Economic analysis of alternative nutritional management of dual-purpose cow herds in central coastal Veracruz, Mexico

Market information was combined with predicted input–output relationships in an economic analysis of alternative nutritional management for dual-purpose member herds of the Genesis farmer organization of central coastal Veracruz, Mexico. Cow productivity outcomes for typical management and alternative feeding scenarios were obtained from structured sets of simulations in a companion study of productivity limitations and potentials using the Cornell Net Carbohydrate and Protein System model (Version 6.0). Partial budgeting methods and sensitivity analysis were used to identify economically viable alternatives based on expected change in milk income over feed cost (change in revenues from milk sales less change in feed costs). Herd owners in coastal Veracruz have large economic incentives, from $584 to$1,131 in predicted net margin, to increase milk sales by up to 74% across a three-lactation cow lifetime by improving diets based on good quality grass and legume forages. This increment is equal to, or exceeds, in value the total yield from at least one additional lactation per cow lifetime. Furthermore, marginal rates of return (change in milk income over feed costs divided by change in variable costs when alternative practices are used) of 3.3 ± 0.8 indicate clear economic incentives to remove fundamental productivity vulnerabilities due to chronic energy deficits and impeded growth of immature cows under typical management. Sensitivity analyses indicate that the economic outcomes are robust for a variety of market conditions

Limitations and potentials of dual-purpose cow herds in Central Coastal Veracruz, Mexico

Feed chemical and kinetic composition and animal performance information was used to evaluate productivity limitations and potentials of dual-purpose member herds of the Genesis farmer organization of central coastal Veracruz, Mexico. The Cornell Net Carbohydrate and Protein System model (Version 6.0) was systematically applied to specific groups of cows in structured simulations to establish probable input–output relationships for typical management, and to estimate probable outcomes from alternative management based on forage-based dietary improvements. Key herd vulnerabilities were pinpointed: chronic energy deficits among dry cows of all ages in late gestation and impeded growth for immature cows. Regardless of the forage season of calving, most cows, if not all, incur energy deficits in the final trimester of gestation; thus reducing the pool of tissue energy and constraining milking performance. Under typical management, cows are smaller and underweight for their age, which limits feed intake capacity, milk production and the probability of early postpartum return to ovarian cyclicity. The substitution of good-quality harvested forage for grazing increased predicted yields by about one-third over typical scenarios for underweight cows. When diets from first parturition properly supported growth and tissue repletion, milk production in second and third lactations was predicted to improve about 60%. Judiciously supplemented diets based on good quality grass and legume forages from first calving were predicted to further increase productivity by about 80% across a three-lactation cow lifetime. These dual-purpose herd owners have large incentives to increase sales income by implementing nutritional strategies like those considered in this study

Improving adoption of technologies and interventions for increasing supply of quality feed in low- and middle-income countries

The global increase in the demand for and production of animal-source foods (four-to five-fold increase between 1960 and 2015), which has been mostly concentrated in low- and middle-income countries (LMIC), provides smallholder livestock producers with an opportunity for improving their livelihoods and food and nutrition security. However, across livestock production systems in many LMIC, limited supplies and high cost of good quality feed severely constrains exploitation of this opportunity. In many of such countries, feeds and feeding-related issues are often ranked as the primary constraint to livestock production and increased consumption of animal-source foods. Here we review the complex biophysical, socio-economic and technological challenges related to improving quality feed supply and the reasons for generally low adoption of apparently proven feed enhancement technologies. We describe also successful interventions and conclude by recommending strategies for improving quality feed supply in LMIC that account for and overcome the prevailing challenges

Herramienta para el diseño de sistemas de posicionamiento tridimensional usados en fabricación digital

Digital manufacturing creates finished parts from designed models in computer-based manufacturing processes such as CAD-CAM processes, opening the road to flexibility and productivity in industry. This paper presents a software tool that assists the design of digital production equipment, creating complex geometry parts through computerized numerical control. It was started by identifying the characteristics of manufacturing processes capable of automation and it was established a benchmark to define the mechanical, electronic, and control design for three-dimensional positioning equipment.Through a computer tool, the parameters of construction positioning systems were defined, besides, the variables, constants, and criteria were noted, so that by applying theories concerning the electromechanical design, necessary calculations for find the right components belonging to the machine are made. Finally, a user interface allows incorporating data, providing results of the machine design, and getting the structural CAD design of the positioning system.La fabricación digital crea piezas terminadas a partir de modelos diseñados en computador con base en procesos de manufactura CAD-CAM, que abren camino a la flexibilidad y a la productividad en la industria. Este trabajo presenta una herramienta informática que asiste el diseño de equipos de fabricación digital para piezas de geometría compleja a través de control numérico computarizado. Se parte de la identificación de las características de procesos de manufactura susceptibles de automatización y se establece un referente para definir el diseño mecánico, electrónico y de control de un equipo de posicionamiento tridimensional, para ello, a través de una herramienta informática, se definen los parámetros de construcción de los sistemas de posicionamiento, se señalan las variables, las constantes y los criterios, para que mediante la aplicación de teorías referentes al diseño electromecánico, se realicen los cálculos necesarios de los componentes pertenecientes al equipo. Finalmente, una interfaz de usuario permite incorporar los datos, proporcionar los resultados del diseño del equipo y obtener el diseño CAD estructural del sistema de posicionamiento

Effect of dietary conjugated linoleic acid (CLA) on the metabolism and reproduction of dairy cows

Rumen-protected conjugated linoleic acid (CLA) reportedly improves fertility in lactating dairy cows by reducing the postpartum interval to first ovulation and enhancing the circulating insulin-like growth factor-I (IGF-I) levels. The objectives of this study were to evaluate the blood metabolites, hormones, follicular fluid (FF) and liver for the effect of CLA supplementation (50 g top-dressed daily from 15 days pre-partum to 65 days in milk –DIM -). Pre-partum Holstein cows (n = 24) were assigned to two treatments: a Control and CLA group (n = 12 cows/group). Dry matter intake (DMI) and milk production were recorded daily. At 26 DIM, ovulation was synchronized and at 34 DIM, plasma and FF were analysed for paraoxonase 1(PON) levels. Moreover plasma was analysed for IGF binding protein 2 and 3 (IGFBP). From 34 DIM, blood samples and FF from follicles >9 mm were collected and analysed for estradiol, progesterone, IGF-I and lipoproteins. A liver biopsy was performed at 65 DIM and analysed for the expression of IGF-I, growth hormone receptor (GHR), pyruvate carboxylase (PC) and cytosolic phosphoenolpyruvate carboxykinase (PECK). CLA supplemented cows, compared to the control group, recorded a significant lower milk fat production, improved DMI and energy balance and recorded significant increased plasma concentrations of IGF-I, cholesterol, low density lipoprotein (LDL) and IGFBP-3 (interaction treatment x DIM). The concentration of IGF-I, high density lipoprotein (HDL) and LDL tended to be higher in FF than plasma. This study confirms the positive effects of dietary CLA supplementation on the metabolism, by improving the energy intake and reducing the negative energy balance. Moreover, the improvement of plasma IGF-I levels observed in this study, coupled with a better energy balance support previous studies showing a positive effect of CLA supplementation on reproduction. However, CLA did not alter the plasma and the FF concentration of PON, nor the liver gene expression.Keywords: Follicular fluid, liver gene expression, postpartum cow

Sistema de posicionamiento aplicado a la técnica de impresión 3D modelado por deposición fundida

This paper presents the design and construction of a mechanical positioning system, which is part of a mechatronic prototype that integrates the areas of electronics, mechanics, control and computing, forming a synergy leading to create an automated machine that meets the technical requirements and requirements for a 3D printer, using a rapid prototyping technology (Fused Deposition Modeling: FDM), to produce a part designed on a CAD software, through the positioning and the action of a plastic extruder tool in three dimensions.The proposed methodology provides, step by step, the design and construction of the mechanical system of three-dimensional Cartesian positioning, which takes into account the variables and processes necessary for optimal response of the machine, with regard to surface finishing, printing time, emergency stops, and so forth.Este artículo presenta el diseño y construcción de un sistema mecánico de posicionamiento, el cual hace parte de un prototipo mecatrónico que  integra las áreas de electrónica, mecánica, control e informática, formando una sinergia conducente a crear una máquina automatizada que responde a las necesidades técnicas y requerimientos de una impresora 3D, aplicando la técnica de prototipado rápido modelado por deposición fundida (FDM), para fabricar una pieza diseñada en un software CAD, a través del posicionamiento y la acción de una herramienta extrusora de plástico en tres dimensiones.  La metodología planteada explica paso a paso el diseño y construcción del sistema mecánico de posicionamiento cartesiano tridimensional, en el cual se tienen en cuenta  las variables y procesos necesarios para la óptima respuesta de la máquina, en lo concerniente al acabado superficial de la pieza, tiempo de impresión, paradas de emergencia, entre otras

The effects of conjugated linoleic acid isomers cis-9,trans-11 and trans-10,cis-12 on in vitro bovine embryo production and cryopreservation

Conjugated linoleic acid (CLA) isomers can affect the lipid profile and signaling of cells and thereby alter their function. A total of 5,700 bovine oocytes were used in a structured series of experiments to test the effects of CLA cis-9,trans-11 and CLA trans-10,cis-12 in vitro. In experiment 1, high doses of each CLA isomer during in vitro maturation (IVM) were compared with high or low doses during the entire in vitro culture (IVC) of parthenogenetic embryos. High doses of the CLA isomers ranged from 50 to 200 μM and low doses were 15 and 25 μM. In experiment 2, the low doses of each CLA isomer were tested during IVM/IVC on embryos produced by in vitro fertilization (IVF). Experiment 3 compared the effects of 15 μM doses of each CLA isomer during IVM or IVC of IVF embryos. In experiment 4, post-rewarming survival rates and blastomere counts were assessed for embryos supplemented with each CLA isomer during IVM or for 36 h before vitrification. In experiment 1, when either CLA isomer was provided only during IVM, we observed no effects on overall rates of maturation, cleavage, or blastocysts (92.2 ± 1.6%, 78.3 ± 4.1%, and 28.9 ± 5.1%, respectively). However, high doses of each CLA isomer, but not low doses, during the entire embryo culture period decreased blastocyst rates (5-20%) in a dose-dependent manner. Cleavage rates improved with 15 or 50 μM CLA trans-10,cis-12. Progesterone concentrations in maturation media were significantly increased by high doses of each CLA isomer compared with control, but low doses of CLA isomers had no effect. In experiment 2 with IVF embryos, low doses of each CLA isomer did not alter cleavage rates (average 84.9 ± 1.9%) and only 25 μM CLA trans-10,cis-12 during IVC reduced blastocyst rates below those of controls (25.5 ± 2.1 vs. 38.2 ± 2.3%). The lipid content of embryos was increased and relative expression of the BIRC5 (baculoviral IAP repeat containing 5) gene was depressed by CLA trans-10,cis-12. In experiment 3, low doses (15μM) of each CLA isomer during IVC significantly reduced blastocyst rates (20.6 ± 2.4% and 27.7 ± 1.2% vs. 34.18 ± 1.2% for CLA trans-10,cis-12 and CLA cis-9,trans-11 compared with control, respectively) with less effect of each CLA during IVM. In experiment 4, adding 100 μM CLA cis-9,trans-11 during the final 36 h of culture resulted in a high survival rate after rewarming and culture, and the higher embryo blastomere count was comparable to that of control embryos not undergoing vitrification. In conclusion, supplementation with either CLA isomer did not improve embryo production, but inclusion of CLA cis-9,trans-11 before vitrification improved the quality of bovine IVF embryos after rewarming and culture

Exogenous paraoxonase-1 during oocyte maturation improves bovine embryo development in vitro.

The aims of this study were (i) to measure the direct effects of exogenous human recombinant PON1 (rPON1) on bovine oocyte maturation at the molecular level (gene expression) and (ii) to measure the carry-over effects of PON1 on pre-implantation embryo development in vitro.201