Animal Reproductive Physiology
Research achievements over the last thirty years are in the areas of animal reproductive physiology and animal breeding. Substantial research has also been carried out in the area of Systems Research through participation in a project commissioned by the International Service for National Agricultural Research (ISNAR), The Hague, The Netherlands. These are summarized below from the most recent (g-a):
g) Development of Small Scale Heliculture System for the Sub-Humid
Tropics (2006 – 1996):
This is a current project which is aimed at the design and testing of a system for raising the giant African Land Snails (Archachatina marginata and Achatina achatina) in plastic cages on a small scale ideal for backyard production by housewives and workers eager to make additional income and to supplement the family diet with a good animal protein source.
So far, the feeding system has been successfully tested. The reproductive management has been developed, and the whole production system is being prepared for on-farm adaptive research.
Scientific studies carried out so far have examined the effects of the following factors on growth and reproduction of the giant African Land Snails:
Photoperiod Species Temperature
Soil moisture Stocking density Season
Type of feed Hatching weight Body weight
Age Duration of aestivation
f) Development of Small-Holder Dairy Goat Production System for
This is an on-going project involving research on goat breeding, milk production and management, involving the three indigenous Nigerian goat breeds, namely West African Dwarf, Red Sokoto and Sahel.
Completed studies include those on Housing, Tethering, Heat stress, Udder traits and milk production, Lactation curves, Milk secretion rates, Milk offtake, Partial daily milk yield and milk yield, Milk composition, Milk pasteurization, Milk products, Birth weight, Weaning weight and Litter size, Milk yield and pre-weaning growth. Studies on Feeding frequency, Feeding level and Milking frequency are on-going.
e) Strengthening the Role of Universities in National Agricultural
Research Systems in Sub-Saharan Africa (1998-1993).
This ISNAR Project had the following objectives:
• To analyze the context in which the University and National Agricultural Research Organization are evolving and to identify constraints limiting their ability to address national agricultural development-oriented research.
• To identify opportunities and imaginative mechanisms to improve the contribution of the University to development-oriented research in agriculture.
• To derive recommendations and action plans that enhance the contribution made by the University and
• To start the building of this capacity.
I participated in this interesting project as one of the two National Consultants for the Nigerian case-study. Phase I of the project focused on Nigeria and the Republic of Benin. Based on the successful outcome on Phase I of the project, ISNAR embarked on Phase II of the project involving four more countries in Sub-Saharan Africa, namely Zimbabwe, Burkina Faso, Uganda and Cote d’Ivoire.
d) Selection for weaning weight and litter in Yankasa sheep (1994 – 1983):
The main objective of this project was the genetic improvement of Yankasa sheep, a medium-sized hair sleep constituting about 60% of the Nigerian sheep population, for weaning weight and litter size. It involved the establishment of a central nucleus breeding centre for the breed at the National Animal Production Research Institute, Ahmadu Bello University, Zaria, Nigeria, acquisition of foundation stock from different locations in north-central Nigeria, supervision of the construction of necessary infrastructural facilities such as sheep housing, paddocks, central handling, yard, reticulation and electrification of the project site.
A semi-intensive management system involving twice-yearly lambing, grazing and concentrate supplementation of the breeding flock was instituted. The breeding method involved oestrus detection, controlled mating either naturally or by artificial insemination followed by the determination of non-return rates, calculation of expected lambing dates and recording of actual lambing details. Pregnancy rates were occasionally determined by progesterone assay. Lambs were weaned at about 90 days of age. Breeding records were maintained n computer database files and periodically analyzed for selection purposes and for generation of genetic and phenotypic parameters. Lambs were selected on the basis of their adjusted weaning weights and the fertility index of their dams, which was a composite measure of average litter size and lambing frequency.
This project generated to a lot of data on the pre-weaning performance of Yankasa sheep and reliable estimates of birth weight, weaning weight, pre-weaning average daily gain, average litter size, lambing rate, lambing interval, gestation length, weaning rate, heritability estimates of the different traits and their phenotypic and genetic correlations. Further analyses also confirmed positive responses of the flock to selection for both weaning weight and litter size.
More importantly, the project generated over 1,000 improved breeding stock which were sold to farmers and other institutional farms around the country to improve their flocks.
c) Artificial insemination of sheep (1994-1983):
This was actually a series of projects undertaken by undergraduate and postgraduate students whom I supervised over a ten – year period. The objective was to develop a suitable protocol for preserving ram semen and its utilization in routine sheep artificial insemination. Different methods investigated included ambient temperature storage either under anaerobic conditions, continuous or discontinuous flow dialysis, chilled storage at – 50C or deep frozen storage in liquid nitrogen at minus 1960C, using the Tris-egg yolk diluent and freezing by the pellet method. Though several of the methods developed showed promise, the method eventually adopted for routine sheep artificial insemination involved fresh semen dilution with heated cow milk – egg yolk diluent and deep cervical insemination with a modified insemination pipette. This method consistently resulted in lambing rates above 75%.
b) Accelerated Lambing in Yankasa Sheep (1987 – 1981):
This project was aimed at capitalizing on the much publicized year-round breeding capabilities of tropical sheep. Our initial investigations showed that post-partum oestrus and conception within 34 and 42 days respectively after lambing were obtainable in Yankasa ewes, provided rams were introduced to nursing ewe flocks within two weeks of lambing. Attempts to further reduce these post-partum intervals by progestagen treatment were unsuccessful. Further investigations showed that with good nutrition and early introduction of rams, postpartum, annual lamb crops of 244 weaned lambs per 100 ewes bred was realizable, naturally, without hormonal treatment.
a) Postgraduate and Post-doctoral research (1979- 1974):
Post-doctoral research on the physiology of washed mammalian spermatozoa (bull and ram) was carried out at the Animal Research Station, AFRC Institute of animal Physiology, Cambridge, from 1978 to 1979 under the supervision of Dr. H.M. Dott. This works was continued independently in Nigeria from 1979 to 1985. The series of studies essentially confirmed earlier observations by other workers of the harmful effects of sperm washing on motility, eosinophilia and morphological integrity. The level of damage increased with the washing efficiency. The interesting finding of the study was that most of the damage could be reversed by the inclusion of bovine serum albumin and citrate in the post-wash diluent. This led to the development of better sperm-washing protocols.
The research conducted for my Ph.D thesis at Ahmadu Bello University under the supervision of Professor S.M. Dennis form 1976 to 1978 explored testicular growth and semen quality of West African bulls. The study established patterns of testicular growth for Bunaji, Ndama and Sokoto Gudali breeds and developed regression equations for predicting testicular size from age or liveweight of bulls of the different breeds. Detailed studies with the Bunaji breed were used to establish relationship between testicular size and accessory sex organ development, gonadal and epididymal sperm reserves.
Master’s thesis research was carried out at the University of Sydney, Australia, under the supervision of Prof. Steve Salamon and involved studies on deep freezing of boar spermatozoa. The study resulted in the development of an improved preservation protocol involving two-stage dilution of boar semen, deep freezing at high spermatozoa concentrations and post-thawing dilution at 370C.
Major research projects initiated and led:
• Artificial insemination in Yankasa sheep
• Postpartum interval to oestrus and conception in Yankasa sheep
• Twice-yearly lambing in Yankasa sheep
• Genetic improvement of growth and fertility rates in Yankasa sheep
• Development of cage culture system for production of Giant African Land snails
• Development of Smallholder Goat Milk production system for Southwestern Nigeria
• Strengthening the role of Universities in the National Agricultural Research System of Nigeria
• Development and On-farm testing of UNAAB improved tether for sheep and goats
• Oestrus synchronization in Yankasa sheep
• Effect of heat stress on the oestrous cycle of Yankasa sheep
• Postnatal development of the reproductive tract in Yankasa rams
• Determination of gonadal and epididymal sperm reserves in Bunaji bulls
• Semen quality of Bunaji bulls
• Formaldehyde preservation of mammalian spermatozoa
Osinowo’s Research Farms