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ThesisItem Open Access Influence of dietary supplementation of protein and iodine on tapioca toxicity(Department of Physiology and Biochemistry, College of Veterinary and Animal Sciences, Mannuthy, 1994) Abdul Latheef; KAU; Ramakrishna Pillai, M GA three phase experiment was carried out to assess the level of cyanogenic glycoside (CNG) content in seven varieties of tapioca, its removal by various processing methods and its effect on metabolism in rats and kids. The role of dietary protein and iodine in modifying the deleterious effects of cyanide v/as investigated. Histopathological studies on the liver, pancreas and heart were also carried out in rats. The first phase of the study revealed that CNG content in terms of cyanide varied from 40.86 + 2.79 to 186.31 + 5.30 ug/g of fresh tuber with the lowest concentration in 'M-4' and higher concentrations in 'H-165' and 'Karkidakkan'. Processings like boiling and sun drying lowered the CNG content by about 50 per cent of the original. In the second phase 60 male albino Wistar rats, divided into six groups were given the following diet. Group I - Protein = 15%; Tapioca = Nil; Iodine = Nil Group II - Protein = 15%; Tapioca = 30%; Iodine = Nil Group III - Protein = 7.5%; Tapioca = 30%; Iodine = Nil Group IV - Protein = 7-5%; Tapioca v/ithout HCN = 30%; Iodine = Nil Group V - Protein = 15%; Tapioca = 30%; Iodine = 0.17 mg/kg Group VI - Protein = 22-5%; Tapioca = 30%; Iodine = 0.17 mg/kg Performance of rats was evaluated by recording growth rate, feed consumption and feed efficiency for a period of 12 weeks. Dry matter digestibility was also determined over a period of 24 h. At the end of 10th, 11th and 12th week of the study the rats were sacrificed and endocrinological, biochemical and histopathological evaluation of blood/serum and tissues were made. Performance of rats v/as poor on tapioca-based diet not supplemented with iodine (Groups II and III). Rats fed on protein deficient diet in the presence of cyanide containing tapioca were the most affected (Group III) . However, there was no significant variation in the performance in Groups V and VI compared to Group I when tapioca-based diet were supplemented with iodine. The digestibility of dry matter in six groups of rats was almost inversely related to the quantity of feed consumed. There was significant increase in DNA and decrease in protein content of thyroid thereby increasing the DNA: protein ratio, followed by extremely low levels of thyroxine and hyperplasia of the thyroid in Group III. In Group II alsothere occurred a significant reduction in the levels ofthyroxine and a resultant hypertrophy of the thyroid.ThesisItem Open Access Soil and crop management for organic carbon sequestration in a coconut based cropping system(Department of Agronomy, College of Agriculture, Vellayani, 2007) Sudha, B; KAU; Annamma, George (GuideI)Soil, the soul of infinite life, despite being the most basic of all natural resources is severely neglected these days. Quality of soil is determined much by the soil organic matter (SOM) content and hence SOM is regarded as the foundation of sustainable agriculture. The lesser addition of carbonaceous organic inputs to soil coupled with oxidative losses associated with tillage are the major reasons for the loss of SOM and hence organic carbon from cultivated soils. The oxidative losses of SOM contributes to release of carbon dioxide, the major greenhouse gas and aggravate the phenomenon of global warming. On the other hand, maintaining adequate carbon levels in soil by means of enriching SOM is important as carbon supports soil microbes by providing energy for their activities. Carbon sequestration is a management strategy which serves the twin purposes of storage of carbon in soil sinks preventing it’s loss as carbon dioxide into the atmosphere. Based on this,the present study was planned with the objective of developing a suitable soil and crop management practice for improving the soil organic carbon content through carbon sequestration in a coconut based cropping system. The study intended to evaluate the effect of the management practices on soil properties, crop growth and yield and to work out the economics of the system. The study was carried out in two experiments. Among the various management options to conserve and sequester carbon in agricultural soils cropping system approach, residue management and tillage holds much significance and were tried in Experiment I entitled “Influence of crops and cultivation practices on soil organic carbon enrichment and crop performance”. This experiment involved three coconut based cropping systems viz. coconut – banana (s1), coconut- maize (s2), and coconut- pineapple (s3). Management of residue was attempted as surface mulch (m1) and soil incorporation (m2) so as to assess their varying impact on carbon sequestration. Conventional tillage operations (t1) ensuring more soil aeration to enhance SOM decomposition was compared with reduced till method (t2). Altogether there were 12 + 1 (coconut alone as control) treatment combinations replicated thrice in factorial randomized block design. Perusal of the results indicated positive influence on most of the soil properties from the initial to the final stage of the experiment with treatments. Coconut- pineapple systems where pineapple residue was recycled, surface mulching of residues and reduced tillage contributed to significant build up of organic carbon and organic matter in the upper soil layer by the end of second year in comparison to other treatments. Significant increase in the enzymatic status of soil for soil enzymes dehydrogenase, phosphatase, urease, cellulase and protease noticed under these treatments is attributed to the maintanance of more SOM . These treatments also maintained higher humic acid status, available phosphorus, available potassium and cation exchange capacity at the final stage of the experiment. With surface mulching and reduced tillage, there was improvement in the aggregate stability of soil which resulted in favourable decrease of bulk density. Under surface mulching, coconut – pineapple and coconut – banana systems recorded higher water holding capacity. The fulvic acid content of soil was more with coconut – pineapple system and reduced tillage. The surface mulched plots maintained higher humic acid : fulvic acid ratios. The total and available nitrogen status of soil was found higher and comparable under coconut – banana and coconut – pineapple systems. With surface mulching and reduced tillage in coconut – banana systems, more number of suckers and higher biomass of banana resulted. For pineapple, these treatments effected in better plant height, plant spread, reduction in the number of days to flowering, increased fruit girth and fruit yield. For first and second crop of maize, higher grain yield resulted from surface mulching. The coconut yield was not significantly influenced by treatments at the end of the study. The Benefit : Cost ratio revealed that coconut – pineapple systems, surface mulching and reduced till were much economical when compared to other treatments. Experiment II on “Carbon dynamics of organic residues” was carried out in microplots by studying the litter decomposition pattern for the three type of residues – maize (r1), banana (r2) and pineapple (r3), which were used in Experiment I. The residues were maintained in plots either as surface mulch (m1)or incorporation (m2). Control plots also were maintained without mulching. 6+1 (control) treatments were replicated thrice in factorial randomized block design. At the end of the study after one year time, it was noticed that maize residue decomposed almost completely whereas pineapple residue the least. With progress of decomposition, there was a decline in the percentage residue constituents except for lignin and ash. Higher status of soil organic carbon, soil organic matter and soil enzymes like dehydrogenase, urease and phosphatase were observed in surface mulched pineapple plots. The availability of nitrogen in soil was significantly high for maize residue plots by six months of time but by the time of one year, pineapple residue added plots had significantly higher nitrogen status. The results of the investigation reveals that pineapple residue with high lignin content and hence slow decomposition rates can enrich the organic matter status of soil even one year after it’s application especially when used as surface mulch. Coconut – pineapple cropping systems can be encouraged with surface mulching of residue and reduced till practices so as to enrich SOM and SOC for improved soil quality and to reap better profits.ThesisItem Open Access Effect of season and antistress agents on physiological and biochemical parameters of Broiler Chicken Under Stress(Department of veterinery physiology, College of veterinary and animal sciences, Mannuthy, 2007) Karthiayini, K; KAU; Philomina, P TThe study was conducted with the objective of ascertaining the efficacy of certain antistress agents as probiotic with multiple strains of bacteria and yeast (Protexin), antibiotic as virginiamycin (Stafac-20) and vitamin C in ameliorating the overcrowding stress induced during summer and rainy seasons in respect of physiological, biochemical, hormonal, immunological and production parameters of broiler chicken. The experiment was carried out on one-month-old Vencob broiler chicks in two separate phases; phase-I during summer and phase II during rainy season. In each seasonal phase, the birds were divided into five groups with 12 birds in each group. Each group was replicated twice. The birds in different groups were G-I – unstressed control birds (provided with a floor space of 696 cm2/bird), G-II – stressed control (floor space reduced by 50% to have a space allowance of 348 cm2/bird), G-III – overcrowded birds supplemented with Protexin at the rate of 0.025 per cent in the diet, G-IV- overcrowded birds supplemented with virginiamycin at the rate of 0.002 per cent in the diet, and G-V- overcrowded birds supplemented with vitamin C at the rate of 0.03 per cent in the diet. Blood samples were collected from six birds in each replicate using appropriate anticoagulants. Haematological parameters were estimated using the whole blood. Plasma samples were separated and used for estimating biochemical and hormonal parameters. Quantification of immunoglobulin G (IgG) and electrophoretic separation of plasma proteins were carried out. Heterophil:Lymphocyte (H:L) ratio and lymphoblastogenic response were also recorded. The data were analysed statistically using appropriate tools. Values of total erythrocyte count (TEC), concentration of haemoglobin (Hb), volume of packed red blood cells (VPRC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), total leukocyte count (TLC) monocyte percentage, concentration of plasma total proteins, plasma alanine amino transferase (ALT) activity, plasma concentration of triiodothyronine (T3) and thyroxine (T4), organ weight of different organs as heart, spleen, liver, gizzard, fat percentage and dressing percentage were not significantly affected by applied stress of overcrowding. The percentage of heterophils, lymphocytes, basophils, H/L ratio, plasma concentration of globulin, total lipids, total cholesterol, and glucose, activities of plasma enzymes such as aspartate amino transferase (AST), lactate dehydrogenase (LDH), body weight, body weight gain, feed intake, and feed efficiency were influenced by overcrowding stress in both summer as well as rainy seasons. Although the concentration of stress hormones (cortisol and corticosterone) increased significantly (P0.05) by overcrowding stress in six week old broilers, continued application of the same stress caused waning off the increase to merely insignificant level. The applied stress and summer heat deteriorated the immune status of the broilers whereas the supplemented feed additives normalised many of the stress-induced changes in the haematological, biochemical and production parameters. Out of the antistress feed supplements used vitamin C was found more efficacious and economical than Protexin and virginiamycin in repealing the stress induced alterations in broilers at six and eight weeks of age both in summer and rainy seasons. Virginiamycin supplementation adversely affected the haematological parameters. Seasons significantly changed the concentration of Hb, VPRC, heterophil count, lymphocyte count, H/L ratio, plasma LDH activity, plasma concentration of T3, T4, and cortisol as well as body weight of broiler chicken. The values of heterophil count, H/L ratio, plasma concentration of LDH, and cortisol were higher in summer, whereas, lower values were observed for Hb concentration, VPRC, lymphocyte count, plasma concentration of T3 and T4 and body weight. The birds in summer gave a better economical gain than those in rainy season. Haematological parameters such as TEC, TLC, MCH, percentages of monocytes, basophils, biochemical parameters such as plasma concentration of glucose, total proteins, albumin, globulin, A:G ratio, plasma concentration of total lipids, triglycerides, total cholesterol, AST, and ALT, corticosterone and production parameters such as body weight gain, organ weight, body fat percentage and dressing percentage were not significantly affected by seasons. Both overcrowding and summer heat stress reduced the feed intake of broilers. The plasma concentration of albumin, total lipids, cholesterol, glucose, AST, ALT, and LDH were increased significantly with the increase in age (4-8 weeks period) in both seasons. Significant reductions in the plasma concentration of corticosterone and T3 were noticed with the advancement of age. The values of VPRC, TLC, plasma concentration of globulin, A:G ratio, plasma concentration of triglycerides and cortisol, were not significantly affected by the age of the birds (4 to 8 weeks). From the results of the study it could be inferred that stress of overcrowding adversely affected many of the physiological, biochemical and production parameters of six and eight week old broiler chicken. Antistress feed supplements such as Protexin, virginiamycin and vitamin C were effective to rectify most of the stress-associated changes, but not all. The vitamin C was found better and more economical than other feed additives as Protexin and virginiamycin. Dietary supplementations of antistress agents were more effective in overcrowded, heat stressed birds of summer season than their counter parts of rainy season.