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La creciente demanda de alimentos en areas urbanas genera cada vez mayor cantidad de desperdicios organicos, incluyendo residuos vegetales. El manejo de estos residuos vegetales causa emisiones de gases efecto invernadero (GEI) por su recoleccion, transporte, y deposito en vertederos. Para identificar su potencial de GEI, en un mercado de alimentos se recolectaron residuos de hojas de lechuga (LS), de col (BOV), de coliflor (BOB), de maiz (HZM), de espinaca (SO) y de nopal (OF), se fermentaron in vitro usando liquido ruminal como inoculo y se compararon con heno de avena (AS), heno de alfalfa (AH) y ensilado de maiz (EZM), forrajes utilizados con frecuencia en la alimentacion de rumiantes. Las variables fueron degradacion in vitro de la materia seca (DIVMS), pH, cinetica de produccion de gas y concentracion de metano (CH 4 ). La fermentacion se realizo durante 96 h a 39 oC y las muestras de gas para medir la concentracion de CH 4 se tomaron a 9, 12, 24, 34 y 48 h de incubacion. La DIVMS de LS, BOV, BOB, HZM y OF fue 12.8 % mayor a AS, AH y EZM. Entre las 9 y 12 h de incubacion la emision de CH 4 a partir de BOV, BOB and HZM fue 44.8 % superior a los tres forrajes. La principal conclusion es que estos residuos vegetales son degradados adecuadamente por los microorganismos ruminales y, por lo tanto, se pueden usar para la produccion de biogas en areas urbanas para disminuir su deposito en vertederos.

This article combines a Policy Analysis Matrix with a sensitivity and poverty line analysis with the objective of evaluating the economic contribution of comparative advantages to the private profitability and competitiveness of small-scale dairy systems. For 1 year, socioeconomic data were collected from 82 farms selected from four strata via statistical sampling. Two scenarios were established to determine the quantitative contribution of comparative advantages: (1) a simulated scenario, which accounted for the cost of purchasing the total food and the opportunity cost of the family labour force (FLF), and (2) an actual production scenario, which accounted for the cost of producing food and eliminating the payment of the FLF and included other income. The E3 and E4 producers were the most profitable and competitive in the simulated scenario and actual production scenario. Of the four scales evaluated, the E2 and E1 producers were the most efficient in taking advantage of the economic contribution provided by the comparative advantages in their own production of food and employment of the FLF, in addition to accounting for other income, a condition that increased their profitability by 171 and 144% and competitiveness by 346 and 273%, respectively. The poverty results indicated that only E3 and E4 producers were non-vulnerable in the simulated scenario and actual production scenario. The purchase of food was the comparative advantage with the greatest sensitivity to cost increases in the two scenarios analysed, which exacerbated the effect on the E1 and E2 producers.

The aim of the present study was to develop and evaluate an equation to predict body weight (BW) using hip width (HW) in Pelibuey ewe lambs and ewes. Five hundred seventy-seven 2-month-old to 3-year-old, non-pregnant, non-lactating, clinically healthy ewe lambs and adult ewes with a mean BW of 34.7 ± 12.4 kg and HW of 15.6 ± 3.4 cm were considered. Three equations were evaluated: BW (kg): − 19.17 + 3.46 × HW (Eq. 1), BW (kg): − 17.79 + 3.25 × HW + 0.007 × HW2 (Eq. 2) and BW (kg): 0.39 × HW1.63 (Eq. 3). Independent data from 80 animals with similar characteristics (BW of 23.4 ± 10.9 kg and HW of 12 ± 3.1 cm) were also considered to evaluate the developed equations. The evaluation was based on the relationship between the observed and predicted values of BW analysed using a linear regression, the mean squared error of prediction (MSEP), the root MSEP (RMSEP) and the concordance correlation coefficients (CCCs). Additionally, cross-validation analyses were performed using the k-folds validation (k = 10) procedure. The correlation coefficient (r) between BW and HW was 0.94 (P 0.95%), accuracy (Cb > 0.98) and reproducibility (CCC > 0.96) in predicting the BW of ewe lambs and adult ewes. Equation (1) accurately predicted observed BW, with a bias (observed − predicted) of 4.3 kg and RMSEP of 9.68% with respect to the observed BW (random error of 84.23%); it also generated the best prediction according to the residual mean squared prediction error, coefficient of determination and mean absolute error. In conclusion, the highly correlated relationship between BW and HW in Pelibuey ewe lambs and adult ewes under humid tropic conditions enabled the development of mathematical models herein to estimate BW with an adequate goodness of fit. The linear model showed the best performance according to the goodness-of-fit evaluation and internal and external validation; hence, this model is proposed for use in both the experimental and commercial farms.

The use of unconventional sources is very relevant in the food area. In the present study the development of active films with the addition of bioextract (BE) or microencapsulated bioextract (MBE) from xoconostle (Opuntia oligacantha) on chayotextle starch was investigated. The film formulations were: 4 g of chayotextle starch, 2 g of glycerol and 180 g of water, three films with BE added (0.4, 0.8 and 1.2 g) and three films with MBE added (0.4, 0.8 and 1.2 g). Total phenols, total flavonoids, antioxidant activity (ABTS and DPPH), Salmonella typhimurium inhibition, color and mechanical properties of the films were analyzed. The film with 1.2 g of MBE showed high concentration of total phenols (54.12 ± 0.77 mg EAG/100 g), total flavonoids (16.65 ± 0.10 mg QE/100 g) and antioxidant activity (29.11 ± 0.48 and 41.42 ± 1.81 mg EAA for ABTS and DPPH respectively). The addition of bioextract from xoconostle is an option for the development of active films with antioxidant properties.

Agronanobiotechnology is a term that refers to the intersection of agronomy, nanotechnology, and biotechnology. Agronanobiotechnology is a discipline in which tools from nanotechnology are developed and applied to the study of agronomic and biological phenomena. The objective of this chapter is to present cutting-edge knowledge regarding agronanobiotechnology, which is aimed at preserving environmental health and improving the welfare of farmers while also increasing crop yields and the production of innocuous feed. Producers of innovative products in agronanobiotechnology are experiencing difficulties in bringing these products to market, because of their high production costs, which regularly are required in high volumes in the agricultural sector, while unclear technical benefits, legislative uncertainties, and negative public opinion are hampering the development of agronanobiotechnology; notwithstanding these difficulties, the possibilities offered by agronanobiotechnology in several agricultural applications are moving forward. Meanwhile, progress in legislation, nanoremediation, environmental monitoring, international safety regulation, and drug delivery techniques could improve the agricultural and livestock sector indirectly. For research and development in agronanobiotechnology to move forward, long-term in situ field trials are required, while social welfare must also be guaranteed in order to shape sustainable development.