Chemical composition and in situ ruminal disappearance of sorghum silages grown in the mexican humid tropic

The purpose was to evaluate the chemical composition and in situ ruminal dry matter disappearance of four types of grain sorghum silages, one brown midrib sorghum (bmr) and, a corn silage, grown under rainfed conditions in a humid tropical region of Mexico. The crops were established at three sites. At harvest, three minisilos per treatment were filled with forage previously chopped. Minisilos opened at 55 days and samples of silage taken to dry and ground to 1 mm to determine the chemical composition and in situ ruminal dry matter disappearance. The crude protein was higher (p<0.05) in sorghum silages than corn silage. In sorghum silages, bmr sorghum had the lowest (p0.05) in ADF and ADL to corn silage. The degradation parameters (a, b, c ) was higher (p0.05) in bmr sorghum and corn silages. In the humid tropics, bmr sorghum silages are a good alternative to corn silage, especially in the dry season.The purpose was to evaluate the chemical composition and in situ ruminal dry matter disappearance of four types of grain sorghum silages, one brown midrib sorghum (bmr) and, a corn silage, grown under rainfed conditions in a humid tropical region of Mexico. The crops were established at three sites. At harvest, three minisilos per treatment were filled with forage previously chopped. Minisilos opened at 55 days and samples of silage taken to dry and ground to 1 mm to determine the chemical composition and in situ ruminal dry matter disappearance. The crude protein was higher (p<0.05) in sorghum silages than corn silage. In sorghum silages, bmr sorghum had the lowest (p0.05) in ADF and ADL to corn silage. The degradation parameters (a, b, c ) was higher (p0.05) in bmr sorghum and corn silages. In the humid tropics, bmr sorghum silages are a good alternative to corn silage, especially in the dry season. &nbsp

Corn kernel and corn fodder yield in four maize varieties in the humid tropics of Mexico

In southeastern Mexico, maize is planted for its corn kernel. Additionally, its bracts are used for tamales and handicrafts, its cobs are used as vegetables for human consumption, and its fodder is used to feed cattle. Objective: To evaluate the growth and yield of maize planted for corn kernel and fodder production in Loma Bonita, Oaxaca, Mexico. Design/Methodology/Approach: The DK7500, H-520, A7573, and VS-536 maize genotypes were used as treatments for the production of corn kernel and fodder, using a randomized blocks design with three replications. Several variables were measured: plant height, stem diameter, chlorophyll, leaf length, leaf width, and leaf area. Finally, the corn kernel and fodder yields were estimated (kg ha-1) at the time of harvest. Results: The genotypes under study showed significant differences (P£0.05) in plant height, stem diameter, leaf length, leaf width, and leaf area. The A7573 genotype recorded the highest corn kernel yield (20,409 kg ha-1), while fodder yield was statistically the same in the four genotypes. Study Limitations/Implications: An analysis of different environments in a multi-year period would help to verify the information obtained. Findings/Conclusions: A7573 maize had the highest corn kernel yield (20,409 kg ha-1): 15.5% higher than that of H-520 and 12.5% higher than VS-536 (control). Fodder yield was statistically similar between genotypes, ranging from 40,529 kg ha-1 (H-520) to 42,104 kg ha-1 (VS-536)

Addition of reduced glutathione to diluent of lamb semen during storage (5 °C)

The objectives were: first, determine a recommended concentration of GSH to be used during cooling of sheep semen to 5°C; and second, evaluate the effects of GSH on the acrosome integrity and sperm capacitation. Experiment 1, 12 ejaculates from two Pelibuey rams were used. Each ejaculate was divided into four aliquots corresponding to the GSH concentrations tested (0.0, 0.5, 1.0 and 5 mM). Aliquots were stored under refrigeration (5°C) for 24 h. Live sperm motility was evaluated at 0, 1, 2 and 24 h of storage and at 24 h after warming to 37°C (reactivation). Experiment 2, 22 ejaculates were evaluated by the technique of chlortetracycline sperm capacitation after 24 h storage at 5°C.. At 0, 1, and 2 h of storage there were no significant differences between sperm motilities using different concentrations of GSH. At 24 h, 5 mM GSH showed the highest sperm motility (29.22%). This concentration also had the highest percentage of motility during reactivation (80.29%) and live sperm concentration, 81.44% (p <0.05). The percentage of non-capacitated and acrosome intact sperm increased to 42% when 5 mM GSH (p <0.05) was used. It is concluded that the antioxidant and protective activity of GSH during cooling is dependent on concentration and storage time

Effect of cutting height, a bacterial inoculant and a fibrolytic enzyme on corn (Zea mays L.) silage quality

This study aimed to evaluate cutting height (CH) effects on ensiled corn without additives (C), with a lactic acid bacteria inoculant (L), a fibrolytic enzyme (F), or a mixture of both (FL), considering chemical composition and both in vitro digestibility dry matter (IVDMD) and in vitro neutral detergent fiber (IVNDFD). Corn was harvested at three different cutting heights (12, 25 or 42 cm above the soil) and ensiled with or without additives (AD). Data was analyzed according to a factorial design, with a 3 x 4 arrangement of treatments and three repeats. Dry matter content was highest in C12 and lowest in F12 (P<0.05) silages. As cutting height was higher, cell wall content was lower (P<0.05). Even considering it increased after the use of additives (P<0.05), the highest values occurred with FL silages. Crude protein was equal (P˃0.05) between CH and increased (P<0.05) with AD. The highest IVDMD was observed for 42 cm CH, while IVDMD and IVNDFD were higher in C and F, but lower with FL. None of the inoculation treatments, alone or combined improved corn silage quality. In fact, FL combination decreased such quality. Highlights: The efficacy of lactic acid bacteria (LAB) and exogenous fibrolytic enzyme (EFE) is a funtion of the amount of cell walls and sugars present in the maize plant at harvest. Adding LAB and EFE to maize forage harvested at different cutting heights did not improve silage quality, in fact, the combination of both additives decreased silage quality. Further studies are needed to prove the efficacy of EFE and its combination with LAB on maize silage quality.This study aimed to evaluate cutting height (CH) effects on ensiled corn without additives (C), with a lactic acid bacteria inoculant (L), a fibrolytic enzyme (F), or a mixture of both (FL), considering chemical composition and both in vitro digestibility dry matter (IVDMD) and in vitro neutral detergent fiber (IVNDFD). Corn was harvested at three different cutting heights (12, 25 or 42 cm above the soil) and ensiled with or without additives (AD). Data was analyzed according to a factorial design, with a 3 x 4 arrangement of treatments and three repeats. Dry matter content was highest in C12 and lowest in F12 (P<0.05) silages. As cutting height was higher, cell wall content was lower (P<0.05). Even considering it increased after the use of additives (P<0.05), the highest values occurred with FL silages. Crude protein was equal (P˃0.05) between CH and increased (P<0.05) with AD. The highest IVDMD was observed for 42 cm CH, while IVDMD and IVNDFD were higher in C and F, but lower with FL. None of the inoculation treatments, alone or combined improved corn silage quality. In fact, FL combination decreased such quality. Highlights: The efficacy of lactic acid bacteria (LAB) and exogenous fibrolytic enzyme (EFE) is a funtion of the amount of cell walls and sugars present in the maize plant at harvest. Adding LAB and EFE to maize forage harvested at different cutting heights did not improve silage quality, in fact, the combination of both additives decreased silage quality. Further studies are needed to prove the efficacy of EFE and its combination with LAB on maize silage quality.

Post-ejaculation incubation of semen as a method to alter the sex ratio of offspring obtained by artificial insemination in rabbits

In mammals, the sex ratio under natural conditions is 50% female and 50% male. However, this ratio can be altered by some methods. The application of warmth (42ºC) to the scrotum has an effect on the functioning of spermatozoa within the epididymis and modifies the sex ratio of offspring obtained through natural mating. The aim of this study was to determine the effect of post-ejaculation incubation temperature (42ºC or 30ºC) on the sex ratio of offspring obtained by artificial insemination. Each ejaculate was diluted and divided into two equal aliquots (0.5mL), one of which was incubated at 42ºC and the other at 37ºC for 30min. The sperm motility and viability at 42ºC was 87.3% and 89.4%, and at 37ºC, 88.2 and 75.5%, respectively. When artificial insemination was performed using semen incubated at 42ºC and 37ºC, 6.38, and 7.83 connies were born per litter, respectively. The sex ratio of offspring when sperm was incubated at 42ºC was 56.2% females and 43.7% males, while for semen incubated at 37ºC it was 52.6% females and 47.4% males. In conclusion, incubation of semen post ejaculation at 42ºC for 30 min could be used to favor the birth of female offspring through artificial insemination

EFECTO DEL SISTEMA DE SIEMBRA Y ESTADO DE MADUREZ SOBRE PRODUCCIÓN Y CALIDAD NUTRICIONAL DE SIETE VARIEDADES DE AVENA (Avena sativa).

Master thesi

Tiller population dynamics in eight cultivars of elephant grass during undisturbed growth

The aim of the study was to assess tiller population dynamics of aerial and basal tillers in eight cultivars of Pennisetum purpureum (Schumach.), syn. Cenchrus purpureus (Schumach.) Morrone, in a warm humid climate in Veracruz, Mexico. This is a pioneer study on tiller population dynamics in elephant grass under conditions of undisturbed growth. The tiller population assays included data from 14 days after cutting until 154 and 182 days after cutting for the dry and wet seasons, respectively. On each sampling date, a distinctive ring was placed on every new tiller, and rings were removed from dead tillers. Tiller density, mortality and appearance were determined. In wet seasons, copious tillering occurred on initial regrowth (by day 42, mostly aerial tillers, with a ratio of 2:1 to 4:1 for aerial to basal tiller appearance), and on day 98 (a higher proportion of basal tillers, with an aerial to basal tiller ratio of 1.5:1). Aerial tillers showed a higher overall mortality rate than basal tillers (29.0 vs 14.4). Younger basal tillers showed higher mortality than older tillers. Higher tiller density occurred during the dry season, where it increased gradually until day 70 and then declined. The cultivars ‘Cameroon’, ‘CT115’ and ‘OM22’ showed remarkably high tillering ability. The findings indicate that harvesting a forage bank is possible from day 70 during a dry season.Keywords: density dynamics, king grass, tiller appearance rate, tiller mortality rate, tropical grasse

Efecto del ácido linoleico conjugado sobre la calidad de la carne de conejas

The use of fatty acids in food animal supplements is to improve animal health and decrease the use of medications. CLA is a bioactive compound and can be incorporated into the diet of non-ruminant animals. The objective of this experiment was to evaluate the effect of incorporating CLA into the diet of New Zealand rabbits on meat quality. The variables evaluated were the microbiological quality of cecotrophs: microbial load of LAB, enterobacteria and clostridium spp., zootechnical parameters and physicochemical quality of meat from rabbits at slaughter. The results obtained showed the presence of LAB and Clostridium and the absence of Enterobacteriaceae during the study period. Proximal analysis of rabbit meat showed no difference (p > 0.05) in live weight (BW), weight gain (WG), feed efficiency (FE) and feed conversion ratio (FCR) in the treatments and the control. But CRA and color showed difference (p≤0.05) between LD and BF muscles. The GA profile showed the presence of CLA in the thigh of rabbits.El uso de ácidos grasos en suplementos para animales de consumo humano es para mejorar la salud del animal y disminuir el uso de medicamentos. El CLA es un compuesto bioactivo y se puede incorporar en la dieta de animales no rumiantes. El objetivo de este experimento fue evaluar el efecto de la incorporación de CLA en la dieta de conejas Nueva Zelanda, sobre la calidad de la carne. Las variables evaluadas fueron la calidad microbiológica de cecótrofos: carga microbiana de BAL, enterobacterias y clostridium spp., los parámetros zootécnicos y la calidad fisicoquímica de la carne de conejas al sacrificio. Los resultados obtenidos mostraron presencia de BAL y Clostridium y ausencia de Enterobacterias durante el tiempo del estudio. El análisis proximal de la carne de conejas no mostró diferencia (p > 0.05) en el peso vivo (PV), ganancia de peso (GP), eficiencia alimenticia (EA) y conversión alimenticia (CA) en los tratamientos y el testigo. Pero la CRA y el color mostraron diferencia (p 0.05) entre los músculos LD y BF. El perfil de AG mostró la presencia de CLA en el muslo de las conejas