Development of testicular dimensions and size, and their relationship to age and body weight in growing Kivircik (Western Thrace) ram lambs (original) (raw)
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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.
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.
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.
Developmental changes in testicular interstitium in the Najdi Ram Lambs
Saudi journal of biological sciences, 2014
This experiment was designed to study the relationship between growth rate and sexual development in Najdi ram lambs. Forty-five Najdi ram lambs were used in nine age groups (1-9th month age), keeping 5 lambs in each group. Results show that mean testis size and scrotal circumference increased at a constant rate, reaching a maximum value of 392.00 ± 2.00 g and 25.00 ± 0.32 cm respectively, at the age of 9 months. A similar trend of growth was observed for the mean body weight, reaching a maximum value of 40.2 ± 0.20 kg at the age of 9 months. There was a positive correlation between the increasing rates of body weight and size of the testis. There were significant differences (P < 0.05) in testis size, scrotal circumference and body weight of lambs between all ages (1-9 months). The histological section of testis showed that a small number of mature sperms appeared in the eighth month of age and their numbers increased in the ninth month. In conclusion, the current findings indic...
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.
Evaluation of mathematical models to describe testicular growth in Blackbelly ram lambs
The primary objective was to compare various mathematical models to describe scrotal circumference (SC) and paired testis volume development in Blackbelly ram lambs. The study was conducted in the state of Querétaro, México (20°43' N, 100°15' W). Spring-born Blackbelly ram lambs (n ϭ 41) were housed outdoors and fed alfalfa hay and concentrate. Body weight, SC, and testis length, diameter, and volume were recorded every 2 wk from 24 to 172 d of age (June 18 to November 3). The following mathematical functions were used to model SC-age and testis volume-age relationship: Von Bertalanffy, Brody, Gompertz, Logistic, and Richards. The suitability of the models was evaluated based on parameter values and standard errors, residual mean square, the coefficient of determination (R 2 ), and the average prediction error (APE). All models, except for Brody's, had good fit to SC (R 2 Ͼ 0.98) and testis volume (R 2 Ͼ 0.95), and produced similar growth curves in the range of ages studied. The logistic model predicted SC at maturity quite well, 33.6 Ϯ 0.6 cm as compared with 33.9 Ϯ 0.5 cm observed in adult animals; all models had APE's smaller than Ϯ7% between 56 and 168 d of age. The Bertalanffy model predicted testis volume at maturity quite well, 513 Ϯ 22 cm 3 as compared with 488 Ϯ 20 cm 3 calculated for adult animals. The logistic model had a good fit to testis volume during the period of study, but underestimated the volume at maturity by 28%. All models, except for Brody's, had APE's smaller than Ϯ14% between 98 and 168 d of age. The logistic and Bertalanffy models predicted the inflection point for SC at 83 and 59 d of age, and testis volume at 116 and 109 d of age, respectively. In conclusion, all models, except for Brody's, had good fit to actual SC and testis volume data in the range of age evaluated, whereas the logistic and Bertalanffy's models made the best predictions for adult SC and testis volume, respectively.
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.
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).
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.
Tarım Bilimleri Dergisi, 2021
This study was conducted to determine some of the reproductive characteristics of young Chios rams. For the purposes of this study, the data was obtained and used from 30 Chios ram lambs born in 2009 between the ages of 90-360 days. The minimum and maximum values of the testicular diameter (cm) and length (cm), scrotal circumference (cm), scrotal length (cm), testicular volume (cm 3) of the Chios ram lambs were 1.59-7.30, 3.05-14.23, 12.00-37.50, 7.00-32.00, 17.39-771.44, respectively. Phenotypic correlations between all testis characteristics were found to be statistically significant (P<0.01). The average testosterone hormone in Chios ram lambs was observed to be 7.05 ± 0.31 ng x ml-1. The ejaculate volume, sperm density, progressive motility ratio, immotility ratio, general averages of the ratio of dead spermatozoa and mass movement-consistency of sperm values were examined on sperm of ram lambs at 240, 270, 300 and 330 age of days. Mean values of these traits were obtained as 1.37 mL; 3.95 x 10 9 mL-1 , 82.20 %, 7.07 %, 10.73 % and 4.40-4.09, respectively. Moreover, progressive motility, the effect of live weight and age in other sperm characteristics was found statistically nonsignificant (P>0.05). The testicular diameter and volume, scrotal circumference and scrotal length enlarged related with positively the rate of the sperm motility. As a result, estimating the rate of live spermatozoa of the ram lambs by taking morphological measurements at an early age can be useful. Therefore, this information was vulnerable in indirect selection programs.