CHAPTER ONE

INTRODUCTION

1.1.            Background of the study

In Nigeria, poultry industry is once again experiencing growth due to the current regime’s effort at encouraging investments in the industry through several economic and agricultural policies and reforms including removal of import duties on agricultural products (Fasina et al., 2007). Notwithstanding, the current trend in growth within the industry it is still experiencing challenges as some species of poultry are left out. For instance, turkey production has not been as successful as chicken production in Nigeria. Its production is largely at the small holder level. This has been attributed to high cost of feed, inconsistencies in feeding program as well as lack of information on its nutritional requirements (Ojewola et al., 2002). Also, reproductive problems experienced under natural mating conditions, low fertility and poor hatchability as a result of poor quality semen due to oxidative stress amongst other factors (Bucak et al., 2010) militate against turkey production in Nigeria.  This situation is also evident from the FAO report (FAOStat, 2011), which shows that the population of  local turkeys in Nigeria is only about 1.05 million, being the smallest when compared with other poultry species. It is important to come to terms with the fact that advancement in the industry depends on the use of birds with high reproductive rate, adoption of better mating methods, use of high quality semen in insemination as well as good nutrition.

According to Donoghue and Donoghue (1997), avian spermatozoa are rich in polyunsaturated fatty acids (PUFA) which makes them vulnerable to lipid peroxidation especially during in-vitro manipulation. In particular fatty acids are the most vulnerable to lipid peroxidation. Generally, some features of avian semen have also been found to put it under pressure of oxidative stress. For instance, there is limitation in antioxidant recycling, because of very low activity or even absences of hexose mono-phosphate shunt in avian spermatozoa (Sexton, 1974). Also, the low production of NADPH (the coemzymes for glutathione reductase) has been implicated as a factor in reducing fertility of avian sperm. There are also observations that leukocyte contamination of the semen is responsible for increased generation of free radicals which affect the performance of turkey sperm (Halliwed and Gutteridge, 1999). Furthermore, the activity of antioxidant enzymes in turkey spermatozoa is also lower compared to that of chicken and this makes turkey sperm more vulnerable to the problem of peroxidation (Aitken, 1999). Worthy of note, is the fact that turkey spermatozoa are very dependent on oxidative metabolism to maintain optimal ATP level needed for sperm metabolism (Wishart, 1982). Therefore, any damage resulting from these discrepancies may leads to alteration of the membrane irreversibly, thereby affecting sperm function and fertilizing ability. In effect, antioxidant protection is thus absolutely vital for maintaining the fertility of turkey spermatozoa.

Studies have revealed how the reproductive efficiency of male breeder can be affected by a variety of factors such as breeding methods, environment (daily photoperiod, temperature housing, and nutrition) and frequency of semen collection and technique of artificial insemination (AI), especially in turkey (Sexton, 1983 and Lake, 1984). In addition, these authors have stressed the importance of evaluating the semen prior to insemination to improve the reproductive efficiency. Antioxidants have been reported to be efficient in diminishing lipid oxidation in avian spermatozoa which is a major factor in reduction of fertility. Worthy of note is the fact that natural antioxidant has the ability to increase the antioxidant capacity of the seminal plasma and reduce the risk of certain deleterious free radicals on sperm fertilizing ability (Chanda and Dave, 2009). Dawson et al. (1990) reported that the antioxidant properties of ascorbic acid are essential in maintaining the membrane and the genetic integrity of sperm cells by preventing oxidative damage to the sperm DNA. Also, studies have shown that antioxidants especially those of plant origin such as Moringa oleifera and Gogronema Latifolium have greater application potential for therapeutic and reproductive uses.

Moringa Oleifera plant in the family of Moringacea is native to India, naturalized in tropic and sub-tropical areas of the world (Price, 2002). It is widely distributed and cultivated in the northern part of Nigeria and it is called Zogale in Hausa. The plant is characterized as fast growing and drought resistant with an average height of 12 meters at maturity (Fuglie, 2001). All parts of the moringa tree is said to have beneficial properties. Nutritional analyses by Gopalan et al. (1989) and Fuglie (2001) indicate that Moringa leaves contain a wealth of essential amino acids, vitamins and minerals with higher values in their dried form than in its fresh form, except for vitamin C which is high in its fresh leaves. Fuglie (1999) also reported some specific plant pigments with demonstrated anti oxidant properties such as carotinoids, lutein, alpha-carotine, beta-carotine, xanthins and chlorophyll. Other phytochemicals contained in moringa which have powerful antioxidant ability include kaempferol, queretin, rutin, kaffeoylquinic acids, vitamins A, C and E, some valuable micro nutrients such as selenium and zinc are also found in the leaves of Moringa.

Recently, scientists have put more interest on the role of this plant in improving male reproduction efficiency. Cabacungan (2008) reported that a steady diet of moringa fruit boost the sperm count of male thus, improving their chances of fertilizing an egg. Interestingly, Serrano M. R (2008) reported an increase in sperm count in male mice when 1% concentration of moringa ethanolic leaf extract was administered. Cajuday and Pocsidio, (2010) also observed that mice administered with high and medium dose of the plant extract had enhanced spermatogenesis. This evidence was supported by increase in testicular and epididymal weights as was confirmed in the report of Gonzales (2001).

On the other hand, Gongronema latifolium of the family asclepiadaceae is a tropical rainforest plant primarily used as spice and vegetable and in traditional folk medicine. It is commonly called Utazi by the Igbo tribe in South Eastern of Nigeria. (Ugochuku et al., 2003; Ugochuku and Babady, 2002).  Phytochemical screening of the ethanolic extract of the plant shows that the root contains poly-phenol in abundance, Alkanoids, glycosides and reducing sugars in moderate amounts (Antai et al., 2009). Other chemicals such as B-sistosterol, lupenylester, pregnane ester and essential oil were found in the plant extracts as reported by Ekundayo (1980). Atawodi, (2005) also reported the antioxidant potentials of the plant, which was confirmed by the report of Nwanjo et al. (2006). In addition, the plant is suggested to be able to mop up reactive oxygen species in the system. According to Ugochuku and Babady (2002); and Ogundipe et al. (2003) ethanolic and aqueous extracts of the plant had hypoglycemic, hypolipidermic and antioxidant properties.

Evaluation of biochemical constituents of semen is an important criterion for assessing male fertility. Biochemical constituents of seminal plasma are said to play a role as sperm metabolites, nutrition of ejaculated sperm and provision of protection to spermatozoa against proteinase inhibitors, which help in sperm capacitation and local immunosuppression (Pesch et al., 2005). Therefore, ensuring that the various major biochemical constituents of semen are available in there right proportions is an indication of semen quality.

1.2 Problem Statement

Turkey is one species of poultry that are bred exclusively by artificial insemination due to the differences in body weight between the male and female. Most times the male weighs twice more than the female, consequently the larger body sizes (weight) of the male accounts for poor mating ability.  Thus tom often spend more time preparing to mate with the female, hence the female might lose interest or is weakened due to the long time spent by the male and this results in ineffective mating. Secondly, studies have revealed that turkey toms are naturally clumsy during natural mating and as such when semen is released little or nothing is discharged into the vulva of the hen turkey as a result of the tom’s awkward mating skills and thus much of the semen is wasted. Unfortunately, the full potentials of artificial insemination technique in Nigeria have not been fully utilized and improvement in turkey production is limited by fewer numbers of experts in artificial insemination technique, particularly those working on local turkey production.

Furthermore, avian semen has been found to be rich in PUFA which put them under pressure of oxidative stress (Donoghue and Donoghue, 1997). The activity of antioxidant enzymes in turkey spermatozoa is lower compared to that of chicken and this makes turkey sperm more vulnerable to peroxidation (Aitken et al., 1999). In effect, an unsatisfactory egg fertility and hatchability due to the low quality semen of turkey constitutes a major problem for turkey breeders. Also, during hatching and early postnatal period, the accumulation of PUFA- producing tissue makes it vulnerable to peroxidation. In poultry, vitamin E (combine with selenium) provides protection against lipid peroxidation especially in turkey semen, this vitamins is effectively transferred both from the paternal and maternal system to the egg yolk and further to the developing embryo (Surai, 2002).

The biochemical constituents such as fructose, potassium and sodium of semen are important for sperm fertility and deviation from normal values or proportion of these biochemical components in seminal plasma may result to low or male infertility (Cevik et al., 2007). Handler and Bulos(1965) reported that fructose serves as fuel supply for sperm cells, and in the absence of fructose infertility would occur. In general, deviation from normal values of biochemical components in seminal plasma is correlated with male infertility (Cevik et al., 2007). The present study was designed to determine the effects of M. oleifera and G. latifolium leaf meals in turkey toms’ diets on semen quality, biochemical parameters and egg hatchability of local turkeys.

1.3              Objectives of the Study

The main objective of the study is to determine Semen Quality and Egg Hatchability in Local Turkey Fed Diets Containing Moringa Oleifera and Gongronema Latifolium Leaf Meals.

Specifically this study seeks to:

i.                    Determine the effects of Moringa oleifera and Gongronema latifolium on daily body weight of turkey toms.

ii.                  Evaluate the effects of Moringa oleifera and Gongronema latifolium on semen quality parameters.

iii.                Determine the fertilizing capacity of the spermatozoa obtained from the treated toms on hatchability of eggs laid by inseminated hens.

iv.                Determine the concentration of some biochemical constituents of turkey semen and correlate them with some notable semen quality parameters.

v.                  Correlate body weight of the treated toms with their semen quality parameters.

1.4  Justification

The greatest achievement of every producer in the poultry industry is to maintain breeder males capable of producing viable spermatozoa that can fertilize eggs which will hatch with minimum mortality. However, the numbers of hatched eggs is dependent on the quality and quantity of the spermatozoa, thereby determining the profitability of the production. Unfortunately, reproductive efficiency in turkey has been compromised due to emphasis on high body weight during genetic improvement. Artificial insemination therefore, has become the most effective and widely used techniques in turkey production and for causing reproductive improvement in most farm animals. The success of artificial insemination is directly dependent on the quality of semen output and appropriate handling procedures to sustain the fertilizing potential of the spermatozoa. In Nigeria, the turkey industry has not yet utilized the high reproductive potentials offered by artificial insemination, as a major tool to improve and optimize the genetic potential of the local breeds and eliminate the reproductive challenges in turkey production.

The practice of using drugs or hormones to enhance reproductive efficiency in poultry has been questioned in many areas because of their cumulative negative health effects in the animal as well as their products (meat and egg) meant for human consumption. Alternative measures are now being recommended for improving reproduction in farm animals through the application of organic extracts of plant components (leaf, seeds, stem and root) administered through feed or water. Most recently, some available underutilized plants have been proved to have nutritional, medicinal and therapeutic properties which can improve semen quality, fertility and even hatchability of the turkey eggs. Moringa oleifera and Gongronema latifolium contain nutrients, vitamins, minerals, some beneficial phytochemicals and antioxidants which are known to stimulate growth and improve reproductive efficiency in humans and animals. The plants have been used as natural feed additives and have generally been proven to be effective and non-toxic when consumed by humans and animals. It is against this background that this research was conducted.

---

Talk to us right now: (+234)906-451-7926 (Call/WhatsApp)

---

Share a Comment