Objective. Aimed to describe the characteristics of the onset of puberty in males in Colombian hair ram lambs (Ovino de Pelo Colombiano, OPC), and their crosses with Katahdin and Santa Inés sheep in a farm located in Villavicencio, Meta. Materials and methods. 15 lambs of three biotypes: OPC x OPC, Santa Ines x OPC (SO) and Katahdin X OPC (KO) from four months of age, five per group. Ram lambs were grazing and they had supplementation with commercial salt and water ad libitum. Monthly body weight, testicular measurement, scrotal circumference (CE) were measured and serum testosterone were determined by Elisa test, an ultrasound of the two testicles was performed to determine the presence of the testicular mediastinum, also evaluating the presence and detachment of the urethral prolongation and then electro ejaculation was performed to determine the macroscopic and microscopic characteristics of the semen. Results. Genotype effect was significant for evolution of body development (BW, SC, TV) over time, Santa Ines and Katahdin crosses presented the highest values in BW during the investigation whereas OPC lambs maintained a lower value until the end of the trial. At least four evaluations were made in the males or until the presentation of a minimum concentration of 150 million of sperm per ml with 30% of individual progressive motility. Conclusions.Around six months old is the puberty onset for ram lambs under tropical conditions, in a non-seasonal country, based on a diversity of variables including body development, semen quality, and testosterone levels among others.
RESUMENPara caracterizar la raza Normando en Colombia se utilizó el análisis multivariado que permitió la identificación de 4 grupos dentro de la raza a partir de 1186 datos de hembras registradas. El grupo minoritario fue el número 1 (8,2 % de la población muestreada), mientras el grupo mayoritario fue el 3 (53,0 % de la población). Destaca el grupo 2 con vacas con lactancias ajustadas promedio de 5608,4 kg y con intervalo entre partos (IEP) de 433,4 días y edad al primer servicio de 28 meses. El 80,6 % de los animales pertenecientes a este grupo se encontraron en sistemas productivos intensivos suplementados. En el grupo 3, se encuentran animales con lactancias ajustadas de 3317,9 kg, y los mejores parámetros reproductivos: IEP de 399,2 días, y edad al primer servicio de 25,7 meses. El 48,3 % de las vacas pertenecientes a este conglomerado se encuentran en sistemas productivos extensivos mejorados, y el 49,9 % en sistemas intensivos suplementados. El sistema predominante de ordeño para este grupo es el doble de tipo manual al cual pertenece el 71,9 % de la población. SUMMARYTo characterize the Normando breed in Colombia, the multivariate analysis on 1186 data allowed the identification of four groups within the breed. The minority group was the number 1 (8.2 % of the sampled population), while the larger is group 3 (53.0 % of the population). Adjusted lactation of cows in group 2 averaged 5608.4 kg and reproductive parameters as calving interval (433.4 days) and age at first service (28 months); 80.6 % of animals in this group are under intensive supplemented production systems. In group 3, adjusted lactation was 3317.9 kg, and it had the best reproductive parameters, such as 399.2 days calving interval, and 25.7 months of average age at first service; 48.3 % of the cows belonging to this cluster are under improved extensive production systems, and 49.9 % under intensive systems with supplements. The prevailing (71.9 % of the population) milking system in this group is manual and twice per day. INTRODUCCIONSe entiende como caracterización, a la descripción de las características y las interrelaciones de una organización (Bolaños, 1999), mientras la tipificación está relacionada con la construcción de grupos cuya base son las características observadas en la realidad. Un análisis multivariado permite manejar una gran cantidad de variables e incluir características cuantitativas y cualitativas (Pardos et al., 1999), analizando las variaciones presentes en un conjunto de
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.