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Sincronização de estro com CIDR reutilizado em cabras lactantes da raça Toggenburg tratadas com somatotropina bovina recombinante (r-bST)[ RESUMOAvaliou-se a resposta de cabras tratadas com r-bST no protocolo de sincronização de estro. Foram utilizadas 26 cabras Toggenburg, divididas em dois tratamentos: T1 (n=13), tratadas com quatro injeções de 250mg de rbST, a intervalos de 14 dias, e T2 (n=13), tratadas com solução salina (controle). Na semana seguinte à última injeção da r-bST, colocou-se o dispositivo intravaginal com progesterona (dia 0), previamente utilizado por cinco dias, e injetou-se PGF 2 (22,5µg) nos animais dos dois tratamentos, e o dispositivo foi retirado no dia 6. Todas as fêmeas em estro foram submetidas à monta natural. A porcentagem de animais em estro e a taxa de gestação foram 76,9 e 70,0 e 84,6 e 72,7%, no T1 e T2, respectivamente. Não houve diferença (P>0,05) na duração do estro, no intervalo tratamento-início do estro, no número de ovulações, nos intervalos: início e final do estro à ovulação e retirada do dispositivo à ovulação entre os animais dos dois tratamentos. O diâmetro médio dos folículos ovulatórios das fêmeas não diferiu (P>0,05). Durante a permanência do dispositivo, as concentrações séricas de progesterona apresentaram valores semelhantes (P>0,05) entre as cabras de T1 e T2. A r-bST não afetou a sincronização de estro.Palavras-chave: caprino, dispositivo intravaginal, estro, taxa de gestação 2 (22.5µg) ABSTRACT The response of goats treated with r-bST in the estrous synchronization protocol was evaluated. Twenty-six Toggenburg females were divided in two treatments: T1 (n=13) treated with four injections of 250mg r-bST, at 14 days intervals, and T2 (n=13) treated with saline solution (control). The intravaginal device previously used by five days was inserted (day 0) one week after the last injection of r-bST and PGF

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Indução da ovulação em cabras, fora da estação reprodutiva, com LH e GnRH e com estro induzido por progestágenos [Induction of the out-of-season ovulation (with LH and GnRH)

RESUMO -Estudou-se a influência da aplicação de somatotropina bovina recombinante sobre a produção e composição do leite, os metabólicos sangüíneos e a concentração hormonal em cabras no terço médio da lactação. Foram utilizadas 24 cabras da raça Toggenburg, divididas em dois tratamentos: T1 (n=12): aplicação de 250 mg de r-bST a cada 14 dias, em um total de quatro aplicações; e T2 (n=12): aplicação de solução salina (controle). O tratamento com r-bST não aumentou a produção de leite e não influenciou os teores de gordura, proteína e extrato seco. A porcentagem de lactose no leite foi maior (4,47 ± 0,2 para T1 versus 4,34 ± 0,2% para T2) e a contagem de células somáticas menor nos animais tratados em relação aos controle (681,1 ± 689,9 para T1 versus 1.001,84 ± 610,9 [x10 3 células/mL] para T2). A administração de r-bST aumentou as concentrações séricas de ácidos graxos não-esterificados de T2 (309,67 ± 169,62 x 247,34 ± 126,38 mEq/L, para T1 e T2, respectivamente) e reduziu as concentrações de uréia (86,84 ± 33,81 x 121,16 ± 42,57 mg/dL, para T1 e T2 respectivamente).A r-bST reduziu as concentrações de colesterol total e HDL (82,46 ± 19,25 x 89,29 ± 23,66 mg/dL e 155,95 ± 19,67 x 177,67 ± 32,79 mg/dL, para T1 e T2 respectivamente), enquanto as concentrações de albumina, glicose, proteínas totais, β-hidroxibutirato e tiroxina não foram influenciadas pela r-bST, que também não influenciou o peso e o escore corporal dos animais. A r-bST aumentou os teores de lactose, reduziu a contagem de células somáticas e promoveu alterações nos metabólicos sangüíneos e no leite de cabras lactantes.Palavras-chave: constituintes do leite, cabras, lactação, metabólitos, tiroxina Milk yield and composition, blood metabolites and hormonal profile of lactating Toggenburg goats treated with recombinant bovine somatotropin ABSTRACT -The objective of this trial was to study the effects of recombinant bovine somatotropin on milk yield and composition, blood metabolites and hormonal profile in lactating goats. Twenty-four Toggenburg goats were assigned to one of two treatments as follows: T1 (n=12) received injection of 250 mg of r-bST, every 14 days (four injections), and T2 (n=12) received injections of saline solution (control). No significant differences on milk yield and composition (fat, protein, and dry extract) were observed comparing r-bST-treated goats with non-treated animals.However, milk lactose content was higher (P<0.05) on goats that received r-bST (4.47 ± 0.2) than on those treated with saline solution (4.34 ± 0.2 %) while somatic cells count was lower on T1 (681.1 ± 689.9) than on T2 [(1,001.84 ± 610.9 (x103 cells/mL)]. Injection r-bST increased the concentration of non-esterified fatty acid compared to the saline-treated animals (309.67 ± 169.62 vs. 247.34 ± 126.38 mEq/L) but the opposite was observed for urea concentration (86.84 ± 33.81 vs. 121.16 ± 42.57 mg/dL). The r-bST treatment reduced the total cholesterol and HDL levels (82.46 ± 19.25 vs. 89.29 ± 23.66 and 155.95 ± 19.67 x 177.67 ± 32.79 mg/dL for T1 and T2...

Altering the lipid composition of sperm plasma membranes affects sperm cryosurvival. Cryopreservation induces many stresses on the spermatozoa, including destabilization of the plasma membrane, which results in the loss of sperm motility and function. Treating bull spermatozoa with cholesterolloaded cyclodextrin (CLC) prior to cryopreservation increases sperm cryosurvival rates. This study compared the effect of adding other sterols, which should incorporate into the membrane and increase membrane fluidity at low temperatures, thereby increasing cryosurvival. Ejaculates from four bulls were divided into two experiments (E). In E1, ejaculates were extended with Tris, and then subdivided into four treatments: No additive (control), 1.5 mg CLC/120 million sperm (positive control), and 1.5 mg/120 million sperm in cyclodextrin pre-loaded with either cholestanol or desmosterol. Spermatozoa were incubated for 15 min at 22�C after which both the ability of fresh spermatozoa to bind to the zona pellucida (ZP) and chicken egg perivitelline membrane (EPM) and their osmotic tolerance were evaluated. In E2, sperm were diluted to 120 million cells mL–1 in a Tris diluent and treated as described for E1. Then, samples were diluted 1:1 (v:v) in Tris with 20% Egg Yolk (EY) and cooled to 5�C. After dilution 1:1 (v:v) with Tris containing 10% EY and 16% glycerol, samples were allowed to equilibrate for 15 min, and then were packaged into 0.5-mL straws, frozen in static liquid nitrogen vapor for 20 min, and plunged into liquid nitrogen for storage. Straws were thawed and the motility and zona-binding ability were determined using a Hamilton Thorne Motility Analyzer (Hamilton Thorne Biosciences, Beverly, MA, USA) and epifluorescence microscopy, respectively. Treatment differences for sperm motility, osmotic tolerance, and zona binding were determined using analysis of variance. Treating spermatozoa with CLC resulted in more fresh bull spermatozoa binding to the EPM and ZP compared to cholestanolor desmosterol-loaded cyclodextrin-treated spermatozoa or control cells (P < 0.05). No differences were observed between EPM and ZP binding (P > 0.05). The percentages of total and progressively motile spermatozoa were higher for fresh samples treated with cholesterol-, cholestanol-, or desmosterol-loaded cyclodextrin than for control cells (P < 0.05) when spermatozoa were exposed to anismotic conditions, and then returned to isosmolality. After cryopreservation, the percentages of motile spermatozoa and number of spermatozoa binding to ZP were similar for spermatozoa treated with CLC (56% and 115 sperm/ZP) and cholestanol (53% and 108 sperm/ZP) compared to spermatozoa treated with desmosterol (42% and 86 sperm/ZP; P < 0.05). All treatments provided higher motility and binding efficiency than control spermatozoa (32% and 62 sperm/ZP; P < 0.05). Therefore, adding cholesterol or cholestanol to bull sperm membranes improved cell cryosurvival. Studies to determine if cholestanol affects sperm capacitation need to be conducted.

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