Characterization of the onset of puberty in Tazegzawt lambs, an endangered Algerian sheep: Body weight, thoracic perimeter, testicular growth, and seminal parameters (original) (raw)
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Sexual Activity and Puberty in the Male Redkaraman and Tushin (Turkish native) Lamb
Journal of Applied Animal Research, 2005
Sexual activity in the prepubertal period (120-300 days of age) and body weight, scrotal circumference and testosterone levels at puberty were studied in 10 Tushin and 8 Redkaraman male lambs. Sexual responses developed earlier [P<O.Ol) in Redharainan than in Tushin ram lambs. Same was the case for age at puberty. There was no significant breed difference in body weight, scrotal circumference and testosterone levels at puberty. Scrota1 circumference and body weight at puberty were correlated (P<O.Ol) with each other (r = 0.68). It is concluded that body weight and not the age determines onset of puberty.
South African Journal of Animal Science, 2007
The study was conducted to measure the development of several testicular characteristics and to investigate the relationship between testicular parameters with body growth, semen characteristics and serum testosterone levels in growing ram lambs. Seventeen single born Kivircik ram lambs from three to four year old ewes were used. When the rams were two months old measurements of the length, diameter and circumference of their testes and body weights started, and blood samples were collected at 20-day intervals for the next 12 months. From seven to 14 months of age semen was collected at monthly intervals. There was a gradual and linear increase in testicular dimensions from two to 11 months of age. A rapid increase in all testicular dimensions was observed between 140 to 160 days of age. All measurements of testes, live weight, age and serum testosterone concentrations were positively and significantly correlated with each other. While a significant positive correlation was found at seven and eight months of age between all testicular measurements and semen volume and motility, no such correlations were observed between nine and 14 months of age. From seven to 14 months of age no correlation was measured between serum testosterone concentrations and spermatological characteristics. These results demonstrated that testicular measurements, especially scrotal circumference, can be used as criteria for early selection of ram lambs to be used in breeding at relatively young ages.
Czech Journal of Animal Science, 2005
Forty-seven Kivircik ram lambs, aged 2 months, raised and managed under an intensive system were used to measure the development of testis diameter and length, and scrotum circumference, length and volume, and their association with the development of body growth. The effects of age and body weight of lambs, type of birth and dam age on the development of the five testicular parameters from weaning at 2-6 months of age were investigated. In ram lambs, the respective least-squares means of testis measurements: testis diameter,
Postnatal testicular development and testosterone changes in Ghezel ram lambs
This study was conducted to investigate the histological structure of testis and hormonal changes during prepubertal Ghezel ram lambs. Histometrical evaluation of the testis was performed in 36 Ghezel lambs from one to 9 months of age. Lambs were allotted into nine groups, and surgically castrated each month from 1 to 9 months of age (n = 4 lambs per group). In addition, blood samples were taken from six animals from 1 month of age to adulthood to measure plasma levels of testosterone. With the age held constant, scrotal circumference and body weight were correlated (r = 0.960, P < 0.01). The sex cords did not have lumen up to the age of 4 months and lumenization process was completed after 8 months of age. A dramatic increase in spermatogonia cells per cross-section of seminiferous tubule was observed from 3 to 5 months of age; their number per tubule cross-section stabilized after 8 months. Spermatogenesis started when the spermatocyte cells were observed at the 4th month, and established at 8 months of age (body weight = 42.39 kg, scrotal circumference = 25.8 cm). Onset of puberty was observed to be established at 8 months of age when spermatozoa, adhered to the adluminal border of the Sertoli cells as well as in the tubular lumen. Leydig cells were visible in 4-month-old lambs. During the 5 months after birth, Leydig cell number showed a similar pattern as that observed for testosterone plasma levels. At 8–9 months of age the testosterone plasma level reached up to 2 ng/ml which contributed to the increase in testicular testosterone secreting capacity of the mature adult Leydig cells, with the accomplishment of this transition, sexual puberty is completed. It can be concluded that establishment of spermatogenesis begins a long time before puberty in 8 month-old Ghezel lambs.
Biometry and Testicular Growth Influenced by Nutrition on Prepubertal Pelibuey Lambs
The growth and testicular development was studied in 48 Pelibuey male lambs 76.6±3.0 days of age and 12.7±1.9 kg body weight (BW), two groups were designed (n=24). 1: Intensive rotational grassing (IRG), 2: Intensive rotational grassing plus nutritional supplement (IRGS). BW was recorded every 15 days from 75 days of age to the onset of puberty. The animals grazed on Panicum maximum. IRGS received a concentrate with 15% of protein. The testicular biometry included scrotal circumference (SC) and testicular volume (TV). Blood samples were collected each 15 days from 90 to 190 days of age for evaluate the testosterone concentrations. BW, SC and TV at histological puberty was higher in IRGS than IRG; 22.5±1.5 vs. 16.06±1.5 kg, 22.0±1.0 vs. 12.2±1.5 cm, 60.5±1.7 vs. 12±3.5 cm 3 respectively (P<0.05) with an average age for the two groups of 162±7.0 days. The correlation coefficient (R) was higher (P<0.05) for SC vs BW than age vs BW (0.884 vs 0.816) and the TV vs. BW than TV vs. age (0.849 vs. 0.777) in the IRGS; the IRG showed lower R for the same comparisons (P<0.05). Seminiferous tubules showed lumen by day 142, spermatids and spermatozoids by day 171 for IRGS, meanwhile in the IRG only showed gonocytes and Sertoli cells. Testosterone concentrations reached a peak (2.5 ng/ml) at 168 days of age for the IRGS meanwhile the IRG showed lower levels than 0.05 ng/ml. Testicular development and testosterone concentrations depends more on BW than age; and they are modified by the nutritional management in prepuberal male lambs.
Animal Reproduction
Thirty healthy Sohagi ram lambs with an average age of 188.6±7.3 days were used to study the effect of pre-pubertal growth rate on some physiological parameters and sexual behavioral patterns at puberty. Ram lambs were divided into three groups (10 animals per each group) according to the previous growth rate until 6 months of age. Groups were marked as fast, medium and slow growing. Animal groups were housed in closed barns with access to an open area. Results showed that age and weight of ram lambs at puberty were significantly affected (P<0.05) by the pre-pubertal growth rate. Ram lambs in the fast growing group were reached to onset puberty firstly at 272.6 days with body weight (BW) 37.1 kg on average then ram lambs in medium group (284.8 days with BW 32.7 kg), while ram lambs in slow growing group were the last (314.1 days with BW 32.5 kg). Blood testosterone concentration at puberty was not significantly different among growing groups (1.494± 0.03 ng/ml on average, ranged from 1.287 to 1.902 ng/ml). Testes measurements from 6 months of age until puberty show that ram lambs in fast growing group had the highest values of testes length, circumference and volume followed by those in medium and slow growing group. Sexual behavioral observation showed that flehmen and mounting behavior were significantly higher for ram lambs in fast growing group (5.63 and 6.75 number/12h) than slow growing group (4.25 and 5.38 number/12h) while in medium growing group were intermediate (4.88 and 5.88 number/12h). From these findings, could be concluded that age, weight and sexual behavioral patterns of Sohagi ram lambs at puberty were affected by pre-pubertal growth rate, and the breeders should strive to achieve good growth rates for their lambs before puberty which led to improving reproductive performance.
Small Ruminant Research, 2001
Ninety-six Awassi ram lambs, aged 2±3 months, raised and managed under a semi intensive system were used to measure development of testicular length, width, circumference and volume, and their association with development of body growth. The effects of parental size, age and body weight of lambs, production line (dairy or meat), type of birth and weight at birth and weaning on development of the four testicular parameters from weaning at 2±17 months of age were investigated. No signi®cant differences were observed between measurements of the left and right testis. The highest increase in testicular parameters occurred between 7 and 10 months of age at 34.6 kg live body weight. Only parental size, age and body weight affected testicular growth (P`0X05). Measurements of testes were correlated (P`0X01) with each other (r 0X68±0.97). They increased progressively and were correlated with body weight more than with age.
TURKISH JOURNAL OF VETERINARY AND ANIMAL SCIENCES, 2016
The aim of this study was to investigate changes of serum testosterone, scrotal circumference, body weight, and semen characteristics in a Meat Institute Sheep (MIS) population during their developing period (between 3 and 17 months). Correlative relationships among parameters were also tested. Body weight and scrotal circumference were measured monthly, blood samples for testosterone levels were taken bimonthly (3-17 months), and semen samples were collected by an electroejaculator between the ages of 9 and 17 months. The analysis showed that the average serum testosterone levels ranged from 1.83 to 13.28 ng/mL and significantly depended on the age of the lambs (P < 0.05). The trend in the level of serum testosterone was characterized by pronounced variability throughout the study period. Changes in scrotal circumference and body weight were significantly dependent on age. Ejaculate volume, sperm motility, and the percentage of live spermatozoa increased with age, except for the percentage of abnormal spermatozoa, which decreased with age. Correlations among serum testosterone, scrotal circumference, and body weight were moderately to highly positive and highly significant. All parameters of semen quality were poorly correlated with testosterone and body weight, while scrotal circumference was in moderate correlation only with ejaculate volume and live sperm count (P < 0.05).
Journal MVZ Cordoba, 2019
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 (OPC), Santa Ines x OPC (SO) and Katahdin X OPC (KO) from four until 12 months old. Ram lambs were grazing and they had supplementation with commercial salt and water ad libitum. Monthly body weight (BW), scrotal circumference (SC), testicular volume (TV) were measured and testosterone level were determined by Elisa test, and 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 BW, SC, TV over time. The SO and KO crosses presented the highest values in BW, whereas OPC lambs maintained a lower value until the end of the assay. At six months old, the three biotypes presented a minimum concentration of 150 million of sperm per ml with 30% of individual progressive motility. Conclusions. In non-seasonal tropical conditions in Colombia (Orinoquia), depending on the variables included, body weight, testicular development, pennis morphology, semen quality, sperm concentration and testosterone levels, it is postulated that around six months of age, the onset of puberty is displayed in the three biotypes.
Appropriate growth model describing some testicular characteristics in Norduz male lambs
thejaps.org.pk
The objective of this study was to determine the appropriate non-linear function describing growth of some testicular traits (testicular length, testicular diameter, scrotal circumference and scrotal length) in Norduz male lambs. Testicular characteristics at 90, 110, 130, 150, 170, and 190 days of age for all the lambs were measured. Four growth (Monomolecular, Logistic, Gompertz, and Richard's) models were used to explain relationship between each testicular trait-age. Growth models were based on averages of measurements on their testicular traits in each period of all the male lambs. As a result, appropriate growth models explaining growth at early age of testicular length, testicular diameter, scrotal circumference and scrotal length in Norduz male lambs were Logistic and Richard's non-linear model. Also, age and body weight had significant effect on these testicular traits.