Histological Characterization of Testicular Interstitium in Najdi Ram Lambs During

Postnatal Development

Ahmed Ali AL-kawmani

Supervised byDr. Mansour Mohammed Furaiji (Advisor)

Dr. Faisal M. Abou-Tarboush (Co- Advisor)

by

Introduction

Domestication of the wild ancestors of sheep occurred around 9000 BC in the countries of Iran and Iraq (Zygoyiannis, 2006).

The needs of humans for clothing and of sheep for protection from the cold were undoubtedly responsible for the evolution of the many wooled-breeds (Owen, 1976).

Sheep give rise to four major products: meat, wool/hair, milk and skins. In many parts of the world, meat is the major product and the importance of meat production is increasing world-wide. (Boutonnet, 1999; de Rancourt et al., 2006).

Today, the world’s sheep population is around 1000 million, which produce annually

approximately 14 million tons of sheep meat (FAO, 2008).

The animals production sector is one of most important economic sectors in the Kingdom

of Saudi Arabia, which aims at achieving food security in the area of different kinds of meat,

dairy, and their derivatives.

Sheep comprise one of the most important livestock species for Saudi Arabia and play an

important role in the livelihood of large portion of small and marginal farmers and nomadic.

The most distinctive features of Najdi sheep.

Estimated numbers of sheep and in the Kingdom :

2005 8,500,941

2009 5,885,532

2005 – 2009 2,612,409 30%

(Statistical Yearbook agricultural- 21- 2008 to 2009).

SHEEP

SHEEP

SHEEP

The amount of meat produced in the Kingdom, covers about 50% of the total

requirements and the amount of meat imported 50% (source: Statistical Yearbook

of agricultural number twenty from 2006 to 2007).

As a result of :

Declining numbers of sheep.

And increasing the amount of imported meat .

Important of the Najdi sheep.

Comes the importance of this study to provide scientific information to

increase the production of sheep in the Kingdom, therefore the aims of the

study as follow:

Objectives

1- To evaluate testicular development during postnatal period in Najdi ram.

2- To study age-related body and testicular development in Najdi ram.

3- To determine the establishment of spermatogenesis in Najdi ram.

4- To provide a basis information for selection sires for minimizing age at puberty

and optimizing fertility in Najdi rams.

5- To establish an easy and simple technique for assessing male fertility that will be

very useable tool in breeding programs.

 

Literature Review

Testis size is indicative of reproductive capacity and fertility in the ram

(Lino, 1972).

Testis size may be useful as a selection criterion for improving

reproductive capacity in both sexes, (Toe et al., 2000; Matos et al., 1992).

Scrotal circumference is often considered the best indicator of male

sexual development (Notter et al., 1981).

Testicular weight cannot be measured in the living animal, but has been estimated

in several ways, such as:

Scrotal circumference (SC).

Testis diameter.

Length.

Volume.

of those measurements, SC is the simplest and most accurate method to estimate

the amount of testis mass (Notter et al., 1981; Celis et al., 1987).

And the degree of testis development (Lunstra et al., 1978).

The rate of testis development in the ram lamb may be indicative of their sexual

performance (Land, 1973; Toe et al., 2000).

Patterns of testicular growth over time might be more useful to predict the testis size in

the adult animal than a single measurement taken at a specific age (Notter et al., 1985).

The various testicular measurements are more correlated with body weight of growing

lambs than age ( Salhab et al,2001 and Salhab et al. 2002).

Very little work has been done to describe the association between age and scrotal

circumference (Notter et al. 1985).

Current knowledge on testis development in sheep comes from studies on wool breeds, with little information on hair sheep.

As testis traits may greatly differ among breeds, it is important to study testis development in various hair breeds (Notter et al., 1985).

Detailed information about the onset of puberty and sexual maturation are needed for good reproductive management of domestic animals (Nishimura et al., 2000).

The time of onset of sexual maturity can exert an important influence on the reproductive efficiency of an individual (Madani & Rahal, 1988).

Thun the characterization of puberty and of early sexual development are important criteria for use in the selection of males within a breed (Madani & Rahal, 1988).

Most breeds of sheep are seasonal breeders but the age of puberty in male differ among them (Hammond, 1944; Mallampati et al., 1971; Fitzgerald and Butler, 1982; Foster and Ryan, 1990).

The onset of puberty determine by first appearance of the spermatozoa in ejaculated semen, (Skinner, 1991 and Bilgin et al., 2004).

Mammalian spermatogenesis is a continuous, throughout the life of the male (Yan Cheng et al,2010; Michelle W.M.et al,2009; Bitencourt.et al,2007; Deiler S. Costa et al 2007; Johnson et al 2000 and Franca et al1999).

The foundation of this system is the spermatogonial stem cell (Huckins, 1971; Clermont, 1972; Meistrich and van Beek, 1993 and Michelle W.M.et al,2009).

Location ,

The experiment will be carried out at Al-Watania livestock project near to Al-Jouf

and 150 kilometers from Domat Al-Jandal, Kingdom of Saudi Arabia (29° 48’N, 38°

23’ E).

2211 4433 55 66 77 88 99

Thirty-six Najdi ram lambs will be used, their aged Thirty-six Najdi ram lambs will be used, their aged

AnimalsAnimals

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

4 rams

Rams will be weaned at approximately 8 weeks of age and will be maintained on

standard growing ration through the end of the experiment, water and mineral block will

be available ad libitum

Scrotal circumference will be measured by using vernier caliper.

Testicular volume will be estimated using displacement of water from a cup.

Body weight (BW).

All rams will be weighted (BW), to determine the relationship between testis and body weight, a gonadosomatic index (GSI) was calculated (100 X testis volume/BW).

Testicular Biopsy will be taken by using 10G biopsy gun.

Sample Histology.

After process biopsy and taking testicular measurement, The tissues were placed in Bouin’s fixative for 48 h and immersed in 70% ethanol for another 48 h.

Histology study

We will be the registration of spermatogenesis, the testicular biopsy score count proposed by Johnsen (1970) was used. Seminiferous tubules of 3 nonconsecutive sections of testicular biopsy were evaluated systematically and to each of them a score from 10 to 1 according to presence or absence of the main cell types arranged in the order of maturity.

Score Description

10Complete spermatogenesis with mature sperm cells .

9Some sperm cells, with a disorganized epithelium .

8Presence of few sperm (<5 to 10).

7No sperm cells, presence of spermatids.

6No sperm cells, few spermatids (<5 to 10) .

5No sperm cells or spermatids, presence of spermatocytes.

4No sperm cells or spermatids, few spermatocytes (<5).

3Only spermatogonia present.

2Sertoli cells only.

1No cells visualized in the tubular cross-section .

Johnsen-like scores for evaluation of rabbit spermatogenesis adapted from Johnsen (1970).

LSDescription

6Maximal hyperplasia (usually with nodulation).

5Pronounced hyperplasia.

4Indicated slight to moderate hyperplasia.

3Indicates normal amounts of Leydig cells

2Indicates a definitely decreased number (very few seen).

1Indicates an absence of Leydig cells.

Leydig-score (LS)

Statistical analysis

Mean differences will be compared between groups by t-tests and evaluated for significance at the 5% level. Data will be analyzed using a simple one-way ANOVA analysis of variance (SAS, 1990).

yij = µ+ Ai + eij

yij = observations.

Ai = age for lambs. eij = Experimental error.

µ = Average.

Schedule of executing the research Plan

Budget

NumberItemRiyals

136 male sheep30000

2Chemicals3000

3Pharmaceutical and Sterilizers .4000

4Wages of workers1000

5Slides and coverings500

6Collectibles1000

7Travel Card from Riyadh to Al-Jouf Round Trip2000

8Wages of the transfer2000

9antibiotic3000

10

11

12Total budget45500

Estimated Budget for the Thesis

sperm

mitosisPrimary

spermatocytePrimary

spermatocyte

SpermatidaSpermatida

Secondary spermatocyte

Secondary spermatocytemeosis

Spermsatozoa (sperm)

Spermsatozoa (sperm)

Testis size

sexual development

testis development

puberty

Scrotal circumference

SpermatogoniaSpermatogonia

sexual performance

sexual performance

نمشاتن