scholarly journals Effects of spring administration of extended-release eprinomectin on fescue toxicosis, performance, and reproduction of fall-born beef heifers

2019 ◽  
Vol 3 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Mareah J Volk ◽  
Jessica M Kordas ◽  
Rebecca S Stokes ◽  
Frank A Ireland ◽  
Daniel W Shike
Keyword(s):  
Extended Release ◽  
Treatment Time ◽  
Average Daily Gain ◽  
Parasite Load ◽  
Underlying Mechanism ◽  
Pregnancy Rates ◽  
Serum Prolactin ◽  
Fescue Toxicosis ◽  
Beef Heifers ◽  
Time Interaction

Abstract The objective of this experiment was to assess the effects of eprinomectin, an extended-release injectable parasiticide, on fescue toxicosis and its impacts on beef heifer performance and reproduction. Fall-born Angus × Simmental heifers (age = 246.3 ± 22.4 d; 264.8 ± 21.1 kg body weight [BW]) were randomly assigned to one of two treatments: extended-release eprinomectin injection (ERE; n = 100) or control (CON; saline; n = 99). Treatments were administered at a rate of 1 mL/50 kg BW. Prior to experiment, heifers were dosed with oral fenbendazole to minimize parasite load. All heifers grazed endophyte-infected tall fescue as a single group and were offered a 50:50 supplement mix of corn gluten feed and soybean hulls (2.7 kg as fed per heifer per day). Body condition scores (BCS), BW, hair coat score (HCS), blood, and fecal samples were collected throughout the experiment. A subset of 40 heifers were randomly selected (20 per treatment) to assess respiration rate (RR). On d 138, heifers began a 14-d controlled internal drug release + prostaglandin synchronization protocol. Following artificial insemination (AI), heifers were exposed to five bulls for 71 d. On d 214 and 291, AI and overall pregnancy rates, respectively, were determined. There was a treatment × time interaction (P < 0.01) for BW, BCS, and average daily gain (ADG). The ERE heifers had greater (P < 0.04) BW and BCS compared to CON heifers from d 55 and 112, respectively. In addition, ERE heifers had greater (P ≤ 0.04) ADG from d 0 to 56, 56 to 112, 112 to 171, and 171 to 214; however CON heifers had greater (P < 0.01) ADG from d 214 to 291. There was no treatment × time interaction or treatment difference (P ≥ 0.27) for HCS, RR, and serum prolactin concentrations. However, serum prolactin decreased (P < 0.01) in all heifers over time. There was a treatment × time interaction (P<0.01) for fecal egg counts (FEC). The FEC did not differ (P ≥ 0.32) on d −1 or 55; however, ERE heifers had decreased (P < 0.01) FEC compared with CON heifers on d 111 (1.52 vs. 13.56 eggs per gram). The ERE heifers tended (P = 0.10) to have greater AI pregnancy rates (69% vs. 58%) and had greater (P = 0.01) overall pregnancy rates (84% vs. 68%) than CON heifers. Spring administration of extended-release eprinomectin improved BW, ADG, BCS, and AI and overall pregnancy rates in fall-born beef heifers. However, the underlying mechanism is still unclear, as there were minimal to no differences in HCS, RR, serum prolactin, and FEC.

scholarly journals Effects of extended-release eprinomectin on fescue toxicosis, performance, and reproduction on fall-calving beef cows

2019 ◽  
Vol 3 (4) ◽  
pp. 1423-1434
Author(s):  
Mareah J Volk ◽  
Taylor R Krause ◽  
Rebecca S Stokes ◽  
Frank A Ireland ◽  
Daniel W Shike
Keyword(s):  
Milk Production ◽  
Tall Fescue ◽  
Extended Release ◽  
Treatment Time ◽  
Beef Cows ◽  
Serum Prolactin ◽  
Fescue Toxicosis ◽  
Time Interaction ◽  
Tick Count ◽  
Fall Calving

Abstract The objective of this experiment was to evaluate effects of extended-release eprinomectin on fescue toxicosis and impacts on performance and reproduction in fall-calving beef cows. Fall-calving Angus × Simmental multiparous cows [n = 335; age = 5.8 ± 2.1 yr; 586.5 ± 6.0 kg body weight (BW); 5.48 ± 0.05 body condition score (BCS)] were stratified by BW, age, and BCS and randomly assigned to one of three treatments. Treatments included a spring injection of extended-release eprinomectin (SERE) on day 0, a fall injection of extended-release eprinomectin injection (FERE) on day 84, and a saline control (CON). All treatments were administered at a rate of 1 mL/50 kg BW. Prior to the experiment, all cows were treated with oral fenbendazole to minimize parasite load. Cows grazed endophyte-infected tall fescue. Hair coat score (HCS), BW, and BCS were recorded on all cattle. Fecal egg count (FEC), respiration rate (RR), horn fly and tick count, hematocrit (% packed cell volume, PCV), and serum prolactin were analyzed on a subset of cows (35/treatment). On day 194, cows were artificially inseminated (AI) and 11 d following AI were exposed to bulls for 51 d. Milk production was estimated on day 210 on a subset of 85 cow–calf pairs (28–29/treatment). There was a tendency for a treatment × time interaction (P = 0.07) for FEC likely driven by an increase in FEC of the CON cattle at day 126 compared to SERE and FERE. There was a tendency for a treatment × time interaction (P = 0.06) for cow BW, largely driven by time differences; however, there was no effect of treatment (P = 0.84) on BW. There was no difference (P ≥ 0.13) in cow PCV, fly and tick count, BCS, HCS, RR, and serum prolactin throughout the experiment. Additionally, there was no difference (P ≥ 0.46) in Julian calving date, calf birth BW, or milk production between treatments. Interestingly, heifer calves born to FERE dams tended to have greater (P = 0.06) weaning BW compared to heifer calves born to CON dams. In addition, there was no difference (P ≥ 0.17) in heat patch scores, AI conception rates, or overall pregnancy rates between treatments. Extended-release eprinomectin did not impact cow growth performance, reproductive performance or fescue toxicity symptoms when grazing endophyte-infected tall fescue; however, calf weaning BW tended to be improved.

scholarly journals PSI-2 Impact of an extended-release dewormer on rumen VFAs and blood metabolites

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 159-159
Author(s):  
Stephanie D Perkins ◽  
Jerica J J Rich ◽  
Emmalee J Northrop ◽  
Julie A Walker ◽  
George A Perry
Keyword(s):  
Repeated Measures ◽  
Extended Release ◽  
Rumen Fluid ◽  
Parasite Load ◽  
Nutrient Utilization ◽  
Blood Metabolites ◽  
Lactating Cows ◽  
Time Interaction ◽  
Fecal Egg Count ◽  
Rumen Ph

Abstract The ratio of glucogenic to lipogenic acids in ruminal VFAs can have a direct impact on nutrient utilization. The objective of this study was to compare the effects of an extended-release injectable dewormer [LongRange® (eprinomectin)] to a traditional shorter-acting injectable dewormer [Ivomec® (doramectin)] on rumen VFA profiles and blood metabolites. Ruminally cannulated lactating cows (2yr of age) were randomly allotted to one of the two dewormers (n = 5/treatment) at the time of being moved to spring grazing (day of AI). Blood samples, rumen pH, and rumen fluid were collected prior to treatment on d 0, d 15, and approximately every 30d thereafter until d 137 and analyzed by analysis of repeated measures. Fecal samples were collected at the start, middle, and end of the study to determine parasite fecal egg count. At the initiation of the study only 3 animals had any detectable parasites by fecal egg count and at the middle of the study all animals treated with the traditional dewormer had detectable parasites. Animals treated with the extended-release dewormer had no detectable parasite load throughout the study. There was no effect of treatment or treatment by time on rumen pH (P = 0.64, 0.55) or circulating NEFA concentrations (P = 0.60, 0.65) but both changed over time (P ≤ 0.01). Circulating glucose concentrations were not affected by treatment (P = 0.71) or time (P = 0.15), but there was a treatment by time interaction (P = 0.03) with glucose concentrations increased on day 32 in the extended-release dewormer. Concentrations of rumen ammonia, total VFAs, acetate, propionate, isobutyrate, butyrate, isovalerate, and valerate were not impacted by treatment (P > 0.20), but there was an effect of time (P = 0.10). In summary, controlling parasite load during a 5mo grazing season can improve nutrient utilization in cattle.

scholarly journals Treatment effect of oil-based contrast is related to experienced pain at HSG: a post-hoc analysis of the randomised H2Oil study

2019 ◽  
Vol 34 (12) ◽  
pp. 2391-2398 ◽  
Author(s):  
N van Welie ◽  
K Dreyer ◽  
J van Rijswijk ◽  
H R Verhoeve ◽  
M Goddijn ◽  
...  
Keyword(s):  
Underlying Mechanism ◽  
Pregnancy Rates ◽  
P Value ◽  
Ongoing Pregnancy ◽  
Research Grants ◽  
Enhancing Effect ◽  
Post Hoc Analysis ◽  
Infertile Women ◽  
Water Based ◽  
Post Hoc

Abstract STUDY QUESTION Does pain or volume of used contrast medium impact the effectiveness of oil-based contrast during hysterosalpingography (HSG)? SUMMARY ANSWER In women who report moderate to severe pain during HSG, the use of oil-based contrast resulted in more ongoing pregnancies compared to the use of water-based contrast, whereas in women who reported mild or no pain, no difference in ongoing pregnancies was found. WHAT IS KNOWN ALREADY We recently showed that in infertile women undergoing HSG, the use of oil-based contrast results in more ongoing pregnancies within 6 months as compared to the use of water-based contrast. However, the underlying mechanism of this fertility-enhancing effect remains unclear. STUDY DESIGN, SIZE, DURATION We performed a post-hoc analysis of the H2Oil study, a multicentre randomised controlled trial (RCT) evaluating the therapeutic effect of oil- and water-based contrast at HSG. Here, we evaluated the impact of pain experienced at HSG and volume of used contrast media during HSG on ongoing pregnancy. PARTICIPANTS/MATERIALS, SETTING, METHODS In a subset of 400 participating women, pain during HSG by means of the Visual Analogue Scale (VAS) (range: 0.0–10.0 cm) was reported, while in 512 women, we registered the volume of used contrast (in millilitres). We used logistic regression analyses to assess whether pain and volume of used contrast media modified the effect of oil-based contrast on ongoing pregnancy rates. Data were analysed according to intention-to-treat principle. MAIN RESULTS AND THE ROLE OF CHANCE In 400 women in whom pain scores were reported, the overall median pain score was 5.0 (Interquartile range (IQR) 3.0–6.8) (oil group (n = 199) 4.8 (IQR 3.0–6.4); water group (n = 201) 5.0 (IQR 3.0–6.7); P-value 0.28). There was a significant interaction between pain (VAS ≤5 versus VAS ≥6) and the primary outcome ongoing pregnancy (P-value 0.047). In women experiencing pain (VAS ≥6), HSG with oil-based contrast resulted in better 6-month ongoing pregnancy rates compared to HSG with water-based contrast (49.4% versus 29.6%; RR 1.7; 95% CI, 1.1–2.5), while in women with a pain score ≤5, 6-month ongoing pregnancy rates were not significantly different between the use of oil- (28.8%) versus water-based contrast (29.2%) (RR 0.99; 95% CI, 0.66–1.5). In the 512 women in whom we recorded contrast, median volume was 9.0 ml (IQR 5.7–15.0) in the oil group versus 8.0 ml (IQR 5.9–13.0) in the water group, respectively (P-value 0.72). Volume of used contrast was not found to modify the effect of oil-based contrast on ongoing pregnancy (P-value for interaction 0.23). LIMITATIONS, REASONS FOR CAUTION This was a post-hoc analysis that should be considered as hypothesis generating. The RCT was restricted to infertile ovulatory women, younger than 39 years of age and with a low risk for tubal pathology. Therefore, our results should not be generalised to infertile women who do not share these features. WIDER IMPLICATIONS OF THE FINDINGS The underlying mechanism of the fertility-enhancing effect induced by HSG with the use of oil-based contrast remains unclear. However, these findings suggest a possible mechanistic pathway, that is increasing intrauterine pressure occurring prior to dislodging pregnancy hindering debris or mucus plugs from the proximal part of otherwise normal fallopian tubes. This information might help in the search of the underlying fertility-enhancing mechanism found by using oil-based contrast during HSG. STUDY FUNDING/COMPETING INTEREST(S) The original H2Oil RCT was an investigator-initiated study that was funded by the two academic institutions (AMC and VUmc) of the Amsterdam UMC. The funders had no role in study design, collection, analysis and interpretation of the data. K.D. reports consultancy for Guerbet. H.V. reports consultancy fees from Ferring. C.B.L. reports speakers’ fees from Ferring and research grants from Ferring, Merck and Guerbet. V.M. reports receiving travel and speakers fees as well as research grants from Guerbet. B.W.M. is supported by an NHMRC Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck KGaA and Guerbet and travel and research grants from Merck KGaA and Guerbet. The other authors do not report conflict of interests. TRIAL REGISTRATION NUMBER The H2Oil study was registered at the Netherlands Trial Registry (NTR 3270). TRIAL REGISTRATION DATE 1 February 2012. DATE OF FIRST PATIENT’S ENROLMENT 3 February 2012.

scholarly journals 233 NaturSafe® supplementation mitigates some aspects of the acute phase immune response to a lipopolysaccharide (LPS) challenge in weaned beef calves

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 117-117
Author(s):  
Nicole C Burdick Sanchez ◽  
Jeffery A Carroll ◽  
Paul R Broadway ◽  
Tom S Edrington ◽  
Ilkyu Yoon ◽  
...  
Keyword(s):  
Acute Phase ◽  
Treatment Time ◽  
Sickness Behavior ◽  
Serum Cortisol ◽  
Post Challenge ◽  
Serum Samples ◽  
Lps Challenge ◽  
Time Interaction ◽  
Tnf Α ◽  
Monitoring Devices

Abstract This study was conducted to determine if feeding calves NaturSafe would reduce the acute phase response (APR) to lipopolysaccharide (LPS) challenge. Crossbred steers (n=32; 274±2 kg) were randomly allotted to two treatment diets: 1) Control, fed a standard receiving ration, and 2) NaturSafe, fed the Control ration supplemented with NaturSafe at 12 g/hd/d (NaturSafe®, Diamond V). On d22, steers were fitted with indwelling jugular catheters and rectal temperature monitoring devices and placed in individual stalls. On d23, steers were challenged i.v. with 0.25 µg/kg BW LPS. Serum samples were collected and sickness behavior scores (SBS) recorded at 0.5-h intervals from -2 to 8h and at 24h relative to LPS challenge. Rectal temperatures were greater (P=0.01) in NaturSafe compared to Control steers for the following time intervals following LPS challenge: 6 to 11h, 13h, 15 to 20h, and 22 to 24h. Additionally, SBS were reduced (P< 0.01) in NaturSafe compared to Control steers. White blood cell concentrations were greater (P=0.05) in NaturSafe compared to Control steers prior to the LPS challenge, yet the response to LPS did not differ between treatments (P >0.05). A treatment × time interaction for serum cortisol concentrations (P< 0.01) showed an increase at 0.5 and 2h post-challenge but a reduction at 3h in NaturSafe compared to Control steers. Additionally, fibrinogen was greater (P< 0.01) in NaturSafe compared to Control steers. There was a treatment × time interaction (P< 0.01) for TNF-α where concentrations were reduced from 1 to 2h post-challenge in NaturSafe compared to Control steers. Serum IL-6 tended (P=0.09) to show a reduction in serum concentrations in NaturSafe compared to Control steers. There was a tendency (P=0.07) for a treatment × time interaction for IFN-γ. Overall these data suggest a priming effect of NaturSafe on the innate immune system of steers, resulting in an attenuated APR to the LPS challenge.

scholarly journals Effects of providing artificial shade to pregnant grazing beef heifers on vaginal temperature, growth, activity, and behavior

2021 ◽  
Author(s):  
Gleise M Silva ◽  
Lautaro R Cangiano ◽  
Thiago F. Fabris ◽  
Victoria R Merenda ◽  
Ricardo C Chebel ◽  
...  
Keyword(s):  
Growth Performance ◽  
Average Daily Gain ◽  
Experimental Period ◽  
Paspalum Notatum ◽  
Beef Heifers ◽  
Shade Treatment ◽  
Growth Activity ◽  
Gps Devices ◽  
And Behavior ◽  
Vaginal Temperature

Abstract This experiment evaluated the effects of providing artificial shade during summer on activity, behavior, and growth performance of pregnant grazing beef heifers. Thirty-six black-hided Angus and Angus crossbred pregnant heifers [418 ± 9 kg body weight (BW); approximately 90 d of gestation] were stratified by breed, blocked by BW, and allocated to 12 ‘Pensacola’ bahiagrass pastures (Paspalum notatum Flüggé; 1.3 ha, n = 3 heifers/pasture) with or without access to artificial shade (SHADE vs. NO SHADE; 6 pastures each) for 7 wk during summer. The shade structures were composed of shade cloth (11 × 7.3 m length, 2.4 m height: 26.8 m 2 of shade per heifer). Shrunk BW was recorded on enrollment (d 0) and wk 7 (d 47), whereas full BW was obtained on wk 2 (d 14), 4 (d 28), and 6 (d 42) to assess average daily gain (ADG). Vaginal temperature was recorded for five consecutive days during wk 1, 3, 5, and 7 using an intravaginal digital thermo-logger, and individual GPS devices were used to quantify the use of shade for an 8-h period. Activity was monitored using automated monitoring devices (HR-LDn tags SCR Engineers Ltd., Netanya, Israel) through the experimental period. Vaginal temperature was lower (P < 0.01) for heifers in the SHADE compared with heifers in the NO SHADE treatment from 1200 to 1600 h and 1100 to 1900 h for wk 1 and 3, respectively. Heifers in the SHADE treatment spent 70% of the 8-h period evaluated under the shaded structure. Provision of shade increased (P < 0.01) daily lying time (11.4 ± 0.2 vs. 10.3 ± 0.2 h/d) and standing bouts per day (P < 0.01; 12.6 ± 0.4 vs. 10.8 ± 0.4 bouts/d), whereas it reduced (P < 0.01) standing bout duration (61.6 ± 3.0 vs. 82.9 ± 3.0 min/bout) relative to heifers without access to shade. The interaction between treatment and hour affected (P < 0.01) daily rumination time because heifers with access to SHADE had greater rumination between 1000 and 1200 h. Although ADG tended (P = 0.08) to be greater for the heifers in the SHADE treatment (0.20 vs. -0.02 kg, respectively), the access to shade did not (P = 0.79) affect the final BW. In conclusion, providing artificial shade during summer to pregnant grazing beef heifers was effective in reducing vaginal temperatures and exerted changes in heifer behaviors that translated into slight improvements in growth performance.

scholarly journals Effects of management system on beef heifer growth and reproductive performance

2020 ◽  
Author(s):  
Parker A Henley ◽  
Frank A Ireland ◽  
Igor F Canisso ◽  
J Lannett Edwards ◽  
Daniel W Shike
Keyword(s):  
Development Strategy ◽  
Breeding Season ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Pregnancy Rates ◽  
Fescue Toxicosis ◽  
Soybean Hulls ◽  
Randomized Design ◽  
Condition Score ◽  
Calf Performance

Abstract This study evaluated the effect of heifer development system on body weight (BW), body condition score (BCS), fescue toxicosis symptoms, reproductive performance, and subsequent calf growth of fall-calving beef heifers. Angus × Simmental heifers [n = 399; 240 ± 20.0 kg initial BW; age = 252 ± 20 d] were stratified by BW and BCS and assigned to 1 of 12 groups in each of the 2 production years. The study utilized a stratified randomized design. Pens were randomly assigned to 4 treatments: drylot (DL) development (fed ad-libitum diet consisting of 90% hay and 10% DDGS on a dry matter basis), grazing endophyte-infected fescue supplemented daily (2.3 kg as-fed/heifer/d; 50:50 mix of soybean hulls and DDGS; E+/S), grazing endophyte-infected fescue and supplemented from the midpoint of treatment period until breeding (4.5 kg as-fed/heifer/d; 50:50 mix of soybean hulls and DDGS; E+/LS), and grazing novel endophyte-infected fescue with no supplement (NE+/NS). Treatments ceased on d 168 [time of artificial insemination (AI)] and heifers were commingled and managed as a group through second breeding season. Heifers in DL had greatest (P ≤ 0.05) BW and BCS from d 28 until d 254. Furthermore, E+/S heifers had greater (P ≤ 0.05) BW and BCS than both E+/LS and NE+/NS from d 28 until d 168. On d 56 and 84, E+/LS heifers had lower (P ≤ 0.05) BW and BCS compared to NE+/NS, but on d 148 treatments reranked and E+/LS remained at a greater (P ≤ 0.05) BW and BCS compared to NE+/NS through the first breeding season. Drylot heifers had greatest (P ≤ 0.05) percentage cycling and percentage of mature BW at AI (66.6%) and had greater (P ≤ 0.05) AI and overall pregnancy rates compared to E+/LS and NE+/NS. The E+/S (55%) and E+/LS (53.7%) heifers were developed to a greater (P < 0.01) percentage of mature BW than NE+/NS (49.3%). A greater (P ≤ 0.02) percentage of DL and E+/S heifers were pregnant at the end of the first breeding season (89.3 and 85.1%; respectively) compared to NE+/NS (61.5%). In summary, DL heifers had the greatest BW and BCS at AI, percentage cycling, and AI pregnancy rate. However, this strategy did not result in differing overall pregnancy rates between DL, E+/S, and E+/LS and there were no differences in milk production, rebreeding reproductive performance, and calf performance between all treatments. Finally, the poorest AI and overall pregnancy rates of the NE+/NS heifers suggests this is not a viable development strategy for fall-born heifers.

scholarly journals 168 The effects of fly control strategies on fly abundance, fly avoidance behaviors, and performance in feedlot bulls and steers

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 15-16
Author(s):  
Courtney McNeff ◽  
Justin Talley ◽  
Colton A Robison ◽  
Blake K Wilson
Keyword(s):  
Treatment Time ◽  
Control Strategies ◽  
Block Design ◽  
Animal Health ◽  
Piperonyl Butoxide ◽  
Stable Fly ◽  
Animal Performance ◽  
Time Interaction ◽  
Avoidance Behaviors ◽  
Fly Control

Abstract The objective of this experiment was to examine the effects of fly control strategies on fly abundance, fly avoidance behaviors, and animal performance in a feedlot setting. Angus bulls (n = 64; BW = 281 ± 36.2 kg) and steers (n = 36; BW = 475 ± 40.4 kg) were blocked by sex and BW and assigned to 1 of 4 experimental treatments in a randomized complete block design (7 pens/treatment; 4 bulls/pen; 3 steers/pen). Treatments included: control (CON; no fly control), abamectin, piperonyl butoxide, and zetacypermethrin insecticide tags (FT; Tri-Zap®, Y-Tex Corporation, Cody, WY), permethrin and piperonyl butoxide pour on (PO; Permectrin® CDS, Bayer Animal Health, Shawnee Mission, KS), or a garlic-powder top dress (GR) administered at 0.28 g •-1 animal •-1d. The experiment was conducted between June and September. Horn and stable fly abundance (FA) and fly avoidance behaviors (FAB; i.e. tail-flicks, stomping, head-tossing) were recorded by trained personnel. Both FA and FAB were recorded once/wk on days with similar temperatures, humidity, wind speed, and without precipitation based on Oklahoma Mesonet data (Stillwater site). There was a tendency for a treatment × time interaction for horn FA with differences in treatments occurring at wk 1, 2, 8, and 14. There was no treatment × time interaction for stable FA or FAB, however both were affected by time (P < 0.001). There were no differences in final BW (P = 0.34), overall ADG (P = 0.30), overall DMI (P = 0.53), or overall G:F (P = 0.39). There was a tendency (P ≤ 0.10) for GR to have decreased BW on d 28 and decreased ADG from d 0 to 28 compared to FT and PO. There was also a tendency (P = 0.09) for decreased DMI from d 0 to 56 for GR compared to CON and FT. Overall FA was less than expected (mean = 1 to 17 flies/animal) throughout the experiment and overall animal performance was unaffected by fly control strategy.

Response of beef heifers and non-suckling beef cows to different oestrous synchronization protocols

2002 ◽  
Vol 74 (3) ◽  
pp. 547-552 ◽  
Author(s):  
D. Cavestany ◽  
N. Negrin ◽  
R. Negrin ◽  
J. F. Groth
Keyword(s):  
Beef Cattle ◽  
Medroxyprogesterone Acetate ◽  
Artificial Insemination ◽  
Experimental Period ◽  
Fixed Time ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Gnrh Analogue ◽  
Beef Heifers

AbstractThe objective was to evaluate different oestrous synchronization schemes in beef cattle under range conditions. In experiment 1, 202 heifers averaging 26 months of age were assigned randomly to three treatments: (a) GnRH-PG. (no. = 44) day 0 (D0): injection of GnRH; D7: injection of PGF2α; D0 to D25 oestrous detection (OD) and artificial insemination (AI); (b) OD-PG. (no. = 45) D0 to D4; OD + AI; D5: injection of PGF2α; D5 to D25 OD + AI; and (c)Ovsynch. (no. = 113) D0: injection of GnRH; D7: injection of PGF2α; D9: injection of GnRH and 16 h later AI at fixed time. In experiment 2, 318 non-suckling cows were assigned randomly to three treatments: (a) GnRH-PG. (no. = 106) D0: injection of GnRH; D7: injection of PGF2α; D0 to D25 OD + AI; (b) GnRH-MAP-PG. (no. = 106) D0: injection of a GnRH analogue and insertion of an intravaginal sponge impregnated with 250 mg of medroxyprogesterone acetate; D7: injection of PGF2α and sponge withdrawal; D0 to D25 OD + AI; (c) controls. (no. = 106) OD and AI. The experimental period lasted 25 days and, with exception of the Ovsynch treatment, oestrous detection was carried out twice a day (a.m./p.m.) and inseminations performed 12 h later. The pregnancy rates assessed by ultrasonography 30 days after AI were: experiment 1: (a) 30·0%; (b) 28·6% and (c) 62·3% (P < 0·05); experiment 2: (a) 60·2%; (b) 57·8% and (c) 45·5% (P < 0·05). It is concluded that in heifers and non-suckling cows, oestrous synchronization treatments result in higher pregnancy rates. In non-suckling cows, the addition of a progestagen did not improve the response.

177 Ad Libitum Consumption of a 1:1 Blend of inorganic:organic Se by Steers Grazing Endophyte-infected Tall Fescue Increases Serum Prolactin and Alkaline Phosphatase Activity, but Not Average Daily Gain

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 94-95
Author(s):  
Kelsie Webb ◽  
Ronald J Trotta ◽  
Phillip Bridges ◽  
James Matthews
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Tall Fescue ◽  
Average Daily Gain ◽  
Serum Prolactin ◽  
Negative Effects ◽  
Ad Libitum ◽  
Ad Libitum Intake ◽  
Daily Gain

Abstract To test the hypothesis that average daily gain (ADG) and clinical parameters of steers grazing novel non-toxic (NTE) or toxic KY-31 (TE) endophyte-infected tall fescue would be improved by ad libitum intake of vitamin-mineral mixes (V-M) that contain 27 ppm Se as a 1:1 blend of SELPLEX:sodium selenite (MIX) vs sodium selenite (ISe), 32 TE-naïve beef steers depleted of Se were randomly assigned to ad libitum consumption ISe vs MIX for 35 d and fed enough of a NTE/alfalfa/grain diet to achieve 0.57 kg BW gain/d. Within Se-form treatments, 2 steers were randomly assigned to each of 4, 2-acre NTE (ISe = 316 ± 31 kg, MIX = 315 ± 22 kg) or TE (ISe = 316 ± 37 kg, MIX = 314 ± 39 kg) paddocks for 84 d and had ad libitum access to their respective V-M. The MIXED procedure of SAS was used to assess effects of day, Se-form (ISe, MIX) and endophyte (NTE, TE) treatments, and their interactions. Whole blood Se decreased (P &lt; 0.01) 31% from d 0 to 84 and was 6.2% greater (P &lt; 0.01) for MIX steers. Serum prolactin decreased (P &lt; 0.01) 18% for NTE and 48% for TE steers from d 0 to 84 and was 17% greater (P = 0.01) for MIX vs. ISe TE steers. Alkaline phosphatase activity (AP) decreased (P &lt; 0.02) 27% from d 0 to 84 and was 15% greater (P &lt; 0.02) for MIX steers. Serum urea nitrogen increased (P &lt; 0.02) 8.2% from d 0 to 84 for TE but not NTE steers. Average daily gain (kg/d) was less (P &lt; 0.01) in TE (-0.18) vs NTE (0.09) steers. We conclude that the ad libitum intake of MIX ameliorated the negative effects of consuming TE on serum prolactin and AP but not ADG.

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