This thesis investigated the relationships between the feeding behaviour and use of stored fat in overwintering Atlantic salmon parr remaining destined to remain resident in freshwater the following year. Experiments investigated the responses to periods of food shortage at different times of the year to assess the influence of season. Investigations were carried out to examine how feeding motivation and fat storage were influenced by changes in those environmental cues that indicate the change of season. The effect of the normal winter behavioural pattern upon feeding and fat was also investigated.

Malnutrition and nutritional deprivation are common in hospital patients. Consequent dysfunction is exacerbated in the presence of an inflammatory state and leads to increased morbidity, mortality and treatment cost. This thesis tested the hypothesis that clinical outcome could be improved, and treatment cost reduced, if enteral nutritional (EN) was; a) initiated earlier after the pathological event, and b) when > 50% of a patient's estimated energy and nitrogen requirements were met by EN (ie. aggressive EN). A Preliminary Investigation found that patients starved for &le; 5 days compared to > 5 days, had a lower mortality (p < 0.003) and shorter duration of nasogastric (NG) feeding (p = 0.049). The population studied was heterogenous and no account was taken of disease severity. The hypothesis was therefore re-tested in burned patients, controlling for disease severity. The delay before attempting aggressive EN was associated with major complications excluding (p < 0.001) and including mortality (p = 0.018), length of (hospital) stay (LOS) (p = 0.011), and treatment cost (p < 0.001). Finally, a prospective randomised controlled trial (PRCT) was used to test the hypothesis. A study of patients undergoing major GI surgery failed due to poor recruitment, but useful aspects of this protocol were adapted for a similar trial in head-injured patients. In this group, early aggressive EN was associated with a reduction in infective complications (p = 0.0195), duration of mechanical ventilation (p = 0.019) and treatment cost (p = 0.006). In certain conditions at least, early aggressive EN is associated with improved clinical outcome and reduced treatment cost. Much of this improvement appears to be due to a reduction in infective complications.

This study was conducted to assess the effect of including Tenebrio molitor larvae (T. molitor L) as a protein source in different diets on broiler performance, carcass characteristics and meat quality. A total of 144 day-old Cobb-500 chicks were randomly allocated into three treatment groups, each was allocated 16 birds and reared in 9 identical pens. Experimental diets used were as follows: T1 Control (no T. molitor L inclusion); T2 and T3 contained levels of T. molitor L at 5 percent and 10 percent of dry matter (DM) intake, respectively. Body weights (BW), average daily gain (ADG), feed intake (FI), and Feed conversion ratio (FCR) were measured for the 1st experimental chapter. For the second experimental chapter; live weights (LW) of broilers were recorded before slaughter and thereafter carcass weights (CW), meat yield (weights of breast, thigh, drumstick and wing) were recorded. The dressing percentage (DP percent) was also calculated. Breast muscles were sampled for meat pH and colour measurements. The LW of birds from T1 (0 percent T. molitor L) were significantly different (P<0.05) from both T2 (5 percent T. molitor L) and T3 (10 percent T. molitor L) which were similar to each other, with T2 exhibiting the highest live weights (2166g) and the control treatment exhibiting the lowest live weights (2018.3g). In CW, T1 was significantly different (P<0.05) from T2 while it was similar (P>0.05) to T3. The dressing percent of T1 was significantly different (P<0.05) from T2 and T3 which were similar to each other, with T2 having the highest dressing percentage (78, 2 percent) and T1 having the lowest DP percent (66 percent). The breasts in T2 were significantly higher and different (P<0.05) from both T1 and T3 which were similar to each other. The drumsticks in T3 were significantly different (P<0.05) from T1 while they were similar to T2 with values with T2 having highest values. After 45 minutes of slaughter, a significant difference (P<0.05) was observed in L⃰ among all treatments. In redness (a⃰), T3 was significantly different from T1 but was similar to T2 and all treatments in this study exhibited a darker red meat, with T3 muscles exhibiting darker red colour than the other treatments. Similar results were observed in yellowness (b⃰), where the breast muscles from T3 were more yellow than the other treatments. After 24 hours of slaughter, T2 L⃰ values were significantly different (P<0.05) from both T1 and T3 which were similar to each other. It was also found that the broiler chickens given diet with no T. molitor L inclusion (T1) had lower values of BW, FI, ADG and FCR throughout the experiment than those that were in T2 and T3 with 5 percent and 10 percent T. molitor L inclusion levels, respectively. However, it was also found that although broilers with 5 percent T. molitor L inclusion (T2) in their diet had high ABW and ADG than the broilers with 10 percent T. molitor L inclusion (T3), the T3 birds compared favourably to T2 birds as they required low feed intake to reach the same slaughter weight due to high FCR. It was, therefore, concluded that T. molitor L meal can be incorporated into the diets of broilers to produce heavy birds either at 5 or 10 percent. However, although 5 percent T. molitor L inclusion yields heavier carcasses, the 10 percent T. molitor L inclusion compared favourably to 5 percent inclusion since it required low feed intake to reach the same slaughter weights and there were slight differences on meat quality attributes between the two treatments.Thus T. molitor L at 10 percent inclusion levels was the best inclusion level to enhance broiler growth performance, carcass yield, meat yield and meat quality.

This study determined the effect of maize-, whole wheat-, soya bean-based-diets on the growth performance, egg quality and dressing percentage of chickens, as well as the potential for soy and gluten allergen carryover to eggs and meat from chickens. Twenty 36-week-old Lorham White (LW) hens were divided into two groups and kept in individual cages until they reached 39-weeks of age, with water and feed supplied ad libitum. Ten LW hens were fed a maize/soya bean-based diet (T1) and the other ten birds were fed a maize/soya bean-based diet with a 15 percent whole wheat inclusion (T2) for a period of four weeks, with weekly individual hen weights and group feed consumption figures being recorded. After a two-week diet adaptation period, six eggs per treatment group were collected every second day from the LW hens’ to measure egg quality traits. Every third day, over a 29-day period, six eggs per treatment were collected and analysed for the presence of soy, gluten and gluten-derived peptides using allergen specific enzyme linked immunosorbent assays (ELISA) kits. For the broiler trial, a total of 160 Ross 308 mixed sex day old chicks were used in a completely randomized design. Two dietary treatments were assigned to eight cages (replicate) per treatment, with ten birds per cage. The Ross 308 broiler feeding programme consisted of three phases, starter (day 1 to day 10), grower (day 11 to day 20) and finisher (day 21 to day 28). At the beginning of the trial all chicks were fed T1 which contained a maize/soya bean-based diet for a period of 10 days and then eight cages with 10 birds per cage were randomly selected and fed the T2 diet, which contained a maize/soya bean-based diet with a 15 percent whole wheat inclusion, until they reached 28 days of age. Weekly live weights, feed intake, average daily gain and the average daily feed intake were recorded and calculated. At the end of the grower (day 21) and finisher phase (day 28), one broiler bird was selected per cage to have eight (8) birds per treatment and 16 birds per phase that were slaughtered and breast meat samples were analysed in duplicate for the presence of soy and gluten allergens using ELISA kits. The dressing percentage of hot carcasses was also determined at the end of the finisher phase on eight birds per treatment. For LW hens, live weight (LW) at 39 weeks of age, the average daily feed intake (ADFI) and weekly feed intakes (FI) were significantly different (P < 0.05) between treatments with birds on T2 recording higher gains. As birds age in weeks increased, significant differences (P < 0.05) in live weight values were recorded. Egg quality traits measured (shell weight, yolk weight, albumen weight, albumen height and Haugh units) were significantly different (P < 0.05) between treatments, with eggs from hens receiving T1 recording higher mean values. As hens got older, the colour of egg yolk improved, producing eggs with higher b* (yellowness) values and lower L* (lightness) and a* (redness) mean values. The Haugh unit, significantly improved (P < 0.05) as the hens got older, signifying better quality of eggs. For the broiler birds, growth traits measured indicated that there were no significant differences (P > 0.05) in live weight (LW), average daily feed intake (ADFI), weekly feed intake (FI), feed conversion ratio (FCR), cumulative feed intake (CFI) and cumulative gain (CG) between treatments. No significant differences (P > 0.05) between dressing percentage of broilers from the two treatments were observed. As birds grew, significant differences (P < 0.05) in LW, FI, AFI, FCR, and CFI, over a four-week period were recorded. Results of the allergen analyses indicated that soy and gluten allergens were not carried over from feed into eggs and meat of chickens fed a maize/soya bean-based diet and a maize/soya bean-based with a 15 percent whole wheat inclusion, respectively. In conclusion, a maize/soya bean-based diet and maize/soya bean-based diet with a 15 percent whole wheat inclusion that contained soy and gluten allergens, are feed sources that promote and stimulate 36-week-old LW hen and Ross 308 chicken growth.

This study aimed to investigate the feeding behaviour of the calanoid copepod, Pseudodiaptomus hessei, particularly whether it prefers to feed on a planktonic or benthic food source. The effect of different microalgae species on the feeding preference, ingestion, and gut evacuation rate were investigated. Two microalgae species (Isochrysis galbana and Tetraselmis suecica) were used, to test gut fullness and gut evacuation of P. hessei. The copepods were starved for 6 h and allowed to feed on monalgae diets, I .galbana and T. suecica, and a 1:1 binary diet mixture of T. suecica and I. galbana. The gut fullness and gut evacuation rates were determined by observing under the dissecting microscope and gut content percentage was recorded (as 0, 25, 50, 75 or 100 percent) along with copepod sex. Copepods that feed on T. suecica fill their gut after 30 min, while those that feed on I. galbana do so after 40 min. There was a significant difference (p= 0.02) between sexes with males filling their gut faster than females. However, copepods that fed on I. galbana evacuated their gut content completely after 30 min, while those fed on T suecica evacuated theirs after 40 min. There was no difference between males and females for gut evacuation. Even though there was high gut fullness rate when P. hessei was feeding on T. suecica, I. galbana is recommended as the best mono-algae diet to culture P. hessei. The feeding behaviour of P. hessei was investigated, as to whether it prefers to feed on a planktonic or benthic food source. Copepods were starved for 3 h and then allowed to feed on two microalgae species (I. galbana and T. suecica), one presented as a benthic and other as planktonic. Controls included swapping the modes of presentation for each algae species. Ingested microalgae species were quantified using real-time PCR, with threshold cycles interpreted as relative abundance ratio (planktonic microalgae divided by benthic microalgae species). Pseudodiaptomus hessei preferred to feed on planktonic food sources initially as there was a difference between planktonic and benthic ingested food (p=0.026). Copepods shifted from planktonic to benthic food sources after 80 min of feeding planktonically. Planktonic food sources were the preferred choice for P. hessei regardless of microalgae species offered. The results from this study also confirm that P. hessei feed on a benthic food source during the day under culture conditions. This information can be used as baseline information for aquaculturists to rear the species as live feed for marine fish larvae.

The understanding of maternal factors associated with child feeding problems is limited due to a lack of research which has examined a comprehensive range of maternal factors and the existing literature focussing on a narrow range of ideas about the wider familial context in which feeding problems occur. The broad aim of this thesis is to investigate maternal parenting of children with and without clinical feeding problems to provide insights into the wider context in which feeding problems occur. In study 1, thematic analysis of interviews with 10 mothers of children with, and 10 mothers of children without, clinical feeding problems revealed that mothers of children with clinical feeding problems appeared to have less maternal self-efficacy for managing parenting challenges than mothers in the non-clinical group. A template analysis found that these perceptions seemed to be informed by four theoretical sources of self-efficacy: mastery experiences, verbal persuasion, vicarious experience and physiological state. In study 2, 278 mothers of children with and without clinical feeding problems completed existing self-report measures of maternal self-efficacy. It was found that lower levels of maternal self-efficacy for establishing structure and routine around instrumental child care tasks and for implementing discipline and setting limits for the child was predictive of problematic child feeding behaviour and maladaptive maternal responses to child feeding problems. In study 3, 215 mothers of children with and without feeding problems completed self-report measures of the theoretical components of self-efficacy (mastery experiences, verbal persuasion, vicarious experience, physiological state). Physiological state was found to be the strongest predictor of maternal self-efficacy for establishing structure and routines as well as for providing discipline and setting limits for the child. Maternal self-efficacy mediated the relationship between physiological state and problematic child feeding behaviour and the relationship between parenting stress and maladaptive maternal responses. The final study was a pilot study using autophotography. This study explored parenting dimensions and tasks which contributed towards perceptions of maternal self-efficacy in 13 mothers of children without clinical feeding problems. Findings suggested that child feeding was an especially difficult and complex task for mothers to manage, with many mothers reporting perceptions of low efficacy for managing mealtimes. This appeared to be due to the large number of health related concerns and the worry mothers felt when children did not eat a healthful diet. Overall, results of this thesis suggest that mothers who lack confidence in their ability to manage child behaviour report more problematic child feeding behaviours and use more maladaptive strategies for managing feeding problems. Findings of the studies in this thesis suggest that mothers of children with feeding problems, and who are experiencing high levels of stress, may be especially vulnerable to lower levels of maternal self-efficacy which may exacerbate difficulties. Increasing maternal self-efficacy for providing structure, routines and discipline in mothers experiencing feeding problems in their children may improve outcomes for those affected.

We analyzed the relationship between prey capture and nematocyst distribution in the tentacles of the ambush predators, Aglantha digitale and Proboscidactyla flavicirrata, and the filter feeders, Clytia gregaria and Mitrocoma cellularia. we used video observations to compare capture locations of Artemia salina nauplii relative to the bell margin of each species. Tentacle pictures were analyzed to determine if nematocyst abundance changes along their length. By analyzing behavior and morphology simultaneously, we found that the ambush predators A. digitale and P. flavicirrata plus Sarsia tubulosa have higher nematocyst density at the tentacle tips and tend to capture more prey toward the tips. In contrast, the filter-feeders Aequorea victoria, C. gregaria and M. cellularia capture most of the prey close to the body, where they also show a slight increase in nematocyst densities.

The preferential grazing of an organism on certain particles from the environment (selective feeding) impacts particle compositions and distributions in aquatic systems. Historically, selective feeding has been examined almost exclusively through the lens of particle size. In this dissertation, I investigated size-based selection alongside particle shape, adhesive interactions, and the mechanical operation of the filter to characterize the selective-feeding capabilities of marine mucous-mesh filter-feeders (the planktonic appendicularian Oikopleura dioica and the benthic ascidians Herdmania momus and Styela plicata). I used high-speed videography to describe the feeding-filter mechanics of O. dioica and tested its capacity for size-based particle selection. I show for the first time how pulsatile flow coupled with elasticity of the filter facilitates prey detachment. Using synthetic beads, I showthat the food-concentrating filter selectively retains smaller particles because of their increased adhesion. Appendicularian houses may therefore retain particles size-selectively, which counters the historically-held assumption that appendicularians are non-selective grazers. I synthesized ellipsoidal microbeads to test the effect of particle length-to-width ratios on the capture efficiency of O. dioica and S. plicata. Both grazers retained ellipsoidal particles according to their minimum diameter. I identified the kinematic mechanism for retention patterns of ellipsoidal particles using high-speed videography and endoscopy of particle interactions with the mucous filters of O. dioica and H. momus, respectively. In the filters of both animals, ellipsoids oriented parallel to fluid streamlines and the minimum dimension of the particle intercepted the filters. I provide the first mesh-scale observations of particle capture by H. momus, show how particle shape influences hydrosol filtration by S. plicata, and suggest that ascidian filtration may not be adequately described by simple sieving.

To determine the relationship between infant-feeding practices and diarrhoeal infections, a descriptive survey was conducted to infants between six to 12 months of age. A guided interview was conducted to 105 mothers of infants who attended the health facilities of Mbabane, Swaziland. The results show that breast-feeding is routinely practiced by the majority of mothers and exclusive breast-feeding is very low, but supplementary feed in the form of formula or solids are introduced by the majority of respondents within the first three months of life. Infants who were given colostrum and breast milk had fewer diarrhoeal attacks. Other factors, for example education and cultural factors influenced the feeding practices and number of diarrhoeal attacks. It is recommended that breast-feeding should be promoted as an important intervention in the control of diarrhoea / Health Studies / M.A. (Nursing Science)

Population density, growth and mortality rates, reproduction, feeding ecology and energy mobilization of dab (Limanda lmanda L) on the North Wales Coast have been investigated between 1998-2001. The total population number is estimated as 2.34 x 10 6. Average catch rates were lower in winterspring than in autumn-summer. 42 hr' in February 2000; 141 hr'in July 2000. Catch rates were generally higher at night than daylight: 1549 hr'at 02: 00 hr, 17 hr'at 10: 00 hr in November. The 2- year old fish form the dominant year class. There was seasonal variation in sex ratio (Females: Males). In the long-term data, in autumn, the females were more abundant (1.83: 1) in trawl catches but the contribution of the males increases in spring (1.15: 1). There were seasonal variations in length and weight relationships: the average relationship was nearly isometric (power bx3.0); in male W=0.01 x TL 91 and in female, W=0.01 x TL 3'04. April 1s' was established as the birthday of the fish and the greatest deposition of the opaque zone in the otolith occurred in summer. The male grows at a faster rate than female in autumn 2000: (Loo=25.7 cm; K= 0.30 y 1) and (loo=33.4 cm; K= 0.25 y-) respectively. The long-term average total mortality rate was significantly higher in males (Z= 1.95 y) than females (Z= 1.16 Y"). This difference was calculated to be largely due to the relatively higher fishing mortality rate on the males. There were cyclical cycles in the gonad, liver weight and condition factors. The peak spawning activity in males was in December-January whilst it occurred in February-March in females. In the 16-20 cm male, the maximum gonadocarcass ratio, GCR, (1.8 %) and hepatocarcass ratio, HCR, (2.9 %) were in January and August respectively. In female, the maximum GCR (17.1 %) and HCR (3.8 %) occurred in February. The GCR was at a minimum in spring-summer. The minimum HCR occurred in spring. The maximum condition factor (K) was in summer for male (K=0.97) and female (K=1.02) but, after spring spawning, declined to 0.67 and 0.72 respectively. The maximum average oocyte diameter (0.56-0.67 mm) was observed in fully ripe fish in the spawning season but, after spring spawning, reduced to between 0.10-0.22 mm. The total estimated egg production was 2.47 x 10 ' eggs but the average per mature female was 3.51 x 105 eggs. Relative fecundity declined from 3045 eggs g' in fish aged I to 1917 eggs g' in fish aged 8. The fecundity-total length (F= 41.6 TL IN) and fecunditysomatic weight (F= 4804SW 0.88) relationships are estimated to be good predictors of dab fecundity. In autumn 2000, the length (Lw%) and age (A w%) at 50 % maturity were lower in males (L = 13.3 cm; Ate, =1.3 yr. ) than females (L = 18.0 cm; A =2.4 yr. ). The long-term averages showed relative stability in the females but a decrease in males, Ate, from about 2 years to about 1.5 years. Five major taxonomic groups dominated the diet of dab: the ophiuroids, bivalves, crustaceans, polychaetes and hydroids. The ophiuroid, Amphiura brachiata, predominated. However, the study suggests size-selective preference for some prey groups. The composition of polychaetes in the diet declined with increasing size of the fish; 22.9 % by weight in the 11-15 cm length group to 5.7 % in the 26-30 cm group. On the contrary, the bivalves increase in the diet with increasing size of the fish, from 11.2 % (by weight) in the 11-15 cm group to 31.4 % in the 231cm group. There is however a significant diet overlap (C; >- 0.60) between the size groups. In general, daily food intake was higher in late spring-summer than in autumn-winter. In May, for example, daily food intake for the 21-25 cm and 26-30 cm female dab was estimated as 1.49 g and 4.61 g respectively. In February it was 0.52 g and 1.76 g respectively. There were distinct seasonal changes in lipid and energy composition in the liver. Lipid content was significantly higher in the summer-autumn period than spring season. In September, it was about 62 and 69 % in male and female livers respectively. After spring spawning, the composition declined to 28 and 24 % respectively. The energy content per dry weight of liver peaked in October (8.50 kcal g' and 8.61 kcal g') in male and female dab respectively. Also, after spring spawning, the energy levels declined to 6.18 and 5.86 kcal g'' respectively. The energy requirement for routine metabolism and gonad development in a 20 cm female is estimated as 111.3 kcal but energy gained from food intake and carcass and liver reserves is estimated as 117.9 kcal. In male, the total energy requirement was 83.4 kcal but energy gained from food intake and carcass and liver reserves is estimated as 113.3 kcal. Feeding (in late autumn and winter) and carcass tissues are the main suppliers of energy for activity and the spawning process.