ABSTRACT Caesalpinia ebano is a tropical tree from Colombia; its conservation status is in the endangered category since the remaining populations are suffering genetic erosion. The objective of this study was to estimate the phenotypic (rF) and genetic (rG) correlations among biometric fruit and seeds traits, and the path analysis for the fruit weight. Ten trees (treatments) were evaluated under the random effects model, with 10 fruits/tree as replications. There was significant variability between trees for seven quantitative traits. The fruit weight showed genetic correlations with six traits (0.56* > rG < 1.00**). The number and weight of the seeds per fruit showed high genetic correlations with five traits (rG ≥ 0.85**). The weight of the seeds per fruit exerted direct and indirect effects of greater importance in determining the fruit weight. It is possible to improve the production and physiological quality of the seed by directly selecting trees with fruits of greater seed weight.

RESUMEN Caesalpinia ebano es un árbol tropical de Colombia, su estado de conservación se encuentra en la categoría de peligro de extinción debido a la erosión genética. El objetivo del estudio fue estimar las correlaciones fenotípicas (rF) y genéticas (rG) entre características biométricas del fruto y semillas y el análisis de sendero para el peso del fruto. Se evaluaron 10 árboles (tratamientos) bajo el modelo de efectos aleatorios, con 10 frutos/árbol como repeticiones. Se presentó variabilidad significativa entre árboles, para siete de las características cuantitativas. El peso del fruto mostró correlaciones genéticas (0,56* > rG < 1,00**) con seis características. El número y peso de las semillas por fruto acusaron altas correlaciónes genéticas (rG ≥ 0,85**) con cinco características. El peso de las semillas por fruto ejerció los efectos directos e indirectos de mayor importancia en la determinación del peso del fruto. Es posible mejorar la producción y la calidad fisiológica de la semilla, seleccionando directamente árboles con frutos de mayor peso de semillas.

RESUMEN El caupí es la leguminosa más importante del Caribe colombiano, por su impacto positivo en la seguridad alimentaria y nutricional de las familias rurales de escasos ingresos. Es cultivada por pequeños productores, pero sus rendimientos por hectárea no superan los 600 kg, debido al uso cultivares obsoletos. El objetivo de la investigación fue estimar las correlaciones entre siete características cuantitativas y el análisis de sendero entre el rendimiento de grano y seis características cuantitativas, con los resultados de la evaluación de 10 genotipos de hábito de crecimiento semi-postrado, de alto rendimiento de grano, cultivados en ocho ambientes del trópico húmedo y seco de la región Caribe colombiana, bajo el diseño bloques completos al azar, con 10 tratamientos y cuatro repeticiones. Se detectaron diferencias significativas entre ambientes, genotipos e interacción genotipo × ambiente. Las correlaciones genotípicas fueron de mayor magnitud que las fenotípicas, destacándose la correlación entre el ancho de grano (AG) y el rendimiento de grano (REND), rF=0,69*, rG=0,78*, igualmente entre el peso de 100 semillas (P100S) y el AG, rF=0,97**, rG=0,99**. Los caracteres AG y número de vainas por planta (NVP) presentaron efectos directos positivos sobre el REND, con efecto indirecto negativo de NVP vía AG, mientras que la altura de la primera vaina (AIPV), el número de semillas por vaina (NSPV) y el P100S influyeron directa y negativamente en el REND de los 10 cultivares de caupí.

ABSTRACT The cowpea is the most important legume in the Colombian Caribbean because of its positive impact on the food and nutritional security of low-income rural families. It is cultivated by small producers but its yields per hectare does not exceed 600 kg because of the use of obsolete cultivars. The objective of the research was to estimate correlations between seven quantitative characteristics and the path analysis between grain yield and six quantitative characteristics, with the results of the evaluation of 10 genotypes with a semi-prostrate growth habit and high grain yield, grown in eight environments in humid and dry tropics in the Colombian Caribbean region. A randomized complete blocks design was used, with four repetitions. Significant differences between the environments, genotypes and genotype ₓ environment interaction were detected. The genotypic correlations had a greater magnitude than the phenotypic ones, highlighting the correlation between grain width (GW) and grain yield (GY), rP = 0.69*, rG = 0.78*, and between the weight of 100 seeds (100SW) and GW, rP = 0.97**, rG = 0.99 **. The characteristics GW and number of pods per plant (NPP) had positive direct effects on the GY, with an indirect negative effect on NPP by way of GW. The height of the first pod (HFP), the number of seeds per pod (NSP) and the 100SW directly and negatively influenced the GY of the 10 semi-prostrate cowpea cultivars.

Abstract Corn is susceptible to drought; a solution strategy is to generate tolerant lines from a segregating population to obtain hybrids or synthetic varieties, so the objectives were to select high yield and short ASI lines based on the irrigation-drought system, to estimate heritability and correlation of quantitative traits. The crossing of the Ac7643 × B39 lines, derived in 193 S1, lines which, together with witness and parents, were evaluated under the alpha-lattice design in a 14 × 14 arrangement with two repetitions in two locations in Morelos, Mexico. The variables were flowering male (MF) and female (FF), anthesis-silking interval (ASI), plant height (HP) and cob (HC), as well as grain yield (GY). We observed a 40 % reduction in GY under drought (0.75 t ha-1) with respect to the irrigation environment (1.26 t ha-1). The ASI was five and two days in drought and irrigation environments, respectively. The heritability for GY and ASI was 0.41. There are lines with transgressive inheritance for GY and ASI. The correlation of the GY with FF and ASI was -0.23 ** and -0.37 **, respectively. The germplasm can generate a synthetic variety or drought tolerant hybrids.

Resumen El maíz es susceptible a la sequía, una estrategia de solución es generar líneas tolerantes a partir de una población segregante para obtener híbridos o variedades sintéticas, por ello los objetivos fueron seleccionar líneas de rendimiento alto y ASI corto con base al sistema riego-sequía, estimar la heredabilidad y la correlación de caracteres cuantitativos. El cruzamiento de las líneas Ac7643 y B39 derivó 193 líneas S1, estas líneas junto con el testigo y progenitores se evaluaron bajo el diseño alfa látice en un arreglo 14 × 14 con dos repeticiones en dos localidades de Morelos, México. Las variables fueron floración masculina (FM) y femenina (FF), intervalo antesis-emergencia de estigmas (ASI), altura de planta (AP) y mazorca (AM); y rendimiento de grano (RG). Se observó reducción del 40 % en RG bajo sequía (0.75 t ha-1) con respecto a riego (1.26 toneladas ha-1), el ASI fue de 5 y 2 d en sequía y en riego, respectivamente. La heredabilidad para RG y ASI fue de 0.41. Existen líneas con herencia transgresiva para RG y ASI. La correlación del RG con FF y ASI fue de -0.23**y -0.37**, respectivamente. El germoplasma puede generar una variedad sintética o híbridos tolerantes a sequía.

Abstract With the aim of quantifying the average Heterosis (Hp) and determine the effects of varietal heterosis (hj) and specific heterosis (sjj´) seven progenitor populations of native maize were used and their 21 direct crosses. The 28 maize genotypes were evaluated in three environments in the state of Morelos (Ayala-O/I-2012/2013, Ayala-P/V-2013 and Tepalcingo-P/V-2013). The experimental design, were complete blocks at random with three repetitions. Four variables were measured and subjected to a combined variance analysis, mean comparison (DMS0.01), Hp was calculated as a percentage, and the varietal heterosis and specific heterosis were determined by the Gardner and Eberhart method. In the percentage expression the Cross-17 presented positive values in Hp in the variables of GM (19.16), HM (11.81), P100G (7.77) and RG (5.36). In the (hj) the progenitors with greater varietal effect were BCP1 and CB029, both impacted in the formation of crosses with the highest sjj´ values as the Cross-26 and Cross-56 this for RG and GM. This allows the selection of native maize populations to improve characteristics related to grain yield through inter-population crossing.

Resumen Con el objetivo de cuantificar la Heterosis promedio (Hp) y determinar los efectos de Heterosis varietal (hj) y Heterosis específica (sjj´), se utilizaron siete poblaciones progenitoras de maíz nativo y sus 21 cruzas directas. Los 28 genotipos de maíz se evaluaron en tres ambientes del estado de Morelos (Ayala-O/I-2012/2013, Ayala-P/V-2013 y Tepalcingo -P/V-2013). El diseño experimental fue bloques completos al azar con tres repeticiones. Se midieron cuatro variables y se sometieron a un análisis de varianza combinado, comparación de medias (DMS0.01), la Hp se calculó de manera porcentual, la Heterosis varietal y Heterosis específica se determinaron por el método de Gardner y Eberhart. En la expresión porcentual la Cruza-17 presentó valores positivos en Hp en las variables de GM (19.16), HM (11.81), P100G (7.77) y RG (5.36). En la (hj) los progenitores con mayor efecto fueron BCP1 y CB029 ambos impactaron en la formación de cruzas con los valores más altos de sjj´ como la Cruza-26 y Cruza-56 esto para RG y GM. Lo anterior permite la selección de poblaciones nativas de maíz para mejorar características relacionadas al rendimiento de grano mediante el cruzamiento inter-poblacional.

ABSTRACT The objective of this study was to evaluate the effects of supra-nutritional level of selected B vitamins in different types of diet on broiler performance. Two experiments were conducted using male and female one-day-old chicks (n=288 each; initial body weights in experiment I and II was, respectively, 47.57 ± 0.43, and 47.98 ± 0.31) reared in batteries up to 18 days. In experiment I, the chicks were fed a corn and soybean meal-based diet and, in experiment II, a diet containing oxidized animal by-product meals and soybean oil was used. Both experiments followed a completely randomized design in a 3 × 2 factorial arrangement, consisting of the factors: i) supplementation levels of selected B vitamins (control, 3- or 6-times control of the vitamins riboflavin, pantothenic acid, niacin, folic acid and vitamin B12); ii) dietary nutritional density (low or high), totaling 6 treatments and 8 replicates of 6 birds each (3 males and 3 females). As result of this study, in Exp. I, chicks showed higher weight gain (741.1 g vs. 697.3 g) and feed intake (920.2 vs. 878.5 g) when fed low-nutritional density diet with supra-nutritional vitamin level 6-times higher than the control. However, this effect was not found in the performance of chickens fed high-nutritional density diet. Despite the poor quality of the ingredients used in Exp. II, no statistical effect was shown of the use of vitamin super-dose in rations with different dietary nutrient density. Feed conversion ratio (FCR) was significantly improved for chickens fed high-nutritional density diet (1.191 vs. 1.246 in experiment I, 1.244 vs. 1.275 in experiment II, p<0.01). We conclude that birds fed a vegetable diet formulated with low-dietary density improved body weight (BW) and feed intake (FI) when receiving supra-nutritional levels of vitamins 6-times higher than the control.

ABSTRACT The purpose of this trial was to supplement commercial broiler diets with optimum vitamin programs and higher availability of mineral sources, and to evaluate the effect on performance, yield and meat quality of broilers. The study used 1800 male broiler chicks randomly distributed in a 2 x 2 factorial design (vitamin programs - optimum and commercial vs. mineral sources - inorganic (sulfates) and carbo-amino-phospho-chelate (CAPC)). Supplementation associating optimum vitamin levels and mineral source CAPC resulted in better feed conversion and higher carcass weight at 42 days of age (p<0.05). Supplementation of diets with optimum vitamin levels resulted in higher absolute and relative breast weight, lower abdominal fat deposition, and reduction (p<0.05) of broiler breast water loss by dripping. Supplementation with CAPC minerals resulted in higher breast weight, lower abdominal fat deposition, less elastic muscle tissue, that is, a higher level of tenderness resulting in less resistance of muscle fibers and skin with higher tear strength than the skin of birds fed inorganic sources. Associating optimum vitamin programs and CAPC mineral source resulted in lower (p<0.05) lipid peroxidation levels in thighs and drumsticks after 10 and 40 days freezing. No difference (p>0.05) was found in the association of vitamin programs and mineral sources on the occurrence of white striping and dorsal myopathy. Supplementing the diets with optimized vitamin programs associated with a more bioavailable mineral source resulted in a positive contribution to the meat quality of broilers.

ABSTRACT This study aimed to evaluate the effect of different reductions in digestible amino acids content (lysine, methionine, and threonine), according to two nutritional requirements in corn, soybean meal, and meat and bone meal based diets, with protease supplementation, on performance parameters and carcass characteristics. A total of 1080 day-old chicks, male, Cobb 500, were allotted to a completely randomized design, in a factorial arrangement 3 x 2, three reductions in digestible amino acids content (lysine, methionine, and threonine) and two nutritional requirements (Rostagno et al. 2005 and Cobb-Vantress Guidelines 2008), and all diets were supplemented with protease (200 ppm) with 6 replicates of 30 birds per pen. There was no significant interaction (p<0.05) between digestible amino acid reductions and both nutritional requirements for the performance variables and carcass yield and cuts. There was an effect of amino acid reduction and protease supplementation only on slaughter weight (p<0.05). Broilers fed according to the nutritional requirements of Rostagno et al. (2005) showed better (p<0.05) performance when compared to broilers fed as specified by the nutritional requirements of Cobb-Vantress (2008) with no significant differences in carcass characteristics. Protease supplementation of corn, soybean meal, and meat and bone meal based diets allows a reduction in the inclusion of crystalline amino acids (lysine, methionine, and threonine).

Abstract In Mexico 7.5 million hectares of corn are grown, with an average grain yield of 3.2 t ha-1, a strategy to increase yield is the use of improved varieties. The objectives of this study were 1) estimate genetic parameters in a segregating population of tropical maize; 2) select S1lines based on grain yield and earliness; and 3) determine the phenotypic and genetic correlation between traits. The germplasm under study consisted of 193 segregating S1 lines, parents and a control, S1 lines come from the F2 population from crossing Ac7643 x B-39. The lines were evaluated under irrigation using an alpha lattice design with two replications during the spring-summer 2013 and autumn-winter 2013/2014 cycle, in Ayala, Morelos. The variables recorded were days to male (FM) and female silking (FF), floral synchrony (SF), plant height (AP) and cob (AM) and grain yield (RG). The results indicate that the coefficient of additive genetic variation for RG was 17% and for FM 4%; heritability for the same traits was 0.42 and 0.80, respectively. The expected genetic gain for RG was 0.143 t ha-1 and for FM -0.62 d. The LUM-80 line turned with positive transgressive inheritance in RG. Phenotypic and genetic correlations between RG and the rest of the traits were low. The high degree of genetic variability present in the segregating population allows continuing with the breeding program.

Resumen En México se cultivan 7.5 millones de hectáreas con maíz, con un rendimiento de grano promedio de 3.2 t ha-1, una estrategia para incrementar el rendimiento es el uso de variedades mejoradas. Los objetivos del presente estudio fueron: 1) estimar los parámetros genéticos en una población segregante de maíz tropical; 2) seleccionar líneas S1 con base en el rendimiento de grano y precocidad; y 3) determinar la correlación fenotípica y genética entre caracteres. El germoplasma de estudio fueron 193 líneas S1 segregantes, los progenitores y un testigo, las líneas S1 provienen de la población F2 de la cruza de Ac7643 x B-39. Las líneas se evaluaron bajo riego usando un diseño látice alfa con dos repeticiones, en los ciclos primavera-verano 2013 y otoño-invierno 2013/2014, en Ayala, Morelos. Las variables registradas fueron días a floración masculina (FM) y femenina (FF), sincronía floral (SF), altura de planta (AP) y mazorca (AM), y rendimiento de grano (RG). Los resultados indican que el coeficiente de variación genético aditivo para RG fue de 17% y en FM de 4%; la heredabilidad para los mismos caracteres resultó de 0.42 y 0.80, respectivamente. La ganancia genética esperada para RG fue de 0.143 t ha-1 y para FM de -0.62 d. La línea LUM-80 resultó con herencia transgresiva positiva en RG. Las correlaciones fenotípicas y genéticas entre RG y el resto de caracteres fueron bajas. El alto grado de variabilidad genética presente en la población segregante permite continuar con el programa de mejoramiento genético.

Abstract This study evaluated the effects of the dietary inclusion of an enzyme blend and a direct-fed microbials in broiler diets on litter production and quality. In total, 900 Cobb 500(r) broiler chicks were distributed according to a completely randomized design into 4 treatments and 9 replicates of 25 birds each. Broilers were reared from 1 to 42 days of age. The treatments consisted of the following diets: NC: negative control; DFM: NC + 500 ppm of direct-fed microbials product (DFM), containing Bacillus subtilis and Bacillus licheniformis; ENZ: diet formulated with an enzyme blend (20 ppm phytase, 200 ppm protease and 200 ppm of xylanase); DFM+E: ENZ + DFM. Birds and litter were weighed at the start and end of the rearing period, for litter production and waste ratio (Rw) determination. Litter samples were analyzed for dry matter (DM) content, total and thermotolerant coliform counts, nutrient composition (nitrogen (N), phosphorous (P) and potassium (K)), and fiber fraction (neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin). The dietary inclusion of the evaluated additivesdid not influence litter production or Rw; however, ADF (%), NDF (kg and kg/kg DM litter), and total and thermotolerant coliform counts were reduced, and N content increased in the litter. The diets containing enzymes (ENZ and DFM+E) reduced litter P content. The addition of exogenous enzymes and their combination with a DFM based on Bacillus spp .Did not affect waste production, and reduced litter microbial load, and the contents of P and insoluble fiber in the litter.

A trial was conducted to evaluate the effects of adding an exogenous α-amylase-β-glucanase complex produced from Bacillus amyloliquefaciens on the growth performance, carcass yield, and relative AME bioequivalence in broilers fed corn-soy diets from 1 to 40 d of age. One thousand seven hundred and fifty one-day-old Cobb x Cobb 500 slow-feathering male broilers were randomly allotted to seven treatments with 10 replicates of 25 birds each as follows: control diet (C); C diet with reduction of 60 (C-60), 90 (C-90), or 120 (C-120) kcal AME/kg; C diet with reduction of 120 kcal AME/kg and supplemented with 200 (C-120-200), 300 (C-120-300), or 400 (C-120-400) mg of the enzyme complex/kg. Each g of the enzyme complex corresponded to 200 kilo-Novo α-amylase and 350 fungal β-glucanase units. On d 40, eight birds were randomly taken from each pen and processed to evaluate carcass and commercial cuts yields. Percent mortality was not affected by the treatments (p > 0.05). Live performance, as indicated by BW gain (BWG) linearly decreased (p < 0.05) and FCR linearly increased with the reduction in AME. Birds fed diets supplemented with the enzyme complex showed weekly improvements in BWG and FCR. There were no effects of the treatments on the yield of the carcass or of commercial cuts; however, abdominal fat was significantly lower (p < 0.0343) in birds fed the C-120-400 compared to the C-120 feeding program (1.67% vs. 1.90%); all other treatments were intermediate. Average AME equivalence of the enzyme complex varied weekly. Estimations for the entire period were 40, 46, and 56 kcal for BWG and 58, 76, and 99 kcal AME/kg for FCR (p < 0.001) for the diets containing 200, 300, and 400 mg enzyme complex/kg, respectively.