Gastrointestinal parasites and ectoparasites were identified in white-tailed deer (Odocoileus virginianus), collared peccary (Pecari tajacu) and brocket deer (Mazama americana) in free-living conditions and captivity in the Mexican tropics. Twelve free-living ungulates were hunted (four white-tailed deer, three brocket deer and five collared peccaries) to obtain samples of faeces and ectoparasites. Fifty-five captive ungulates (14 white-tail deer, 16 brocket deer and 35 collared peccaries) were sampled to obtain faeces and ectoparasites. To identify the genera and order of parasites, faecal samples were analyzed by Flotation and McMaster techniques. Egg and oocyst per gram of faeces were also calculated. Ectoparasites collected from ungulates were classified to genera and species level using specific identification keys. Positive samples of nematode of the order strongylida and protozoos of the order Eucoccidiorida were cultivated and classified. In white-tailed and brocket deer the following genera of parasites were identified: Strongyloides, Trichuris, Capillaria, Mammomonogamus and Eimeria. In collared peccaries the genera Oesophagostomun, Eimeria and Isospora were identified. The flea Pulex irritans and the louse Gliricola porcelli infested brocket deer and collared peccary, while the fly Lipoptena sp was collected from white-tailed deer. The tick Amblyomma cajennese was found parasitizing the three ungulate species studied. It is concluded that wild ungulates are parasitized with gastrointestinal nematodes, protozoa of the order Eucoccidiorida, fleas, lice, flies and ticks.

Variations in progesterone (P 4 ) and testosterone (T) levels in the gonad of Octopus maya from Sisal in Yucatan State, Mexico, were investigated by radioimmunoassays and in relation to four gonad maturation stages (GMS) and to the reproductive cycle, as represented by two maturity indices (microscopic 'MiMI' and macroscopic 'MaMI'). According to the GMS and the maturity indices, the reproductive season of O. maya from Yucatan occurred from February to June. In females, P 4 and T displayed the same pattern, with a tendency to increase at the same time, although on average, P 4 had seven-fold higher concentrations than T. In contrast, P 4 and T in male gonads displayed a different pattern, where T concentrations were relatively stable throughout all of the study months. In the female gonad P 4 was lowest (close to 0 pg g -1 ) during both developing (GMS-I) and maturing (GMS-II) stages, and increased (189 ± 53 pg g -1 ) approaching the mature stage (GMS-III) to a maximum value of 611 pg g -1 . Concentrations of T in the male gonad were lowest (106 ± 9 pg g -1 ) during the maturing stage (GMS-II) and increased up to the mature stage (GMS-III), reaching a maximum of 440 pg g -1 . Pearson's correlation (r) between hormones and maturity indices showed strong relationships for females (around 0.4 and − 0.7; p < 0.05), but there were negligible or weak relationships for males (0.2 and − 0.1; p > 0.05). Hormone correlations in females were inverse with MaMI and direct with MiMI. Our major findings showed that gonadal P 4 levels were elevated during GMS-III and GMS-IV (i.e. periods of vitellogenic oocytes), where the characteristic aspect is an ovary with very high oocyte diameters, with the primary follicle cells deeply infolded in the ooplasm for yolk synthesis. These results suggested a synchrony between P 4 and the process of folliculogenesis, and in turn, vitellogenesis.

The legume Leucaena leucocephala (Leucaena) is widely used to supplement forage in silvopastoral livestock systems in Latin America. Little is known about its possible effects on the cow reproductive dynamic. The aim was to evaluate the effect of Leucaena foliage intake on re-establishment of ovarian activity and estrus behavior in early postpartum (7-90 days) cows. Twenty-four multiparous Bos taurus × Bos indicus cows were divided into two homogenous groups and assigned to one of two treatments: a silvopastoral system (SS, n = 12), consisting of an association of Cynodon nlemfuensis grass and L. leucocephala; and a control system (CS, n = 12), consisting of C. nlemfuensis alone. Intake of Leucaena in the SS ranged from 3.80 to 6.43 kg DM/cow/day. Plasma mimosine concentrations ranged from 1270 to 1530 μg/mL, and those for 2,3-dihydroxypyridine (DHP) from 147 to 729 μg/mL. No 3,4-DHP was detected in plasma. No difference (P > 0.05) between treatments was observed for the number of cows exhibiting small, medium, or dominant follicles, or estrus behavior. The number of cows which re-established ovarian cyclicity (n = 6) was lower (P < 0.05) in the SS than in the CS (n = 9). Corpus luteum lifespan was longer (P < 0.05) in the SS than in the CS. Intake of Leucaena affected the number of cows exhibiting ovarian cyclicity and extended corpus luteum life, but did not affect follicular development and estrus behavior.

El objetivo del trabajo fue caracterizar la cacería de venados O. virginianus y M. americana en tres comunidades rurales del municipio de Tzucacab, Yucatán, México. Se utilizó la técnica de muestreo de bola de nieve para identificar a los campesinos/cazadores, y con ellos se aplicó la técnica de encuesta, entrevista abierta y a profundidad, observación participativa y el registro de datos biométricos de los ejemplares cazados. Los resultados mostraron que la principal técnica de cacería es la batida. La cantidad de cazadores para la batida fluctúa entre 3 y 14, esta actividad se efectúa a lo largo del año. La cantidad total de animales extraídos en una semana de registro para cada uno de los cuatro meses fue de 12 ejemplares, con una biomasa total de 512 kg, siendo 455 kg de carne de O. virginianus y 57 kg de M. americana. Se cazan hembras y machos de diferentes pesos, sin embargo, se informa de la extracción de venados que no son aprovechados, denominados heridos-mal tirados, porque sufren el impacto del disparo, pero no son derribados y escapan a la cosecha. El impacto que tiene la cacería frecuente de venados sobre la viabilidad de sus poblaciones se desconoce y es necesario investigarla.

Valoración de metabolitos de testosterona, progesterona y estrógeno en excretas de venado cola blanca (Odocoileus virginianus) como método para determinar el sexo Measurement of fecal testosterone, progesterone and estrogen metabolites as a method to determine sex in white tailed deer (Odocoileus virginianus