CARBON SEQUESTRATION IN PASTURES WITH TREES, TREELESS PASTURES AND DECIDUOUS FOREST FROM HUATUSCO, VERACRUZ

It was compared the amount of carbon (C) sequestered in a pasture with trees (P+Ar) and in conventional treeless pastures (P) and deciduous forest (BC), typical of the region of Huatusco, Veracruz, Mexico. Total C sequestered by the systems evaluated was 49.9, 63.0 and 469.8 ton ha-1 for P, P+Ar and BC, respectively. The system with the highest amount of C sequestered was BC, with almost equal proportions in the aerial (268.4 ton ha-1) and belowground parts (201.4 ton ha-1). The amount of C sequestered in the livestock systems represented about one tenth of that sequestered in BC, being higher the proportion obtained in P+Ar (13.4 %) compared to P (10.6 %). In both livestock systems, a significantly greater amount of C was sequestered in the soil organic matter than in the aerial biomass, with 59.7 and 3.29 ton ha-1 in P+Ar, and with 48.2 and 1.78 ton ha-1 in P, respectively. It is expected that as trees of the P+Ar system gain volume, C sequestration will increase, especially in the aerial biomass

PREVALENCE OF BOVINE CRYPTOSPORIDIOSIS IN THREE ECOLOGICAL REGIONS FROM THE CENTRAL REGION OF VERACRUZ, MEXICO

Prevalence of Cryptosporidium spp. in cattle from three ecological regions in the central area of the state of Veracruz, Mexico, was determined. A transversal study was conducted in 72 calves 3 to 12 months old from six production units from the municipalities of Zentla, Tlacotalpan and Manlio F. Altamirano. Fecal samples were collected from the calves and analyzed using the Kinyoun stain technique. Overall prevalence of cryptosporidiosis was 73.6 %, and by municipality it was 66.7 % in Zentla, 75 % in Tlacotalpan, and 79.2 % in Manlio F. Altamirano. Prevalence by age was 72.4 % in calves 3 months old and 74.4 % in calves 6 to 12 months old. Prevalence was higher in females (78.7 %) than in males (45.5 %). Prevalence by breed was 78.8 % in Brown Swiss/Zebu, 83.3 % in Brown Swiss, 50 % in Holstein/Zebu, and 50 % in Brown Swiss/Holstein, with no difference among crosses (P > 0.05). There was no association among infection by Cryptosporidium spp. and sex, breed, age and ecological region. In conclusion, Cryptosporidium spp. is present in the dual purpose cattle production systems in the three municipalities studied located in the central region of Veracruz, Mexico

TRACE ELEMENTS IN SHEEP AND GOATS REPRODUCTION: A REVIEW

The reproduction of small ruminants like goats and sheep managed under extensive range grazing conditions can be affected by nutrients availability and especially by the mineral content of the forages resources on the rangeland. It has been particularly demonstrated that trace elements can have equally, beneficial or detrimental effects, depending on its balance, on reproductive functions in small ruminants. Trace elements as copper, molybdenum, selenium and zinc play key role on the metabolism of carbohydrates, proteins and lipids; however, the mode of action by which these elements affect reproduction in sheep and goats are not completely understood, due to the complexity in the mode of action of the metallobiomolecules and the neuro-hormonal relationship. In this way, their absence or presence of these minerals in several organs, fluids, or tissues of the reproductive tract have allowed obtaining information on the metabolism and the role of these elements on reproduction in sheep and goats. On this regard, the objective of this document is to review the relationships and effects of some trace elements, on reproductive events in sheep and goats

EFFECT OF SEASON ON SERUM COPPER AND ZINC CONCENTRATIONS IN CROSSBRED GOATS HAVING DIFFERENT REPRODUCTIVE STATUS UNDER SEMIARID RANGELAND CONDITIONS IN SOUTHERN MEXICO STATE

The effect of season (rainy: RS, and dry: DS) and reproductive status on copper (Cu) and zinc (Zn) concentrations in blood serum of crossbred goats (BW= 36.01 ± 1.59 kg) were studied under semiarid rangeland conditions in Southern Mexico State. Blood samples from 80 crossbred goats were taken each season (RS and DS). The goats were clustered into 10 different groups considering their reproductive status. Concentrations of Cu and Zn in serum were assayed using atomic absorption. Data were analyzed using a general linear model procedure for a completely randomized design and differences among means were examined using a Tukey test. Blood serum concentrations of Cu and Zn were affected by reproductive status and season (