Showing papers on "Compensatory growth (organism) published in 2009"

Changes in glucocorticoids, IGF-I and thyroid hormones as indicators of nutritional stress and subsequent refeeding in Steller sea lions (Eumetopias jubatus).

Abstract: Physiological responses to changes in energy balance are tightly regulated by the endocrine system through glucocorticoids, IGF-I and thyroid hormones. Changes in these hormones were studied in eight captive female Steller sea lions that experienced changes in food intake, body mass, body composition, and blood metabolites during summer and winter. During a period of energy restriction, one group of sea lions was fed reduced amounts of Pacific herring and another was fed an isocaloric diet of walleye pollock, after which both groups returned to their pre-experimental diets of herring. Cortisol was negatively and IGF-I was positively associated with changes in body mass during periods of energy restriction (mass loss associated with increase in cortisol and decrease in IGF-I) and refeeding (body mass maintenance associated with stable hormone concentrations in summer and compensatory growth linked to decrease in cortisol and increase in IGF-I in winter). Cortisol and IGF-I were also correlated with changes in lipid and lean mass, respectively. Consequently, these two hormones likely make adequate biomarkers for nutritional stress in sea lions, and when combined provide indication of the energetic strategy (lipid vs lean mass catabolism) animals adopt to cope with changes in nutrient intake. Unlike type of diet fed to the sea lions, age of the animals also impacted hormonal responses, with younger animals showing more intense hormonal changes to nutritional stress. Thyroid hormones, however, were not linked to any physiological changes observed in this study.

Compensatory responses to food restriction in juvenile green turtles (Chelonia mydas)

Abstract: The purpose of this study was to assess the compensatory responses to food restriction and subsequent increased food availability in juvenile green turtles (Chelonia mydas). Turtles were fed an ad libitum ration for 12 weeks (AL), a restricted ration for 12 weeks (R), or a restricted ration for 5 weeks and an ad libitum ration for 7 weeks (R-AL). Analysis of covariance was used to test the relationships between (1) growth and body size, (2) intake and body size, and (3) growth and intake for each of the three treatment groups. Body composition of turtles in each group was also evaluated at the beginning of the study and after weeks 5 and 12. After the switch to ad libitum feeding, R-AL turtles consumed comparable amounts of food and grew faster than AL turtles on a size-adjusted basis, but mean body sizes did not converge, although the overlap in their size ranges increased with time. The R-AL turtles also converted food to growth more efficiently and allocated proportionally more nutrients to protein accretion, thereby restoring body composition (except mineral content) to AL levels by the end of the study. Thus, accelerated size-specific growth without hyperphagia restored body condition but not size. These results indicate that (1) intake in juvenile green turtles is maximal when food is readily available and cannot be increased to compensate for a previous period of food limitation, (2) growth rates of ad libitum-fed turtles are only mildly plastic in response to past nutritional history, and (3) priority rules for nutrient allocation favor the attainment of an optimal condition rather than an optimal size. Nutritional setbacks experienced during the vulnerable juvenile stage could therefore have long-lasting consequences for wild turtles in terms of size-specific mortality risk, but these risks may be mitigated by the potential benefits of maintaining sufficient body stores.

Cyclical feed deprivation and refeeding fails to enhance compensatory growth in Nile tilapia, Oreochromis niloticus L.

Abstract: A 12-week experiment was carried out to evaluate compensatory growth of 6.6 g Nile tilapia Oreochromis niloticus L. under three cyclical regimes of feed deprivation and refeeding. The deprivation and refeeding regimes included four cycles of 1 week of deprivation and 2 weeks of refeeding (S1F2), two cycles of 2 weeks of deprivation and 4 weeks of refeeding (S2F4) and one cycle of 4 weeks of deprivation and 8 weeks of refeeding (S4F8). A group of fish fed to satiation twice daily throughout the experiment served as control. At the end of the refeeding periods, fish deprived and refed cyclically had higher feed intake and specific growth rates (SGR), but lower body weight, than that of the control fish. There was no significant difference in feed efficiency ratio (FER) between the control and fish subjected to feed deprivation during the refeeding periods, and nitrogen retention efficiency (NRE) was not different between any two treatments throughout the experiment. At the end of the experiment, fish subjected to feed deprivation had lower body weight but similar body composition, relative to those of the control fish. No significant differences were found in final body weight, NRE and body composition between the fish subjected to different cycles of deprivation and refeeding, but the fish subjected to one cycle of deprivation and refeeding exhibited high mortality. Our results indicate that partial growth compensation induced by various cycles of feed deprivation and refeeding does not confer a huge advantage in terms of enhancing the production efficiency and reducing the nitrogen waste output in Nile tilapia farming 29–30 °C.

Linking marine and freshwater growth in western Alaska Chinook salmon Oncorhynchus tshawytscha

Abstract: The hypothesis that growth in Pacific salmon Oncorhynchus spp. is dependent on previous growth was tested using annual scale growth measurements of wild Chinook salmon Oncorhynchus tshawytscha returning to the Yukon and Kuskokwim Rivers, Alaska, from 1964 to 2004. Firstyear marine growth in individual O. tshawytscha was significantly correlated with growth in fresh water. Furthermore, growth during each of 3 or 4 years at sea was related to growth during the previous year. The magnitude of the growth response to the previous year’s growth was greater when mean year-class growth during the previous year was relatively low. Length (eye to tail fork, LETF) of adult O. tshawytscha was correlated with cumulative scale growth after the first year at sea. Adult LETF was also weakly correlated with scale growth that occurred during freshwater residence 4 to 5 years earlier, indicating the importance of growth in fresh water. Positive growth response to previous growth in O. tshawytscha was probably related to piscivorous diet and foraging benefits of large body size. Faster growth among O. tshawytscha year classes that initially grew slowly may reflect high mortality in slow growing fish and subsequent compensatory growth in survivors. Oncorhynchus tshawytscha in this study exhibited complex growth patterns showing a positive relationship with previous growth and a possible compensatory response to environmental factors affecting growth of the age class.

Effect or ractopamine on growth and body composition of pigs during compensatory growth.

Abstract: The purpose of this study was to measure the growth and body composition of pigs during normal or compensatory growth from 60 to 100 kg, without (cont) or with ractopamine (rac) supplementation (20 mg/kg of diet). Thirty-four pigs were scanned by dual X-ray absorptiometry (DXA) for body composition analysis at a starting weight of 61.4 ± 0.3 kg and at a final weight of 100.4 ± 0.5 kg. Half the pigs were fed ad libitum throughout (8 cont and 9 rac). The other half were fed at maintenance for 8 weeks and then scanned again by DXA. Following the maintenance feeding, the pigs were fed ad libitum (9 cont and 8 rac) to the final weight. Compensatory growth resulted in a 30% increase in the rate of weight gain (1.23 v. 0.94 kg/day, P 0.05). Feeding rac resulted in a 13% increase in the rate of weight gain (1.15 v. 1.02 kg/day, P < 0.05), consisting of a 29% increase in the rate of lean tissue deposition (0.86 v. 0.67 kg/day, P < 0.05) and an 18% reduction in the rate of fat deposition (0.27 v. 0.33 kg/day, P < 0.05). The effects of ractopamine on the rates of fat and lean tissue deposition were similar for pigs continuously fed ad libitum and those experiencing compensatory growth. Both compensatory growth and the addition of ractopamine to the diet resulted in an improvement in efficiency of protein deposition; however, ractopamine also resulted in a reduction in the efficiency of energy deposition. For both growth rate and lean tissue deposition, there was an additive effect for ractopamine and compensatory growth. Thus, feeding ractopamine will enhance the growth and body composition during compensatory growth in swine.

Annuals sprouting adventitiously from the hypocotyl: their compensatory growth and implications for weed management

Abstract: Habitats, disturbed severely at least once a year, are often dominated by annual plants, which avoid disturbance by means of a short life span and massive production of seeds. Contrary to perennials, they lack pools of reserve meristems on and storage carbon in below-ground organs necessary for vegetative regeneration after disturbance. However, some annuals are able to initiate a bud bank on the hypocotyl after loss of their shoot. In three experiments, we investigated how the timing of disturbance or population origin affects adventitious bud formation on the hypocotyl for regeneration and compensatory growth in some annual weeds. The best regenerative abilities were observed in Kickxia spuria and K. elatine, with 87% and 80% of individuals regenerating, respectively, followed by Microrrhinum minus with almost 70%. Less than 30% of individuals regenerated in Euphorbia peplus and Anagallis arvensis. The time of injury did not affect the regeneration capacity of species for which the timing was examined, nor their consequent compensatory growth. The best compensation for biomass and fruit production was observed in M. minus, albeit two populations differed in this respect. The injured plants were shorter and produced more shoots than intact plants. Mechanical control of weeds capable of forming adventitious buds on hypocotyl by harrowing, brushing, or cutting may not be sufficient in organically farmed lands.

The compensatory growth in juveniles of sea bass: gastric distributive pattern of molecules regulating metabolism.

Abstract: The aim of this work was to investigate the distribution of regulative molecules in the stomach of juvenile Dicentrarchus labrax during compensatory growth, using immunohistochemical methods Antisera against galanin, neuropeptide Y, ghrelin, leptin, and serotonin were used on fasted and refed D labrax The results show a characteristic distributive pattern for the sought molecules in fish refed after 35 days of fasting, with a high increased presence of both ghrelin and leptin

Effect of initial size on daily growth and survival in freshwater Chondrostoma nasus larvae: a field survey

Abstract: Effects of initial size on the growth and survival of a freshwater fish, Chondrostoma nasus, were tested in a field survey, where individually tagged larvae were introduced into a potential nursery habitat. Characteristics of individual daily growth trajectories were utilized as a basis to explain growth, as well as survival patterns, in relation to ontogeny. Initial size only affected growth rates during the larval phase. Survival patterns could not be explained solely based on size-selective mortality processes because prey-predator interactions played a major role as well. This is confirmed by the Lande-Arnold selection model because directional, as well as stabilizing gradients, showed significant values. Thus, for the 0+ year freshwater fish, inherited size-specific effects were a significant advantage for growth performance and survival in early ontogeny. As fish grew older, however, other effects such as compensatory growth and prey-predator interactions apparently gained in importance.

1. Effect of Compensatory Growth on Performance of Sudanese Female Goats

Abstract: Tow groups of female goats less than one year in age, Nubian ecotype (15 goat/group) and of the same initial weight (16.5 kg/kid) were subjected to tow dietary levels of energy for 105 days, the first group was offered the highest energy diet (11.5 MjME/kcl) while the second group was given the lowest dietary energy diet (8.5 MjME/kcl). Through this term of the experiment (105 days) goats of the second group were found just to maintain their weight. Then seven goats from the second group was offered the highest energy diet (11.5 MjM E/kg) to reach the final weight obtained by the first group, it spent 175 days to reach that weight. These goats which were raised on the lowest dietary energy level (8.5 MjME/kg) were used to study the effect of compensatory growth on the performance of Sudanese female goats. Weekly, daily rate of gains and total dry matter intake were significantly (p< 0.001) lower in the compensating female goats than the first group. It could be concluded that compensatory growth significantly (p<0.01) affected daily and weekly rate of gain and total dry matter intake which were lower in the compensating goats than the normally growing goats.

Influence of feed texture and early quantitative feed restriction on performance, growth development and carcass composition of two broiler strains.

Abstract: Genetic selection and optimisation of nutrition have contributed to increasing growth rates and higher body weights at market age of modern broiler strains. These increased growth rates are associated with a higher feed and nutrient intake. On the other hand, they have also led to a more frequent occurrence of metabolic diseases, skeletal and cardiac disorders (SALEH et al., 2005; LEESON, 2007). It is well established that crumbles and pellets give higher growth rates than mash diets (SAVORY, 1974; HAMILTON and PROUDFOOT, 1995). According to NIR (1997) adaptation to changes in feed texture includes feed consumption, capacity and evacuation of the gastro-intestinal tract, synthesis and secretion of digestive enzymes, lipogenesis, eating behaviour and activity. Also, due to the pelleting process, a higher digestibility of some nutrients or inactivation of heat-labile toxic factors can be realised, depending on feed ingredients used (HUYGHEBAERT and DE GROOTE, 1979, 1980; LEESON and SUMMERS, 2001). In general, it is to be expected that for the extreme selected strains with very high growth rates the occurrence of the mentioned metabolic diseases will be more pronounced (PROUDFOOT and HULAN, 1989; JULIAN, 2005). To avoid these negative effects, feed restriction programmes have been introduced. As predisposition for metabolic disorders already occurs during the first weeks of life, it can be understood that reducing initial growth and thus, the metabolic load and oxygen requirements in this crucial phase, is a good way of avoiding metabolic disorders (BUYS et al., 1998). The consequent compensatory growth is expected to give similar final body weights and better feed conversion in comparison with ad libitum fed birds (PLAVNIK and HURWITZ, 1988, 1991). Moreover, previous investigations indicated that these programmes are able to reduce leg problems, metabolic diseases (GONZALES et al., 1998; LIPPENS et al., 2000; 2002) and mortality (CARTER et al., 1994; LIPPENS et al., 2000).

Compensatory growth in slaughter pigs reared under organic conditions

Abstract: BACKGROUND: Compensatory growth is the physiological process leading to accelerated growth following a period of growth retardation. This study assessed different feeding strategies thatmay induce compensatory growth. Pigs from two sire breeds, reared under organic conditions, were subjected to: (1) ad libitum feeding; (2) 0.7× ad libitum feeding; (3) 0.7× ad libitum feeding for 25 days followedby adlibitum feeding toslaughter; and(4) as (3) butfinished with an energy- andvitamin E-enriched diet. RESULTS: Compared to the performance of ad libitum fed pigs, re-alimentation was not capable of fully compensating the effect of the imposed feed restriction either in the number of days used to reach the same slaughter weight (+4% to 7%) or in the slaughter weight achieved in the same number of feeding days (−0.5% to 2.0%, P = 0.65 and 0.11). CONCLUSION: It is reasonable to propose that although compensatory growth does occur by re-alimentation after feed restriction, the compensation is far from always complete. The latter is a crucial aspect that has to be taken into account when considering the application of feeding strategies expected to lead to compensatory growth in organic pig production. The expectation of compensatory growth alone does not necessarily justify the application of these strategies.

Compensatory Weight Gain and Muscle Tissue Biochemical Composition of GET Excel Tilapia (Oreochromis niloticus) Juveniles

Abstract: The ability of tilapia (Oreochromis niloticos) for compensatory growth response following a period of starvation was investigated in the MSUN-IFRD Laboratory. The effects of food deprivation on growth performance, feed response, survival, and chemical composition of fish muscle of GET Excel tilapia juveniles were studied. The juveniles (1.19 - 1.62g) were subjected to different periods of starvation : 0, 2, 3, 4, and 5 days (representing the control T1 and experimental treatments T2, T3, T4 and T5), after which they were fed for 30 days. Periodic sampling was done every seven days to determine survival and change in weight of tilapia juveniles. Juveniles starved for shorter periods (2-3 days) recovered faster ( 0.05) with T1 (2.86% BW.d -1 ) after 18 days of culture (DOC). Feed conversion efficiencies (FCE) of T2 (53.68%) and T3 (54.01%) were significantly higher (P 0.05) in all treatments. Difference in weight gain, SGR, FCR, feed requirements, and protein content of fish muscle were not significant among the treatments (P>0.05) when the experiment was terminated. The result showed that GET Excel tilapia juveniles demonstrated a positive compensatory growth and high survival rate after being subjected to up to 5 days of starvation.

Psychosocial deprivation as a cause of growth retardation in children

Abstract: Patient A, a 3-year-old boy with short stature, in whom a partial growth hormone deficiency had been diagnosed, was treated with growth hormone. Further evaluation, however, showed that there was evidence of psychosocial deprivation as a result of an unstable family situation. After psychosocial circumstances improved, growth hormone therapy was discontinued, following which no further growth retardation was observed. In the case of patient B, a 10-year-old girl with short stature, reconstruction of the growth curve showed that growth stagnation had occurred around the age of 6 years. The cause was psychosocial deprivation during a severe illness in one of her triplet sisters. Following stagnation, there was insufficient compensatory growth, resulting in short stature. These cases emphasize the importance of reconstruction of the growth curve and of taking a thorough psychosocial case history in all children with growth retardation or small stature. The clinical picture of psychosocial growth retardation can be similar to the picture of idiopathic, isolated growth hormone deficiency. Prompt and accurate diagnosis prevents unnecessary, extensive investigations and enables adequate treatment and support.

Effect of Starvation and Compensatory Growth on Growth and Body Biochemical Composition in Juvenile Carassius auratus Red Variety

Abstract: The changes of growth and body biochemical composition was examined after different starvation and re-feeding treatment in juvenile Carassius auratus red variety. The index of weight,hepatosomatic,CF,HIS declined under state of starvation. The weight of all starvation groups had very notable difference compared with that of the same term comparison group(P﹤0.01) .The weight of starvation-15-days-group had very notable difference compared with the initial weight(P﹤0.01) . The content of liver glycogen,protein and lipid declined when the content of moisture and ash raised after starvation. All of the index had recovered to have no notable difference with the comparison group after re-feeding except the content of liver glycogen of starvation-15-days-group. In this experiment,all starvation groups had very notable difference compared with that of the same term comparison group(P﹤0.01) .The results indicated that the fish displayed completely compensatory growth and it was achieved by improving feed conversion rate(FCE%) . The fish made glycogen and lipid as major energy substance when it faced short period starvation.