Reproductive characterization of hair ewe in the American tropics: a review part 1

Objective: to make a reproductive characterization of the hair sheep breeds in the American tropics. Design/methodology/approach: reproductive variables information was collected from scientific search engines, such as Web of Science, Redalyc, Dialnet, PubMed, SciELO and Latindex. Results: the age of puberty in ewe lambs is highly variable. Similar results were found in adult ewes regarding estrus duration and incidence, estrous cycle length, seasonal anestrus, ovulation rate, fertility, gestation, and prolificacy. Limitations on study/implications: information on reproductive variables of hair sheep breeds is poorly known or non-existent. Findings/conclusions: puberty onset in ewe lambs ranges from 175 to 335 d of age when animals weight 15 to 43 kg. The length of the estrous cycle of hair sheep in Mexico is 17 d during the autumn-winter and 21 d in spring-summer. In Brazil, it lasts 17 d in spring-summer and 18 d in autumn-winter. In the United States of America and Venezuela, the estrous cycle length was similar in both periods of the year. The estrous occurrence was 97.1% in autumn-winter and 76.5 % in spring-summer. The estrous duration ranges from 16 to 52 hours. Seasonal anestrous occurs from May to July. The ovulation rate ranges from 1 to 3 oocytes. Fertility is 80 to 100 % in temperate and 37 % in warm months. Gestation length ranges from 144 to 152 d. Prolificacy ranges from 1.0 to 2.2 offspring per ewe. The lambing interval range from 244 to 294 d.Objective: To carry out a reproductive characterization of the breeds of hair ewe in the tropical region of the Americas. Design/Methodology/Approach: A search of scientific information about the reproductive variables of breeds of hair ewe was carried out and the results were analyzed in the Web of Science, Redalyc, Dialnet, PubMed, SciELO, and Latindex databases. Results: We described and discussed the highly-variable onset of puberty in ewe lambs. Similar results were found in adult ewes regarding the duration and occurrence of the estrous, estrous cycle length, seasonal anestrous, ovulation rate, fertility, gestation, and prolificacy. Study Limitations/Implications: Information about the reproductive variables of breeds of hair ewe is poorly known or non-existent. Findings/Conclusions: The onset of puberty in 15-43 kg ewe lambs ranges from 175 to 335 d of age. The estrous cycle of hair ewe in Mexico lasts 17 d in autumn-winter and 21 d in spring-summer. In Brazil, this cycle lasts 17 d in spring-summer and 18 d in autumn-winter. In the United States of America and Venezuela, the estrous cycle length was similar in both periods of the year. The occurrence of the estrous reached 97.1 % in autumn-winter and 76.5 % in spring-summer. The duration of the estrous ranges from 16 to 52 hours. Seasonal anestrous occurs from May to July. The ovulation rate ranges from 1 to 3 oocytes. The percentage of fertility fluctuates between 80 and 100 % in temperate months and reaches 37 % in warm ones. Gestation lasts from 144 to 152 d. Prolificacy ranges from 1.0 to 2.2 offspring per ewe. The lambing interval ranges from 244 to 294 d

Comparação de pH e matéria seca em três processos de silagem com forragem de gergelim (Sesamum indicum) nos trópicos secos.

El objetivo de este estudio fue comparar el pH y la materia seca (MS) en tres procesos de ensilaje con planta de ajonjolí en climas secos. Los experimentos se realizaron en la Facultad de Medicina Veterinaria y Zootecnia No. 1 de la Universidad Autónoma de Guerrero. En el experimento 1, se ensiló forraje de maíz combinado con forraje de ajonjolí (T1: 100:00, T2: 75:25, T3: 50:50, T4: 25:75 y T5: 00:100% respectivamente). En el experimento 2 se ensiló forraje de ajonjolí mezclado con melaza (T1:0, T2:4, T3:8 y T4:12% respectivamente) En el experimento 3 se ensiló planta de ajonjolí sola (T1), con melaza 8% (T2), planta presecada sola (T3) y planta presecada con melaza 8% (T4). Se realizaron síes microsilos por tratamiento (6 réplicas). Los diseños experimentales fueron completamente al azar. En el experimento 1, el pH más bajo fue para el T1 con un valor de 3.83, en el experimento 2 fue para el T4 con un valor de 3.94 y en el experimento 3 fue para el T2 con un valor de 4.00. Para la MS, el contenido fue mayor para el T1 con 28.55%, en el experimento 2 fue para el T4 con 27.63% y en el experimento 3 fue para el T3 con 36.00%. Todos los experimentos mostraron diferencia estadística (p< 0.0001) entre tratamientos. Sin embargo, los valores para pH y MS son aceptables para prácticamente todos los tratamientos, en acuerdo con otras investigaciones. Por lo tanto, se concluye que al ensilar forraje de ajonjolí mezclado con forraje de maíz, melaza o planta presercada se logra mejorar la fermentación ácida y se incrementa el contenido de materia seca. Sin embargo, es necesario realizar evaluaciones posteriores de las propiedades físico-químicas y determinar su valor nutritivo.The objective of this study was to compare the pH and dry matter (DM) in three silage processes with sesame plants in dry climates. The experiments were carried out at the Faculty of Veterinary Medicine and Zootechnics No. 1 of the Autonomous University of Guerrero. In experiment 1, corn forage combined with sesame forage was ensiled (T1: 100:00, T2: 75:25, T3: 50:50, T4: 25:75 and T5: 00:100% respectively). In experiment 2 sesame forage mixed with molasses (T1:0, T2:4, T3:8 and T4:12% respectively) was ensiled. In experiment 3 sesame plant alone (T1) was ensiled with 8% molasses ( T2), pre-dried plant alone (T3) and pre-dried plant with 8% molasses (T4). Six microsilos per treatment (6 replicates) were made. The experimental designs were completely randomized. In experiment 1, the lowest pH was for T1 with a value of 3.83, in experiment 2 it was for T4 with a value of 3.94 and in experiment 3 it was for T2 with a value of 4.00. For DM, the content was higher for T1 with 28.55%, in experiment 2 it was for T4 with 27.63% and in experiment 3 it was for T3 with 36.00%. All the experiments showed statistical difference (p< 0.0001) between treatments. However, the values for pH and DM are acceptable for practically all treatments, in agreement with other investigations. Therefore, it is concluded that ensiling sesame forage mixed with corn forage, molasses or presercated plant improves acid fermentation and increases the dry matter content. However, it is necessary to carry out further evaluations of the physical-chemical properties and determine its nutritive value.O objetivo deste estudo foi comparar o pH e a matéria seca (MS) em três processos de silagem com plantas de gergelim em climas secos. Os experimentos foram realizados na Faculdade de Medicina Veterinária e Zootecnia nº 1 da Universidade Autônoma de Guerrero. No experimento 1, a forragem de milho combinada com a forragem de gergelim foi ensilada (T1: 100:00, T2: 75:25, T3: 50:50, T4: 25:75 e T5: 00:100% respectivamente). No experimento 2 a forragem de gergelim foi ensilada misturada com melaço (T1:0, T2:4, T3:8 e T4:12% respectivamente) - planta seca sozinha (T3) e planta pré-seca com 8% de melaço (T4). Seis microsilos por tratamento (6 réplicas) foram feitos. Os delineamentos experimentais foram inteiramente casualizados. No experimento 1, o menor pH foi para T1 com valor de 3,83, no experimento 2 foi para T4 com valor de 3,94 e no experimento 3 foi para T2 com valor de 4,00. Para MS o teor foi maior para T1 com 28,55%, no experimento 2 foi para T4 com 27,63% e no experimento 3 foi para T3 com 36,00%. Todos os experimentos apresentaram diferença estatística (p< 0,0001) entre os tratamentos. No entanto, os valores de pH e MS são aceitáveis ​​para praticamente todos os tratamentos, concordando com outras investigações. Portanto, conclui-se que a ensilagem de forragem de gergelim misturada com forragem de milho, melaço ou planta preservada melhora a fermentação ácida e aumenta o teor de matéria seca. No entanto, é necessário realizar mais avaliações das propriedades físico-químicas e determinar seu valor nutritivo