Loading...
![Thumbnail Image](assets/images/Collection.png)
Theses
Browse
Search Results
ThesisItem Open Access Effect of environmental heat stress on performance of crossbred dairy cattle(Department of Livestock Production Management, College of Veterinary and Animal Sciences, Mannuthy, 1989) Thiagarajan, M; KAU; Thomas, C KAmple evidences are available on the poor performance of livestock inhabiting the tropical regions of the world, compared to their counterparts in the temperate zones. By and large, the management practises adapted in the warmer areas are to be quite different from cooler regions to reach optimum productivity. Among the management practises, housing and feeding aspect needs to be given more emphasis in bringing about the much desired results to meet the ever increasing demand for livestock products. In the present work, an attempt has been made to investigate the effects of housing and feeding inter alia. On the growth and production of B. Taurus x B. indicus crossbred cattle. Besides these, some of the important climatic components, such as solar radiation, mean radiation, temperature of the surrounding and the wind velocity, the factors which have hither to been widely neglected, were tried to be methodically quantified and presented in relation to their direct effect on the physiological and productive responses of cattle. To assess the effect of shelter and the type of ration on the physiological responses and growth performance of crossbred cattle, an experiment involving 20 weaned heifer calves, was conducted at the University Livestock Farm (KAU), Mannuthy. The experiment included four treatments encompassing protection and exposure to solar radiation, and concentrate and roughage – oriented feeding in different combinations. The selected calves were distributed equally to the four treatments, observing the standard statistical procedures. Physiological variables like cardiac rate, respiration rate, rectal temperature and skin temperature were measured and recorded for all the calves twice a day on a fixed day in a week and for 14 weeks of the study by using standard equipments and procedures. The body weights and body measurements were recorded once in a fortnight at a fixed time in a day. The body measurements included height, length and girth. All the measurements were made on individual calves. The climatic data, atmospheric temperature, relative humidity, wind velocity, black globe temperature and vapour pressure were recorded inside the shed and atmospheric temperature, solar radiation, relative humidity, wind velocity, vapour pressure and rainfall were recorded in the open paddock. A continuous recording “Solar Radiation Balance Meter” was used to record the solar radiation continuously throughout the experiment. The average daily maximum air temperature that prevailed in the unshaded location during the hot – dry period was 350 C and in the shaded location, 300 C. During the rainy period the maximum temperature ranged from 25.37 to 29.310 C under the shade and 29.36 to 33.500 C in the unshaded location. The relative humidity ranged from 76 to 93 per cent in the mornings and 55 to 88 per cent in the afternoons. The wind velocity ranged from 0.13 to 0.97 m per sec in the unshaded area and almost zero in the shaded area. The vapour pressure ranged from 21.41 to 25.98 mm of Hg. The rectal temperature of the calves in the unshaded location was significantly higher than those of the shaded ones (P < 0.01) during the hot – dry period. Significantly lower value for rectal temperature was obtained for the concentrate – fed unshaded calves during the morning recording of rainy period and higher values were obtained in the afternoons indicating a diurnal rhythm. The skin temperature of the calves was always higher than the rectal temperature in all the cases except in the shaded calves on rainy days. During the hot – dry period, the respiration rates were significantly higher (P < 0.01) in the unshaded group compared to the shaded lot for the morning recordings and in the afternoons, in all the treatments, it was almost double of what was recorded in the mornings. In general, the cardiac rates were found to be higher in the afternoons, than the mornings and lower during the rainy period. Highly significant variations (P < 0.01) in all the physiological reactions measured were noticed between the housed and unhoused treatments, the calves exposed to direct solar radiation recording higher values of rectal and skin temperature and respiration and cardiac rates, with few exceptions. The higher physiological reactions of the calves in the open could be attributed to higher effective temperature caused by direct solar radiation. The analysis of growth parameters indicated significant differences in certain fortnights only. It was observed that maximum gains in live weight, height and girth were obtained by the calves exposed to solar radiation and fed roughage – oriented ration but the gain in length was the least in this group. The next best was the housed and concentrate oriented feeding group which had the highest gain in length, second highest gains in live weight and girth, but the lowest gain in height which implies that under housed conditions concentrate – oriented feeding and under exposed conditions roughage – oriented feeding favour better growth. In general, it was observed that housing in open conditions increased physiological reactions significantly but these increases were not physiologically meaningful to cause retardation in growth. With a view to study the effects of housing on cows with respect to milk production and other traits, eight cows were subjected to a switch over trial in which sheltered and unsheltered conditions alternated. The experiment ran for eight periods of one month each and in total, milk production for 33 weeks were partitioned into 15 weeks of early lactation and the remaining 18 weeks of late lactation periods. The cows were divided into two groups based on their milk yield. The cows of one of the groups at random were kept in an open paddock exposed to direct solar radiation while cows of the other group were housed in a tile – roofed shed. At the end of every month the groups were interchanged. For feeding the cows, adequate measures were taken to meet both maintenance and production requirement and requirements were worked out every fortnight. The physiological variables like the cardiac rate, respiration rate, rectal temperature and skin temperature of the individual cows were measured and recorded twice in a day, two days in a week, by following standard procedures. The twice daily milk yields of the cows were measured by individually weighing the quantity in kg at each milking. Milk fat and protein were estimated from samples collected with due precautions at every milking. The feed, grass and water consumption were measured for individual cows. Standard statistical methods were employed to analyse the data. Multiple regression analysis was resorted to find out the relationship of climatic variables with physiological responses. Highly significant (P < 0.01) differences were found between the shaded and unshaded locations in the relative humidity levels. This may probably be due to accumulation of moisture in the atmosphere inside the animal house resulting out of interference with free exchange of air by housing arrangements. Analysis also revealed highly significant (P < 0.01) difference in wind velocities between locations. The wind velocities recorded in the present experiment generally were lower than what had been suggested as ideal for tropical animal husbandry. The analysis of climatic factors revealed that the animals housed in the shaded location were under additional stress due to radiated heat from the surroundings apart from experiencing stress of the high air temperature. The same phenomenon was observed in the unshaded location also. Both the day and night total radiation values remained high. The rainfall distribution was not uniform during the period of study. In the early lactation period, the cardiac rates, respiration rates, rectal temperature and skin temperature of cows under exposed condition were high in the afternoons. Similar trend was observed in the late lactation period also. In both the treatment groups, all the physiological parameters recorded were on the higher side than the normally accepted standards. The cows had the physiological ability to bring the skin temperature on par with rectal temperature and sometimes even higher than that. The cows in the open seem to compensate during the night and bring down their body temperature to the level of sheltered and eat as much or more of grass and feed. This resulted in similar milk yield in late lactation and slightly higher milk yield in early lactation. Under the hot humid conditions, the higher wind velocity in the open seem to favour the cows considerably. The generally held view that under hot humid conditions ventilation is most important and animals do not need much elaborate housing gets further strengthened from these findings. It was observed that the fat percentages varied significantly (P <0.01) between treatments from both morning and afternoon milk obtained from the cows, the milk fat content being lower when they were exposed to direct solar radiation. The exposed cows though they had maintained their milk production higher, the milk fat content had dropped. A highly significant (P < 0.01) difference had been found between treatments in protein content of the afternoon milk indicating that exposure of cows to day time stress in the open sun considerably altered milk composition and reduced the protein percentage. During late lactation period, both fat and protein content in milk were lesser for the unshaded treatment but statistically there was no significant difference between treatments. A highly (P < 0.01) significant difference was observed in concentrate feed intake between shaded and unshaded treatments during early lactation and the reverse was observed in the case of grass consumption. The difference in overall mean water consumption under shaded and unshaded condition was highly (P < 0.01) significant, cows remaining in the open paddock drinking 21 to 23 per cent more water. Observations on physiological reactions revealed that the cows in the unsheltered condition made physiological compensations through increased circulatory and respiratory activities and by physical means during the night to bring down the rectal temperature in the morning to normal levels. During the late lactation period, no significant differences were found in the consumption of grass and concentrate feed by the cows between treatments. A highly significant difference (P < 0.01) was found only with water consumption. During the early lactation, the solar radiation was found to exert a negative, significant (P < 0.05) influence on the cardiac rates but the influence by wind velocity was positive and highly significant (P < 0.01). In the same way, the rectal and skin temperatures also were influenced significantly only by the wind velocity, the effect being negative and highly significant (P < 0.01). During the late lactation stage, the physiological parameters studied had not been influenced by the explanatory variables chosen except in the case of respiration rate which was positively and significantly (P < 0.05) influenced by black globe temperatures. The relationships between climatic variables and animal responses were not as intense when they were housed as when they remained exposed. However, the black globe thermometer readings which represented the combined influence of ambient temperature, wind speed and solar radiation, was found to have significant influence on the respiration rate. This may indicate that the black globe thermometer deserves to be used more extensively for evaluating thermal characters of animal environments. The results of the study clearly indicate the beneficial effects of ‘open – air’ conditions in a hot – humid tropical environment. Factors such as comfort of men tending animals and hygiene preclude cattle keeping without housing structures. The result of these experiments however point to the advisability of loose housing system in which cattle have continuous access to an open paddock shaded by trees. The sheltered area of the loose houses also should be simple roofs on pillars allowing maximum ventilation and air movement. It was also found that growing heifers can be maintained equally well on a roughage – oriented feeding schedule.ThesisItem Open Access Village level livestock and poultry production under the industrialization scenario(Department of Livestock Production Management, College of Veterinary and Animal Sciences, Mannuthy, 2007) Rajaganapathy, V; KAU; Francis, XavierAn in depth assessment and analysis of two villages, one an industrial area and the other an agrarian hamlet, was taken up. The effect of industrialization and pollution in village level livestock and poultry production and toxic heavy metals content as an indicator of pollution in water, soil, fodder and in biological samples were studied. Based on the observation and scientific validations, changes in livestock farming system and methodologies to alleviate the extent of pollution were sorted out. This study was conducted in Plachimada village - industrial area - in Perumatty Panchayat and in Nallepilly village- control area in Nallepilly Panchayat in Chittoor taluk in Palakkad district. A detailed survey of the existing husbandry systems was done in the selected study area using a schedule. Collection of samples of water, soil, fodder and biological samples milk, meat, egg, blood and dung samples were collected and examined from both industrial and control area. The samples were analyzed for presence of heavy metals like copper, cadmium, lead and arsenic by using Atomic absorption spectrophotometer. A detailed survey was done among fifty farmers from the Plachimada (industrial area) and Nallepilly (control area) villages respectively. The farmers were interviewed with a schedule and the data was obtained. The socio-economic status of the farmers indicated that the middle aged persons were more involved in the agricultural and animal husbandry activities. Most of the farmers had an average monthly income per family of Rs. 2000 in the study area. Cultivation of crops and plantations were less in both industrial and control area. The study revealed that majority of the farmers possessed dairy cattle with major source of income from livestock farming in both these study areas. Economic viability of rearing cattle was better in control area than that of industrial area. Most of the farmers surveyed stayed very near to the industry in the industrial zone. The study revealed that nearness of the industry to the grazing lands may be affecting their livestock farming system. The presence of heavy metals cadmium and lead in drinking water and soil samples of industrial area was more than that of the control zone and the WHO (1995) recommendations. The presence of copper and cadmium in meat samples was higher whereas cadmium and lead in blood samples of the industrial area was found more than that of the control zone and the permitted levels as per the WHO recommendations. The level of copper, cadmium and lead in fodder, milk, egg and dung samples of the industrial area was found more than that of the control zone and the permitted levels as per the WHO recommendations. This study aimed also to find out the relationship between water, soil, plant and animal system. Correlation of fodder and blood heavy metals with other biological samples was done in industrial area. Fodder lead showed a highly significant correlation with milk lead content. Correlation between fodder arsenic and milk arsenic concentration was also significant. Correlation between fodder cadmium with blood cadmium was significant. Correlation was observed between fodder lead with dung lead values. Correlation existed between blood copper with dung copper at a significant level. Similarly correlation of fodder and blood heavy metals with other biological samples was done in control area also. Blood and fodder cadmium was significant and positively correlated. Correlation of fodder lead with milk and dung lead were significant. Fodder arsenic and milk arsenic were significantly correlated. In blood the copper content of milk and dung showed a positive significant correlation. The heavy metals lead, cadmium, arsenic and mercury from industrial pollution are of high environmental concern due to their toxicity even at low concentrations. These metals may persist in the system for several days due to cumulative nature and may cause severe health effects in man and animals. Bioaccumulation of toxic heavy metals, especially lead, cadmium and arsenic in milk, meat and in egg have evoked great concern during the recent years. Heavy metals contaminants may enter the animal system through pollution of air, water, soil, feed polluted by industrial sources. From the present study it was found that the industrial area had contaminated water, soil, and fodder under observation. The heavy metal contamination was from copper, cadmium and lead whereas arsenic was almost within the permissible limits. The biological samples milk, meat, egg, blood and dung collected from the industrial zone were also contaminated with copper, cadmium and lead when compared with the control area samples. The level of heavy metals in the biological samples of industrial area was above the WHO permissible limits. Arsenic was present within the maximum permissible level in all the biological samples. It is also concluded that industrialization may add pollutants to the area thereby causing an indirect effect on livestock production systems and in turn to the human beings. The following recommendations may be suggested. 1. Monitoring the level of pollution in water, soil, plants and fodder crops, animals and in man in industrial zones at regular intervals. 2. Treatment of waste water and other discharges/effluents from industries with implementation of strict rules and regulations 3. Safe disposal of the discharges, effluents and waste materials from the industries and factories. Efficient waste management to be adopted. 4. To create awareness among farming community to adopt better management practices. 5. Encouragement of organic farming. 6. Recommendation of rearing indigenous animals and adoption of Mixed farming - system to improve economic status of farmers. 7. Phytoremediation may be done to decontaminate soil and water to reduce the soil heavy metal content. 8. Identify and growing of trees/ plants to reduce the level of toxic elements from the industrial zones.ThesisItem Open Access Comparative evaluation of porcine production performance in terminally sired and purebred progenies under different management conditions(Department of Livestock Production Management, College of Veterinary and Animal Sciences, Mannuthy, 2007) Murugan, M; KAU; Joseph, MathewA study was conducted to evaluate the production performance of terminally sired and purebred progenies under different management conditions. Twenty gilts were selected from Large White Yorkshire and also each combination of Large White Yorkshire x Landrace, Landrace x Desi and Large White Yorkshire x Desi . After attaining maturity, they were bred to terminal sire (Duroc). Large White Yorkshire was maintained as pure line. Litter performance of LWY and three breed combinations viz., D x (LWY x LR), D x (LR x Desi) and D x (LWY x Desi) were comparatively evaluated. Twenty four weaned piglets were selected at random from each genetic combination and they were divided into four groups having six animals in each group. Piglets T1 were fed with concentrate feed and T2, T3 and T4 from each genetic group were fed with left over food from hotels, restaurants, slaughter house waste and waste available from agricultural fields. In addition to this, T3 group were supplemented with inorganic minerals and T4 group were supplemented with organic minerals @ one per cent level on dry matter basis from third month to ten months of age. The crossbreds viz., D x (LWY x Desi) and D x (LR x Desi) had highly significant (P<0.01) difference in litter size at birth, litter weight at birth, birth weight, litter size at weaning, litter weight at weaning and weaning weight compared to LWY and D x (LWY x LR) pigs. There was no significant difference between LWY and D x (LWY x LR) ; D x (LWY x Desi) and D x (LR x Desi) pigs in all these litter traits. There were no significant differences (P>0.05) in maximum and minimum temperature and relative humidity between farm and field. There was no significant difference (P>0.05) in mean rectal temperature, pulse and respiration rate between treatments and genetic groups. Significant difference (P<0.01) were observed between morning and afternoon pulse and respiratory rates irrespective of treatment and genetic groups. At the time of feeding, majority of the pigs in different treatments and genetic groups showed eating greedily with drooling of saliva and ear biting, belly nosing and tail biting very frequently. Quantity of faeces voided had a highly significant (P<0.01) difference between treatment in all four genetic groups. LWY pigs voided significantly lesser quantity of faeces than other genetic groups within the treatment. Frequency of defaecation had no significant difference, between treatments and genetic groups. There were no significant differences (P>0.05) in the faecal cortisol level between the treatments and genetic groups of pigs. The proximate composition (percentage) of pooled swill feed samples are comparable to farm concentrate except ether extract (24.56; 6.05 and 4.13) which was very higher in swill feed. Total ash content was higher in the farm concentrate (10.91, 10.13; 6.61). Availability of minerals was higher in inorganic form compared to organic form. Mineral assay revealed that chicken waste showed higher levels of minerals followed by hotel waste and vegetable waste. There was no significant difference between genetic groups within the treatment in serum mineral concentration. The feeding system had highly significant (P<0.01) effect on the mineral concentration. It was highest in T4 followed by T3 and T1 and least in T2. It was comparable between T3 and T2. There was no significant difference in monthly body weights (kg), body measurements viz., body length, girth and height (cm), average daily weight gain and average daily feed intake (g) of pigs between concentrate (T1) and swill feeding (T2). T4 significantly (P<0.01) better than other treatment groups. T3 was significantly (P<0.01) better than T2 and T1. Crossbred pigs had significantly (P<0.01) higher monthly body weight, linear body measurements, average daily weight gain and average daily feed intake than LWY pigs within the treatment. Among the three crossbreds there was no significant difference observed in monthly body weight, linear body measurements, average daily gain and average daily feed intake except in concentrate feeding. In concentrate feeding, D x (LWY x Desi) crossbred consumed significantly (P<0.01) less feed than the other crossbred pigs. There was significant (P<0.01) difference in feed efficiency between T1 and T2. No significant difference was observed between T2, T3 and T4. There was no significant difference between LWY and crossbred pigs within the treatment. T4 attained significantly (P<0.01) higher slaughter weight (kg), hot carcass weight (kg) and carcass length (cm) than the other treatment groups. T3 group attained significantly (P<0.01) higher slaughter weight, hot carcass weight and carcass length than the T2 and T1 treatment groups. No significant difference between T1 and T2 was noticed. T1 had significantly (P<0.01) higher dressing percentage than other treatment groups. T1 had significantly (P<0.01) lesser back fat thickness. There was no significant difference between T2, T3 and T4 in dressing percentage and back fat thickness. T2 had significantly (P<0.01) lesser loin eye area and meat-bone ratio than other treatment groups and there was no significant difference between T1 and T3 and T4. Gut weight was significantly (P<0.01) lesser in T1 than other treatment groups. There was no significant difference between T2, T3 and T4. There was significant (P<0.01) difference between LWY and crossbreds in terms of slaughter weight, hot carcass weight, carcass length, back fat thickness and loin eye area, within the treatment. There was no significant difference noticed between dressing percentage, meat-bone ratio and gut weight within the treatment. Cost of production per kg live weight on feed basis was high in T1 followed by T4, T3 and T2. It was inferred that swill feed supplemented with minerals can increase the profit margin provided a cheaper substitute for the organic minerals presently available in the market is absolutely essential for the field fattener pig production. Swill feed was found to be equally effective compared to concentrate feed in promoting growth of the fattener pig production existing under field conditions. Growth performance and carcass characteristics can be improved by supplementation of minerals in the diet of fattener pigs. Crossbred pigs excelled over pure LWY in terms of post weaning growth performance and carcass characteristics under terminally sired pigs. The crossbreds viz., D x (LR x Desi) and D x (LWY x Desi) had better litter performance than D x (LWY x LR) and LWY pigs. Considering both litter performance and post weaning growth performance, the recommendation is that D x (LR x Desi) and D x (LWY x Desi) crossbreds are best suited for the field fattener pig production in the hot-humid climatic conditions.ThesisItem Open Access Effect of enrichment of environment and halothane sensitivity on performance of large white yorkshire and desi pigs(Department of Livestock Production Management, College of Veterinary and Animal Sciences, Mannuthy, 1997) Joseph Mathew; KAU; Thomas, C KThe effect of environmental variables, halothane sensitivity and environmental enrichments in the form of wallowing, water sprinkling and access to a shaded range on various production and reproduction traits of exotic(LWY) and Desi pigs was assessed by conducting a study in Kerala Agricultural University Pig Breeding Farm , Mannuthy (UPBF). Significant correlations were found between environmental variables and important production and reproduction traits in both breeds . The incidence o f . halothane sensitivity was found to be higher in LWY when compared to that of Desi.A clear breed difference was noticed between Desi and LWY with respect to traits such as body weight,daily weight gain,body measurements, feed intake, feed conversion efficiency(FCE), weaning weight,cost of production for unit meat and weaned piglet.Environmental enrichments were found to- be beneficial for most of the traits such as body weight, daily weight gain,FCE,conception rate,live litter size at birth,birth weight,litter weight at weaning ' and average weaning weight.When halothane sensitive animals were better in FCE and growth rate, halothane resistant animals came out with good reproduction results.But positive animals with environmental enrichments performed better than negative in certain traits.The biochemical traits associated with halothane sensitivity were inconsistent.But clear trends with breed and genetic groups existed between halothane positive and negative animals.An apparently clear interaction between breeds, genotype and environmental enrichments were niticed in certain production and reproduction traits.Provision for access to a shaded range was found to be beneficial for fattening pigs with respect to FCE and growth rate.Wallowing and water sprinkling have got negative effect on these traits.But for reproduction traits all the above enrichments had beneficial effeet.Based on the observations and the results suitable combinations of various environmental enrichments for different breeds, genotypes and purpose were’ designed which may be used as tools for developing managemental systems under different situations.ThesisItem Open Access Influence of chitin on growth and fatty acid composition in growing pigs(Department of Livestock Production Management, College of Veterinary and Animal Sciences, Mannuthy, 1993) Chitta Ranjan, Pradhan; KAU; Rajagopalan, T GA study was carried out to find out the influence of feeding chitin to pigs on their growth, carcass characteristics, blood cell count and haemoglobin concentration, serum cholesterol and triglyceride levels, and fatty acid profile of muscle and backfat. Twenty-four weaned female piglings of Large White Yorkshire breed were assigned to three groups of eight each. Two groups were fed chitin with a standard farm ration at levels of 0.5 per cent (Group I) and I per cent (Group 2), and the remaining group, which served as the control, was fed only the ration without addition of chitin (Group 3). All animals were housed individually and were fed in two I-hour feeding periods daily. Digestibility of chitin did not differ between the two chitin-fed groups. The percentage of digestibility increased from age 3 months (79.37 ± 1.85 to 80.49 ± 1.85) to 5 months (95.36 ± 1.13 to 96.54 ± 1.05) and thereafter remained constant at 7 months (95.35 ± 1.33 to 95.77 ± 1.57). The chitin-fed groups had significantly (P<0.05 or 0.01) higher body weights than the controls from 18th to 40th week of age. Compared with the controls, the chitin-fed groups had higher total gains in weight by 11 to 12 kg. Both the chitin-fed groups also had significantly (p<0.05 or 0.01) higher average daily gains than the controls from 18th to 40th week of age. The pigs in all groups showed a peak rate of gain at 32nd week of age. The chitin-fed groups also averaged higher body lengths, heights and girths, and also higher daily gains in these measures as compared with the control group. Daily feed intake increased with age of animals in all the groups. Daily feed intake did not differ significantly between the groups. For all the groups, maximum feed efficiency was recorded between 16th and 30th week of age. As compared with the controls, the chitin-fed groups showed higher feed efficiency. The difference between the control and chitin-fed groups were found to be significant (P<0.05) at the end of the experiment. The pigs in the chitin-fed groups averaged higher slaughter weights than the controls at 5, 7 and 9 months of age. For all the pigs in all groups, carcass length, ham weight and eye-muscle area showed higher percentages of gain between 5 and 7 months than between 7 and 9 months of age. The percentage of ham decreased with increase in age and weight of animals. The chitin-fed groups of pigs showed higher carcass lengths, ham weights and eye-muscle areas than the control group at each stage of slaughter. The backfat deposition showed a higher deposition between 5 and 7 months than between 7 and 9 months of age, while the majority of leaf fat deposition took place between 7 and 9 months of age. The percentage of leaf fat increased with increase in age and weight of animals in all the groups. The chitin-fed groups showed lower backfat thickness and lower percentages of leaf fat than the controls at each stage of slaughter. The increase in dressing percentage was found to be higher between 7 and 9 months than between 5 and 7 months of age, for all groups of pigs. The chitin-fed groups yielded higher dressing percentages than the control group at each stage of slaughter. The weight of internal organs increased with age of animals, whereas weight of internal organs as percentage of live weight decreased. The control group of pigs had higher percentages of internal organs than the chitin-fed groups at each slaughter age. The haemoglobin concentration, total erythrocyte count, total leukocyte count, and differential leukocyte count did not differ significantly between the groups of pigs at 5, 7 or 9 months of age. The pigs in group 2 averaged the lowest serum cholesterol and triglyceride levels followed by the pigs in group I and group 3, in that order, at 5,7 and 9 months of age. The difference in serum cholesterol concentration between the pigs in group 2 and the pigs in either group 1 or group 3 were found to be significant (p<0.05) at 7 months and highly significant (p<0.01) at 9 months of age. The serum triglyceride concentration followed the same trend as serum cholesterol concentration, between the groups of pigs. However, the differences were not found to be statistically significant. The fatty acid composition of muscle and backfat did not differ noticeably between the groups at 5 months of age. At the subsequent ages of 7 and 9 months, the chitin-fed groups showed markedly higher degree of unsaturation and lower saturation than the control group. Higher percentages of oleic acid and lower percentages of palmitic acid were recorded for the chitin-fed groups as compared with the control group. The results revealed that chitin had growth-promoting, hypolipidemic and hypocholesterolemic effect in pigs. It also improved the degree of unsaturation in pig meat.ThesisItem Open Access Effect of season of birth and energy levels of feed on production performance of pigs(Department of Livestock Production Management, College of Veterinary and Animal Sciences, Mannuthy, 1992) Sebastian, K S; KAU; Rajagopalan, T GA detailed investigation was carried out to study the effect of season and level of energy intake on growth rate, feed efficiency, carcass quality and economics of production of fattening pigs reared upto a slaughter weight of 90 kg. Thirty two weaner pigs of large white Yorkshire breed belonging to the University Pig Breeding Farm, Mannuthy born in two seasons were distributed under two dietary treatments. All animals were slaughtered on attaining the target weight of 90 kg. Animals born in season II were superior to animals born in season I in all the parameters like growth rate, feed efficiency, average daily gain and carcass characteristics. The energy level in the ration had a moderate influence on the performance of grower pigs. Animals on NRC level of feed were found to be better than animals on 15 per cent less than NRC levels in all the traits under study except for fat characteristics. The cost production per kg pork was found to be less (Rs 18.72) in NRC group. The overall results obtained during the course of present study is that the unit cost of production is less for animals maintained on NRC level of ration. Animals born in season II were found to be better than animals born in season I in production performances.