To evaluate meloxicam plasma concentrations using a microneedle patch, 12 pigs (initial BW = 2.5 ± 0.53 kg) were stratified into of 4 treatment groups. Treatment groups were: 1) pigs (n = 2) received 0.5 mg/kg meloxicam via oral drench (oral); 2) pigs (n = 2) received a patch with no meloxicam (placebo); 3) pigs (n = 4) received microneedle patch dosed at 2.5 mg/kg (low dose); and 4) pigs (n = 4) received 2 microneedle patches dosed at 5 mg/kg (high dose). Blood was collected for plasma analysis at 0, 2, 4, 8, 12, 24, 48, 72, 96, and 168 hours. Microneedle patches were adhered on the pinna of the ear after blood collection at 0 hour. Statistical analyses were performed using the MIXED procedure of SAS 9.4, assessing effects of treatment, time, and treatment × time interaction. Statistical significance was determined at P ≤ 0.05, with tendencies at 0.05 < P ≥ 0.1. There was a treatment × time interaction (P < 0.0001), with the oral treatment group having greater meloxicam plasma concentrations at 2, 4, and 8 hours than placebo, low dose, and high dose treatment groups (P < 0.0001), but there were no differences for 24, 48, 72, 96, and 168 hours (P > 0.1). The oral treatment group tended to have greater meloxicam plasma concentrations at 12 hours compared with placebo (P = 0.09), low dose (P = 0.054), and high dose (P = 0.054) treatment groups. There were no differences between placebo, low dose, and high dose treatment groups for any blood collection timepoint (P > 0.1). Meloxicam concentrations in plasma were detectable but low for both the low dose treatment group (0.21 ng/mL) and high dose treatment group (1.14 ng/mL). Research is continuing to determine the ideal meloxicam dosage needed on the patch to deliver desired plasma concentrations.
The study was conducted to identify effects of a decreased interval of progesterone on the ovulatory follicle before fixed-timed artificial insemination (FTAI) by altering the day of a gonadotropin-releasing hormone agonist (GnRH;00µg gonadorelin; Cystorelin) administration. Evaluation of the 7 & 7 Synch and altered estrous synchronization protocols was done using estrus expression (EE) and FTAI pregnancy rates (PR). Using frozen conventional Angus semen (Select Sires, Inc. Plain City, OH), Angus-cross heifers (n = 68) from the University of Arkansas beef cattle research unit near Fayetteville were stratified into two treatment groups by cyclicity status (CYC) and age. Cyclicity status was determined by using a reproductive tract score (RTS) taken one week prior to beginning synchronization. Scores ranged from 1-5, where RTS 1-3 were considered pre- or peripubertal while scores 4 and 5 were considered cycling. Heifers with a RTS of and 2 were culled prior to synchronization. Each treatment used a controlled internal drug releasing device (CIDR; Eazi-breed; 1.38g progesterone) inserted intravaginally on –14 d simultaneous to the administration of a prostaglandin F2α analogue (PGF; 500 µg cloprostenol sodium; Synchsure). In the first treatment (7 & 7), GnRH was administered on –7 d. In the second treatment (8 & 6), GnRH was administered on –6 d. Both treatments were then administered PGF simultaneous to CIDR removal on 0d, 72 ±h prior to FTAI and the administration of GnRH. Estrus expression was recorded at the time of FTAI using an Estrotect patch (Rockway Inc., Spring Valley, WI). Estrus expression was determined as a patch with 50% or more of the color rubbed off. On the contrary, a patch with less than 50% of the color rubbed off, was not. Pregnancy rates was determined via ultrasound on 58 d. Estrus expression and PR were analyzed by treatment using the GLIMMIX procedure on SAS 9.4 (SAS Institute Inc., Cary, NC) with CYC as a fixed effect for EE; CYC and EE as fixed effects for PR. Statistical differences were determined with α ≤ 0.05 and tendencies were observed between 0.06-0.1. There was an effect of CYC on EE (P = 0.001) and a tendency to affect PR (P = 0.088). There was no treatment effect on EE (P = 0.892) or PR (P = 0.708). In conclusion, the altered time of GnRH administration in the 7 & 7 synch at 72 ± hours did not affect EE or PR; however, research will continue to investigate adjusting length of time from PGF injection to FTAI to evaluate the effects.
The objective was to investigate the influence of progesterone exposure time and breeding time on fixed-time artificial insemination (FTAI) protocols using sex-sorted semen in Angus-cross heifers (n = 85; mean BW = 324 kg.). Heifers were assigned randomly into four treatment groups. Treatments 1 and 2 used a 6-day CO-synch + controlled internal drug release (CIDR) protocol with gonadotropin releasing hormone (GnRH) administration and CIDR insertion on day 0 and prostaglandin F2α (PGF) administration on day 6, upon simultaneous CIDR removal. Treatment 1 heifers underwent FTAI 72 h post CIDR removal, and Treatment 2 heifers underwent FTAI 80 h post CIDR removal. Treatments 3 and 4 used a 7-d CO-synch + CIDR protocol with GnRH administration and CIDR insertion on d 0 and PGF administration on d 7, upon simultaneous CIDR removal. Treatment 3 heifers underwent FTAI 54 h post CIDR removal, and Treatment 4 heifers underwent FTAI 62 h post CIDR removal. Estrus expression was determined using an estrus detection patch (Estrotect™, Rockway Inc., Spring Valley, WI). Estrus expression was classified as a patch with 50% or more of the color rubbed off and the absence of estrus expression as a patch with less than 50% of the color rubbed off. All heifers were inseminated using female sex-sorted semen from a single Angus sire (SexedULTRA 4M™, STgenetics, Navasota, TX). Pregnancy was determined by ultrasound 57 d following FTAI. Pregnancy rates and patch scores were analyzed using the GLIMMIX procedure of SAS 9.4 with treatment as a fixed effect. There was no effect of treatment on the first service AI rates (P = 0.91) or on estrus expression (P = 0.17) in heifers. In conclusion, the combinations of progesterone and breeding time in this study did not affect first service AI conception rates or estrus expression in beef cattle heifers.
The CowManager (Agis, Harmelen, the Netherlands) ear sensor technology was developed for dairy cows in confinement and has recently been adopted for pastured beef cows. The sensors fit around the ‘840’ RFID button and houses a 3-dimensional accelerometer that registers movement of the cow’s ear. Each sensor stores up to 7 d of internal data at a time and is transmitted by solar powered routers in the pasture. The objective was to determine the effectiveness of the CowManager system’s estrus detection (ED) feature in beef cows during estrous synchronization (ES), AI, and during exposure to bulls for 60 d. Fifty 6-8 yr multiparous commercial Angus-crossbred cows with calves, were fitted with CowManager ear sensors for 14 d to allow for acclimation. Cows then underwent ES using a 6-d CO-Synch + controlled internal drug release (CIDR) protocol with AI at 72 h post CIDR + prostaglandin F2α with sexed female semen. Estrus detection was determined using breeding patches (Estrotect™, Rockway Inc., Spring Valley, WI), with estrus classified as greater than 50% of color rubbed off, and CowManager sensors with a notification to a smartphone and/or computer. The CowManager sensors were effective in determining estrus in 92% (46/50) of the synchronized cows, and the first service conception rate was 74% (37/50). CowManager sensors detected 100% (37/37), and ESTROTECT patches detected 91% (34/37) of the cows in estrus that conceived by AI. During bull exposure, CowManager detected 100% (13/13) of estrus and the natural breeding dates were confirmed by ultrasound fetal aging. ESTROTECT patches were not used during exposure to bulls. However, CowManager detected 5 of the AI pregnant cows as in estrus during the exposure to bulls. CowManager’s ED feature was highly effective in determining estrus for beef cattle and was similar to breeding patches for ED.
The objective was to assess heifer weight and reproduction response to a peanut skins plus corn supplement during spring wheat grazing. In spring of 2021 and 2022, 10 and 8 pastures (1.62 ha/pasture) of fall overseeded wheat were randomly assigned to supplement (SUP) or control (CONT) constrained to the same number of replications per treatment. Pastures were stocked with 6 heifers/pasture each year. The initial goal was to use peanut skins as a single ingredient; however, testing palatability in year 1, before spring grazing, demonstrated a need to create a mixed supplement for improved acceptance. Over 5 weeks from initiation of grazing to breeding, heifers were transitioned from a 33:67 to a 50:50 peanut skins:corn mix. Supplement was offered at 0.5% BW, as-fed, at the start of spring wheat grazing in early March. An additional 2.4% and 8.3% inclusion of dried molasses was incorporated to further enhance acceptance in year 1 and 2, respectively. Estrus synchronization (ES) began March 31 and April 5 for each year. Data were analyzed across year with year considered as a random effect and pasture the experimental unit. Initial weight was 12 ± 5.8kg greater (P = 0.05) for SUP. Weight at ES tended (P = 0.11) to be 9.4 ± 5.55kg greater for SUP. Reproduction tract score was similar (P = 0.55), averaging 4.2 ± 0.13, and heifers were of similar (P = 0.33) age (405 ± 4.1 days) at time of insemination. Average daily gain from initial wheat grazing until removal for natural service breeding did not differ between treatments (P = 0.92) and averaged 1.0 ± 0.21 kg. Body condition score was similar (P = 0.43) at ES and averaged 5.7 ± 0.7. The heavier initial BW of SUP heifers was sustained through wheat grazing (P = 0.05). Ultrasound determined pregnancies averaged 66.7 and 50.0 ± 6.6% for SUP and CONT, respectively, for an odds ratio of 2.1 ± 0.79 (P = 0.08) at 30 days after insemination. Overall pregnancy rates following natural service averaged 88.9 and 79.6 ± 4.88% for SUP and CONT, respectively with an odds ratio of 2.1±1.12 (P=0.19). High dietary protein has been associated with reduced reproductive performance. Using the peanut skins plus corn supplement was hypothesized to improve reproduction on a high protein diet due to the possible effect of peanut skins tannins on dietary protein utilization and corn altering the rumen degradable protein to organic matter ratio. While the fixed time artificial insemination pregnancy rates for CONT would not be considered poor, there was a tendency for SUP to secure more pregnancies among heifers of similar age, reproductive tract score, and body condition.
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