Serum progesterone concentration and conception rate of beef cows supplemented with ground corn after a fixed-time artificial insemination protocol

Pescara, J.B.; Filho, O. G. Sá; Losi, Tiago Creste; Cooke, Reinaldo F; Vasconcelos, José Luiz Moraes

doi:10.1590/s0102-09352010000100018

Cited by 2 publications

(1 citation statement)

References 26 publications

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“…Therefore, adequate nutrition during the pre-partum period and the amount of dry matter available in postpartum are key elements for the return to cyclicity in dairy and beef cows (Crowe et al, 2014). Studies have shown that cows with adequate body condition pre and postpartum have greater fertility after calving (Sa Filho et al, 2009; Ayres et al, 2014) and that energy and/or protein supplementation increases the conception rate (Pescara et al, 2010). In a recent study by our research group (Orlandi et al, 2018), the effect of energy and protein supplementation on follicular growth and pregnancy rate of Bos indicus lactating cows was evaluated.…”

Section: Energetic and Protein Supplementationmentioning

confidence: 99%

Pre-TAI protocol strategies to increase reproductive efficiency in beef and dairy cows

Sales¹,

Simões²,

Orlandi³

et al. 2019

Anim Reprod

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Ovulation synchronization protocols are well established in beef and dairy cows. However, the protocol response rate is around 70-90%. In beef cows, factors such as inadequate nutrition and calf presence negatively impact the response of progesterone (P4)/estradiol-based ovulation synchronization protocols by interfering with GnRH release and consequently reducing LH pulsatility and final follicular development. In dairy cows, protocols based on GnRH and prostaglandin (Ovsynch) are the most widely used in the world. However, the efficiency of Ovsynch is dependent on the presence of a large follicle at the time of administration of the first GnRH. In these ovulation synchronization protocols, pre-synchronization protocols (Prostaglandins, Double Ovsynch and P4synch) are usually attempted in an effort to increase responses. Thus, the objective of this review was to discuss pre-ovulation synchronization strategies (administration of injectable P4 or energetic/protein supplementation or presynchronization with intra-vaginal progesterone devices) aiming to increase the LH pulsatility in beef cows or induce the formation of a GnRH-responsive follicle at the beginning of the Ovsynch protocol in dairy cows.

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Section: Energetic and Protein Supplementationmentioning

confidence: 99%

Pre-TAI protocol strategies to increase reproductive efficiency in beef and dairy cows

Sales¹,

Simões²,

Orlandi³

et al. 2019

Anim Reprod

View full text Add to dashboard Cite

show abstract

Plasma progesterone concentration in beef heifers receiving exogenous glucose, insulin, or bovine somatotropin1

Cooke

Cappellozza

Bohnert

et al. 2012

Journal of Animal Science

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Three experiments were conducted to evaluate plasma concentrations of glucose, insulin, IGF-I, and progesterone (P4) in pubertal beef heifers receiving exogenous glucose, insulin, or sometribove zinc. All heifers used had no luteal P4 synthesis but received a controlled internal drug-releasing device containing 1.38 g of P4 to estimate treatment effects on hepatic P4 degradation. In Exp. 1, 8 pubertal, nulliparous Angus × Hereford heifers (initial BW = 442 ± 14 kg; initial age = 656 ± 7 d) were randomly assigned to receive, in a crossover design containing 2 periods of 10 h, intravenous (i.v.) infusions (10 mL) of insulin (1 μg/kg of BW; INS) or saline (0.9%; SAL). Treatments were administered via jugular venipuncture in 7 applications (0.15 μg insulin/kg BW per application) 45 min apart (from 0 to 270 min). Blood samples were collected immediately before each infusion as well as at -120, -60, 330, 390, and 450 min relative to the first infusion. Heifers receiving INS had greater (P < 0.01) plasma insulin, reduced (P ≤ 0.04) plasma glucose and IGF-I, and similar (P = 0.62) plasma P4 concentrations compared with SAL heifers. In Exp. 2, the same heifers were assigned to receive, in a similar experimental design as Exp. 1, i.v. infusions (10 mL) of 1) insulin (1 μg/kg BW) and glucose (0.5 g/kg BW; INS+G) or 2) SAL. Heifers receiving INS+G had greater (P ≤ 0.02) plasma insulin, glucose, and P4 but reduced (P = 0.01) plasma IGF-I concentrations compared with SAL heifers. In Exp. 3, the same heifers were assigned to receive, in a crossover design containing 2 periods of 14 d, subcutaneous (s.c.) injections of 1) 250 mg of sometribove zinc (BST) or 2) SAL. Blood samples were collected 3 h apart (0900, 1200, 1500, and 1800 h) from heifers on d 6, 8, and 10 relative to treatment administration (d 1). Heifers receiving BST had greater (P < 0.01) plasma glucose and IGF-I and similar (P ≥ 0.67) plasma insulin and P4 concentrations compared with SAL heifers. Results from this series of experiments suggested that concurrent increases in glucose and insulin are required to reduce hepatic catabolism and increase plasma concentrations of P4 in bovine females.

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Serum progesterone concentration and conception rate of beef cows supplemented with ground corn after a fixed-time artificial insemination protocol

Cited by 2 publications

References 26 publications

Pre-TAI protocol strategies to increase reproductive efficiency in beef and dairy cows

Pre-TAI protocol strategies to increase reproductive efficiency in beef and dairy cows

Plasma progesterone concentration in beef heifers receiving exogenous glucose, insulin, or bovine somatotropin1

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