Skin follicle development in the Australian cashmere goat

Follicle densities, S/P ratios and follicle number indices (FNI) of fibre-bearing primary (Pf) and secondary (Sf) follicles, and body weights, were taken sequentially on 224 kids at birth and at mean ages of 57, 107 and 301 days. All primary follicles but few secondary follicles were mature (fibre-bearing) at birth and Sf number increased 10 fold in the first 57 days after birth. A decline in Pf number was recorded between 57 and 107 days of age. SFNI’s, but not Sf density increased to weaning (107 days of age) then declined thereafter to 301 days of age. Single kids had higher (P < 0.01) SFNI than twin kids at all ages except birth, though Sf/Pf ratios of singles were significantly higher (P < 0.05) than those of twins at 57 days of age only. At 107 and, 301 days of age, males had higher PFNI than females (24.8 v. 22.0 and 24-7 v. 22.0) and higher SFNI than females (179.0 v. 150.4 and 151.6 v. 131-1). Sex differences were not observed in Sf/Pf ratio. A description of follicle arrangement and accessory structures is given

Avaliação de programas hormonais para a indução e sincronização do estro em caprinos Evaluation of hormonal programs to induce and synchronize estrus in goats

O objetivo deste trabalho foi estabelecer alternativas para indução e sincronização do estro em cabras leiteiras manejadas semi-intensivamente. Foram conduzidos quatro experimentos com 411 cabras na Embrapa-Centro Nacional de Pesquisa deCaprinos, Sobral, CE. No protocolo básico, utilizaram-se esponjas intra-vaginais com 50 mg de acetato de medroxiprogesterona (MAP) por dez dias e aplicação intra-muscular de 100 mig de cloprostenol e 200 UI de gonadotropina coriônica eqüina (eCG) no 8º dia; a inseminação artificial (IA), com sêmen congelado foi feita 38 horas após remoção da esponja. No experimento1 substituiu-se a e CG pelo "efeito macho"; no experimento 2 substituiu-se a dose de MAP para 60 mg; no experimento3 compararam-se diferentes momentos de IA: 38, 44 e 50 horas e no experimento 4 substituiu-se a eCG pela gonadotropina humana (hCG). Nenhuma das alternativas testadas modificou (P>0,05) a prolificidade. A IA em cio natural gerou maior (P<0,05) índice de parição no experimento2(67,7%) e no experimento 4 (73,3%). A dose de 60 mg de MAP permitiu realizar a IA mais tarde (44 horas apósretirar a esponja) sem detrimento da fertilidade. A hCG equivaleu a eCG, se aplicada 48 horas antes de retirar a esponja.<br>The objective of this study was to establish alternatives to induce and synchronize estrus in dairy goats managed under semi-intensive conditions. Four experiments were carried out using 411 goats at the Embrapa-Centro Nacional de Pesquisa de Caprinos, Sobral, CE, Brazil. In the basic protocol, intra-vaginal sponges were used with 50 mg of medroxyprogesterone acetate (MAP) over ten days, associated with intra-muscular shots of cloprostenol, and equine corionic gonadotropin (eCG) at the 8th day. Artificial insemination (AI) with frozen semen took place 38 hours after sponge withdrawal. In the first experiment, eCG was replaced by "buck effect"; in the second experiment, 60 mg MAP replaced the usual dose; the third experiment compared different pre-fixed time for AI: 38, 44 and 50 hours and in the fourth experiment, hCG (human corionic gonadotropin) given at different moments, replaced eCG. Prolificacy was not influenced (P>0.05) by any changes of basic protocol.After natural estrus, AIprovided higher (P<0.05) parturition rates in the second (67.7%) and fourth experiment (73.3%). Sponge with 60mg MAP allowed to inseminate later (44 hours after removal) without impairing fertility. As long as hCG is given 48 hours before sponge removal it results equals to eCG ones