Fertility in Cebú × brown Swiss cows treated with prostaglandins, progesterone and eCG

Objective: To evaluate the application of 1 or 2 doses of prostaglandin F2? (PGF2?), the use of progestogen on different days of the estrous cycle, and the use of eCG in estrus and fertility synchronization of Zebu × Brown Swiss cows. Design / Methodology / Approach: The study was based on three protocols. Protocol 1 consisted of two treatments: PGI) 26 cows were injected with a single dose of 25 mg PGF2?, and 10 cows with two doses of 25 mg PGF2? with a 14 day interval. Protocol 2 consisted of two treatments: NG14) 11 cows were implanted with 3 mg Norgestomet on day 7 of the estrous cycle, and NG7) 11 animals received the same dose on day 14. In protocol 3, all the cows were implanted with 3 mg Norgestomet for 9 days, 48 h before removing the implant, 25 mg PGF2? was applied. Once the implant was removed, the cows were distributed into two treatments. Norgestomet (n=11) without eCG and Norgestomet + eCG (500 IU) (n=11).    Results: The application of PGF2? on two occasions had no influence (p> 0.05) on the percentages of estrus or pregnancies. NG7 achieved estrus synchronization in 81.8% of the cows between 24 and 36 h, compared with 45.4% of NG14; however, the pregnancy rate was lower (p<0.05). The application of eCG synchronized 90.9% estrus between 24 and 36 h, compared with 36.4% in the group where no eCG was applied. Study limitations / implications: The use of transrectal ultrasound is required to evaluate the ovarian structures present at the time of initiating an estrus synchronization protocol. Findings / conclusions: Cows that present corpus luteum do not require more than one injection of PGF2?, the percentage of pregnancy increases when Norgestomet is implanted on day 14 of the estrous cycle, in addition the application of eCG increases the percentage of synchronization of heat of the 24 to 36 h after withdrawal of progestogenObjective: To evaluate the application of one or two doses of prostaglandin F2?(PGF2?), the application of a progestogen on different days of the estrous cycle and theusage of eCG in the estrus synchronization and fertility of Zebu × Brown Swiss cows.Design / methodology / approach: The study was based on three protocols. The firstconsisted of two treatments: PGI) 26 cows were injected with a single 25 mg dose ofPGF2? and 10 cows with two 25 mg doses of PGF2? at a 14-day interval. Protocol 2consisted of two treatments: NG14) 11 cows were implanted with 3 mg of Norgestometon day 7 of their estrous cycle and NG7) 11 animals received the same dose on day 14.In protocol 3 all cows were implanted with 3 mg of Norgestomet for 9 days, 48 h beforeremoving the implant, 25 mg of PGF2? was applied. Once the implants were removed,they were distributed into two treatments. Norgestomet (n = 11) without eCG andNorgestomet + eCG (500 IU) (n = 11). Results: The application of PGF2? at two times had no influence (p > 0.05) in theestrous percentages and conception. The NG7 achieved estrous synchronization in 81.8% of the cows, in between 24 and 36 h, compared to 45.4 % of the NG14; however, theconception rate was lower (p ? 0.05). The eCG application synchronized 90.9 % ofestrous between 24 and 36 h, compared with 36.4 % of the group with no eCGapplication.Study limitations / implications: Transrectal ultrasounds are required to assess theovarian structures present at the time of the estrus onset in a synchronization protocol.Findings / conclusions: Cows that present corpus luteum do not require more thanone injection of PGF2?, the pregnancy percentage increases when Norgestomet isimplanted on day 14 of the estrous cycle, in addition the application of eCG increasesthe synchronization percentage of the heat between 24 to 36 h after the progestogenwithdrawal

Productive Performance of Alfalfa (Medicago sativa L.) at Different Age of Resprout in the Spring Season

The objective was to determine the growth and productive behavior curves, to obtain the optimal cutting momento in alfalfa, depending on the grwth age, in the spring season. The treatments were cuts at different age of the plant and the variables evaluated: Dry Matter Yield (DMY) Botanical and Morphological composition (CBM), Plant Height (PH), Ration: Leaf/Stem (R:L/S)and Intercepted Radiation (IR). The stastical analysis was with the PROC GLM procedure, of the SAS and the adjustedcurves were obtained with the Curve Expert Professional 2.0 program. There was an increase in the DMY, leaf, stem, PH, and IR, as the regrowth age advanced, but not, the R:L/S had an inverse behavior. In week seven the máximum DMY was obtained (4,768 kg DM ha-1). There was a greater amount of leaf with an average 52 %, followed by the steam (36 %), weeds (7 %), dead material (4 %) and inflorescence (1%). The PH was higher in week seven with 53 cm. Likewise, the highest IR in week tree with 86 %. However, the R:L/S was higher in week one with 2,4. The RI and R:L/S presented the lowest R2 (0.90 and 0.93, respectively). In contrast, DMY and PH presented a positive relationship (R2 of 0.98 and 0.97, respectively). The productive performance of Premium variety alfalfa was variable depending on the regrowth age, in wich the botanical and morphological characteristics changed, with better characteristics in the fifth week.Objective: To determine the growth and productive performance curves, to obtain the optimal cutting moment in alfalfa, depending on the age of resprouting, in the Spring season.Design/Methodology/Approach: The treatments were cuts at different age of the plant and the variables evaluated: Dry Matter Yield (DMY) Botanical and Morphological composition (BMC), Plant Height (PH), Leaf/Stem Ratio (L/SR), and Intercepted Radiation (IR). The stastical analysis was with the PROC GLM procedure, of the SAS software, and the adjustedcurves were obtained with the Curve Expert Professional 2.0 software.Results: There was an increase in the DMY, leaf, stem, PH, and IR, as the resprouting age advanced, but not, the L/SR which had an inverse behavior. The maximum DMY was obtained (4,768 kg DM ha-1) in week seven. There was a greater amount of leaf with average 52%, followed by the stem (36%), weeds (7%), detritus (4%) and inflorescence (1%). The PH washigher in week seven with 53 cm. Likewise, the highest IR in week tree with 86%. However, the L/SR was higher in week one with 2.4. The IR and L/SR presented the lowest R2 (0.90 and 0.93, respectively). In contrast, DMY and PH presented apositive relationship (R2 of 0.98 and 0.97, respectively).Study Limitations/Implications: There were no limitationsFindings/Conclusions: The productive performance of Premium variety alfalfa was variable depending on the resprouting age, in which the botanical and morphological characteristics changed, with better characteristics in the fifth wee

Yield estimation of forage oat (Avena sativa L.) Chihuahua variety: ruler and plate methods

Objetive: To analyze forage estimations with the direct method and the plant height. Diseño/Metodología/Aproximación: The treatments were the plants age, assessed in a random block design, with three repetitions. Simple linear regressions were carried out and adjusted using the SPSS statistical software. Resultados: The highest and lowest yields occurred at 105 and 30 days after sowing (DAS), with 5,412 and 783 kg DM ha-1, respectively. Height with the rule had a significant effect on forage production, with an R2 of 0.83. For each increase per cm the plants increased 56,134 kg DM ha-1. The height with the plate had an R2 of 0.97, so that 65.032 kg DM ha-1 are produced for each cm in height. Limitaciones del estudio/implicaciones: None Hallazgos/conclusiones: The forage accumulation in Avena sativa L., var. Chihuahua varied depending on the age of the plant. The heights calculated with the plate method, had greater reliability for the forage yield estimate, compared to the graduated rule method

Dry matter distribution of banderita grass [Bouteloua curtipendula (Michx.) Torr.] at different plant strata

Objective: To evaluate the dry matter distribution of banderita grass [Bouteloua curtipendula (Michx.) Torr.] in different plant strata. Design/Methodology/Approach: A randomized block experimental design with five repetitions was used for the experiment. Each repetition consisted of three plants which were evaluated at different days after sowing (DAS), in three different plant strata: basal stratum (BS), middle stratum (MS), and upper or apical stratum (AS). The following variables were evaluated: dry matter yield (DMY), morphological composition (MC), leaf area (LA), plant height (PH), leaf:stem ratio (L:SR), and aerial part:root ratio (Ap:rR). An analysis of variance was performed, using the PROC GLM procedure of the SAS software; in addition, a comparison of means was carried out using Tukey’s test (α<0.05). Results: SB made a greater contribution to DMY at 50 DAS, with a 16 g DMY plant-1 average, followed by MS, with 9 g DM plant-1, and AS with 3 g plant-1. The MC (g) in the BS registered that the stem made a greater contribution than the rest of the components (average: 12.3 g plant-1), while leaves from the MS and AS made the greatest contribution (2.6 g plant-1) up to 64 DAS. However, they were surpassed by the stem in the MS and by the inflorescence in the AS. In addition, BS registered the highest LA (173.4 cm2). The largest PH was recorded at 120 DAS (96 cm). The highest L:SR ratio reached 1.10 at 50 DAS, while Ap:rR recorded 3.82 at 92 DAS. Study Limitations/Implications: The experiment was carried out under greenhouse conditions. Therefore, any extrapolation or comparison with field conditions should be done with caution. Findings/Conclusions: The basal and middle part of a banderita grass (Bouteloua curtipendula) plant contains the highest forage accumulation (mainly in the leaves and the stem), while the highest biomass content in the apical part is produced by the inflorescence

Response of tomato varieties (Solanum lycopersicum L.) to water stress

Background and objectives: Water scarcity is limiting for tomato (Solanum lycopersicum L) production, because they are sensitive to water stress in the different phases of development, so irrigation should be done in an optimal way; because of this, the objective was to evaluate four varieties of tomatoes in four levels of irrigation in greenhouse plants. Methods: A completely randomized experimental design with factorial arrangement was used and various agronomic variables, fruit quality and biomass were measured as response variables. Key results: Tomatoes were significantly affected (P ? 0.05) by variety (V), irrigation (R) factors and their interaction. 100% of P variety presented fruits of greater weight (122 g); while, reducing water up to 25%, weight was reduced to 84, 90, 34 and 18 g in cid, P, E and C, varieties respectively. However, in terms of yield and leaf area, 100% of the Cid variety presented the highest values, around 3.3 kg / plant and 8.6 m-2. Conclusions: Variety c was tolerant to water stress and also does not present blossom end rot (calcium deficiency) in the fruit.Background and Objectives: Water scarcity is limiting for tomato (Solanum lycopersicum L) production, due to its sensitive to drought in the different phases of development, so irrigation should be done in an optimal way; because of this, the objective was to evaluate four levels of irrigation in greenhouse tomato varieties. Methods: A completely randomized experimental design with factorial arrangement was used and various agronomic variables, fruit quality and biomass were measured as response variables. Results: Tomatoes were significantly affected (P?0.05) by variety factors (V), irrigation (R), and their interaction. 100% of variety P presented fruits of greater weight (122 g); while weight decreased to 84, 90, 34 and 18 g when reducing water up to 25%, in varieties Cid, P, E and C, respectively. However, in terms of yield and leaf area, 100% of the Cid variety presented the highest values, around 3.3 kg/plant and 8.6 m-2. Conclusions: Variety c was tolerant to water stress and also does not present apical rotting (calcium deficiency) in the fruit

Forage and vegetal characterization of three native mexican grasses in Tulancingo de Bravo, Hidalgo

Objective: To carry out an agronomical assessment and a quantitative description of the yield components of switchgrass (Panicum virgatum), eastern gamagrass (Tripsacum dactyloides), and alkali sacaton (Sporobolus airoides) under rainfed conditions in Tulancingo, Hidalgo, Mexico. Design/Methodology/Approach: A completely randomized block design was used in 31-month-old pastures to determine forage production, morphological composition, seed yield, and weight of 1,000 caryopses. The plants were characterized in 7-month-old pastures, recording (per plant) the number of total and floral stems, as well as the basal twigs in alkali sacaton and switchgrass. Meanwhile, in the case of eastern gamagrass, the dome number and androecium sections were recorded. Results: The highest forage dry matter production was observed in switchgrass: 9,322 kg ha-1 (P < 0.05). Eastern gamagrass had a higher leaf ratio (1:3). The highest number of seeds was recorded in alkali sacaton: 211 kg ha-1, with 43% physical purity. After 7 months of sowing, a total of 250, 355, and 280 stems and 193, 150, and 87 floral stems were recorded in switchgrass, alkali sacaton, and eastern gamagrass, respectively. Study Limitations/Implications: Eastern gamagrass produces a low number of seeds; therefore, it must be propagated by plant material. In rainfed soils, grasses help to recover pasture areas, since rainfed agriculture poses a risk in many places as a result of poor rainfall distribution or early frosts. Findings/Conclusions: The three grasses studied are productive due to the amount of forage accumulated. Alkali sacaton produces more seeds

Scarification treatments in chepil seeds (Crotalaria longirostrata Hook. & Arn.) used to improve their germination

Objective: The objective was to evaluate different treatments of scarification to improve the germination, in seeds of chepil (Crotalaria longirostrata Hook. & Arn.). Design / Methodology / Approach:  The research was established at the Faculty of Veterinary Medicine and Animal Husbandry No. 2 of the Autonomous University of Guerrero. The chepil seeds were weighed and counted; Using a DCA, 2 experiments were established with 4 treatments of 4 repetitions each. Imbibition and germination were evaluated. The data was analyzed using a SAS® 9.0 statistical package. Results: The use of water at different temperatures and times presented positive results in imbibition and increased germination percentages; because when using water at 100 °C until cooling, the germination was 80 % and the control it barely reached 12.3 %. Study limitations / implications: Chepil is a wild species that has seeds with physical dormancy, which requires further research to accelerate and increase germination rates. Findings / conclusions:  The imbibition and germination was affected by the applied treatments. The seeds are chepil present physical or superficial dormancy that can be eliminated with the use of heat treatments; however, evaluations are needed to accelerate and find a higher percentage of germination.Objective: The objective was to evaluate different scarification treatments to improvegermination in chepil seeds (Crotalaria longirostrata Hook. & Arn.).Design/Methodology/Approach: The study was established in the School of VeterinaryMedicine and Zootechnics N. 2 of the Universidad Autónoma de Guerrero. The chepilseeds were weighed and counted; 2 experiments were established through a CRD with4 treatments of 4 repetitions each. Imbibition and germination were evaluated. The datawere analyzed with the statistical software package SAS® 9.0.Results: The use of water at different temperatures and times presented positive resultsin imbibition and increased the germination percentages. The treatment with water at100°C until cooling reached a germination of 80%, and the control of 12.3%. Study Limitations/Implications: Chepil is a wild species that has seeds with physicaldormancy, which is something that requires more research in order to accelerate andincrease the germination percentages.Findings/Conclusions: The imbibition and germination was affected by the treatmentsapplied. Chepil seeds presented physical or superficial dormancy that may be eliminatedwith the use of heat treatments; however, evaluations still need to be performed toaccelerate and find a higher percentage of germination

Rendimiento de trébol rojo (Trifolium pratense L.) a diferente edad de cosecha

Objective: The objective of this research was to obtain the optimum cutting moment of the red clover by varying the cutting frequency in the spring season. Design/methodology/approach: The treatments were cuts at different ages (eight weeks) in the spring season. The variables studied were: forage accumulation, botanical and morphological composition, foliar area per stem and photosynthesis. The statistical analysis of the data obtained was performed with the GLM procedure of the SAS statistical package. The results obtained in yield of dry matter showed an increase as the age of regrowth advanced, in week 8, 5013 kg MS ha-1 total were obtained, resulting in the maximum value registered. There was a direct positive relationship between the mass of green leaves, rate of photosynthesis, leaf area per stem and leaf: stem ratio, with the best values ??recorded at the fourth week of regrowth. The morphological component that contributes most to forage yield was the stem with an average of 55% in all the weeks except the fourth. Limitations on study/implications: After the fourth week the unwanted structural characteristics increase. Findings/conclusions: It is concluded that the yield increases as the evaluation time passes and it is recommended to harvest the red clover in the fourth week of regrowth.Objetivo: El objetivo de esta investigación fue obtener el momento óptimo de corte del trébol rojo variando la frecuencia de corte en la estación de primavera. Diseño/metodología/aproximación: Los tratamientos fueron los cortes a diferente edad (ocho semanas) en la estación primavera. Las variables estudiadas fueron: acumulación de forraje, composición botánica y morfológica, área foliar por tallo y fotosíntesis. El análisis estadístico de los datos obtenidos se realizó con el procedimiento GLM del paquete estadístico SAS. Resultados: Los resultados obtenidos en rendimiento de materia seca mostraron un aumento conforme avanzo la edad de rebrote, en la semana 8 se obtuvieron 5,013 kg MS ha-1 total que resulto el máximo valor registrado. Existió una relación positiva directa entre la masa de hojas verdes, tasa de fotosíntesis, área foliar por tallo y relación hoja:tallo, registrándose los mejores valores a la cuarta semana de rebrote. El componente morfológico que más contribuye al rendimiento de forraje fue el tallo con un promedio de 55 % en todas las semanas excepto la cuarta. Limitaciones del estudio/implicaciones: Después de la cuarta semana aumentan características estructurales no deseadas. Hallazgos/conclusiones: Se concluye que el rendimiento se incrementa conforme pasa el tiempo de evaluación y se recomienda cosechar el trébol rojo en la cuarta semana de rebrote

Evaluación cuantitativa de diez variedades de alfalfa (Medicago sativa L.).

En México, la alfalfa es la leguminosa más utilizada en la alimentación del ganado lechero, debido a su alto rendimiento y valor nutritivo. El objetivo del presente estudio fue evaluar las variables que determinan el crecimiento y rendimiento de diez variedades de alfalfa a intervalos de corte definidos estacionalmente. El estudio se realizó de septiembre de 2011 a septiembre de 2012 en el Colegio de Postgraduados, Campus Montecillo, Texcoco, México. Las variedades de alfalfa estudiadas fueron: Vía Láctea, Chipilo, Atlixco, Oaxaca, San Miguelito, Cuf-101, Milenia, Aragón, Valenciana y Júpiter, distribuidas aleatoriamente en un diseño experimental completamente al azar con cuatro repeticiones. El mayor rendimiento (14,510 kg MS ha-1), tasa de crecimiento anual (40 kg MS ha-1 d-1), radiación interceptada (43%), índice de área foliar (3.2), relación hoja:tallo (1.8), densidad de plantas (19 plantas por m2), densidad de tallos (578 tallos m2) y peso por tallo (0.45 g), lo registró la variedad Júpiter (P<0.05), mientras que el menor rendimiento (7,890 kg MS ha-1), índice de área foliar (1.2), densidad de tallos (282 tallos m-2), lo presentó la variedad San Miguelito (P<0.05). La menor tasa de crecimiento la presentaron las variedades San Miguelito, Cuf-101 y Valenciana con 22 kg MS ha-1 d-1 (P<0.05), en tanto que Cuf-101 y San Miguelito registraron la menor radiación interceptada con 27% (P<0.05). La variedad Valenciana mostró la menor densidad de plantas con 8 plantas m-2 (P<0.05). El menor peso por tallo lo registró la variedad Cuf-101 con 0.31 g. La mayor altura la presentó la variedad Vía Láctea (35 cm) y la menor las variedades Cuf-101 y Valenciana con 29 cm (P<0.05). En conclusión debido a sus atributos cuantitativos la mejor la variedad fue Júpiter. _______________ QUANTITATIVE EVALUATION OF TEN ALFALFA VARIETIES (Medicago sativa L.). ABSTRACT: In Mexico, alfalfa is the legume most used to feed dairy cattle, due to its high herbage yield and nutritional value. The aim of this study was to evaluate the different variables that determining plant growth and herbage yield of ten alfalfa varieties cut at specific intervals defined according to the year season. The study was carried out from September 2011 to September 2012 at the experimental field in the Colegio de Postgraduados Campus Montecillo, Texcoco, Edo. de México. The evaluated alfalfa varieties were: Vía Láctea, Chipilo, Atlixco, Oaxaca, San Miguelito, Cuf-101, Milenia, Aragón, Valenciana, and Júpiter. The experimental design was a complete randomized deseing with four replicates. The highest herbage yield (14,510 kg DM ha-1), annual growth rate (40 kg DM ha-1 d-1), intercepted radiation (43%), leaf area index (3.2), leaf:stem ratio (1.8), plant density (19 plants m-2), tiller density (578 tillers m-2), and tiller weight (0.45 g) were observed in the Júpiter variety (P<0.05), whiles the lowest herbage yield (7890 kg DM ha-1), leaf area index (1.2), tiller density (282 tiller m-2), were observed in San Miguelito variety (P<0.05). The lowest annual growth rate was observed in Cuf-101, San Miguelito, and Valenciana varieties with 22 kg DM ha-1 d-1 (P<0.05), whiles Cuf-101 and San Miguelito varieties showed the lowest radiation intercepted with 27% (P<0.05). Valenciana variety showed the lowest average plant density with 8 plantas m-2 (P<0.05). The lowest tiller weight was observed in Cuf-101 variety with 0.31 g (P<0.05). Vía Láctea had the highest height (35 cm) whiles Cuf-101 and Valenciana had the lowest value with 29 cm (P<0.05). In conclusion, due to its good quantitative attributes and highest herbage yield the best variety was Jupite.Tesis (Maestría en Ciencias, especialista en Ganadería).- Colegio de Postgraduados, 2013.Consejo Nacional de Ciencia y Tecnología (CONACYT)