Effects of rate of gain on scrotal circumference and histopathologic features of the testes of half-sibling yearling beef bulls

M. W. Ohl From the Departments of Veterinary Clinical Medicine (Ohl, Ott, Hornbuckle II), Veterinary Biosciences (Hess), and Continuing Education and Public Service (Zinn), College of Veterinary Medicine, and Department of Animal Sciences (Faulkner, Cmarik), College of Agriculture, University of Illinois, Urbana, IL 61801.

Search for other papers by M. W. Ohl in
Current site
Google Scholar
PubMed
Close
 MS, DVM
,
R. S. Ott From the Departments of Veterinary Clinical Medicine (Ohl, Ott, Hornbuckle II), Veterinary Biosciences (Hess), and Continuing Education and Public Service (Zinn), College of Veterinary Medicine, and Department of Animal Sciences (Faulkner, Cmarik), College of Agriculture, University of Illinois, Urbana, IL 61801.

Search for other papers by R. S. Ott in
Current site
Google Scholar
PubMed
Close
 DVM, MS
,
D. B. Faulkner From the Departments of Veterinary Clinical Medicine (Ohl, Ott, Hornbuckle II), Veterinary Biosciences (Hess), and Continuing Education and Public Service (Zinn), College of Veterinary Medicine, and Department of Animal Sciences (Faulkner, Cmarik), College of Agriculture, University of Illinois, Urbana, IL 61801.

Search for other papers by D. B. Faulkner in
Current site
Google Scholar
PubMed
Close
 PhD
,
T. Hornbuckle II From the Departments of Veterinary Clinical Medicine (Ohl, Ott, Hornbuckle II), Veterinary Biosciences (Hess), and Continuing Education and Public Service (Zinn), College of Veterinary Medicine, and Department of Animal Sciences (Faulkner, Cmarik), College of Agriculture, University of Illinois, Urbana, IL 61801.

Search for other papers by T. Hornbuckle II in
Current site
Google Scholar
PubMed
Close
 DVM, MS
,
R. A. Hess From the Departments of Veterinary Clinical Medicine (Ohl, Ott, Hornbuckle II), Veterinary Biosciences (Hess), and Continuing Education and Public Service (Zinn), College of Veterinary Medicine, and Department of Animal Sciences (Faulkner, Cmarik), College of Agriculture, University of Illinois, Urbana, IL 61801.

Search for other papers by R. A. Hess in
Current site
Google Scholar
PubMed
Close
 PhD
,
G. F. Cmarik From the Departments of Veterinary Clinical Medicine (Ohl, Ott, Hornbuckle II), Veterinary Biosciences (Hess), and Continuing Education and Public Service (Zinn), College of Veterinary Medicine, and Department of Animal Sciences (Faulkner, Cmarik), College of Agriculture, University of Illinois, Urbana, IL 61801.

Search for other papers by G. F. Cmarik in
Current site
Google Scholar
PubMed
Close
 PhD
, and
G. M. Zinn From the Departments of Veterinary Clinical Medicine (Ohl, Ott, Hornbuckle II), Veterinary Biosciences (Hess), and Continuing Education and Public Service (Zinn), College of Veterinary Medicine, and Department of Animal Sciences (Faulkner, Cmarik), College of Agriculture, University of Illinois, Urbana, IL 61801.

Search for other papers by G. M. Zinn in
Current site
Google Scholar
PubMed
Close
 DVM, PhD

Click on author name to view affiliation information

Abstract

Objective

To determine the effects of high and low gain on production variables and reproductive characteristics of bulls, including histopathologic lesions in the testes, as determined by quantitative measurements.

Animals

23 half-sibling, 11.6-month-old beef bulls, averaging 326 ± 8.3 kg in weight and having a mean scrotal circumference of 28.7 ± 0.4 cm.

Design

Bulls were randomly assigned within pairs to high- or low-gain rations and fed ad libitum for 112 days.

Procedures

Scrotal circumference and body weight were measured on days 0, 28, 56, 84, and 112. Bulls were castrated on day 112. Morphologic characteristics of spermatozoa were determined from samples taken on days 50 and 111. Testis sections from each bull were examined, using light microscopy, for changes in the seminiferous epithelium and interstitium. A grading scheme was used to quantify testicular lesions by histologic techniques. Pathologic changes in 600 cross sections from each bull were classified into 9 grades. The degree of germinal epithelial loss per 100 tubules was calculated by assigning a value to each grade according to the severity of loss of germinal epithelium.

Results

Scrotal circumference (mean ± SEM cm), 34.0 ± 0.8 vs 31.7 ± 0.5 (P < 0.001), body weight (kg), 512.3 ± 19.6 vs 421.9 ± 9.4 (P < 0.001), and paired testicular and epididymal weight (g), 532 ± 31 vs 425 ± 24 (P < 0.0001) and 73.8 ± 1.9 vs 56.3 ± 3.7 (P < 0.001) were greater in the high-gain than in the low-gain group. Morphologic characteristics of spermatozoa were similar for both groups. Means for graded seminiferous epithelial effects were similar in each group. Hypoplastictype tubules were found in bulls with small scrotal circumference in both the high- and low-gain groups.

Conclusion

High gain resulted in greater testicular growth but testicular structure and function were similar for both groups. (Am J Vet Res 1996;57:844–847)

Abstract

Objective

To determine the effects of high and low gain on production variables and reproductive characteristics of bulls, including histopathologic lesions in the testes, as determined by quantitative measurements.

Animals

23 half-sibling, 11.6-month-old beef bulls, averaging 326 ± 8.3 kg in weight and having a mean scrotal circumference of 28.7 ± 0.4 cm.

Design

Bulls were randomly assigned within pairs to high- or low-gain rations and fed ad libitum for 112 days.

Procedures

Scrotal circumference and body weight were measured on days 0, 28, 56, 84, and 112. Bulls were castrated on day 112. Morphologic characteristics of spermatozoa were determined from samples taken on days 50 and 111. Testis sections from each bull were examined, using light microscopy, for changes in the seminiferous epithelium and interstitium. A grading scheme was used to quantify testicular lesions by histologic techniques. Pathologic changes in 600 cross sections from each bull were classified into 9 grades. The degree of germinal epithelial loss per 100 tubules was calculated by assigning a value to each grade according to the severity of loss of germinal epithelium.

Results

Scrotal circumference (mean ± SEM cm), 34.0 ± 0.8 vs 31.7 ± 0.5 (P < 0.001), body weight (kg), 512.3 ± 19.6 vs 421.9 ± 9.4 (P < 0.001), and paired testicular and epididymal weight (g), 532 ± 31 vs 425 ± 24 (P < 0.0001) and 73.8 ± 1.9 vs 56.3 ± 3.7 (P < 0.001) were greater in the high-gain than in the low-gain group. Morphologic characteristics of spermatozoa were similar for both groups. Means for graded seminiferous epithelial effects were similar in each group. Hypoplastictype tubules were found in bulls with small scrotal circumference in both the high- and low-gain groups.

Conclusion

High gain resulted in greater testicular growth but testicular structure and function were similar for both groups. (Am J Vet Res 1996;57:844–847)

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 31 31 7
PDF Downloads 20 20 2
Advertisement