PSV-3 Ovarian dynamics of brahman cows submitted to five-day or twelve-day progesterone-based estrus synchronization protocol

The aim of this study was to investigate the ovarian response of Brahman cows submitted to two different estrus synchronization protocols and to determine the estrus response and ovulation time. A total of 153 Brahman cows were randomly assigned to receive one of the following estrus synchronization protocols: 1) CIDR insert and an injection of prostaglandin F2α (25 mg, PGF) on Day -5 and CIDR removal with PGF on Day 0 (CIDR5; n = 77); 2) CIDR insert on Day -12 and an injection of PGF on Day -12, Day -5 and Day 0 upon CIDR removal (CIDR12; n = 76). Estrotect breeding indicator patches were placed on Day 0 and cows were artificially inseminated (AI) 12h after estrus detection; cows not detected in estrus after 96h received TAI coupled with 100 µg of GnRH. Ovarian dynamics were observed during the protocol and follicular diameter were measured every 12h after AI until ovulation. Cows synchronized with CIDR12 had increased follicular diameter (CIDR5, 10.19 ± 0.51 vs. CIDR12, 13.12 ± 0.52 mm; P = 0.01) and decreased serum concentrations of progesterone (CIDR5, 1.68 ± 0.12 vs. CIDR12, 0.81 ± 0.12 ng/ml; P < 0.01) at CIDR removal. The percentage of cows exhibiting estrus did not differ between treatments (CIDR5, 66.2 vs. CIDR12, 64.5%; P = 0.25). No difference was observed in ovulation rate (CIDR5, 94.1 vs. CIDR12, 94.1%; P = 0.6). Time of estrus expression and ovulation time after CIDR removal did not differ (CIDR5, 59.9 ± 2.3 vs. CIDR12, 61.5 ± 2.3h; P = 0.71 and CIDR5, 88.1 ± 2.6 vs. CIDR12, 90.9 ± 2.6h; P = 0.75; respectively). In conclusion, extended length of CIDR with additional PGF increased follicular diameter and decreased concentrations of progesterone but did not influence estrus response and ovulation time in Brahman cows.

PSVII-26 Follicular growth in beef cows when using a low dose of FSH and hCG at the time of CIDR removal in a 7-day co-synch + CIDR protocol

The aim of the study was to compare the growth of the periovulatory follicle in crossbreed cows receiving either a low dose of hCG (150 IU; Chorulon®, Merck) or a low dose of FSH (20 mg)Folltropin®, Vetoquinol) vs. a control group when applied at CIDR removal during an estrus synchronization protocol. At d0, a CIDR (Eazi-Breed CIDR®, Zoetis) was placed, a dose of GnRH (Factrel®, Zoetis) was applied i.m. and transrectal ultrasound was conducted to evaluate cyclicity status. On d7, cows (n = 79) were randomly assigned to three treatments (Control n = 27, FSH n = 26, and hCG n = 26) according to body condition score (1 to 9 scale) and cyclicity status. On the same day, CIDR was removed, a dose of prostaglandin analog (Lutalyse HighCon Injection®, Zoetis) was administered i.m. and an Estrotect™ patch was placed between the hip and tail head. Transrectal ultrasound was conducted to evaluate the diameter of the preovulatory follicle (DPF) at d7 and every 12h from d8 until ovulation was detected. Five cows that did not ovulate were removed from the study. Data were analyzed using GLIMMIX and LIFETEST procedures (SAS). The diameter at ovulation was not different among treatments (Control: 13.02 ± 0.53 mm; FSH: 12.38 ± 0.54 mm; hCG; 11.69 ± 0.47 mm; P = >0.10). Also, the time to ovulation was not different among treatments (P = 0.65; Figure 1a). However, cows of the control group presented estrus signs earlier than FSH and hCG groups (P = 0.02, Figure 1b). In conclusion, the use of a low dose of hCG or FSH at the time of CIDR removal did not increase the DPF or the time to ovulation.

Pulse-Coupled Synchronization Protocol and Its Optimized Algorithm for Wireless Sensor Networks

This paper proposed a pulse-coupled synchronization protocol for wireless sensor networks. The time information of the node can be encoded at the Mac layer and then sent and received in the form of pulse waves. During the exchange of time information between a pair of nodes, one node will adjust its own clock information according to certain rules after receiving the pulse time signal of the other node. This process is repeated in the entire wireless sensor network. Under certain environmental and estimated parameter conditions, all nodes in the network can finally converge to a coherent frequency and phase, thus realizing time synchronization. The relationship between time synchronization and coupling coefficient was proved theoretically, and the optimal coupling coefficient was derived. An optimized algorithm was proposed after the optimization of the protocol. Finally, the correctness of the proposed protocol and its optimized algorithm was verified by data simulation.

GPGMH, a New Fixed Timed-AI Synchronization Regimen for Swamp and River Crossbred Buffaloes (Bubalus bubalis)

The crossbreeding of Swamp and River type buffalo breeds is practiced for the improvement of milk yield and reproductive performance in swamp buffalo herds. This study aimed to modify the Ovsynch synchronization protocol (GPG) and improve the fixed-timed artificial insemination (FTAI) for better reproductive performance of crossbred buffaloes. Comparison of four conventional synchronization protocols [pregnant mare gonadotropin-prostaglandin F2α-gonadotropin-releasing hormone (PmPG), gonadotropin-releasing hormone-prostaglandin F2α-gonadotropin-releasing hormone (GPG), prostaglandin F2α-gonadotropin-releasing hormone-prostaglandin F2α-estradiol benzoate (PGPE), and progesterone-pregnant mare gonadotropin-prostaglandin F2α-gonadotropin-releasing hormone (P4PmPG)] in crossbred buffaloes showed that the GPG protocol treated buffaloes displayed higher (P < 0.05) estrus response with an increasing tendency in ovulation (84.6%) and pregnancy rates (30.8%) than PmPG, PGPE, and P4PmPG treated buffaloes. Buffaloes treated with a dose of 0.4 (mg/kg) mifepristone combined with GPG, exhibited higher (P < 0.05) estrous response (82.4%), ovulation (94.1%), and pregnancy (47.1%) rates compared with other doses (0, 0.3, or 0.5 mg/kg) groups. Injection of mifepristone along second GnRH injection in buffaloes improved (P < 0.05) pregnancy rate (35.3%) when compared to before or after the second GnRH of GPG protocol. Single AI after 24 h of mifepristone or second GnRH injection seems the best time to enhance the pregnancy rates in buffaloes compared to double or other single AI times in the modified GPGMH protocol. In comparison, GPGMH reduced the follicular cyst incidence (P < 0.05) with increasing ovulation (P > 0.05) and pregnancy rates (P > 0.05) than the P4GPG and GPG protocols in crossbred buffaloes. The current study supported that new synchronization protocol (modified of GPG protocol; GPGMH) by the inclusion of mifepristone (with a dose of 0.4 mg/kg along second GnRH), AI after 24 h of mifepristone or second GnRH, and human chorionic gonadotropin (hCG at day 5 of AI) enhance the ovulation and pregnancy rates in crossbred buffaloes.