Evaluation of clinical and reproductive parameters in Mangalarga Marchador mares treated with different doses of Cloprostenol or Dinoprost

Avaliou-se a ação de doses reduzidas e convencionais de substâncias luteolíticas sobre parâmetros clínicos e reprodutivos de éguas. As femeas receberam intramuscularmente, 125 ?g (n = 20) e 250 ?g (n = 20) de Cloprostenol e 2.5 mg (n = 20) e 5.0 mg (n = 20) de Dinoprost. A temperatura retal e as frequências cardíaca e respiratória foram aferidas antes e após a administração desses luteolíticos, considerando-se ainda a ocorrência de sudorese, diarreia, cólica e prostração. Monitorou-se o estro e o desenvolvimento folicular até a ovulação, quando realizou-se a inseminção artificial. A gestação foi diagnosticada com 300 e confirmada no 60o dia. Apenas as éguas tratadas com 2,5 e 5,0 mg de Dinoprost apresentaram alteração (P < 0.05) da frequência respiratória e os demais parâmetros não foram alterados (P > 0.05). A sudorese ocorreu em 5% e 10% das éguas tratadas, respectivamente, com 2.5 mg e 5.0 mg de Dinoprost e a diarréia em apenas 5% daquelas que receberam 5.0 mg desse luteolítico. As porcentagens de estro e prenhez das éguas tratadas com 125 ?g de Cloprostenol (45%/35%) e 2.5 mg de Dinoprost (50%/30%) foram menores (P < 0.05) do que os daquelas que receberam 250 ?g de Cloprostenol (85%/70%) e 5 mg de Dinoprost (90%/75%). O estro e a prenhez das éguas Controle foram menores (P < 0.05) do que nas tratadas. Conclui-se que apesar de não promoverem alterações significativas dos parâmetros clínicos, as doses reduzidas não apresentam as mesmas eficiências dos tratamentos com doses convencionais para induzir o estro

Influence of male-to-female ratio and climatic conditions on the reproductive performance of Anglo Nubian goats

The objective of this study was to test the “male effect” on the reproductive performance of Anglo Nubian does (n = 180), aged between 24 and 60 months, under different male-to-female ratios (1:20 – T20, 1:30 – T30, and 1:40 – T40) and climatic conditions (dry season – DS, and rainy season – RS). Does were randomly distributed into three groups (T20, T30, and T40) and were isolated from bucks at a distance of 300 m for 60 days before the start of the experiments. The first manifestation of estrous during the DS occurred 6.83 ± 4.54 (T20), 6.72 ± 4.56 (T30) and 7.05 ± 5.23 (T40) days following the onset of the breeding season (P>0.05). In the RS, onset of estrous was observed 6.60 ± 4.74 (T20), 6.70 ± 4.43 (T30) and 7.46 ± 4.54 (T40) days after the beginning of the breeding season (P>0.05). Estrous induction in females during the DS occurred in 95% (T20), 80% (T30), and 75.5% (T40) of all females. During the RS, estrous detection reached 100% (T20), 100% (T30), and 97.5% (T40) of all females, with no difference between all RS and DS groups. Estrous synchronization during the DS occurred in 35.00% (T20), 36.66% (T30), and 32.50% (T40) of all females, for an average occurrence of 34.72%. During the RS, synchronization occurred in 65% (T20), 70% (T30) and 62.25% (T40) of all females, for an average occurrence of 65.75%; no difference was detected between the RS and the DS. Pregnancy rates in the DS groups were 65.0% (T20), 70.0% (T30), and 62.5% (T40), while pregnancy rates in the RS were 90.0% (T20), 86.6% (T30), and 95.0% (T40). No difference was observed for conception rates between any of the RS and DS groups. Prolificacy during the DS was 1.30 (T20), 1.30 (T30) and 1.35 (T40), while in the RS prolificacy was 1.29 (T20), 1.25 (T30) and 1.30 (T40). Thus, the male effect can be used effectively for goats under 1:20–1:40 male-to-female ratios in a 45-day mating season under varying climatic conditions