Progesterone supplementation to lactating dairy cows without a corpus luteum at initiation of the Ovsynch protocol.

The objectives were to determine the effect of progesterone supplementation on fertility responses in lactating dairy cows without corpora lutea (CL) at initiation of the timed artificial insemination (AI) program. Holstein cows from 5 commercial dairy farms were subjected to the Ovsynch-56 protocol (d -10 GnRH, d -3 PGF2α, d -0.7 GnRH, d 0 AI). Ovaries were scanned by ultrasonography on d -10. Within farm, cows without CL were blocked by pen and assigned randomly to remain as nonsupplemented controls (CON; n = 652) or to receive 2 controlled internal drug-release (CIDR) inserts containing 1.38 g of progesterone each from d -10 to -3 (2CIDR; n = 642). Cows with CL were randomly selected within pen and used as positive controls as cows in diestrus at the initiation of the Ovsynch protocol (DIEST; n = 640). Signs of estrus were detected beginning on d -9 based on removal of tail chalk, and cows in estrus received AI on the same day. Blood samples from subsets of cows on d -10, -9, -7, -5, -3, and 0 (n = 109) and on d 6, 13, and 19 (n = 156) were analyzed for progesterone concentrations. Pregnancy was diagnosed on d 32 and 60 after AI. The average progesterone concentration during the timed AI program was lowest for CON, intermediate for 2CIDR, and highest for DIEST (0.92, 2.77, and 4.93 ng/mL, respectively). The proportions of cows that ovulated in response to the first GnRH (63.6, 61.1, and 47.2%, respectively) and that had a new CL on d -3 at PGF2α injection (72.4, 67.9, and 47.4%, respectively) were greater for CON and 2CIDR compared with DIEST, respectively. The diameter of the ovulatory follicle and the proportion of cows that ovulated in response to the second GnRH did not differ among treatments. A greater proportion of CON and 2CIDR cows were detected in estrus at AI compared with DIEST cows (35.8, 39.6, and 30.6%, respectively). Pregnancy per AI was less for CON compared with 2CIDR and DIEST on d 32 (31.3, 42.2, and 38.4%, respectively) and d 60 after AI (28.9, 37.2, and 33.9%, respectively), indicating that progesterone supplementation reestablished fertility in cows lacking a CL similar to that of cows in diestrus at the initiation of the timed AI program. Treatment did not affect pregnancy loss between d 32 and 60 of gestation. Pregnancy from a subset of cows with plasma progesterone concentrations indicated that a minimum concentration of 2.0 ng/mL was needed to optimize fertility. A single ultrasound examination effectively identified a low-fertility cohort of cows based on the absence of CL at the first GnRH injection of the Ovsynch protocol. Supplementation with 2 CIDR inserts increased progesterone in plasma by an additional 1.85 ng/mL compared with CON, resulting in concentrations of 2.77 ng/mL during development of the ovulatory follicle, which restored fertility in dairy cows lacking CL to a level similar to that of cows in diestrus.

Effect of progesterone supplementation on fertility responses of lactating dairy cows with corpus luteum at the initiation of the Ovsynch protocol.

The objectives of this study were to determine the effects of supplemental progesterone on fertility responses of lactating dairy cows with a CL at the initiation of the timed artificial insemination (AI) program. Holstein cows were subjected to the Ovsynch protocol (Day -10 GnRH, Day -3 PGF2α, Day -0.7 GnRH, and Day 0 timed AI). Ovaries were scanned by ultrasonography on Day -10 and cows with CL were blocked by pen and assigned randomly to receive no supplemental progesterone (control, n = 863) or to receive a controlled internal drug-release (CIDR) insert containing progesterone from Days -10 to -3 (1CIDR, n = 862). Cows were observed for signs of estrus beginning on Day -9 based on removal of tail chalk and those in estrus received AI on the same day. Blood sampled from a subset of cows was analyzed for progesterone concentrations on Days -10, -9, -7, -5, -3, 0, 6, 13, and 19. Pregnancy was diagnosed on Days 32 and 60 after AI. Supplementation increased (P < 0.01) progesterone concentrations between Day -9 and -3 compared with control (7.5 vs. 6.2 ng/mL). Treatment had no effect on the ovulatory response to the first and final GnRH injections of the Ovsynch protocol, the proportion of cows that maintained their CL until the day of PGF2α injection, or the diameter of the ovulatory follicle before AI. Although the overall proportion of cows in estrus at AI did not differ between treatments, progesterone supplementation prevented (P < 0.01) cows from coming into estrus from Days -9 to -3 (0.0% vs. 4.7%), whereas it increased (P = 0.02) the proportion of cows inseminated in estrus from Days -2 to -1 (7.1% vs. 4.5%). Pregnancy per AI (P/AI) tended to be reduced (P = 0.06) by supplemental progesterone on Day 32 (40.5% vs. 45.0%), but not on Day 60 after AI (36.6% vs. 39.7%). A tendency for an interaction (P = 0.09) between treatment and the presence of CL at the PGF2α injection was observed for P/AI on Day 32 in cows that received timed AI because progesterone supplementation reduced P/AI in cows that maintained their CL until Day -3 (40.3% vs. 46.7%); however, it increased P/AI in those that did not have a CL at PGF2α (38.1% vs. 27.7%). Treatment did not affect pregnancy loss between Days 32 and 60 of gestation. In conclusion, incorporating a single intravaginal insert to the timed AI program increased progesterone concentrations in plasma by 1.3 ng/mL, but did not benefit fertility in dairy cows that have CL at the initiation of the synchronization protocol.

[Mastocytosis in children. Report of 3 cases]. / Mastocitosis en la edad pediátrica. Comunicación de tres casos.

The mastocytosis is a disease characterized by an increase in mast cell number, and may present in childhood. It is classified as cutaneous or systemic mastocytosis. Cutaneous mastocytosis generally is selected in childhood. It is important to be aware of systemic complications. Systemic mastocytosis is adult-onset and its clinical presentations is caused by histamine, leucotrienes, prostaglandins and other mediators' release. The treatment is directed at symptomatic relief. Several cases are reported at Hospital Infantil de México Federico Gómez. Only 3 cases are presented of these benign child-onset diseases.