Caracterização dos sistemas de produção de leite bovino na microrregião Seridó do estado do Rio Grande do Norte

The objective was to contribute to a reading of the characteristics and diversity of production systems from bovine milk in the microregion Seridó of Rio Grande do Norte, discuss the social, economic, environmental and husbandry-related primary activity of milk production. We randomly selected 28 agricultural establishments that performed the activity of dairy bovine culture with subsequent applicat ion of a structured questionnaire during September and October 2011. Data were analyzed with application of measures of descriptive analysis and determination of the index rural development (IRD). The results showed that 53.57% of the interviewees were owners of the land, the median area of the properties amounted to 135 hectares, the median number of animals in the herd was 51 head, with minimum 11 and maximum of 350 heads establishments in the sample, 85.72% of establishments had maximum 23 cows in lactation, 100% performed manual milking with suckling calves, average productivity of 3.91 liters / cow / day, 92.86% of the interviewees did not produce silage and / or hay, 64.29% had no access to technical assistance, the average age of interviewees was 51 ± 10.85 years, 78.57% had only elementary education. The average of the IRD computed in the test sample amounted to 0.43 ± 0.11 on a scale 0-1. The sites were grouped into 04 classes, based on your IRD. The average IRD in each dimension was 0.43, 0.55 and 0.34, respectively for economic / husbandry, social and environmental. The determination of the rate of rural development - IDR found for the sample could add establishments hierarchically. It is necessary that the inclusion of best practices in herd management, bookkeeping zootechnical, technical assistance and reorganization practices in land and environmental preservation

Avaliação genética da eficiência reprodutiva em vacas pardo-suíças por meio da análise de sobrevivência

Among the traits of economic importance to dairy cattle livestock those related to sexual precocity and longevity of the herd are essential to the success of the activity, because the stayability time of a cow in a herd is determined by their productive and reproductive lives. In Brazil, there are few studies about the reproductive efficiency of Swiss-Brown cows and no study was found using the methodology of survival analysis applied to this breed. Thus, in the first chapter of this study, the age at first calving from Swiss-Brown heifers was analyzed as the time until the event by the nonparametric method of Kaplan-Meier and the gamma shared frailty model, under the survival analysis methodology. Survival and hazard rate curves associated with this event were estimated and identified the influence of covariates on such time. The mean and median times at the first calving were 987.77 and 1,003 days, respectively, and significant covariates by the Log-Rank test, through Kaplan-Meier analysis, were birth season, calving year, sire (cow s father) and calving season. In the analysis by frailty model, the breeding values and the frailties of the sires (fathers) for the calving were predicted modeling the risk function of each cow as a function of the birth season as fixed covariate and sire as random covariate. The frailty followed the gamma distribution. Sires with high and positive breeding values possess high frailties, what means shorter survival time of their daughters to the event, i.e., reduction in the age at first calving of them. The second chapter aimed to evaluate the longevity of dairy cows using the nonparametric Kaplan-Meier and the Cox and Weibull proportional hazards models. It were simulated 10,000 records of the longevity trait from Brown-Swiss cows involving their respective times until the occurrence of five consecutive calvings (event), considered here as typical of a long-lived cow. The covariates considered in the database were age at first calving, herd and sire (cow s father). All covariates had influence on the longevity of cows by Log-Rank and Wilcoxon tests. The mean and median times to the occurrence of the event were 2,436.285 and 2,437 days, respectively. Sires that have higher breeding values also have a greater risk of that their daughters reach the five consecutive calvings until 84 months

Práticas agroecológicas para o cultivo do gergelim (Sesamum indicum L.)

The exceeded use of the natural resources required by the modern agriculture has been caused soil impoverishment, soil salinization and soil compaction. The unreasonable use of chemical fertilizers and pesticides causes chemical imbalances in the plant tissues, nutritional losses, taste chances and human health problems. The monocrops are more vulnerable to the pest and disease attacks. The aim of this work were to indicate the better relative planting time of the cowpea bean for the sesame/cowpea bean intercropping based on the evaluation of agronomic, economic, ecological and physiological parameters and to evaluate the viability of the cow urine and cassava wastewater use as alternative fertilizers on the sesame cultivation. In a field essay, when the sesame/cowpea bean was evaluate, the mainly treatments were the single planting of the two cultures and the multiple cropping, with the cowpea bean being planted on the same time, 7, 14 and 21 days after the sesame. The mainly treatments of the second essay were the combined doses of the cow urine (0 and 50 ml) and cassava wastewater (0, 500 and 1000 mL). In the intercrop evaluation significant differences were found between the treatments for the most of the parameters. It was verified that as the sowing of the cowpea bean was retarded in relation to the sesame sowing, the sesame performance increased when the cowpea bean performance decreased. The treatment 7 days balanced the competition relations that occurred between the two crops in the intercrop. The sesame presented little pronounced responses to the different doses of cassava wastewater. The cow urine affected the sesame growth and the growth rates increased with the increasing of the application of the product. The responses of the sesame growth to the cow urine application must be related both the nutritional richness of the product and the presence of growth stimulating substances. The obtained results indicated that in the sesame/cowpea bean intercropping, when the sesame is planted 7 days after the sesame, there is a higher possibility of the net gains to the farmer. Cow urine and cassava wastewater may be used as additional organic fertilizers