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

Criopreservação do sêmen de curimba (Prochilodus lineatus) mediante adição de diferentes diluidores, ativadores e crioprotetores Cryopreservation of curimba (Prochilodus lineatus) semen after addition of different diluters, activators and cryoprotectants

Amostras de sêmen de cinco espécimes de Prochilodus lineatus (Valencienes, 1847) foram utilizadas para avaliação dos efeitos tóxicos e crioprotetores de seis soluções à base de BTS (Beltsville Thawing Solution®) 4,5% enriquecidas com metanol e DMSO nas concentrações de 10% (A = BTS 4,5% + Metanol 10%; B = BTS 4,5% + DMSO 10%; C = BTS 4,5% + KCl 0,072% + metanol 10%; D = BTS 4,5% + KCl 0,072% + DMSO 10%; E = BTS 4,5% + KI 0,036% + metanol 10%; e F = BTS 4,5% + KI 0,036% + DMSO 10%). Foram avaliadas ainda três soluções ativadoras (água destilada, NaHCO3 60 mM e NaHCO3 119 mM), antes e após o congelamento. Estudaram-se a taxa e a duração da motilidade espermática. Não houve diferença significativa entre as soluções crioprotetoras utilizadas. O sêmen ativado por NaHCO3 60 e 119 mM apresentou as maiores taxas de motilidade espermática. A ativação por NaHCO3 119 mM possibilitou as maiores durações de motilidade no sêmen de P. lineatus.<br>Semen samples of five specimens of Prochilodus lineatus (Valencienes, 1847) were used to test the toxic and cryoprotectants effects of six solutions based on BTS (Beltsville Thawing Solution®) 4.5%: A - BTS 4.5% + Methanol 10%; B - BTS 4.5% + DMSO 10%; C - BTS 4.5% + KCl 0.072% + Methanol 10%; D - BTS 4.5% + KCl 0.072% + DMSO 10%; E - BTS 4.5% + KI 0.036% + Methanol 10% and F - BTS 4.5% + KI 0.036% + DMSO 10%). The effect of other three activator solutions (Distillated Water, NaHCO3 60 mM and NaHCO3 119 mM) on the rate and duration of sperm motility were also evaluated before and after freezing. No significant differences were observed among the cryoprotectant solutions. Sperm motility rates for P. lineatus were higher for semen activated by NaHCO3 60mM and NaHCO3 119mM, which propitiated the highest sperm motility duration

Assessment of dietary lecithin and cholesterol requirements of mud crab, Scylla serrata, megalopa using semi-purified microbound diets

The effects of varying dietary lecithin and cholesterol levels on growth, development and survival of mud crab, Scylla serrata, megalopa were evaluated using six semi-purified, microbound diets formulated to be iso-energetic and containing three levels of supplemental lecithin (0, 20 and 40 g kg−1 diet dry weight) and two levels of supplemental cholesterol (0 and 7 g kg−1 diet dry weight). Fifteen megalopa were reared individually in each treatment and the nutritional value of diets was assessed on basis of mean dry weight and mean carapace width of newly settled first crab stage, as well as development time to the first crab stage and overall survival. A significant interaction between supplemental dietary lecithin and supplemental dietary cholesterol was found for final mean dry weight of newly settled crabs, and highest survival (60%) was recorded for megalopa fed diets containing the highest levels of dietary lecithin (39.7–44.1 g kg−1) (diet 5 and 6) regardless of whether diets were supplemented with cholesterol; this rate of survival was identical to that of megalopa fed live Artemia nauplii. The results indicate that supplemental dietary cholesterol may not be essential for mud crab megalopa when fed diets containing sufficient levels of supplemental dietary phospholipids