Twenty-four lambs (Pelibuey x East Friesian), weighing 22.7 ± 3.2 kg, were fed a basal diet of corn silage, oat hay, alfalfa hay, and concentrate (60% forage and 40% concentrate). Treatments consisted of oral doses of rumen-protected methionine (RPM) (0 and 1.5 g/day) and herbal choline (biocholine) (0 and 4 g/day) in a completely random block design with factorial arrangement of treatments, where lambs were blocked by sex. The experiment was conducted for 60 days, and measurements of live weight and dry matter intake were obtained. No effects of the treatments were observed on performance variables (lamb growth, consumption and feed conversion). Non-esterified fatty acids (NEFA) were increased by biocholine and unaffected by methionine (Met). Biocholine increased glucose and cholesterol, whereas methionine increased triglycerides, albumin and plasma protein. The dietary supplementation with biocholine and RPM did not improve lambs' growth; however, biocholine and Met showed a lipotropic effect by mobilizing NEFA and stimulating glucose and cholesterol synthesis.

Resumo Nós avaliamos a nidificação numa população de Crocodylus moreletii no Lago de Catemaco, Veracruz, sudeste, México. Durante as temporadas de nidificação e eclosão buscamos ninhos ao longo das margens situadas ao norte do lago e pequenos riachos associados. Estabelecemos a mortalidade de ovos por semana monitorando cada ninho achado, registrando qualquer sinal de predação (rastros e buracos cavados no ninho) e o efeito das flutuações no nível da agua. Não achamos nenhuma preferência para aninhar na terra ou em áreas inundadas. Por outro lado, achamos que o tamanho de ovo foi significativamente diferente entre os tipos de ninho. Em ninhos construídos na terra, a predação foi a principal causa da mortalidade de ovos enquanto que nas áreas inundadas, inundação foi um fator importante na morte dos ovos. Em comparação com depredação, a ruptura acidental e colonização fúngica, as inundações mataram 25% de ovos monitorados. Nós sugerimos que para aumentar o sucesso de aninhamento do crocodilo do Morelet é preciso promover a conservação das áreas de nidificação ao redor do lago, recentemente ocupadas pelo desenvolvimento urbano ou turístico.

Abstract We evaluated the nesting by Crocodylus moreletii in Lago de Catemaco, Veracruz, southeastern, Mexico. During the nesting and hatching seasons, we searched for nests along the northern margins of the lake and small associated streams. We investigated egg mortality by weekly monitoring each of the nests found, recording sign of predation (tracks and holes dug into the nest) and the effect of water level fluctuations. We not found differences to nest between inland or flooded zones. However, we found that egg size varied among nests. In nests built inland, predation was the major cause of egg mortality whereas flooding resulted in more deaths of eggs in the flooding zone. Flooding killed 25% of eggs monitored in this study. We suggest that to increase nest success in the Morelet’s crocodile it is necessary to promote conservation of nesting areas around the lake, recently occupied by urban or tourist developments.