scholarly journals Effects of endophyte-infected tall fescue seed and protein supplementation on stocker steers: I. Growth performance and hemodynamic responses

2019 ◽  
Vol 97 (9) ◽  
pp. 3776-3785 ◽  
Author(s):  
Rebecca K Poole ◽  
Carrisa M Womble ◽  
Matthew H Poore ◽  
Daniel H Poole ◽  
Carrie L Pickworth
Keyword(s):  
Body Temperature ◽  
Growth Performance ◽  
Treatment Period ◽  
Tall Fescue ◽  
Repeated Measures ◽  
Negative Impact ◽  
Protein Supplementation ◽  
Fescue Toxicosis ◽  
Hemodynamic Responses ◽  
Minimal Impact

Abstract Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue and is detrimental to growth and performance. Recent research has shown that supplementing protein has the potential to enhance growth performance in weaned steers. Therefore, the objective of this study was to evaluate the effect of supplemental CP on physiological parameters in stocker steers experiencing fescue toxicosis. Thirty-six weaned Angus steers (6 mo of age) stratified by weight (196.1 ± 3.6 kg) were assigned to a 2 × 2 factorial arrangement for 56 d: endophyte-free (EF) seed and 14% CP (EF-14; n = 9), EF seed and 18% CP (EF-18; n = 9), endophyte-infected (EI) seed and 14% CP (EI-14; n = 9), and EI seed and 18% CP (EI-18; n = 9). Steer growth and hemodynamic responses were collected weekly during ergot alkaloid exposure. On day 14 of the trial, iButton temperature data loggers were subcutaneously inserted in the lateral neck region to record hourly body temperature for 42 d. Data were analyzed using PROC MIXED of SAS with repeated measures. No differences were observed in DMI, BW, ADG, F:G, or BCS during the treatment period (P > 0.05). Hair shedding scores, rectal temperatures, surface temperatures, and respiration rates were greater in EI steers compared to EF steers regardless of supplemental CP (P < 0.05). However, subcutaneous body temperature was greater in EI-14 steers (37.94 °C) compared to other steer groups (37.60, 37.68, 37.72 ± 0.04 °C for EF-14, EF-18, and EI-18, respectively; P < 0.05). Prolactin concentrations tended to be greater in EF steers when compared to EI steers (P = 0.07). Heart rate and hematocrit were reduced for EI-18 steers compared to other steer groups (P < 0.05). Caudal artery diameter was reduced in EI-18 steers compared to EI-14 steers (2.60 vs. 2.75 ± 0.05 mm, respectively; P < 0.05) and caudal vein diameter was reduced in EI-18 steers (3.20 mm) compared to all other steer groups (3.36, 3.39, 3.50 mm for EF-14, EF-18, and EI-14, respectively; P < 0.05). However, there was no difference observed in systolic or diastolic blood pressure during the treatment period (P > 0.05). Based on the data, exposure to low to moderate levels of ergot alkaloids during the stocker phase had a negative impact on hemodynamic responses and supplemental CP had minimal impact to alleviate symptoms. Therefore, feeding additional protein above established requirements is not expected to help alleviate fescue toxicosis.

scholarly journals Effects of endophyte-infected tall fescue seed and protein supplementation on stocker steers: II. Adaptive and innate immune function

2019 ◽  
Vol 97 (10) ◽  
pp. 4160-4170 ◽  
Author(s):  
Rebecca K Poole ◽  
Alecia R Brown ◽  
Matthew H Poore ◽  
Carrie L Pickworth ◽  
Daniel H Poole
Keyword(s):  
Immune Response ◽  
Inflammatory Cytokines ◽  
Tall Fescue ◽  
Repeated Measures ◽  
Crude Protein ◽  
Protein Supplementation ◽  
Innate Immune ◽  
Fescue Toxicosis ◽  
Diarrhea Virus ◽  
Anti Inflammatory

Abstract Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue that affects performance; however, little information is available pertaining to its effects on immunity. Recently, it has been shown that supplemental CP can improve performance in weaned steers postvaccination. Thus, the objective of this study was to evaluate the effect of supplemental CP on innate and adaptive immune responses in stocker steers chronically exposed to ergovaline. Angus steers (n = 12 pens; 3 steers/pen) were stratified by weight and assigned to a 2 × 2 factorial arrangement to examine crude protein levels of supplement (14% or 18%) and ergovaline exposure (0 or 185 μg ergovaline/kg BW/d via ground endophyte-free (EF) or endophyte-infected (EI) tall fescue seed, respectively) on immune response. Consumption of low to moderate concentration of ergovaline from EI tall fescue seed was sufficient to induce mild symptoms associated with fescue toxicosis. Blood samples were collected at day 0, 42, and 56 to evaluate infectious bovine rhinotracheitis (IBR) and bovine viral diarrhea virus (BVDV) type 1b titers following vaccine challenge. Additionally, serum cytokine concentrations were evaluated using Quantibody Bovine Cytokine Arrays on day 0, 28, and 42. Data were analyzed using PROC MIXED of SAS with repeated measures. Regardless of treatment, no differences were observed in IBR and BVDV-1b seroconversion following vaccine challenge (P > 0.05). Regardless of crude protein concentration, EI steers had greater concentrations of proinflammatory cytokines (TNF-α, IFN-γ, IL-1α), chemokines (CCL2, CCL4, MIG), anti-inflammatory cytokines (IL-2, -13, -15, -21), and various growth factors (FGF-1, IGF-1, VEGF-A) when compared to EF steers (P < 0.05). Furthermore, VEGF-A and IGF-1 concentrations were greater in EI-14 steers on day 28 compared to EI-18, EF-14, and EF-18 steers (P < 0.05), however, this difference was not observed on day 0 or 42 (P > 0.05). Based on these data, steers exposed to ergovaline have an increase in pro- and anti-inflammatory cytokines and supplemental CP had minimal impact to mitigate this response. However, in the current study, exposure to ergovaline had little to no effect on adaptive immunity and response to vaccination. Together, chronic exposure to ergovaline results in a hyperactive innate immune response, which may lead to an immuno-compromised animal.

scholarly journals Cervical Cancer Screening with Pap Smear in Rural Population in Health Camp

2020 ◽  
Vol 22 (1-2) ◽  
pp. 62-66
Author(s):  
Astha Shrestha ◽  
S KC
Keyword(s):  
Repeated Measures ◽  
Blood Donors ◽  
Pap Smear ◽  
Blood Donation ◽  
Negative Impact ◽  
Muscle Tension ◽  
Plain Water ◽  
Hemodynamic Responses ◽  
Chi Square ◽  
Oral Rehydration

Adverse effects (AE) like vasovagal reactions (presyncope and syncope) have negative impact on old as well as new blood donors. Various methods have been suggested to prevent or attenuate AE in blood donors. This study assessed the effectiveness of prehydration with different fluids or applied muscle tension (AMT) during blood donation in preventing or attenuating AE. Consenting and eligible voluntary blood donors (n=448) were randomly allocated to Control (n=115), prehydration with 500 mL plain water (PW, n=97), prehydration with oral rehydration solution (ORS, n=71), prehydration with 400 mL fruit juice (FJ, n=74), or leg muscle tensing during blood removal (AMT, n=91) groups. Donors’ hemodynamic responses to blood donation were assessed by comparing blood pressures (systolic–SBP and diastolic–DBP) and heart rate (HR) recorded before blood removal to values midway during, and at 0 min, 5 min, 10 min and 15 min after blood removal. Presyncope and syncope were defined by BP and HR changes. Subjective AE were also recorded. Overall, 35 donors (7.8%) suffered AE with highest rates in PW (13.4%) and ORS (11.3%) groups and lowest in Control (3.5%) although group differences were not significant (p>0.05, Chi square). Blood removal was associated with significant falls in SBP and DBP (mean falls by 6.63 and 3.35 mmHg, respectively; p<0.001) but an insignificant rise in HR (mean increase by 0.67 bpm, p>0.05). Hemodynamic responses showed significant differences between groups (p<0.001, repeated measures ANOVA). Therefore, role of the interventions in relation to AE in blood donors could not be established.

Changes in Cytochrome P450 in Katahdin Ewes Fed Endophyte-infected Tall Fescue Seed Diets in Spring and Fall

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 40-41
Author(s):  
Mohan Acharya ◽  
Joan M Burke ◽  
Erin Wood ◽  
Yan Huang ◽  
Palika Dias Morse ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Serum Concentration ◽  
Rectal Temperature ◽  
Tall Fescue ◽  
Repeated Measures ◽  
Ergot Alkaloids ◽  
Serum Prolactin ◽  
Fescue Toxicosis ◽  
Pregnancy Status ◽  
Soy Hulls

Abstract Objective was to examine the activity of cytochrome P450 (CYP), a liver enzyme that metabolizes ergot alkaloids which is hindered by this fescue toxin, as an indicator of fescue toxicosis in sheep. In spring and fall, ewes were blocked by age and BW, and randomly assigned to 1 kg/ewe/d of endophyte-infected (E+; 61% of diet in fall, 13% of diet in spring; 0.8 µg/g of ergovaline; and soy hulls, alfalfa pellets, cottonseed hulls, molasses) or non-infected (E-; same proportion of E+/season and same feeds) tall fescue seed supplement (n = 10/diet in each season) for 28 d, plus hay, mineral and water. Ewes were exposed to teaser, d -21 to 0, and intact rams, d 0 (first day of diet) to 30. Rectal temperature (RT), serum concentration of prolactin (using RIA), and CYP were determined every 7–14 d between d 0–28, and pregnancy status on d 56. PromegaTM P450-Glo assay was used to determine CYP from serum. Data were analyzed by using PROC MIXED with repeated measures (SAS). Rectal temperature of E+ compared with E- ewes was elevated on at least one day in fall and spring (diet × season × d, P &lt; 0.001). Serum prolactin was lower in E+ compared with E- ewes (diet × d, P &lt; 0.001) and lower in fall (P &lt; 0.001). CYP was higher in E- ewes on d 28 in fall (diet × season × d, P = 0.008), but otherwise similar between diets, and higher in fall than spring (P &lt; 0.001). There was an unexpected negative correlation between CYP and prolactin (R = -0.24; P &lt; 0.009), but there appears to be a subpopulation of ewes with low prolactin and lower CYP. CYP activity in sera may not be a marker for fescue toxicosis in ewes.

scholarly journals 155 Evaluation of cytokine response as an indicator of genetic resistance to fescue toxicosis in purebred Angus cattle

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 45-46
Author(s):  
Kyle Mayberry ◽  
Rebecca K Poole ◽  
McKayla A Newsome ◽  
Piush Khanal ◽  
Matthew H Poore ◽  
...  
Keyword(s):  
G Protein ◽  
Tall Fescue ◽  
Repeated Measures ◽  
Genetic Resistance ◽  
Cytokine Response ◽  
Serum Prolactin ◽  
Fescue Toxicosis ◽  
Animal Performance ◽  
Negative Effects ◽  
G Protein Coupled

Abstract Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue. However, varying responses among cattle potentially implies genetic tolerance to the syndrome. Therefore, the objective was to evaluate the cytokine response of cows deemed either tolerant or susceptible to endophyte-infected fescue. Angus cows, 2–4 yrs old, grazed endophyte-infected tall fescue at two locations for 13 weeks starting mid-April 2016. A post-hoc analysis of animal performance was utilized to designate cattle into either tolerant (n = 20) or susceptible (n = 20) groups, based on physiological responses (changes in ADG) to chronic exposure to endophyte-infected fescue. Blood samples collected on weeks 1, 7, and 13 were used to evaluate serum prolactin (PRL) concentration. Cytokine concentrations were evaluated via Quantibody Bovine Cytokine Arrays. Data were analyzed using PROC MIXED of SAS with repeated measures. There were no differences by location or week. Tolerant cows tended to have decreased overall PRL concentrations compared to susceptible cows (98.3 and 138.4 ng/mL, respectively; P = 0.08). G protein-coupled receptor associated sorting protein (GASP)-1, a down-regulator of G protein-coupled receptors including D2-dopamine receptor a regulator of PRL secretion, was greater in tolerant cows when compared to susceptible cows (4.7 and 4.2 ng/mL; P = 0.03). Vascular endothelial growth factor (VEGF)-A was greater in tolerant cows when compared to susceptible cows (0.5 and 0.2 ng/mL; P = 0.02). Finally, interleukin (IL)-4, an anti-inflammatory cytokine, tended to be greater in tolerant cows when compared to susceptible cows (2.2 and 0.8 ng/mL, respectively; P = 0.07). Based on these data, greater concentrations of GASP-1, VEGF-A, and IL-4 in tolerant compared to susceptible cattle may mitigate the detrimental effects of fescue toxicosis, including suppressed PRL and vasoconstriction, leading to improved animal performance in a fescue environment. Additionally, these cytokines may serve as potential biomarkers for determining an animal’s tolerance or susceptibility to negative effects associated with endophyte-infected tall fescue

scholarly journals 111 Changes in proinflammatory cytokines and chemokines in beef steers chronically exposed to endophyte-infected tall fescue seed

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 42-43
Author(s):  
Alecia R Brown ◽  
Rebecca K Poole ◽  
McKenzie Lane Jackson ◽  
Matthew H Poore ◽  
Carrie L Pickworth ◽  
...  
Keyword(s):  
Immune Response ◽  
Proinflammatory Cytokines ◽  
Tall Fescue ◽  
Dietary Protein ◽  
Repeated Measures ◽  
Statistical Significance ◽  
Protein Supplementation ◽  
Beef Steers ◽  
Cytokine Analysis ◽  
The Impact

Abstract Endophyte-infected tall fescue consumption adversely effects health and immune response. The aim of this study was to evaluate the impact of protein supplementation on cytokine response in steers consuming ergovaline, found in endophyte-infected tall fescue. Thirty-two beef steers were fed a total mixed ration (TMR) and randomly assigned to receive one of four treatments for 56 days: endophyte-free seed (0 ug/kg ergovaline) with either 18% (EF-18; n = 8) or 14% dietary protein (EF-14; n = 8) and endophyte-infected seed (500 ug/ kg ergovaline) with 18% (EI-18; n = 8) or 14% dietary protein (EI-14; n = 8). Blood samples were collected for cytokine analysis on d 28 and d 42 of the feeding period representing when steers vaccinated and boostered for bovine viral diarrhea (BVD) types 1 and 2 and infectious bovine rhinotracheitis (IBR). Cytokine concentrations were evaluated using Quantibody Bovine Cytokine Arrays. Data were analyzed using PROC MIXED of SAS with repeated measures. Statistical significance was determined at P0.05). Interestingly, concentrations of cytokines, IL13 (912±148 vs. 410.9±135 pg/mL) and IL21 (1636.0±295 vs. 629±305 pg/mL), which are involved in chronic inflammatory process were greater (P < 0.05) in EI steer compared to EF steers on d 28 and d 42. Concentrations of chemokine CCL4 and proinflammatory cytokines IFNG and IL-1alpha tended to be greater in EI steers compared to EF steers (P < 0.10). Overall, these data demonstrate that consumption of ergovaline increased proinflammatory cytokines and induced a chronic immune response. Developing a better understanding of overall immunity in cattle exposed to endophyte-infected tall fescue is fundamental to improve cattle health within the beef industry.

scholarly journals Can prehydration with different fluids or applied muscle tension prevent or attenuate adverse effects in blood donors?

2020 ◽  
Vol 22 (1-2) ◽  
pp. 54-61
Author(s):  
Mrigendra Amatya
Keyword(s):  
Adverse Effects ◽  
Repeated Measures ◽  
Blood Donors ◽  
Blood Donation ◽  
Negative Impact ◽  
Muscle Tension ◽  
Plain Water ◽  
Hemodynamic Responses ◽  
Oral Rehydration ◽  
Applied Muscle Tension

Adverse effects (AE) like vasovagal reactions (presyncope and syncope) have negative impact on old as well as new blood donors. Various methods have been suggested to prevent or attenuate AE in blood donors. This study assessed the effectiveness of prehydration with different fluids or applied muscle tension (AMT) during blood donation in preventing or attenuating AE. Consenting and eligible voluntary blood donors (n=448) were randomly allocated to Control (n=115), prehydration with 500 mL plain water (PW, n=97), prehydration with oral rehydration solution (ORS, n=71), prehydration with 400 mL fruit juice (FJ, n=74), or leg muscle tensing during blood removal (AMT, n=91) groups. Donors’ hemodynamic responses to blood donation were assessed by comparing blood pressures (systolic–SBP and diastolic–DBP) and heart rate (HR) recorded before blood removal to values midway during, and at 0 min, 5 min, 10 min and 15 min after blood removal. Presyncope and syncope were defined by BP and HR changes. Subjective AE were also recorded. Overall, 35 donors (7.8%) suffered AE with highest rates in PW (13.4%) and ORS (11.3%) groups and lowest in Control (3.5%) although group differences were not significant (p>0.05, Chi square). Blood removal was associated with significant falls in SBP and DBP (mean falls by 6.63 and 3.35 mmHg, respectively; p<0.001) but an insignificant rise in HR (mean increase by 0.67 bpm, p>0.05). Hemodynamic responses showed significant differences between groups (p<0.001, repeated measures ANOVA). Therefore, role of the interventions in relation to AE in blood donors could not be established.

204 An Investigation into the Role of Dietary Essential Fatty Acids Ratios and Linoleic Acid Level on Growth Performance and Inflammation of Grow-finish Pigs

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 63-63
Author(s):  
Spenser Becker ◽  
Laura L Greiner
Keyword(s):  
Linoleic Acid ◽  
Synovial Fluid ◽  
Growth Performance ◽  
Repeated Measures ◽  
Fixed Effects ◽  
Acid Level ◽  
Essential Fatty Acids ◽  
Growing Pigs ◽  
Inflammatory Status ◽  
Linoleic Acid Level

Abstract The objective was to investigate the effects of dietary linoleic acid level and the ratio of linoleic acid:linolenic acid (n6:n3) on the growth performance and inflammatory status of grow-finish pigs. A total of 300 growing pigs (BW = 41.1 ± 6.3 kg) were randomly assigned to either a high (30 g/kg; HLA) or low (15 g/kg; LLA) linoleic acid level with a high (20:1; HR), moderate (12:1; MR) or low (4:1; LR) n6:n3 in a 2 x 3 factorial design. Diets were fed across three 28-day phases and were balanced for dietary metabolizable energy. Pigs were housed 5 pigs per pen. Blood samples were collected on weeks 1, 3, 6, and 12, and synovial fluid was collected from the hock joint on weeks 1 and 12 for inflammatory marker analysis. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with initial body weight as a covariate, pen as the experimental unit, and linoleic acid level, ratio, and their interaction as fixed effects. Compared to HLA, LLA pigs had increased BW (P &lt; 0.05) at d56 (103.2 vs. 101.3kg) and tended to have increased BW at d84 (P &lt; 0.10; 129.1 vs. 127.8kg). Pigs receiving LR tended to have higher d84 BW compared to MR (P &lt; 0.10; 129.1 vs. 127.3kg). There was no effect of linoleic acid ratio interaction for growth performance. In phase 2, pigs receiving LR had higher feed intake (P &lt; 0.05) compared to MR. Pigs receiving HR performed intermediate of LR and MR. Overall, C-reactive protein was reduced in the plasma of pigs receiving HLA (P &lt; 0.05; 19.3 vs. 26.2mg/mL). Across all treatments, CRP was reduced in synovial fluid and plasma in week 12 vs. week 1 (P &lt; 0.05). In conclusion, LLA and a low ratio of n6:n3 improved final pig BW, and HLA is potentially beneficial in improving inflammation.

scholarly journals 191 Effects of injectable vitamin C at weaning and prior to transit on growth performance and immune function of beef steers

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 152-153
Author(s):  
Aubree M Beenken ◽  
Erin L Deters ◽  
Colten W Dornbach ◽  
Stephanie L Hansen ◽  
Joshua C McCann ◽  
...  
Keyword(s):  
Vitamin C ◽  
Growth Performance ◽  
Repeated Measures ◽  
Fixed Effects ◽  
Average Daily Gain ◽  
Experimental Unit ◽  
Beef Steers ◽  
Diarrhea Virus ◽  
Plasma Ascorbate ◽  
Antibody Titers

Abstract Ninety-one early-weaned (65 ± 11 d) Angus steers (92 ± 4 kg) were blocked by age to a 2 × 2 factorial examining effects of injectable vitamin C (VC) at weaning and/or prior to transport to the feedlot on antibody titers and growth performance. Injections (20 mL/steer) of VC (250 mg sodium ascorbate/mL) or saline (SAL) were given at time of weaning on d 0 (WEAN) and/or prior to a 6 hr trucking event to a feedlot on d 49 (TRANS). Steers were given booster vaccinations on d 0. Steers were weighed on d 0, 1, 14, 48, 49, 64, 106, and 107. Blood was collected (12 steers/treatment) on d 0, 1, 2, 14, 49 (pre- and post-transit), 50, and 51. Data were analyzed via Proc-Mixed of SAS (experimental unit = steer; n = 22–23/treatment) with fixed effects of block, WEAN, TRANS, and WEAN × TRANS. Plasma ascorbate concentrations for weaning (d 0, 1, and 2) and transit (d 49-pre-trucking, 49-post-trucking, 50, and 51) were analyzed as repeated measures (repeated effect = day). Plasma ascorbate concentrations were greater on d 1 and 2 for steers that received VC at weaning (VC = 19.6, SAL = 8.8 ± 1.26 µM; WEAN × day P &lt; 0.01). Similarly, ascorbate concentrations were greater on d 49 post-trucking, 50, and 51 for steers that received VC pre-transit (TRANS × day P = 0.01). Treatments did not affect bodyweight or average daily gain throughout the trial (P &gt; 0.32). There were no effects of treatment on serum Bovine Viral Diarrhea Virus type 2 antibody titers on d 14 or 51 (P &gt; 0.33). An injection of VC administered to early weaned beef steers at weaning or pre-transit increases plasma ascorbate concentrations but does not improve growth performance or antibody response to vaccination booster.

305 Methane Emissions and Apparent Total Tract Nutrient Digestibility of Feedlot Beef Steers Under Intensive Management with or Without an Added Nutritional Packet

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 166-167
Author(s):  
Andrea M Osorio ◽  
Kaue T Tonelli Nardi ◽  
Igor Gomes Fávero ◽  
Kaliu G Scaranto Silva ◽  
Kymberly D Coello ◽  
...  
Keyword(s):  
Treatment Period ◽  
Repeated Measures ◽  
Fixed Effects ◽  
Block Design ◽  
Random Effect ◽  
Methane Emissions ◽  
Nutrient Digestibility ◽  
Experimental Unit ◽  
Beef Steers ◽  
Ch4 Production

Abstract The effects of a nutritional packet were evaluated on CH4 emissions and apparent total tract nutrient digestibility of feedlot beef steers. Thirty Angus-crossbred steers (BW = 542 ± 8.4 kg) were used in a randomized complete block design and allocated into pens equipped with SmartFeed (C-Lock; 15 steers/treatment). Steers were consuming a steam-flaked corn-based diet (88% concentrate DM basis) ad libitum for the last 65 d on feed, and received the following treatments: 1) control and 2) a nutritional packet [0.29% DM basis; live yeast (Saccharomyces cerevisiae; 8.7 Log CFU/g); Vitamin C (5.4 g/kg); Vitamin B1 (13.33 g/kg); NaCl (80 g/kg); KCl (80 g/kg)]. Methane emissions and apparent total tract nutrient digestibility were measured during 3 periods with 5-d of collections each. Gas emissions from steers were measured utilizing the SF6 tracer technique. Feed and fecal samples were collected once and twice (0700 h and 1600 h) daily, respectively, to determine digestibility of nutrients using iNDF as an internal marker. Steer was considered the experimental unit. Data were analyzed as repeated measures using the MIXED procedure of SAS with the fixed effects of treatment, period, and their interaction, and the random effect of block. No treatment × period interactions (P ≥ 0.125) were observed for DMI and any of the CH4 production variables (g/day, g/kg BW0.75, g/nutrient intake, and g/nutrient digested). Moreover, treatments did not affect digestibility of DM, OM, or ADF (P ≥ 0.300); however, digestibility of NDF was increased for treated cattle (P = 0.013), which resulted in a tendency (P = 0.098) to decrease CH4 production in g per kg NDF intake and decreased (P = 0.020) grams CH4 per kg NDF digested. The nutritional packet may be altering ruminal fermentation on intensively managed steers and improving fiber digestibility, which can have benefits on CH4 emission intensity.

scholarly journals Effects of Low-Stress Weaning on Calf Growth Performance and Carcass Characteristics

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
E. Gubbels ◽  
R. R. Salverson ◽  
K. M. Cammack ◽  
J. K. Grubbs ◽  
K. R. Underwood ◽  
...  
Keyword(s):  
Growth Performance ◽  
Repeated Measures ◽  
Covariance Structure ◽  
Carcass Characteristics ◽  
Marbling Score ◽  
Time Period ◽  
Body Weights ◽  
Haptoglobin Concentration ◽  
Wire Fence ◽  
Α Level

ObjectivesThe objective of this study was to compare the influence of two low stress weaning methods with conventional weaning on post-weaning performance and carcass characteristics of beef steers.Materials and MethodsAngus × Simmental crossbred steer calves (n = 90) from a single source were stratified by body weight and dam age into three groups; one treatment was randomly assigned to each group: ABRUPT (calves isolated from dams on the day of weaning), FENCE (calves separated from dams via a barbed wire fence for 7 d prior to completely weaning), and NOSE (nose-flap inserted and calves remained with dams for 7 d prior to completely weaning). At d +7 post-weaning calves were transported to a commercial feedlot where they received standard step-up and finishing rations typical for a Northern Plains feedlot. To understand the influence of each weaning method on haptoglobin (an acute-phase protein), blood samples were collected via coccygeal venipuncture at d –7 (PreTreat), 0 (Weaning), and +7 (PostWean) from a subsample of calves (n = 10 per treatment) and analyzed using a bovine haptoglobin ELISA kit. Body weights (BW) were recorded on study d –34 (PreWean), –7 (PreTreat), 0 (Weaning), 7 (PostWean), 32 (Receiving), 175 (Ultrasound), and 253 (Final) and average daily gains (ADG) were calculated between each time period. On d 175 post-weaning BW were recorded, and ultrasound fat thickness and intramuscular fat were determined and utilized to project marketing dates. Carcass measurements were recorded at the time of harvest and included hot carcass weight, 12th rib backfat, ribeye area, USDA Yield Grade and Quality Grade, and marbling score. Haptoglobin, BW, and ADG data were analyzed as repeated measures using the ante-dependence covariance structure in the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC) for effects of weaning treatment, day, and their interaction; birth weight was included as a covariate for ADG and BW. Carcass traits were analyzed for the effect of weaning treatment using the MIXED procedure. Separation of least-squares means was performed using LSD with a Tukey’s adjustment and assuming an α level of 0.05.ResultsWeaning method interacted (P < 0.0001) with time period for ADG and BW. Calf BW increased in all treatments until the PostWean period, wherein BW decreased (P < 0.0001) in ABRUPT and NOSE and was maintained (P > 0.05) in FENCE. From the Receiving to Final time periods BW increased similarly (P > 0.05) for all treatments. Calf ADG was greater (P < 0.01) in calves in the NOSE treatment at Weaning than ABRUPT or FENCE. In the PostWean period, the FENCE calves had ADG that was not different (P > 0.05) than zero but was greater (P < 0.0001) than the negative ADG of ABRUPT and NOSE calves. During the Receiving period ADG was greater (P < 0.05) for ABRUPT compared to NOSE and FENCE. Time influenced (P < 0.001) haptoglobin concentration. No difference in haptoglobin was observed between the PreTreat and Weaning or PostWean periods; however, haptoglobin concentration was greater (P < 0.001) at PostWean compared to Weaning. Weaning method did not influence (P > 0.05) carcass measurements.ConclusionCollectively these data suggest low stress weaning methods do not significantly improve post-weaning growth performance or carcass merit compared to calves weaned using conventional methods.

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