Department of Animal Science

Assessment Of Quality of Table Eggs from Different Layer Strains and Ages Raised in Different Housing Systems Using Conventional and Non-Conventional (Nir) Methods

2025-05-28T09:19:10Z

Assessment Of Quality of Table Eggs from Different Layer Strains and Ages Raised in Different Housing Systems Using Conventional and Non-Conventional (Nir) Methods Thomas, Akowuah The objective of this research was to assess the quality of table eggs from two different strains of layers at different ages raised in two distinct housing systems using both conventional (breaking of eggs) and non-conventional (near-infrared spectroscopy) methods. The study was done in two parts, namely: the use of conventional method and the use of non-conventional or the Near Infra-red Spectroscopy (NIR) method for the egg quality assessment. In all five (5) different experiments, namely: physical, nutritional, microbiological, organoleptic egg quality assessment and presence of antibiotic residues in eggs, were carried out. In the first phase of the experiment, a total of 2,490 freshly laid eggs from the two layer strains (Lohmann brown and Lohmann white) aged 24, 39, and 68 weeks, raised in deep litter and battery cage systems, were randomly assessed for the physical, nutritional, microbiological, and organoleptic properties of the eggs as well as the presence of antibiotic residue. The data obtained were subjected to a three-way analysis of variance using the General Analysis of Variance of GenStat (Discovery edition), with strain, housing system, and layer age as fixed factors. The second phase of the study involved the possibility of using the NIR method to predict the physical, nutritional, microbiological and presence of antibiotic residues in the egg. Results obtained from the conventional experiment showed some significant effects of the fixed factors on some of the important physical egg characteristics such as egg weight and egg freshness (Haugh unit); an indication that for improved physical characteristics of eggs, the strain of layers used, the age of the layers when eggs are laid and the type of housing system used for egg production are very important. The portable NIR spectrometer, along with qualitative algorithms, indicated that eggs stored under room temperature had a 95.54% identification rate at five principal components. On the other hand, eggs stored in cold storage had a 100% identification rate at five principal components for determining the lay date. In the independent set, PLS-R produced R = 0.87 and RMSEI = 2.57 for ambient storage, and R = 0.88 and RMSEI = 2.66 for cold storage. Data obtained from the conventional experiments showed significant strain, housing and age effects on the egg internal qualities proximate content and sensory properties of eggs but showed no significant effects on the microbiological properties of eggs. The novel handheld NIR spectroscopy was able to classify (PCA-MSC-LDA gave IR = < 95%) and predict the freshness, storage duration (MSC-PLSR of R = 0.83) and proximate content of eggs. The data from conventional experiments largely correlated with the NIR spectroscopy. The research indicated that portable NIR spectroscopy methods might be employed as a rapid, nondestructive tool for simultaneous egg examination. Moreover, distinct consideration should also be directed to protect eggs against contamination ensuring on-farm biosecurity, reducing cross-contamination, and inspection of eggs and poultry feed. xx 228p:, ill

Hatchery Waste Meal as Protein Source in Diets for Grower-Finisher Pigs (Sus Domesticus)

2024-07-17T13:32:53Z

Hatchery Waste Meal as Protein Source in Diets for Grower-Finisher Pigs (Sus Domesticus) Asiedu, Peter The series of experiments reported in this work considered the possibility of utilising hatchery waste as replacement for fish meal in grower finisher diet. An initial survey in the Greater Accra region estimated that as high as 15 (fifteen) tons of waste was generated per annum from just 5 (five) hatcheries. Analysis of the waste showed however, that it had some levels of microbial load, although the presence of Escherichia Coli and Salmonella were not detected. Methods of processing waste using temperature and time combinations showed that simple steaming for 5 minutes at 80°C (5M80T) gave a product that retained high CP as well as had low microbial load suitable for inclusion in feed formulated for pigs. A 16-week study using sixty (60) Large White grower intact male pigs (average liveweight of 17.55 ± 0.1 kg) randomly allotted to 5 dietary treatments [designated 0% Hatchery Waste Meal, 2.5% Hatchery Waste Meal, 5.0% Hatchery Waste Meal, 7.5% Hatchery Waste Meal and 10.0 %] in which HWM replaced Fish Meal directly in the diet. The study again shows that HWM could be processed into a form that can be used after simple processing (steaming) without much loss in nutrient content, particularly protein. The inclusion of HWM up to 5.0% had no significant (p > 0.05) effect on weight gain, feed conversion ratio as well as economy of gain. In the course of the feeding trial, some biochemical and haematological indices assessed also indicated levels within normal ranges for good health in pigs. At the end of the feeding trial the effects of HWM replacement of FM on carcass characteristics (primal cuts, organs weights and measurement of fats) indicated no significant (p > 0.05) dietary treatment effects on all the parameters assessed, except for weight of the empty stomach, GIT (Gastro Intestinal Tract) and thymus gland. Finally, comprehensive survey to determine volumes of HWM generated across hatcheries in Ghana should be done to indicate more accurately the cost saving potential of this feed ingredient for pig fanners in Ghana. ii, ill: 267

Breeding and Selection for Faster Growth Strains of the Nile Tilapia, Oreochromis Niloticus in Ghana

2024-07-09T13:26:34Z

Breeding and Selection for Faster Growth Strains of the Nile Tilapia, Oreochromis Niloticus in Ghana Attipoe, Felix Yao Klenam Three wild stocks of Nile tilapia, Oreochromis niloticus were collected from three different agro-ecological zones in the Volta system in Ghana., A fourth stock of the same species was obtained from a farm at Nsawam. These were used in a study aimed at generating strain(s) of 0. niloticus with an improved growth rate or performance compared to the wild stocks. Equal aged brood stock were generated under similar environmental conditions from all four stocks and evaluated for growth and reproductive performance in monoculture and polyculture systems. Diallele crossing of the four stocks was conducted. The growth performance of progeny from the crosses were tested in three culture environments. Least square means of body weight and total body length at harvest were computed for each stock combination within the culture environments. Heterosis and breeding values (BVs) were estimated. A genetically mixed base population was established by creating a selection line and a control line. Response to selection in the performance of progenies from the selection and control line was evaluated. The additive genetic variance (62 A), phenotypic variance (62 P) and heritability (h2) were estimated for the base population. Results mainly indicated the following: (i) Reference reproductive performance, the Yeji stock (Transitional zone) produced the highest number of seed (0.17 fry /g female /day) followed by the Nawuni stock (Guinea Savana zone) and then the Kpando stock (Semi-deciduous forest zone). The Farm stock produced the least value (0.10 fry /g female /day). (ii) Growth performance assessment showed that males were significantly heavier compared to females in all stocks. The ratio of the weight of females to males ranged from 0.61 - 0.70 for Yeji and Nawuni stocks respectively. (iii) Observed Sex ratio was skewed towards females, being 1: 1.8 and towards females, being 1:1.8' and 1 :2.2 in the extensive and semi-intensive culture environments respectively. (iv)With respect to growth performance of stocks, the Nawuni stock was superior to the other three stocks. It had the highest mean daily growth rate in almost all growth evaluation trials while the lowest growth rate occurred in the Yeji stock. (v) Expression of heterosis was negative for all crosses. (vi)The genotype-environment interaction was very low (0.1 %) suggesting that it would not be necessary to develop specialized O. niloticus strains for different culture environments. (vii) A positive response to selection of over 10 % in improvement in growth rate of the selection line over the control line was observed. Recommendations for further investigations and implications of selecting appropriate stocks for improving the growth rate of O. niloticus in Ghana are discussed. ii, ill: 171

The Development of Radiation-Induced Inherited Sterility for the Management of Lepidopterous Maize Stem Borers: Eldana Saccharina Walker (Pyralidae) and Sesamia Calamistis Hampson (Noctuidae)

2024-07-04T12:57:11Z

The Development of Radiation-Induced Inherited Sterility for the Management of Lepidopterous Maize Stem Borers: Eldana Saccharina Walker (Pyralidae) and Sesamia Calamistis Hampson (Noctuidae) Annoh, Charles Emmanuel Radio-sterilization study was conducted on the biology of two lepidopterous maize stem borers, Eldana saccharina Walker and Sesamia calamistis Hampson to induce inherited sterility for insect pest management programme in Ghana. Bioecology of the two borer species was also studied for a 3-year period, 1997-1999 at Medie, a predominantly maize growing community in the Ga District of Greater Accra Region, to determine the population dynamics and climatic factors influencing the population of the borer species. It was observed that Sesamia species usually attacked the young maize crop, with peak infestations occurring about 6-8 weeks after emergence of the crop. Eldana species preferred mature maize with peak infestations around 10-12 weeks after emergence of the maize crop. Larval numbers of E. saccharina showed inverse relations with rainfall, r= 0.5899; p= 0.043. Infestation levels of larvae of both species were relatively higher during the minor rainy season than the major season. Larvae and pupae of E. saccharina that developed separately on natural and artificial diets did not show significant difference in most of their biological parameters. In both borer species, pupal weights of natural dieters were slightly heavier than those of artificial dieters. Exposure of young pupae (less than 6 days old) of the two borer species to increasing doses of ionizing radiation, 80-180 Gy, resulted in high percentage of deformity and unemerged adults. Mature pupae of 6-8 days old were less susceptible to increased doses and exhibited fewer body deformities and unemerged adults. The mating capability of adults emerged from irradiated mature pupae of E. saccharina was not adversely affected. In the parent generation (P), fecundity and fertility decreased with increased doses of radiation for crosses involving irradiated males and normal females as well as irradiated females and normal males. While the treatment in the former crosses resulted in partial fertility (400!o at 180 Gy), the latter produced almost sterile individuals (96%, with doses above 100 Gy). In the F) generation, both fecundity and fertility were inversely related to increased doses of radiation. Crosses involving F) males showed lower fertility than their corresponding F) females. Fertility was reduced to l00!o with radiation dose of 100 Gy in the former, whilst similar reduction in F) females required about 150 Gy or more. The overall sex ratio of emerged adults in F) and F2 generations shifted in favour of males. Thirty pairs of chromosomes were observed in normal meoitic gametes (metaphase 1) of E. saccharina. Chromosomal aberrations resulting from induced radiations were found in the form of fragments, rings and chains. In experimental field cages, moths treated with radiation dose of 150 Gy, resulted in decrease in fecundity and fertility of F) generation when the ratios of sterile to fertile moths was increased. Fecundity was reduced by 47% with ratio of 1 sterile to 1 fertile and 79% with mating ratio of 5 sterile to 1 fertile, as compared with the control of 1 fertile to 1 fertile. Since significant reduction in fecundity and fertility was 0 bserved with radiation doses between 120-180 Gy, it is suggested that this range could be used to induce inherited sterility in E. saccharina. The substantial reduction of population of the borer species due to induced sterility in the progeny implies that inherited sterility could be used as a control strategy to suppress the stem borer populations in insect pest management programme in Ghana. ii, ill: 171