Investigation of serum testosterone level, scrotal circumference, body mass,semen characteristics, and their correlations in developing MIS lambs (original) (raw)
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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.
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.
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.
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.
Veterinary World, 2018
Aim: The aim of the present study was to define the onset of puberty in Tazegzawt ram lambs, an Algerian sheep breed in endangered status with a small population in its local area. Materials and Methods: Body growth (body weight and thoracic perimeter), scrotal circumference (SC), penis development stages, and seminal parameters (volume, concentration, and motility) were measured. Data were recorded at fortnightly intervals in 10 animals from 9 to 49 weeks of age. Results: On the basis of seminal analyses, puberty occurred between 29 and 45 weeks of age. At 29 weeks of age, 30% of lambs reached puberty, and at 45 weeks of age, puberty was observed in 100% of the analyzed animals. Body weight appeared as the most determinant factor, and the onset of puberty was observed when animals reached 43.2±6.4 kg body weight with 25.8±3.7 cm of SC. Seminal analyses revealed that all parameters increased regularly from puberty onset except for sperm concentration. The mean semen volume during the study period was 0.48±0.33 mL with 0.84±0.6 mL at 37 weeks of age. Sperm concentration evolved similarly as semen volume; at 29 and 43 weeks of age, the sperm concentration was 942×10 6 and 1904×10 6 spermatozoa/mL, respectively. Kinematic parameters including the percentage of motility, the percentage of progressive motility, and gametes velocities as determined by Computer-Aided Sperm Analyzer showed the highest values at 49 weeks of age. Conclusion: The current results revealed that, in Tazegzawt ram lambs, puberty occurs between 29 and 45 weeks when animals reach 43.2±4.6 kg body weight.
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,
Indian Journal of Animal Research
The present work was conducted to elucidate the relationships between chronological age, testosterone concentration and testis size of Najdi and Naemi ram lambs under desert conditions to determine the reproductive capacity of the above two breeds. The postnatal development of the seminiferous epithelium of the testes was also monitored. A total of 90 (45 Najdi and 45 Naemi lambs) aged between one and nine months, with five lambs at each month of age for each breed were used. The results showed that the testosterone concentration increased dramatically and rapidly between five and six months, followed by a period of gradual growth where testicular size was increased from 3 to 6 months of age. There was a significant (P > 0.05) difference in testosterone concentration (TC) and testis size (TS) in ram lambs between different age groups, similarly there were significant differences between body weights and lamb age between one and nine months. A positive correlation between the incr...
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.
Small Ruminant Research, 2001
The aim of the experiment was to determine whether supplementation of the lamb-ewe unit during intra-uterine and postnatal life affects testicular stereology, particularly Sertoli cell numbers, in 120 pregnant Corriedale ewes grazed either native pastures (control group) or improved pastures grain supplement (treated group). Ewes bearing single ram lambs were maintained under the same feeding regime until lambs were castrated (99 days of age). Body weight, testosterone and FSH blood serum levels were recorded at 45, 75 and 99 days of age. Body weight was higher (P`0X01) in the treated group from birth on. Serum testosterone values did not differ between groups. Serum FSH values tended to differ at 45 days of age (P`0X06). Testicular weight and testes histology showed earlier pubertal development and a tendency for higher Sertoli cell numbers in the treated (supplemented) group. This tendency may indicate that extensively reared lambs supplemented during fetal and postnatal life have higher testicular growth and sperm production in later life. #
Blood testosterone level and growth of castrated, uncastrated, and cryptorchid lambs
Semina-ciencias Agrarias, 2017
O estudo foi realizado com objetivo de avaliar os efeitos da condicao sexual nos niveis sanguineos de testosterona e sua influencia no crescimento de cordeiros. Foram utilizados 49 machos cruza Texel x Corriedale, oriundos de partos simples, divididos em tres grupos: nao castrados (n=16), castrados (n=17) e induzidos ao criptorquidismo (n=16), criados na regiao do Bioma Pampa, no Estado do Rio Grande do Sul, em condicoes extensivas de pastagem natural, com suplementacao alimentar apos o desmame. Foi utilizada a analise de variância para avaliar o efeito da condicao sexual. Cordeiros nao castrados e castrados apresentaram valores superiores de peso corporal entre o 35o e o 203o dia de idade, assim como no perimetro toracico e compacidade corporal. Cordeiros nao castrados foram superiores aos criptorquidas na media de peso no periodo total. Criptorquidas apresentaram ganho medio de peso superior aos castrados entre o 203o e 259o dias. Castrados apresentaram escore de condicao corporal...