Decreasing the dose of equine chorionic gonadotropin does not affect ovarian or pregnancy responses of purebred taurine and crossbred beef heifers.

In this study there was evaluation of effects of different doses of equine chorionic gonadotropin (eCG: 200, 300, or 400 IU) administrated at progesterone (P4) plus estradiol-based timed AI (TAI). A total of 1080 heifers were included in the study. There was insertion of the intravaginal P4-device plus administration of 2 mg of estradiol benzoate IM. On D7, 12.5 mg of dinoprost tromethamine IM was administered and on D9, the P4 insert was removed and 0.5 mg of estradiol cypionate IM was administered. Heifers were categorized according to Reproductive Tract Status (RTS; 1-5) and were assigned to one of three treatments: 200 IU (n = 387), 300 IU (n = 357), or 400 IU (n = 336) of eCG. Estrous occurrence was evaluated at TAI 48 h later (D11). A subset of heifers (n = 213) had the largest follicle (LF) evaluated on D9 and on D11, and the formation of a new CL evaluated on D18.There was no effect of eCG treatment on LF on D11 (P = 0.79), occurrence of estrus (P = 0.92), and pregnancy at 30 days after AI (P/AI; 52.2%, 49.8%, and 51.5% for 200 IU, 300 IU, and 400 IU, respectively; P = 0.46). Regardless of the treatment, there was a greater P/AI when heifers had a functional CL, at initiation of the estrous synchronization treatment regimen. It, therefore, is efficacious to reduce the dose of eCG to 300 or 200 IU in purebred taurine and crossbred beef heifers without negative effects on ovarian, estrous or pregnancy responses.

Intoxicação crônica por Pteridium arachnoideum em bovinos no nordeste do estado do Rio Grande do Sul, Brasil / Chronic poisoning by bracken fern (Pteridium arachnoideum) in cattle in the northeast region of the state of Rio Grande do Sul, Brazil

Pteridium spp., popularmente conhecida como samambaia, comumente encontrada em solos ácidos, arenosos e de baixa fertilidade. A intoxicação ocorre quando os animais passam por privação alimentar ou ingestão acidental. O objetivo deste estudo é relatar a ocorrência de dois casos de intoxicação crônica por samambaia em bovinos na região nordeste do estado do Rio Grande do Sul, Brasil. Ambos os casos cursaram com sinais clínicos de disfagia, halitose, salivação e presença de tumores na orofaringe. A baixa oferta e qualidade de forragem, superlotação das áreas de pasto, manejo inadequado das pastagens, a presença de Pteridium arachnoideum, os sinais clínicos em conjunto com os achados de necropsia e o exame histopatológico confirmaram o diagnóstico de intoxicação crônica.

Pteridium spp., commonly known as fern, is commonly found in acidic, sandy and low fertility soils. Poisoning occurs when animals go through food deprivation or accidental ingestion. The objective of this study is to report the occurrence of two cases of chronic intoxication in cattle in the northeast region of the state of Rio Grande do Sul, Brazil. Both cases had clinical signs of dysphagia, halitosis, salivation and the presence of tumors in the oropharynx. Low supply and quality of forage, overcrowding of pasture areas, inadequate pasture management, presence of Pteridium arachnoideum, clinical signs, necropsy and histopathological of lesions confirmed the diagnosis of chronic intoxication.

Intoxicação crônica por Pteridium arachnoideum em bovinos no nordeste do estado do Rio Grande do Sul, Brasil / Chronic poisoning by bracken fern (Pteridium arachnoideum) in cattle in the northeast region of the state of Rio Grande do Sul, Brazil

Pteridium spp., popularmente conhecida como samambaia, comumente encontrada em solos ácidos, arenosos e de baixa fertilidade. A intoxicação ocorre quando os animais passam por privação alimentar ou ingestão acidental. O objetivo deste estudo é relatar a ocorrência de dois casos de intoxicação crônica por samambaia em bovinos na região nordeste do estado do Rio Grande do Sul, Brasil. Ambos os casos cursaram com sinais clínicos de disfagia, halitose, salivação e presença de tumores na orofaringe. A baixa oferta e qualidade de forragem, superlotação das áreas de pasto, manejo inadequado das pastagens, a presença de Pteridium arachnoideum, os sinais clínicos em conjunto com os achados de necropsia e o exame histopatológico confirmaram o diagnóstico de intoxicação crônica.

Pteridium spp., commonly known as fern, is commonly found in acidic, sandy and low fertility soils. Poisoning occurs when animals go through food deprivation or accidental ingestion. The objective of this study is to report the occurrence of two cases of chronic intoxication in cattle in the northeast region of the state of Rio Grande do Sul, Brazil. Both cases had clinical signs of dysphagia, halitosis, salivation and the presence of tumors in the oropharynx. Low supply and quality of forage, overcrowding of pasture areas, inadequate pasture management, presence of Pteridium arachnoideum, clinical signs, necropsy and histopathological of lesions confirmed the diagnosis of chronic intoxication.