 25% (134 g/d) of the wean population. From d 0 to 42, the lightest 12.5% WW pigs had slower average daily gain (ADG; P &lt; 0.001), less ADFI (P &lt; 0.001), and reduced exit BW (P &lt; 0.001) than the other WW groups. Neither ADG nor ADFI differed (P &gt; 0.05) among the median 50% of the population from d 0 to 42. No differences (P &gt; 0.10) in overall nursery G:F between any WW groups were observed. Across the population, regression analysis indicated a 0.45 kg increase in WW resulted in a 1.0 kg increase (linear, P &lt; 0.001) in nursery exit BW. Moreover, both ADG and ADFI as a percentage of BW increased as WW decreased, suggesting lighter WW pigs have competitive growth capacity to their heavier WW counterparts through 20 kg BW. Data demonstrates WW influences nursery exit weight of pigs fed a common diet. Future research should explore solutions to increase growth rate of light WW pigs.
218 Weaning weights associated with improved performance of grow-finish pigs
Authors: Krahn Gregory , McCallum Michelle , Mahoney Julie , Hinson Rodney , Eden Chris L 
Published: May 2024

Abstract
This study was conducted to evaluate the downstream impact of wean weight (WW) on finishing pig performance. Individual body weights (BW) were recorded at the time of weaning using the LeeO individual animal identification system. Finisher performance evaluation started at d 57 post-weaning. Pigs (n = 1,276; PIC 800 x DNA 241 F1) were blocked by wean age (20.6 ± 1.5 d) and sex, ranked in order of individual WW (6.05 ± 1.43 kg), and divided into BW quartiles to create four WW treatment groups [WW Quartile (Q) 1, 2, 3, and 4; Table 1]. Pigs (n = 21) in the same Q were housed in each pen yielding 15 replicate pens per quartile. Pigs were fed common diets formulated in a 4-phase sequence from the time of placement in the finisher through marketing, which occurred on a fixed-BW basis targeting 131.5 kg. Pen BW and feed disappearance were recorded every 3 wk and at marketing, and individual BW were recorded on d 134 post-weaning. Data were analyzed using linear mixed effects models in the lme4 package of R. Differences in mean BW of each Q were evident at weaning (P &lt; 0.001), start of finisher evaluation (d 57, P &lt; 0.001), and through d 121 (P &lt; 0.001); by d 144, the BW between Q3 and Q4 did not differ (126.6 vs 129.0 kg, respectively, P &gt; 0.05). Overall average daily gain (ADG) and average daily feed intake (ADFI) were greater (P &lt; 0.001) for finishing pigs of either Q3 or Q4 compared with Q1, but no difference (P &gt; 0.10) in gain to feed ratio (G:F) was observed between quartiles from 28.0 to 131.5 kg BW. Pigs in Q3 and Q4 required fewer (P &lt; 0.001) days on feed than pigs in either Q1 or Q2, which culminated in an overall linear (P &lt; 0.001) effect such that a 0.45-kg advantage in WW resulted in 2.25 d less to reach a market BW of 131.5 kg. Coefficient of variation (CV) in BW at d 134 post-weaning was greater (P &lt; 0.001) for pigs in Q1 compared with pigs in Q2, Q3, or Q4. Backfat depth was thicker (P &lt; 0.05) for Q1 pigs compared with Q4 pigs but did not differ from pigs in Q2 or Q3. A decrease (P &lt; 0.001) in carcass ADG was seen for pigs in the lightest 50% of the population compared with those in Q4. In conclusion, even though feed efficiency was not impacted by WW, heavier WW resulted in fewer days to reach desired market weight while simultaneously resulting in improved carcass characteristics.
219 Effect of stocking density on F1 gilt grow-finish performance
Authors: Self Rachel , Henry Clara K , Mainquist-Whigham Christine , Cross Amanda , Stephenson Ethan , McNeil Brady 
Published: May 2024

Abstract
As replacement rates in the swine industry have increased, gilt development units have increased the number of females developed in the same allotted space. The impact of decreasing space is not well understood on the developing gilt. Therefore, the objective of this study was to evaluate differences in grow-finish performance for developing gilts housed at different stocking densities. At 10 wk of age 824 F1 females (DNA L241, DNA Genetics, Columbus, NE) were randomly allotted to 12 pens per treatment of either 0.71 m2 (n = 360), 0.93 m2 (n = 264), or 1.25 m2 (n = 204). Body weights (BW) were individually collected at 10, 24, and 31 wk of age. Backfat and loin depth were measured using an Exxago Ultrasound between the 10th and 11th rib at 24 and 31 wk of age. Feed consumption was measured at the pen level using a Feed Logic system. Mortality date, reason, and BW were recorded throughout the grow-finish phase. At 10-wk of age, there was no significant difference in BW between the treatments. Differences in BW were observed between treatment 0.71 m2 at 119.3 kg compared with 0.93 m2 and 1.25 m2 at 123.4 kg and 125.6 kg, respectively (P &lt; 0.01). All stocking densities were significantly different (P &lt; 0.01) at 31 wk of age with 0.71 m2 at 142.4 kg, 0.93 m2 at 152.4 kg and 1.25 m2 at 156.5 kg. Backfat and loin depth were significantly different at 24 wk for 0.71 m2 compared with 0.93 m2 and 1.25 m2 (P &lt; 0.05). At 31 wk of age, all treatments were significantly different for backfat with 0.71 m2 at 16.1 mm, 0.93 m2 at 18.0 mm and 1.25 m2 at 19.1 mm (P &lt; 0.05). Feed conversion was not different across treatments from 71 d of age until 84 d of age and from 84 until 111 d of age. However, feed conversion was significantly different from 111 d until 167 d of age for 0.71 m2 at 3.83 compared with 1.25 m2 at 3.40 (P &lt; 0.10). Mortality was not different between treatments (P &lt; 0.05). Gilts that were assigned to the least square foot treatment grew slower and had decreased backfat and loin depth. This could potentially impact the timing of the estrus detection and matings in the replacement gilt population. Overall, producers looking to improve the BW of females entering the breeding herd should evaluate increasing the space allotted per female in their gilt developer.
41 Is there anything we can do to lessen the severity of PRRSv?
Authors: Yeske Paul 
Published: May 2024

Abstract
Veterinarians and the swine industry continue to battle PRRS virus (v), as demonstrated by both the MSHMP (Morrison Swine Health Monitoring Project) and the SDRS (Swine Disease Reporting System). Both systems depict a continued increase in PRRSv prevalence and percentage of positive cases. The PRRSv variants that are circulating today seem to be more severe, especially in the last 2 to 3 yr, with more significant health and production losses in the nursery and finishing phases for prolonged periods of time. The best thing that can be done is to avoid having the virus with a good bioexclusion plan and if sites become infected, a strong biocontainment plan to avoid contaminating more sites should be considered. Realizing that bioexclusion is not always possible and sites will become infected, there are methods to help to reduce the impact of the virus. With the concerns of recombination pushing the virus evolution along faster, more producers are working toward eliminating field viruses from their systems. The use of filtration both on sow farms and nurseries has become more common as well as an additional method of bioexclusion. In the face of an outbreak, obtaining an accurate diagnosis is still one of the most important things that we do. In farrow to wean farms, serum samples are generally used when clinical signs (e.g., abortions, off feed) are observed to target testing to specific animals that are more likely to allow for early detection. In nursery and finishing sites, the use of oral fluid has worked very well as a screening tool when there are clinical signs or problems within a group or flow. Fortunately, there are differential tests that can be used to identify field infection and vaccines strains (since most wean to finish pigs are vaccinated in pig dense areas). With severe strains, depopulation and repopulation strategies have become more popular as a control method, but the majority of herd would use a herd closure. However, the amount of time required for these closures is extending, which lengthens the impacts on sow farms. Among wean to finish systems, the use of depopulating and cleaning up the site is used most, with only routine down times. Anti-inflammatories can also be administered in the acute phase of the outbreak in addition to the use of antibiotics to control secondary bacterial infections, as well as providing a good environment to allow the pigs to better deal with the disease. It’s best to keep the virus out of the herd with a good bioexclusion program. However, when we do have outbreaks, anti-inflammatory and antibiotics to help the pigs through it are important to utilize as we work to eliminate the field virus from the herd.