bluuebunny/crossref_metadata_2025 huggingface dataset:
PSVIII-A-2 How Does the Duration of Low Feed Intake Affect the Ruminant Gastrointestinal tract?
Authors: Lambert Koralie , Chagas Anne Clair , Burakowska Katarzyna , Hare Koryn S , Watanabe Daniel H M , Penner Greg B
Published: November 2023

The objective of this study was to determine the effect of 5 and 10 d low feed intake (LF) on the ruminant gastrointestinal tract (GIT). Twelve rams and nine wethers were used in a randomized complete block design where they were blocked by castration status and BW. After 5 d of ad libitum feeding, lambs were either exposed to 0 (CON; 100% DMI; n = 7), 5 (LF5; 30% DMI; n = 7), or 10 d (LF10; 30% DMI; n = 7) of LF. At the end of the study, lambs were euthanized, the GIT was removed to determine the digesta and tissue weights by region and the weights of the liver, spleen, and kidneys were recorded. There were no castration × treatment interactions (P ≥ 0.32). Initial (P = 0.97) and final (P = 0.19) BW did not differ by treatment. The weight of the reticulo-ruminal tissue tended to be less (P = 0.06) for LF10 than CON, with LF5 being intermediate but not different. Ruminal digesta weight was not affected (P = 0.98). Omasal tissue weight did not differ among treatments (P = 0.24), but digesta weight tended (P = 0.07) to be greater for CON compared with LF10 and LF5. Abomasal tissue weight was reduced for LF10 (P = 0.04), with LF5 being intermediate but not different. Abomasal digesta weight was less for LF5 and LF10 than CON (P = 0.04). The weight of the duodenum tended (P = 0.08) to be greater for CON than LF10 and LF5, but digesta weight was not affected (P = 0.16). For the jejunum, tissue and digesta weight tended (P = 0.07) to be greater for CON than LF10, with LF5 being intermediate. The weight of the ileum tended to be the greatest for CON, intermediate for LF5, and the least for LF10 (P = 0.10), but digesta weight was not affected (P = 0.81). Cecal tissue weight was not affected by treatment (P = 0.89); whereas digesta weight was the greatest (P = 0.03) for LF10, the least for CON, and intermediate but not different for LF5. In contrast, colonic tissue weight was less for LF10 relative to LF5 and CON (P = 0.01) and digesta weight tended (P = 0.05) to be greater for CON than LF5 and LF10. Liver weight was reduced (P < 0.01) for both LF5 and LF10 relative to CON, but kidney and spleen weights were not affected (P ≥ 0.33). This study indicates that exposing ruminants to LF rapidly reduces the weights for regions of the GIT and liver. These changes likely implicate a reduced absorptive capacity of the GIT and a lesser metabolic capacity of the liver.
PSVIII-A-6 Effects of Feeding Ground Whole Flaxseed, Defatted Flaxseed Meal and Organic Flaxseed Meal on Production Performance, Rumen Fermentation, and Total-Tract Nutrient Digestibility in Dairy Cows
Authors: Warnasooriya Viraji B , Penner Greg B , Christensen David , Yu Peiqiang , Mutsvangwa Timothy
Published: November 2023

This study aimed to determine the effects of feeding ground whole flaxseed and two types of mechanically extracted flaxseed meals on dry matter intake (DMI), milk production and composition, ruminal fermentation characteristics, and total-tract nutrient digestibility in dairy cows. Twelve multiparous Holstein cows [122 ± 20 days in milk (DIM) at the start of the study] were used in a replicated 4 × 4 Latin square design with 4 dietary treatments. One square had 4 ruminally cannulated cows that were used to determine dietary effects on ruminal fermentation characteristics and total tract nutrient digestibility. The 4 dietary treatments tested were a barley silage-based diet with canola meal (CM; 21.1% of diet DM) as the main protein source (designated CON), and diets containing ground whole flaxseed (designated GWF; 4.92% of diet DM), defatted flaxseed meal (designated DFM; 19.7% of diet DM), or organic flaxseed meal (designated OFM; 20.2% of diet DM) as partial replacements for CM. The crude fat contents of CM, GWF, DFM, and OFM were 3.20, 37.7, 9.9, and 12.9% (DM basis), respectively, and experimental diets were balanced for crude fat content (4.51%; DM basis). Experimental periods consisted of 18 d of dietary adaptation and 10 d of data and sample collection. Orthogonal contrasts were used to test for the following treatment differences: CON vs. GWF; CON vs. [DFM + OFM]; and GWF vs. [DFM + OFM]. Dry matter intake was lower (P < 0.01) for cows fed CON compared with those fed GWF and [DFM + OFM]. Milk yield tended to be greater (P = 0.06) for cows fed CON compared with those fed GWF (P = 0.06) and [DFM + OFM] (P = 0.06). Milk fat content and yield were unaffected by diet; however, milk protein content was reduced for cows fed CON compared with those fed GWF (P = 0.001) and [DFM + OFM] (P < 0.001). Milk urea-N (MUN) concentration was greater (P ≤ 0.001) in cows fed CON compared with those GWF and [DFM + OFM]. Also, MUN concentration was decreased for cows fed GWF compared with those fed [DFM + OFM]. Ruminal NH3-N concentration was less (P ≤ 0.04) in cows fed CON than those fed GWF and [DFM + OFM], but ruminal pH and short-chain fatty acid concentrations were unaffected by diet. Fecal N excretion (g/d) was greater (P < 0.01) for cows fed CON compared with those fed GWF and [DFM + OFM] and, therefore, total-tract CP digestibility was reduced (P < 0.001) in cows fed CON compared with those fed GWF and [DFM + OFM]. In conclusion, partial replacement of CM with GWF or [DFM + OFM] increased DMI; however, it tended to reduce milk yield.
PSVIII-A-8 Growth and Physiological Responses to Heat Stress and Zilpaterol Hydrochloride in Angus and Brahman Steers
Authors: Rios Andrea P , Grijalva Pablo Cesar C , Reith Rachel R , Garcia Samuel R , Webster Chelsea , Beard Joselyn K , Peterson Jessica L L , Yates Dustin T , Schmidt Ty B B , Diaz Duarte E E
Published: November 2023

The response to zilpaterol hydrochloride supplementation by two breeds of beef steers under controlled heat stress conditions were evaluated for impacts on growth, carcass merit, and physiological stress indicators. In two separate studies, Brahman and Angus steers were placed in environmental chambers and housed for 21 d under 1 of 2 environmental conditions 1) heat stress (THI = 73 to 85) or thermoneutral (THI = 68). In a 2 x 2 factorial, steers also received 8.38 mg· kg-1· d-1 on 88% DM of zilpaterol hydrochloride (ZH) or soybean meal carrier only for the 21-d period. Feed intake, respiratory rate, and rectal temperatures were evaluated daily. Total weight gain was recorded and used to calculate average daily gain (ADG) and gain-to-feed ratio (G:F). Brahman steers were harvested at the market weight (489.31 ± 97.7 kg) and Angus steers on d ~22 after treatment (307.26 ± 6.23 kg). In both studies, body weight gain and ADG did not differ between environments or supplements. Brahman steers exposed to heat stress exhibited greater (P < 0.05) respiratory rate than thermoneutral steers, regardless of supplement. An environment x day interactions (P < 0.04) was observed for rectal temperature. On d 8, unsupplemented heat-stressed Brahman steers had higher (P < 0.05) rectal temperatures than ZH-supplemented thermoneutral steers. On d 11, ZH-supplemented heat-stressed Brahman steers had higher (P < 0.05) rectal temperatures than unsupplemented thermoneutral steers. Angus steers exposed to heat stress exhibited greater (P < 0.05) respiration rates throughout the experiment than thermoneutral steers. On d 8, unsupplemented heat-stressed Angus steers exhibited greater (P < 0.05) respiration rates than ZH-supplemented heat-stressed steers. On d 8 and 19, heat-stressed Angus steers exhibited greater (P < 0.05) rectal temperatures than thermoneutral steers. Angus steers exhibited an environment x supplement x day interaction (P < 0.05) for rectal temperature, with a decrease (P < 0.05) rectal temperature in ZH-supplemented steers. Carcass merit traits did not differ between environments in Brahman steers. Cold carcass weights were lighter (P < 0.05) in heat-stressed Angus steers compared with thermoneutral steers. ZH-supplemented Angus (but not Brahman) steers exhibited decreased (P < 0.05) respiration rates and rectal temperatures. Together these findings indicate that Brahman steers were more resistant to heat stress than Angus steers but were less efficient, with ~10% less G:F. Based upon the data collected, supplementation with zilpaterol hydrochloride did not negatively impact production in either breed.
PSII-15 Effects of Tillage Method and Fertilization Rate on Fall Performance of Stocker Cattle Grazing Wheat Pasture and Stand Performance
Authors: Gruber Cody , Johnson Michelle , Hess Tom , Moss Nate T , Rivera Daniel , Gadberry Shane
Published: November 2023

The objectives of this study were to determine the effects of fertilization rate and wheat pasture establishment method on fall stocker and wheat stand performance. Twenty-four, 1.62-ha pastures were utilized, with 8 pastures per fertilizer (N) treatment. Fertilization consisted of urea applied at 50.44, 67.25, or 84.06 kg N/ha. To measure responses associated with tillage method, 2 fields from each N treatment were prepared using clean-till (CT, n = 6), and the remaining fields were prepared with a no-till (NT) method. Beef steers (278.51 ± 29.42 kg) were randomly allocated at a fixed rate of 2.47 steers/ha (4 steers/pasture), with a combined total of 240 steers used in fall of 2021 and 2022. Steers were weighed upon arrival, at turnout, every 28 days, and when pulled off pasture. Steers were pulled off pasture when forage mass (FM) became insufficient, or temperatures became too cold to support forage regrowth. Forage mass sampling was recorded with a 0.25 m2 plate meter. Sampling dates coincided with weigh dates. Twenty plate meter readings were taken in every field (600 readings in total per sampling date) and 0.25 m2 grass clippings were obtained from 15 fields every sampling date to form a regression curve to estimate FM. An analysis of co-variance using the Mixed Model procedure in JMP was used to analyze this data. Tillage method and N rate were fixed categorical and continuous covariates, respectively. Year was modeled as a random effect. Tillage × N interaction was used to examine differences in slope estimates for N rate between CT and NT. Non-significant interactions were removed from the model. Total weight gain per hectare and final weight were both greater in CT compared with NT (P = 0.01), More grazing days was observed with CT (P < 0.01), as well as a trend toward greater mean FM (P = 0.06). Ending FM was also greater for CT pastures (P < 0.05). No significant effects from tillage were found for initial weight, average daily weight gain, initial FM, or FM slope change. No differences (P > 0.1) among responses were associated with a linear response to N rate. In conclusion, CT demonstrated greater performance than NT, with CT having greater FM response, more grazing days, and greater body weight gain per hectare, and N rates greater than 50.4 kg/ha did not appear beneficial for the studied stocking rate and climate conditions.
PSIV-20 The Effect of Silage Additives on Male Sterile Sorghum Fermentation Heat Production and Feed-Out Stability
Authors: Duhatschek Douglas , Bell Jourdan M , Keys Kristie , Druetto Diego , Ferraretto Luis F , Raver Katie , Mendonca Filipe , Garcia Matheus C , Gouvea Vinicius N , Piñeiro Juan M
Published: November 2023

The objective was to compare the effect of applying silage additives to male sterile sorghum hybrids on temperature production during ensiling time (30 d) and at feed-out period after 30 or 90 d of ensiling period. Two male-sterile sorghum hybrids; F430 and F465, with and without BMR12 trait, respectively (Richardson Seed Ltd.); were randomly allocated in plots blocked by irrigation section in a dairy farm in West Texas. During harvest, duplicate samples from each plot were obtained, placed on plastic trays, and transported to one of three stations to be treated with chemical silage preservative (SG, SiloGuard), heterofermentative bacteria inoculant with mold inhibitor solution (SM, Silage Maker 250) or distilled water (DW, control). Treatments were applied with spray bottles following a protocol that consisted of two sets of 5 sprays (1.1 mL each and 11 mL total) followed by mixing of the forage. Personnel applying the treatment were blind as to which treatment they were applying and all spray bottles, trays and tables from each station were color coded to prevent cross contamination. After treated, 3.63 kg of forage was packed in three consecutive steps using a manual press on 4.7L buckets (Uline) and a temperature data logger was placed in the center of each of the 30 d mini silos. The amount of material packed was estimated to achieve a 230 kg of DM/m3 compaction at 30% DM of the forage. At opening, the material from each silo was moved to a tray and mixed to be homogenized and exposed to oxygen. Then, the material was added back to its correspondent bucket until it filled up to the border without compressing. Heat production during the feed-out period and air-stability were assessed for both ensiling periods, whereas fermentation heat production during ensiling period was only assessed for 30 d silos. Statistical analysis was performed using mixed linear regression models (GLIMMIX procedure of SAS) with ensiling period, hybrid, treatment and the interaction of day and treatment included in the model as independent variables. Fourth root and natural log transformation were performed to obtain a normal distribution of residuals, back transformed LSM and 95% CI are reported in Table 1. Treatment effected the silage temperature during the feed-out period (P < 0.0001) and air-stability test (P = 0.02). Whereas a tendency was observed for daily heat production during the ensiled period (P = 0.07). Male-sterile sorghum silage treated with SG had the least temperature during the ensiling period and longer air-stability than SM.
PSX-21 Evaluation of the Effect of Extended-Term Delivery of Local Anesthetic on Mitigating the Pain Caused By Castration
Authors: Dee Natalia , Allan Nick , Olson Merle , Ralston Brenda , Ross Joe , Schatz Crystal , Beaugrand Kendall , Schwartzkopf-Genswein Karen S , Campbell John R , Erickson Nathan , Moya Diego
Published: November 2023

The objective of this study was to evaluate the effects of the extended-term delivery of anesthesia on the physiological and behavioral signs of pain caused by band castration in 1-month-old bull calves. Forty-eight calves (37.04 ± 8.98 days of age) were homogenously assigned by age to one of three band castration protocols (n = 16/protocol); 1) regular elastrator bands (REG), 2) regular elastrator bands preceded by two 2-mL injections of lidocaine (REG+L; LIDO-2 with epinephrine, Rafter 8 Products Inc, Calgary, Canada), and 3) lidocaine elastrator bands (LBAND; Care-Ring, Chinook Contract Research Inc., Calgary, Canada). During the castration procedure, two observers scored (from 1 to 10) how much pain each animal was experiencing (visual analog score, VAS), number of body shakes and leg kicks for each calf. Calves were weighed on d -1, 0, 14, 28, 42, and 56. Hair cortisol concentration was measured on d -1, 28, and 56. Saliva cortisol concentration was measured right after castration, 60, 120, 240 minutes after castration, on d 1 and weekly thereafter until d 56. Flight speed (FS) was recorded on d -1, right after castration, 60, 120, 240 minutes after castration, d 1, and weekly thereafter until d 56. Calf behaviors in the pen indicative of pain and discomfort were recorded on d 0, 1, and weekly thereafter until d 56. The REG+L calves tended to have decreased (P = 0.09) VAS scores than REG calves. The average daily gain was greater (P < 0.01) from d 42 to 56 than from d 1 to 42, and from d 1 to 28 compared with d 28 to 42 in all treatment groups. The REG calves had decreased (P < 0.01) hair cortisol concentrations than both REG+L and LBAND calves. Saliva cortisol concentrations were greater (P < 0.01) 60 minutes after castration than any other sample time in all treatment groups. There was an interaction between treatment and time (P = 0.04), where only LBAND had a greater FS immediately after castration compared with d -1. When calves were observed in the pen there were no treatment effects (P > 0.10) but only time differences (P < 0.05) in the frequency of head turns, oral behaviors, tail flicks, and number of standing and walking bouts. The behavioral and physiological parameters assessed showed expected results on the effects of band castrating calves, while the administration of lidocaine via REG+L or LBAND did not show any pain mitigation effect compared with the standard industry banding method (REG).
PSXIV-10 Estimation of Genetic Parameters of Traits Associated with Water Efficiency, Feed Efficiency and Growth in Beef Cattle
Authors: Thekkoot Dinesh M , Blake Nathan , Mata-Padrino Domingo , Garossino Kevin C , Wilson Matthew E
Published: November 2023

Concerns about water availability, quality and accessibility have intensified. The livestock industry, particularly the beef sector, is under pressure to adopt more sustainable practices that optimize water usage while improving growth and feed efficiency. The objective of this study was to estimate the genetic parameters of traits associated with water efficiency, feed efficiency and growth in beef cattle. The data were collected from 916 seedstock bulls and heifers representing six breeds (Angus, Charolais, Hereford, Limousin, Simmental and Sim-Angus) in a facility equipped with Vytelle SENSE feed intake, water intake and in-pen body weight recording systems, located at the West Virginia University central testing facility in Wardensville, WV. The animals were part of six performance tests between November 2019 and September 2022, with an average age at the start of the test of 284 days, and an average test duration of 73 days. The rations were formulated to achieve 1.5 to 1.6 kg/d ADG (depending on the test) and had a high forage inclusion (>75% corn silage and >15% dry hay, as fed). The facility consists of 5 pens and animals were rotated every two weeks through the pens, so all animals are exposed to all pens. The phenotypes analyzed were average daily water intake (DWI), residual water intake (RWI), average daily dry matter intake (DMI), residual feed intake (RFI), and average daily gain (ADG). RWI and RFI were used to measure the water and feed efficiency of the animals. The genetic parameters were estimated with multi-trait animal models using Echidna mixed model software. In all models, breed, sex and the contemporary group (trial number and pen group) were included as fixed effects, the age at the start of the test was added as a covariate, and the animal was treated as a random effect. RWI and RFI were analyzed by adding ADG and metabolic mid-weight as additional covariates. The estimates of heritability for DWI, RWI, DMI, RFI and ADG were 0.49 (± 0.11), 0.40 (± 0.10), 0.35 (± 0.11), 0.16 (± 0.07) and 0.47 (± 0.11) respectively. Average daily water intake exhibited a positive genetic correlation with RWI (0.90), DMI (0.71), and ADG (0.76). On the other hand, the genetic correlation between RWI and RFI was not significantly different from zero, and genetic correlation between RWI and ADG was slightly positive. These results suggest that selecting for enhanced water efficiency in beef cattle can effectively decrease the daily water consumption without any adverse effect on feed efficiency, although it may have a small impact on growth. The complete genetic and phenotypic correlations are in Table 1. In conclusion, the traits associated with water intake and efficiency in beef cattle have a sizable genetic component and show potential for genetic improvement.
PSXIV-5 Classification of Postpartum Beef Cows as Estrous Cycling Or Anestrous Through the Use of Estrus Detection Patches
Authors: Ricardo Kim , VanWye Genevieve , Palcheff Lucas , Thomas Jordan M
Published: November 2023

Application of estrus detection patches for an extended period of time was evaluated as a means of classifying postpartum beef cows as estrous cycling or anestrous at the start of the breeding season. Estrus detection patches (Estrotect Breeding Indicators; Hermitage, TN) were applied to 269 primiparous and multiparous postpartum beef cows in three locations 24 days prior to the start of an estrus synchronization protocol. At the start of the protocol, patches were scored using a 1 to 4 scale (1 = 0-25%; 2 = 25-50%; 3 = 50-75%; 4 = 75-100%), with scores of 3 or 4 considered activated. Estrous cyclicity status was determined via transrectal ovarian ultrasonography performed by experienced technicians coincident with the start of an estrus synchronization protocol. Cows were classified as cycling based on the presence of a corpus luteum (CL). Based on transrectal ovarian ultrasonography, 59% (161/269) of cows were cycling at the start of estrus synchronization. Of cows receiving patches, 95% (256/269) of cows retained patches for the full 24-day period. Among cows retaining patches, 67% (171/256) of cows presented with activated patches, and 33% (85/256) of cows presented with non-activated patches at the start of the synchronization protocol. Among these, 139 cows presented with activated patches and were observed to have CL via ultrasound, therefore being considered true positives (i.e., estrous cycling). A total of 69 cows presented with non-activated patches and were observed to have no CL via ultrasound, therefore, being considered true negatives (i.e., anestrous). Among cows for which patch score did not result in the same classification as an ultrasound-based characterization of CL status, 32 were considered false positives (i.e., activated patch but no CL observed via ultrasound), and 16 were considered false negatives (i.e., non-activated patch but CL observed via ultrasound). Based on these observations, use of activated patches to infer cyclicity resulted in 89% sensitivity, 68% specificity, and a positive predictive value of 78%. When retained, estrus detection patches are a sensitive tool to classify postpartum cows as cycling prior to the start of an estrus synchronization protocol.
PSVII-21 Protective Effect of Peptide Extract Derived from Beef Protein By Hydrolysis Against Oxidative Damage
Authors: Lee Seung Yun , Kim Jong Hyuk , Hur Sun Jin
Published: November 2023

This study was conducted to determine the protective effects of peptide extract with 3 kDa from beef myofibrillar protein by Alkaline-AK enzyme (AK3K) against oxidative damage in SH-SY5Y cells and in the brains of spontaneously hypertensive rats (SHRs). All data were presented as the mean ± standard deviation of three replicates. All statistical analyses were performed using the one-way analysis of variance procedure in SPSS 20.0. A Tukey's multiple comparison test was used to determine significant differences between mean values, and evaluations were based on a significance level of P < 0.05. The AK3K did not affect cytotoxicity in SH-SY5Ycells (Figure 1). The resulting AK3K decrease the apoptotic ratio by 33.25%, DNA fragmentation, and reactive oxygen species (ROS) generation in oxidative damage induced SH-SY5Y cells (Figure 2). The SHR brains treated with the AK3K (400 mg/kg body weight, AK3K400) showed a significant decrease in malondialdehyde and ROS contents at 0.33 and 23.92 μM, respectively (P < 0.05) compared with the control. The SOD activity for AK3K was 61.26%, around 20% greater than the control. Therefore, this study suggest that the peptide extract from beef have neuroprotective effects such as inhibition of apoptotic factors and increment of antioxidant enzyme against oxidative stress and could possibly be used for neuronal hypertension therapy.
PSXI-21 Inclusion of Former Food Products in Post-Weaning Diet of Piglets: Impact on the Fatty Acid Profile of Subcutaneous Adipose Tissue and on Serum Metabolites
Authors: Pinotti Luciano , Manoni Michele , Luciano Alice , Mazzoleni Sharon , Ottoboni Matteo , Tretola Marco
Published: November 2023

Livestock production is facing the feed-food competition, use of natural resources, and environmental sustainability. To address these issues, the use of food leftovers in animal nutrition could satisfy the principles of circular economy. Among the different food leftovers, former food products (FFPs) consist mainly of unsold/defective food from industrial production (i.e., bread, croissants, biscuits, chips). FFPs can be classified in sugary confectionary FFPs (FFPs-C) and salty bakery FFPs (FFPs-B). The aim of this study was to assess the impact of the inclusion of FFPs into post-weaning diet of piglets on the fatty acid profile of subcutaneous adipose tissue and on serum metabolites. Thirty-six post-weaning female piglets (Large White×Landrace, BW 8.52±1.73kg) were assigned to a standard diet (CTR), or with a 30% replacement (wt/wt) of conventional cereals with FFPs-C or FFPs-B for 42 days. Growth performance and feeding behavior were measured. Subcutaneous abdominal fat samples were collected from 12 selected piglets after slaughtering. Gas chromatography was performed on feed samples from control diet and experimental diets and on adipose tissue samples. Untargeted metabolomics was performed on blood samples (d 0 and d 42) using UHPLC/MS-MS. Data were analyzed with the software MetaboAnalyst (version 5.0). The inclusion of FFPs did not alter growth performance or feeding behavior. The CTR diet had greater PUFA concentrations than FFPs diets. In FFPs diets, the fatty acid profile was equally distributed among SFA, MUFA, and PUFA. The ω-6/ω-3 ratio was greater in FFPs-C diets than CTR and FFPs-B diets. The subcutaneous adipose tissue showed no differences between groups for SFA concentrations. The MUFA concentrations were reduced in CTR compared with FFPs groups, whereas PUFA concentrations were reduced in FFPs-C group compared with FFPs-B and CTR groups. The ω-6/ω-3 ratio was less in FFPs-C group compared with CTR and FFPs-B groups. The untargeted metabolomics identified a total of 104 metabolites, with 2 significantly different between groups. Specifically, the serum concentration of theobromine and caffeine was greater in FFPs groups compared with CTR. To conclude, piglets were able to rebalance the fatty acids profile despite the differences observed in the diets. The metabolic status was not strongly altered by the inclusion of 30% FFPs in the diet. Thus, FFPs could be safely applied in post-weaning pig diets. Further studies are needed to assess the effect of FFPs on pig physiology and metabolic status in growing phase pigs and for a longer feeding time. (funded by ASSO Project- Regione Lombardia)
PSXI-19 A Novel Calculation Method in the Difference Procedure for Determining Energy Digestibility of Ingredients for Pigs
Authors: Kim Hansol , Kim Beob G
Published: November 2023

The objective was to suggest a novel calculation method in the difference procedure for determining the apparent total tract digestibility (ATTD) of gross energy (GE) of ingredients for pigs. This procedure involves formulating a basal diet (BD) and a test diet (TD) which contains a test ingredient (TI), feeding these diets to pigs, determining ATTD of GE in the diets, and calculating ATTD of GE in a TI by extrapolation. To calculate ATTD of GE in a TI, it is necessary to calculate the proportional contribution of GE in the BD (PBD) and the TI (PTI) to the TD using the following equations: PBD = (analyzed GE of BD × inclusion rate of BD)/analyzed GE of TD; PTI = (analyzed GE of TI × inclusion rate of TI)/analyzed GE of TD. One of the assumptions for the difference procedure is that GE values in a BD and a TI are additive (PBD + PTI = 1). However, the analyzed GE in the TD is not always exactly equal to the calculated value based on analyzed GE values in the BD and the TI. To investigate the influence of non-additivity of GE in a TD on the ATTD of GE in a TI, 33 observations were collected from 9 studies that determined ATTD of GE using the difference procedure. A ratio of analyzed GE in TD to calculated GE in TD (GEAnalyzed:GECalculated, %) ranged from 98.7 to 101.3%. The following relationship was established: PTD = PTI + PBD = (GEAnalyzed:GECalculated)–1. Corrected PBD and PTI were calculated: corrected PBD = PBD × (GEAnalyzed:GECalculated)–1; corrected PTI = PTI × (GEAnalyzed:GECalculated)–1; and corrected PTD = corrected PBD + corrected PTI = 1. Four values for the ATTD of GE in TI were obtained or calculated: 1) presented in the literature (ATTDLiterature), 2) calculated based on the PTI (ATTDNon-corrected), 3) calculated based on the corrected PTI (ATTDCorrected), and 4) calculated based on the calculated GE in TD (ATTDCalculated). Three ratios (%) for each observation were computed, namely, ATTDLiterature:ATTDCalculated, ATTDNon-corrected:ATTDCalculated, and ATTDCorrected:ATTDCalculated. The GEAnalyzed:GECalculated was used as an independent variable against the ratios as dependent variable. Results indicated that a 1 percentage unit increase in GEAnalyzed:GECalculated led to 3.47% (r2 = 0.67) and 4.28% (r2 = 0.92) increases in ATTDLiterature:ATTDCalculated and ATTDNon-corrected:ATTDCalculated, respectively. However, for the ATTDCorrected:ATTDCalculated, a 1 percentage unit increase in GEAnalyzed:GECalculated only increased the value by 0.54% (r2 = 0.88). Overall, even a small deviation between analyzed and calculated GE can cause large errors in the digestibility of TI, but the use of corrected proportional contributions suggested in the present work can mitigate the problem.
PSXIII-6 Effects of High Humidity Under High-Temperature Conditions on Growing Pigs
Authors: Kim Yonghee , Kyoung Hyunjin , Park Kyeong Il , Ahn Jinmu , Lee Jae In , Ha Sewon , Nam Jinwook , Kim Kimoon , Kang Yonggu , Park Youngmin , Shin Ikcheol , Song Minho
Published: November 2023

Global warming and climate change have become major concerns. These changes have led to more frequent and prolonged heat waves, resulting in economic losses for livestock industry. Pigs are particularly vulnerable to heat stress under high temperatures due to their thick skin layers and limited sweat glands. Panting is a common behavior in pigs to dissipate heat through evaporation, but this process is less effective in high humidity environments. This study was conducted to investigate the effects of high humidity under high temperature conditions on rectal temperature, growth performance, blood profiles, and immune responses of growing pigs. A total of 48 growing pigs [(Landrace × Yorkshire) × Duroc; initial body weight (BW): 23.21 ± 3.77 kg] were randomly assigned to two environmental treatments (2 pigs/pen; 12 replicates/treatment) in a randomized complete block design (block = initial BW): thermal neutral conditions (TN: 23.5℃, 35%) and heat stress conditions (HS: 32.5℃, 80%). Throughout two weeks of experiment, the pigs had ad libitum access to a basal grower diet based on corn and soybean meal. The rectal temperature of each pig was measured daily throughout the experimental period to monitor changes in body temperature. Blood samples were collected from 1 pig per pen at the beginning and end of the experiment. Measurements included growth performance [BW, average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio], blood profiles [the number of white blood cells (WBC), red blood cells, hemoglobin, hematocrit, and platelet] measured by an automated hematology analyzer calibrated for porcine blood, and immune responses (cortisol, tumor necrosis factor-alpha, interleukin-6, interleukin-1beta, and transforming growth factor-beta1) by the ELISA kits. Statistical analysis was performed using the general linear model procedure of the SAS program. Experimental unit was a pen. The statistical model included environmental treatment as a main effect and BW as a covariate for rectal temperature, growth performance, blood profiles, and immune responses. During the entire experimental period, the mean rectal temperature was 39.9℃ for TN and 40.5℃ for HS. Pigs under HS had decreased (P < 0.05) ADG and ADFI than those under TN. The WBC counts of pigs under HS were decreased (P < 0.05) than those under TN. In contrast, serum cortisol concentrations of pigs under HS were greater (P < 0.05) than those under TN. In conclusion, this study suggests that exposure to high humidity in combination with high temperatures has a negative impact on the growth performance and immune responses of growing pigs.
PSXIII-10 Effects of Dietary Lactobacillus Reuteri on Growth Performance, Frequency of Diarrhea, and Blood Biochemical Parameters of Weaned Pigs
Authors: Kang Yonggu , Kyoung Hyunjin , Park Kyeong Il , Kim Yonghee , Ahn Jinmu , Lee Jae In , Ha Sewon , Nam Jinwook , Kim Kimoon , Park Youngmin , Shin Ikcheol , Song Minho
Published: November 2023

Weaning stress of pig causes reduction of growth performance and high risk of diseases. These effects are directly connected to economic losses. Antibiotic growth promotors commonly used for improving the negative effects of weaning stress of pigs, but are banned for public health concerns. Therefore, probiotics can be one potential of an antibiotic alternative. Dietary Lactobacillus reuteri is one of the strains of probiotics which has the ability to enhance growth performance of animals. This study was conducted to investigate the effects of dietary Lactobacillus reuteri on growth performance, frequency of diarrhea, and biochemical parameters of weaned pigs. A total of 48 weaned pigs [Duroc × (Landrace × Yorkshire); initial body weight (BW) = 6.51 ± 0.87 kg; 21 days old)] were randomly assigned to two dietary treatments (4 pigs/pen; 6 replicates/treatment) and fed for 4 weeks in a randomized complete block design (block = initial BW and sex). Dietary treatments consisted of a basal weaner diet (CON) and CON supplemented with 0.02% Lactobacillus reuteri IDCC 3701 (LR; ILDONG Bioscience Co., Ltd., Pyeongtaek, Republic of Korea). The frequency of diarrhea was calculated daily during two weeks in each pen with optical diarrhea scores. The scoring of diarrhea was from 1 to 5, and a score of over 4 was considered diarrhea. Blood samples were obtained from randomly selected one pig per pen at the end of the experiment. Sera were obtained from the blood sample to measure the blood biochemical parameters using the specific kits and a clinical auto-analyzer. All data were analyzed using PROC GLM of SAS. The experimental unit was a pen. Statistical model for growth performance and blood biochemical parameters included dietary treatments as a main effect and initial BW as a covariate. The frequency of diarrhea was analyzed by the Chi-square test. Pigs fed LR increased (P < 0.05) average daily gain from day 1 to 7 and 15 to 28 and gain to feed ratio from day 1 to 7 compared with those fed CON. Pigs fed LR tended to have reduced (P < 0.10) frequency of diarrhea during the first two weeks of experiment than those fed CON. In addition, pigs fed LR tended to have greater (P < 0.10) serum alanine aminotransferase than those fed CON, but no differences were observed in other blood biochemical parameters. In conclusion, addition of dietary Lactobacillus reuteri in weaner diet improved growth performance, reduced the frequency of diarrhea, and modulated the blood biochemical parameters of weaned pigs.
PSIV-16 Factors Affecting the Lh Release and Ovulatory Response to a Gnrh Treatment in Lactating Dairy Cows on Day 7 of the Estrous Cycle
Authors: Silva Lucas O e , Alves Rodrigo L O R , Cavalcanti Patrícia R , Cortat Paula R , Dias Mirela B , Monteiro Pedro L J , Gonzales Bruno , Caetano Heitor D , Hellu José Abdo A , Wiltbank Milo C , Sartori Roberto
Published: November 2023

This study evaluated factors affecting LH release and ovulation in response to a treatment with a conventional dose of gonadorelin (GnRH), in lactating dairy cows on day 7 of the estrous cycle. Factors evaluated were: GnRH preparation (ready-to-use vs. lyophilized), body condition score (BCS), parity, days in milk (DIM), milk yield and dominant follicle (DF) diameter, at the time of GnRH treatment. Seven days after an artificial insemination, preceded by a synchronization protocol, lactating Holstein cows were evaluated by ultrasound and those with a corpus luteum (CL) and a DF ≥10 mm were randomly assigned to receive 100 µg GnRH ready-to-use solution (Fertagyl; MSD, Brazil) or lyophilized (Profertil; J.A. Animal Health, Brazil) diluted just before its administration. Overall, 106 cows (BCS = 3.1 ± 0.1; DIM = 96.7 ± 4.2; 39.7 ± 0.7 kg of milk/d) were assigned to GnRH treatments. Ovulation was determined by ultrasound examinations 2 d after GnRH treatment, by disappearance of the DF, and confirmed 5 d later by the presence of an accessory CL. In a subset of cows (n = 33), blood samples were collected just before the GnRH treatment, and 2 and 4 h later, to evaluate circulating P4 and LH concentrations. Data were analyzed by GLIMMIX (SAS 9.4). Treatment effect and its interaction were included in the analyses of all other factors. Differences were declared when P ≤ 0.05 and tendency when 0.053.0 (1.4 ± 0.2 vs 0.7 ± 0.1 ng/mL; Table 1). Moreover, cows with DF ≤12 mm had greater LH peak than cows with DF >12 mm (1.3 ± 0.2 vs. 0.9 ± 0.1 ng/mL; Table 2). However, these factors did not affect ovulation. Neither milk yield nor DIM affected LH peak or ovulation. In conclusion, although no differences were detected on LH peak, primiparous cows on day 7 of the estrous cycle had greater ovulation when treated with Profertil compared with Fertagyl. Moreover, regardless of treatment, greater BCS and larger DF (>12 mm) at the time of GnRH treatment were associated with decreased LH peak, however, without impairing ovulation.
PSXI-8 Comparison of Spectral and Motion Sensing for Grazing Behavior Determination in Extensive Systems
Authors: Wright Ryan , Simcik Charleez , White Robin R
Published: November 2023

There is a need to classify eating behaviors of grazing animals to better understand time budgets and intake levels of extensively managed livestock. The objective of this work was to compare spectral and motion-based sensing for classification of animal grazing versus standing behaviors within extensive production systems. The sensor was an open-source setup with a TTGO-T-Beam microprocessor (Shenzhen Xin Yuan Electronic Technology Co, China), soldered with an AS7265x Spectral Triad (SparkFun Electronics, Niwot, CO) and generic 9 degree of freedom inertial motion unit. The sensors were attached to a mesh face mask and placed on 5 horses for 10 minutes of data collection. Within the data collection period, animals were allowed to graze for 5 minutes, and required to stand for 5 minutes. The order of grazing and standing was randomized among animals. Data were collected by the microprocessor at 100 hertz and averaged over a 20 second period. Average data were transmitted via long range radio (LoRa) to a base station. Data were matched by timestamp to ground truth observations of animal standing vs grazing behaviors. A random forest algorithm was used to explore predicting animal grazing versus standing behaviors based on motion data (average pitch, yaw, and roll of animals over the experimental period) individually, based on the top features selected from the spectral data individually, or based on all collected data together. The model using the motion data only returned an out of bag estimated error rate of 26.5%. The model using the top features selected from the spectral data yielded a much lower out of bag estimated error rate (8.82%), which was not improved by leveraging all data together. By comparing the spectral data with GPS coordinates attached to each observation, we were able to clearly distinguish the spatial area used for grazing compared with that used for standing. One potential impact of this preliminary exploration is in low-cost, low-power, more precise behavioral classification for grazing livestock. Because the spectral sensed data generated more reliable ability to distinguish grazing and standing behaviors, we may be able to rely on lower frequency observations, or lower data acquisition rates to achieve acceptable classification accuracies. Similarly, given the success of NIR in analyzing feed composition values, there is likelihood that spectral sensing could be used not only to identify grazing, but to character forage quality grazed.
PSIII-22 Substituting Palm Oil By Polyunsaturated Fatty Acid Rich Oils Reduces Methane Emissions at a Different Degree Depending on Concentrate Formula of Dairy Beef Calves: in Vitro Screening
Authors: Devant Maria , Llonch Lourdes , Marti Sonia , Verge Gerard , Riera Joan , Medinya Carles , Cucurull Jordi , Perez Anna , Fernandez Belen
Published: November 2023

In dairy beef calves fed high-concentrate diets even methane emissions may be lesser than calves fed high-roughage diets there is still room to improvement. Substituting palm oil, an ingredient that is questioned by the impact on deforestation of some regions, by polyunsaturated fatty acids (PUFA) may be a good strategy that needs to be tested. Therefore, the aim of this study was to evaluate the rumen in vitro methane gas production by substituting palm oil by different oils rich in polyunsaturated fatty acids in two different concentrates in T1 the main protein source was SBM (8%) and in T2 the main protein source was corn DDG (15%); the remaining concentrate ingredients were 50% corn, 15 to 13% barley, 15 to 16% wheat middlings, beet pulp (5.5% in T1), 1.8% calcium carbonate, 0.5% salt, 0.2% premix. Palm oil was substituted (4 or 3.5 % in T1 or T2, respectively) by canola oil (CO), sunflower oil (SU) or soybean meal oil (SO), so 8 treatments were tested (T1, T1-CO, T1-SU, T1-SO, T2, T2-CO, T2-SU, T2-SO), which are rich in polyunsaturated fatty acids in two. Samples were 1-mm grinded at 1-mm and used in an in vitro digestibility assay as described by [Goeser and Combs (2009)]. The rumen liquid, obtained from rumens at slaughterhouse of beef animals fed high-concentrate diets with a close formula to T1 and T2, was strained through a cheesecloth, collected into pre-warmed thermal flasks, and kept at 39ºC until being used. Two incubation sets were done in parallel and in triplicate: one lasted 48 hours to calculate the DM digestibility; the second lasted 12 days to monitor the methane gas production. A tendency (P = 0.10) in the interaction among basal diet and oil source was observed in total methane production corrected by blank methane production; numerically the same trend (P = 0.14) was observed in net volume of CH4 per degraded DM. After 12 days, the least methane production values were observed in T1-SO and T2-CO (30 and 29 mL ± 4.6, respectively), while the largest methane values were observed in T1-SU (45 ± 4.6 mL) being the remaining treatments intermediate values (42, 39, 31, 38, 41 ± 4.6 mL for T1, T1-CO, T2, T2-SU, T2-SO, respectively). In conclusion, depending on the concentrate formula (protein source used) the effect of fat source used to substitute palm oil and reduce methane emission may differ.
PSVI-25 A Phytogenic Additive Improves Immune Responses of Growing Beef Cattle on Grazing System
Authors: de Matos Isabelle Errobidarte , Perdigão Alexandre , de Carvalho Victor Valério , Acedo Tiago S S , Santana Yohana Clara Siqueira , Timóteo Silvia Isabella , Ferreira Cecília Ayala , da Silva Aline Gomes , Fernandes Henrique Jorge
Published: November 2023

Our objective was to evaluate the effect of a phytogenic additive in protein supplement for grazing Nellore young bulls on serum protein profile. One hundred and fourteen animals (iBW, n = 114; 273 ± 4.46 kg) were allocated for 152 days in six pastures of Brachiaria brizantha cv. Marandu (̴7 ha each), and randomly distributed in six treatments with or without additives on protein supplement (30% crude protein). Treatments were: 1) Negative Control (CON), with no additive; 2) Positive Control, with 15 ppm of Monensin (MON); 3) Digestarom (DSM Nutritional Products) at 0.2 g· animal-1· /day-1 (D0.2); 4) Digestarom at 0.4 g· animal-1· /day-1 (D0.4); 5) Digestarom at 0.6 g· animal-1· /day-1 (D0.6) and 6) Digestarom at 0.8 g· animal-1· /day-1 (D0.8). Supplement was offered ad libitum. Additives dosages were adjusted weekly to achieve the targeted dose/animal. Blood samples were collected in the last day and analyzed for positive acute phase proteins (increases with the inflammation response), haptoglobin (HAP) and glycoprotein (GLY); negative acute phase protein (decreases with the inflammation), transferrin (TRA); and Immunoglobulins A and G. Data were analyzed using SAS PROC GLIMMIX. Significance of 5% was adopted. Contrasts of use of Monensin, use of Digestarom, type of additive, and linear and quadratic effects of Digestarom were evaluated. Compared with MON, Digestarom decreased (P < 0.05) HAP (124 vs. 76.2 mg/dL) and GLY (1,361 vs. 85.6 mg/dL). TRA increased (P < 0.05) with Digestarom (310 and 307 mg/dL for D0.6 and D0.8, vs. 204 and 177 mg/dL for CON and MON). Digestarom increased (P < 0.05) immunoglobulins A (193, 218 and 225 mg/dL for D0.4, D0.6 and D0.8) and G (1.5 g/dL for D0.4, D0.6 and D0.8) compared with CON (IgA 146 mg/dL and IgG 0.9 g/dL) and MON (IgA 93 mg/dL and IgG 0.3 g/dL). Digestarom levels also showed a quadratic effect on TRA (including 165 and 245 mg/dL for D0.2 and D0.4) and on IgA and IgG (including 124 mg/dL and 0.8 g/dL for D0.2). Overall serum protein responses of the animals receiving Digestarom (reduced haptoglobin and glycoprotein, and graeter transferrin, IgA and IgG) demonstrates that these animals had improved immune responses and could be better able to respond to infectious and stress challenges.