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Open Access
Low dose gamma irradiation on the keeping quality of minced beef
(Department of Livestock Products Technology College of Veterinary and Animal Sciences Mannuthy, 2006) Jenifer, P; Kuttinarayanan, P
Open Access
Effect of gooseberry (Emblica officinalis) and Indian gall nut (Terminalia chebula) on the immune response in cockerels under induced heat and cold stress
(Department of Veterinary Physiology, College of Veterinary and Animal Sciences, Mannuthy, 2006) Mejo, K R; Ramnath, V
The study was conducted with an objective of finding the physiological and immunological variations that could be brought about with heat /cold stress in cockerels and the role of Gooseberry (GB) and Indian gallnut (IGN) supplementation as an antistress. Gramapriya cockerels of 1kg bw (3-4 months) were subjected to heat (40 ±1o C and relative humidity (RH) 60-70 percent) and cold stress (8 ±1o C and RH 40-50 per cent) each for 4h/day in a controlled environmental chamber (floor space 875 cm2 /bird) for a maximum of 10 days and the controls were reared randomly under ambient temperature of 30±1o C and RH 65 percent. GB+IGN supplementation was done @ 2.0 g/kg for 20 days (prior to and during the period of heat/cold stress). To a certain extend alternations in haematological parameters such as haemoglobin, packed cell volume, H/L ratio, biochemical parameters such as serum total protein, albumin, globulin, C-reactive protein, electrolytes like sodium and potassium, enzymes like lactate dehydrogenase and creatine kinase, cortisol, triiodothyronine (T3), thyroxine (T4) could be reversed by GB+IGN supplementation during heat stress. In the present study, the haemagglutinin (HA), hemolysin (HL), IgG and IgM titres and the spleenic antibody forming cells (plaque forming cells) and rosette forming cells (RFC) against known antigen were studied. The results indicated that GB+IGN supplementation not only maintained the preformed antibody titre but also improved the humoral immune response against a challenged antigen during the period of heat stress. In the present study, it was found that during cold stress, the GB+IGN supplementation could bring about an early tendency to restore the normal homeostasis of haematological, biochemical, and hormonal parameters. Cold stress resulted in a low profile of humoral immune response indicated by low anti-SRBC haemolysin (HA), Haemolysin (HL), IgG and IgM titres in untreated, CST cockerels when compared to GB+IGN treated counterparts, which showed better tires during cold stress. Similarly, treated cockerels exhibited more spleenic cells that produce antibodies against rat red blood cells. Thus, the immunopotentiative property of GB+IGN was reconfirmed and that the drug supplementation stimulated the humoral arm of immunity in cold stressed cockerels. Results of the present study indicated that combined supplementation of GB+IGN @ 2.0 g/kg bw in poultry could augment the humoral response during heat and cold stress
Open Access
Polymorphism of ovine fecundity gene linked microsatellite markers in malabari goats
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 2006) Seena, T X; KAU; Raghavan, K C
The objective of the present study was to explore the polymorphism of ovine fecundity gene linked microsatellite markers in Malabari goats. Malabari goats are one of the most prolific breeds in India. The microsatellite markers OarAE101, BMS2508 and BM1329 linked to the Booroola gene (FecB) and the microsatellite markers TGLA54 and TGLA68 linked to Inverdale (FecX1) gene in sheep were selected for the study. The DNA samples from 120 Malabari goats which had given birth to singles, twins, triplets and quadruplets in the second and subsequent parities were utilized for the study. DNA was isolated by phenol chloroform extraction procedure with some modifications. The DNA samples were amplified by PCR using the radioactively labeled microsatellite primers. The amplified products were resolved by polyacrylamide gel electrophoresis followed by autoradiography. The genotypes of animals were determined for each microsatellite loci by comparing the sizes of alleles with M13 phage DNA sequencing ladder. The microsatellite markers OarAE101, BMS2508 and TGLA54 were found to be monomorphic in the population under study. The microsatellite markers BM1329 and TGLA68 were found to be highly polymorphic in Malabari goats. A total of 15 alleles with 167-195 bp for the locus BM1329 and 8 alleles with a size range of 98-114 bp were observed for the locus TGLA68. The total number of genotypes observed was 34 for BM1329 locus and 12 for TGLA68 locus. Heterozygosity of 0.8660 for the locus BM1329 and 0.8024 for the locus TGLA68 were observed. The polymorphic information content (PIC) computed was 0.8526 and 0.7823 for the loci BM1329 and TGLA68 respectively. A significant difference in the alleles 181bp and 191 bp (P≤0.01) and the alleles 179 bp and 185 bp (P≤0.05) and the genotype 177/191 (P≤0.01) for the locus BM1329 were found in different types of births. The genotype 175/185 of the microsatellite marker BM1329 was found to be significantly related to a higher litter size when compared to the mean litter size of the population in Malabari goats (P≤0.01). The allele 104 bp of the locus TGLA68 was found to be significantly different in different types of births (P≤0.01). The highest frequency (0.4545) was observed in triplets followed by twins (0.2177) and singles (0.1847). The genotype 104/106 was found to be significantly different in different types of birth with triplets having a frequency of (0.4545), followed by singles (0.1087) and twins (0.0333). The season of birth had no significant effect on the type of birth and number of kidding in Malabari goats. Identification and selection of individuals that carry the alleles and genotypes associated with high prolificacy is possible in Malabari goats based on the above result. So new breeding strategies involving selection for high prolificacy can maximize the net profit of farmers. This study has brought to light important information improving the reproductive performance of Malabari goats by marker assisted selection.
Open Access
Tenderisation of buffalo meat by calcium chloride marination
(Department of Livestock Products Technology, College of Veterinary and Animal Sciences, Mannuthy, 2006) Kavitha, Rajagopal; KAU; George, T Oommen
The present study on the tenderisation of buffalo meat by calcium chloride marination was designed to assess the effect of marination on tenderness and other organoleptic qualities of meat and to compare the effects with those of natural ageing. Samples of longissimus dorsi muscle between 9th and 12th thoracic vertebrae from 14 healthy crossbred Murrah buffaloes of 4 – 8 years old were collected. They were assorted for three treatments, viz., samples neither aged nor calcium chloride marinated; and stored at room temperature for 6 h postmortem (NAM), samples aged only (A), samples which are marinated (AM). Samples of A and AM were stored at 2-4o C. The aerobically packaged samples for the treatment AM after 24 h of storage were marinated by injection with 200 mM calcium chloride solution (5% w/w) at multiple sites. The pH, WHC, cooking loss, color, MFI, WBSF and sensory quality attributes such as juiciness, ease of fragmentation, amount of connective tissue, overall tenderness, flavour intensity and colour of the steaks were assessed. The samples for the treatment NAM were subjected to the study at 1 h and 6 h and the steaks from A and AM at 1 h, 6 h and on days 1, 2, 4, 6 and 8. The pH of the steaks was not affected by CaCl2 marination. It followed the normal postmortem pattern, with a pH of 6.7 ± 0.01 at 1 h in all treatments. The ultimate pH of 5.6 reached on day 1 was significantly lower (P < 0.05) than on all days, which gradually increased until day 8 in treatments A and AM. The samples followed a normal rigor with sufficient amount of m-calpain and the increase in pH was due to the accumulation of products of proteolysis. The WHC at 1 h was 0.37 ± 0.021 which declined to a significantly lower (P < 0.05) value of 0.31± 0.021 at the ultimate pH on day 1. This remained almost static till day 8 in both treatments A and AM. On day 1 the pH and calcium induced shrinkage caused loss of water. Later changes in the cytoskeleton improved WHC by removing rigor induced shrinkage of myofibrils. WHC was not significantly affected by calcium chloride marination. The percentage of cooking loss increased significantly (P < 0.05) on da 1 and thereafter it remained static till day 8. Calcium chloride was not found to affect the percentage of cooking loss. The comparatively higher loss observed in the study could be attributed to the lack of external fat covering and marbling in the buffalo LD steaks. Ageing is found to improve the colour of fresh meat from day 1 onwards. But calcium chloride marination did not have any additional effect on the colour of aged meat. The decline in postmortem pH to 5.6 on day 1 contributed to higher L, a, b values which increased the light scattering properties. On subsequent days, L, a, b values remained without significant changes. This could be due to the antioxidant action of amino acids and dipeptides formed during postmortem proteolysis, which preserve the methmyoglobin reducing activity. In treatments A and AM the MFI followed a gradual significant decrease (P < 0.01) from 768.0 ± 40.52 to 541.78 ± 34.63 on day 1 and day 8, respectively in aged steaks. While in marinated it declined to 465.28 ± 29.79 on day 8. Significantly lower (P < 0.01) value of 630 ± 42.88 on day 2 in marinated samples was comparable to that in the aged samples on day 4, indicating the early achievement of tenderness in marinated samples. MFI varied little with ultimate pH. MFI is deemed as a very useful indicator of meat tenderness particularly when sample size is smaller for the determination of shear force or sensory evaluation. Significantly highest (P < 0.01) WBSF value of 11.37 ± 0.61 obtained on day 1 could be attributed to rigor induced shortening. The values declined significantly in treatments A and AM. The values obtained for the marinated steaks were significantly lower (P < 0.01) than the aged samples on all days postmortem. It reduced from 10.48 ± 0.48 at 1 h postmortem to 4.88 ± 0.45 in a course of 8 days. This indicated a 53.44% reduction in values from 1 h to day 8, while in aged sample only a 35.59% reduction was noticed in a course of 8 days. The sensory panel evaluation of organoleptic qualities showed that calcium chloride marinated steaks significantly improved (P < 0.01) in the scores for the different attributes studied on each day of ageing. No flavor problems or alterations in cooked color were noticed at 200mM CaCl2. Correlation studies in between MFI and WBSF revealed a significant positive correlation (P < 0.01) with r = 0.85 in A and 0.84 in AM on all days from 1 to 8. This indicates that MFI could be used as an indicator of tenderness of fresh meat rather than cooked. WBSF and MFI were strongly correlated with the overall tenderness measured by taste panel evaluation. The overall tenderness was more negatively correlated with SF (r = 0.70) rather than MFI (r = 0.65). The tenderness and other organoleptic qualities of buffalo longissimus steaks could be improved significantly by post-rigor marination with 200mM CaCl2 (5 % w/w) on day 1 and subsequent ageing at 2 – 4o C for 4 – 8 days. The tenderness improved by 53.44 per cent in marinated steaks as against 35.59 per cent in those aged without marination. The improvement in tenderness could be attributed to the activation of μ- and m-calpain by calcium ions and the autolysis of calpastain at 2 - 4o C of ageing.
Open Access
Effects of preslaughter stress and irradiation on physicochemical qualities of meat
(Department of Livestock Products Technology, College of Veterinary and Animal Sciences, Mannuthy, 2006) Vivek, A K; KAU; Kuttinarayanan, P (Guide)
The effect of stress on the blood parameters and physicochemical qualities of meat as well as effect of irradiation on the qualities of fresh meat from stressed cattle were investigated in the present study. A total of 27 culled adult cattle from different farms were grouped into three, having nine animals in each group. Group I animals were considered as control while group II animals were transported for 2 h and slaughtered immediately after transport. Group III animals were transported for 6 to 7 h and given rest for 18 h before slaughter. Blood samples were collected prior to transport in all the animals, immediately after transport in group II and III and after 18 hours rest, before slaughter, in group III animals. Meat samples were collected from all the animals in which half of the samples were subjected to irradiation at 2.0kGy with gamma irradiation, as Cobalt 60 as source. The samples were stored at 40C for further studies. Animals in all the groups were having homogenous blood values prior to transport in cortisol, CK, BUN, creatinine and PCV. After transport, group II had a significant increase in cortisol (P<0.01), CK (P<0.01) and BUN (P<0.05), while group III had a significant increase in cortisol (P<0.01), CK(P<0.01), BUN (P<0.05) and creatinine (P<0.05) except PCV, in which the increase in cortisol and CK were significantly (P<0.01) greater than that in group II. By giving rest, even though there was significant (P<0.01) reduction in cortisol and CK values, the after rest values of cortisol (P<0.01), CK (P<0.01) and BUN (P<0.05) were significantly higher than that of the before transport values. In the case of pH and WHC, the trend was almost similar, with a higher value at zero hour and the decline was drastic in zero to 6 h, followed by 6 to 12 and 12 to 24 h and the control and irradiated samples did not show any significant difference in the decline. Cooking loss of the control and irradiated samples did not have a significant difference at zero hour storage, while the 24h storage brought a significant (P<0.01) increase in cooking loss in all the samples and irradiated samples had a significantly (P<0.05) higher cooking loss at 24h. Shear force values were significantly (P<0.01) less for irradiated samples while storage significantly (P<0.01) increased the values of all the samples. The Hunterlab colour values, L, a, b, C and hue angle, were significantly (P<0.01) higher in irradiated samples at zero hour storage. At 24h storage, the values were significantly (P<0.01) higher than that at zero hour, and only the hue angle values were significantly (P<0.05) higher in irradiated samples. Even though there existed a slight difference between control and irradiated samples in various organoleptic qualities like colour, flavour, juiciness and tenderness, there was no significant difference in overall acceptability between control and irradiated samples. In the present study, the differential response due to irradiation for the stress given to the animals, found to be statistically non significant leading to the result that irradiation conditions did not have an impact on the meat obtained from stressed animal.
Open Access
Bacterial quality of milk at the point of production with special emphasis o the quality assuarance programme
(Department of Veterinery Public Health, College of Veterinary and Animal Science, Mannuthy, 2006) Lekha, Chacko K; KAU; Nanu, E
In the present study a total of 108 milk samples were collected from farmers of three societies (S1, S2 and S3) and analysed for microbial quality, by estimating various microbial counts and also by assessing the presence of certain bacteria of public health importance. Antibiotic susceptibility of Escherichia coli and Staphylococcus aureus was also evaluated. The samples were graded based on total viable count and also by methylene blue reduction test. The critical control points of bacterial contamination of milk at various stages of production were also assessed during the investigation. Analysis of variance test of the data revealed highly significant difference (P0.01) between the mean counts of milk samples collected from three societies. Milk samples from S2 had the highest mean total viable count (6.57 ± 0.13 log10 cfu/ml), coliform count (3.89 ± 0.08 log10 cfu/ml), Escherichia coli count (1.11 ± 0.19 log10 cfu/ml), faecal streptococcal count (3.86 ± 0.08 log10 cfu/ml) and psychrotrophic count (5.57 ± 0.12 log10 cfu/ml). But the highest mean yeast and mould count (4.08 ± 0.01 log10 cfu/ml) was observed in samples collected from S1. Milk samples from S2 revealed maximum contamination. Analysis of data revealed that highly significant (P<0.01) and positive correlation between various bacterial counts. Highly significant (P<0.01) and positive association was observed between total viable count and psychrotrophic count and also between the former count and faecal streptococcal count. Microbial analysis of milk samples collected from six farmers of S1 revealed that samples from F4 had highest mean total viable count (7.44 ± 0.01 log10 cfu/ml) and the lowest in samples of F3 (4.82 ± 0.03 log10 cfu/ml). Similarly, the other bacterial counts, viz., coliform count, Escherichia coli count, faecal streptococcal count, psychrotrophic count was also seen in the highest level in the samples of F4. Whereas the highest mean yeast and mould count was observed in the samples of F1. Microbial analysis of the samples collected from farmers of S2 revealed that the highest mean total viable count (7.42 ± 0.08 log10 cfu/ml) and coliform count (4.44 ± 0.08 log10 cfu/ml) was seen in the samples of F5. Whereas these counts were lowest in the samples of F2. But the Escherichia coli count was highest in the samples collected from F3. However, the organism was not detected in the samples of F2 of S2. The highest mean faecal streptococcal count and psychrotrophic count was also seen in samples of F5, indicating that the hygienic practices followed by the farmer is very poor. Microbial analysis of the milk samples collected from six farmers of S3 revealed that the samples from F4 had the highest mean total viable count, coliform count, Escherichia coli count, faecal streptococcal count and psychrotrophic count indicating the poor hygienic practices followed by the farmer. The highest yeast and mould count was observed in the samples of F6. The presence of these organisms revealed the unsanitary condition of production of milk. The public health impact on the consumer was assessed by isolation and identification of Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Yersinia enterocolitica, Aeromonas and Salmonella. The presence of coliforms and faecal streptococci indicate unhygienic handling of milk and possible faecal contamination. Escherichia coli was isolated from 41.67 per cent of the samples examined. A total of 45 isolates were obtained. Only 22 (48.89 per cent) out of 45 isolate were serotyped. The isolates fell into 10 serotypes viz., O116, O24, O84, O145, O172, O125, O79, O87, O103 and O157. Out of these serotypes except 024, 079 and 087 showed a positive congo red binding test which indicate the property of pathogenisity of isolates. Staphylococcus aureus was isolated from 33 (30.56 per cent) samples. The highest number of isolates was obtained from S2 (14) followed by S1 (12) and S3 (7). Listeria monocytogenes was isolated from 3 (2.70 per cent) samples. All isolates were obtained from F5 of S1. Bacillus cereus was isolated from 3.70 per cent of the total samples. Of the four isolates obtained, one was from S3 and three from S2. The per cent of isolation of Aeromonas was 18.51. Two species of Aeromonas were obtained viz., Aeromonas hydrophila and Aeromonas caviae. None of the samples tested revealed the presence of salmonella and Yersinia enterocolitica. Antibiogram of Escherichia coli isolates obtained from the samples belonging to various sources revealed that all isolates were sensitive to chloramphenicol, co-trimoxazole and gentamicin. None of the isolates showed resistance to all the antibiotics used. Antibiogram of Staphylococcus aureus isolates revealed that all the isolates were sensitive to chloramphenicol. Highest per cent (36.36) of organisms showed resistance against erythromycin followed by oxytetracycline (21.22). None of the isolates revealed resistance to all the antibiotics used. Milk samples collected from three societies were graded based on total viable count. Out of the 108 samples analysed 16.67, 29.63, 20.37 and 33.33 per cent were graded as very good, good, fair and poor quality based on BIS (1977). However 16.67 per cent from S1 and 33.33 from S3 were graded as very good. The per cent of samples graded as good, fair and poor from S1 was 19.44, 30.56 and 33.33, respectively. However, the corresponding per cent from S2 was 33.33, 16.67 and 50.00. The per cent of good, fair and poor samples from S3 was 36.11, 13.89 and 16.67, respectively. Milk samples collected from three societies were graded based on methylene blue reduction test and the result showed that 22.22, 34.26, 25.00 and 18.52 per cent of samples were graded as very good, good, fair and poor, respectively. The various critical control points of bacterial contamination of milk was evaluated by collecting samples of air, water, rinsinging of utensils, hand wash of the milker and udder washes of the animals and estimating their bacterial load. The highest bacterial counts were observed in the hand wash samples of the milker, followed by udder wash of the animal and these two were considered as the point of major source of contamination of milk. The highest bacterial counts in water, utensil rinsings, hand wash of milker and udder washes of animal were observed in samples collected from S2. Thus it may be inferred that the high bacterial load of milk samples from S2 might be due to the contamination of milk from these sources. Therefore, utmost care should be given to monitor the microbial quality of milk at various stages of production, and also to identify various sources of bacterial contamination of milk. Then only we can improve the quality and shelf life of milk produced.
Open Access
Morphological and histological studies on the skin of the pig (sus domesticus)
(Department of Clinical Medicine, College of Veterinary and Animal Sciences, Mannuthy, 2006) Sumena, K B; KAU; Lucy, K M
Studies on the skin of Large White Yorkshire pigs were conducted using 12 animals of six to ten months of age. The project was undertaken to study the morphology, morphometry, histology and the distribution of hair and to compare the sex differences if any, in the skin of pig. Skin samples were collected from eight areas of the body viz., the snout, dorsal nasal, dorsal neck, ventral neck, dorsal abdomen, lateral abdomen, ventral abdomen and carpal regions. After recording gross parameters, material was fixed in 10 per cent neutral buffered formalin and standard procedures were adopted for histoarchitectural and histochemical studies. In general, skin of male animals was slightly thicker than that of the females. Maximum thickness for the skin, epidermis and the dermis was noticed in the snout and minimum in the ventral abdomen. Skin was thicker on the dorsal surface of the body than on the ventral surface. Contribution of the epidermis to the total skin thickness was maximum in the snout region. Subcutaneous fat layer was slightly thicker in females. A highly significant positive correlation was noticed between the skin thickness and the thickness of the epidermis in the snout, dorsal nasal and carpal regions in both male and female animals. Among the five layers of the epidermis, stratum basalis, spinosum and corneum were always present and formed continuous layers throughout the body surface. The stratum granulosum was not continuous in ventral neck and lateral and ventral abdominal regions. A definite stratum lucidum was seen only in the snout, dorsal nasal and ventral abdominal areas. The rete pegs and the dermal papillae were most abundant in the snout region and minimum in the lateral abdominal region. Stratum basalis was made up of a single layer of columnar to cuboidal cells. Clear cells could be located in the stratum basalis and stratum spinosum. Stratum spinosum was the thickest layer of the epidermis consisting of large, irregular and polyhedral cells with distinct boundaries. Prekeratin granules were detected in the upper layers of stratum spinosum. Thickness of this layer was maximum in the snout. Stratum granulosum consisted of two to four rows of flattened, diamond-shaped cells. Cytoplasm showed keratohyalin granules. Stratum lucidum appeared as a clear, bright, homogenous, strongly eosinophilic layer. Stratum corneum consisted of keratinized, scale-like polygonal, clear cells. There was a significant positive correlation between the thickness of the skin and that of dermis in all regions under study in both sexes. Papillary layer of the dermis was made up of collagen fibres predominantly, which were finer and more closely arranged. Reticular layer consisted of large, coarse and loosely interwoven bundles of collagen fibres. Glomi were most numerous in the snout. Hair arrangement in swine was simple, but grouping of hairs was evident. Maximum hair density was noticed in the dorsal nasal area. Density of hair distribution was more in the male animals. Hair shaft was composed of a cuticle, thicker cortex and slender medulla. Hair follicle was composed of four parts, viz., hair papilla, hair matrix, inner root sheath and outer root sheath. Largest arrector muscles were noticed in the abdomen dorsal region. Interfollicular muscle connected adjacent hair follicles of its characteristic hair group. Sweat glands were of apocrine type in all the regions under study except in the snout and dorsal nasal regions where it was of eccrine type. In the latter, both clear and dark cells were identified. Sebaceous glands appeared as large, lobulated, sac-like structures associated with the hair follicles. The secretory units consisted of a solid mass of epidermal cells. Maximum subcutaneous fat thickness was noticed at the neck dorsal region. The subcutaneous tissue was composed of a loose meshwork of connective tissue fibres, cells, blood vessels and nerve fibres. PAS - alcian blue positive areas were detected in middle region of the epidermis and ground substance of the dermis. Cells of stratum corneum, stratum spinosum, sebaceous glands, their ducts and clear cells of eccrine sweat glands showed a positive reaction to Oil Red O. Most of the layers of the epidermis and the dermal papillae, blood vessels surrounding the hair follicles and the sweat glands showed a positive reaction to alkaline phosphatase. Epidermis and sebaceous glands showed a positive reaction for acid phosphatase.
Open Access
Pathology of utero-ovarian disorders in cow
(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2006) Shanmugasundaram, K; KAU; Mammen J, Abraham
The present study aimed to find out various utero ovarian disorders affecting cows. A total number of 1000 genital tracts were examined for utero-ovarian disorders. Out of which 115 genitalia showed one or more lesions in the ovary, oviduct and uterus. Among these 84 cases showed lesions in the ovaries. The follicular cyst was the most common condition and was recorded in 29 cases (2.9%). The other conditions encountered were luteal cyst (0.3 %), cystic corpus luteum (0.3%), embedded corpus luteum (1.2 %), persistent corpus luteum (0.1 %), ovarian haematoma (0.2 %), ovarian sclerosis(0.2 %), senile atrophy(0.5 %), follicular atresia (0.2 %), epoophoron (0.1 %), serous inclusion cyst (0.1 %), par ovarian cyst (2.2 %) and perioophoritis(0.1 %). Seven cases showed lesions in the oviduct. The conditions encountered were hydrosalpinx (0.1 %) and hyperplasia of the salpingeal epithelium (0.3 %).Uterine disorders recorded in 24 cases. The conditions encountered were endometrial hyperplasia (0.2%), adenomyosis (0.3 %), mucometra (0.1 %), perimetrial cyst (0.1%), serous vascular protrusions (0.5 %), endometritis (1.1 %) and metritis (0.1%). The histopathological changes of all these conditions have been studied in detail and the possible pathogenesis described. The various pathological changes associated with reproductive disorders are suggestive of endocrine imbalances, multiple nutritional deficiencies, infectious origin, managemental factors and developmental defects. The results of the study also highlight the need to monitor the hormonal levels in the blood, micronutrients and managemental factors.
Open Access
Effect of different levels of dietary calcium on performance and mineral availability in crossbred dairy cattle
(Department of Animal Nutrition, College of Veterinary and Animal Sciences, Mannuthy, 2006) Smitha Wilson; KAU; Syam Mohan, K M
An investigation spread over a period of four months was undertaken in crossbred dairy cattle to assess the effect of different levels of dietary calcium on the performance and mineral availability in cross bred dairy cattle. Twelve healthy crossbred cows in the last month of pregnancy having an average peak yield of minimum eight litres per day in their previous lactation were selected. They were divided into two groups of six each as uniformly as possible with regard to age and milk yield and allotted to two dietary treatments viz., T1 (control ration) where in the compounded cattle feed contained 0.5 per cent calcium as per IS (1992) standards and T2 (experimental ration) where in compounded cattle feed contained 1.0 per cent calcium. Paddy straw was the sole roughage source in both the rations. All the experimental animals were fed as per ICAR (1999) standards except for dietary Ca and maintained individually on their respective dietary regime from the last month of calving to three months of lactation. Average dry matter intake, fortnightly body weight, milk yield, milk fat percentage, total solids, solids not fat, serum minerals, mineral content of milk, balance of Ca, P, Mg and Zn and incidence of metabolic disorders were the criteria employed for evaluation. Average body weights and dry matter intake of animals revealed no significant difference for both the groups during all the fortnights studied. Highest dry matter intake for the group I was recorded during the third fortnight and for group II in the second and third fortnight. Average daily milk yield, fat percent, total solids and solids not fat per cent in milk in all the six fortnights did not differ significantly between the groups. The average mineral concentration in milk collected after calving, and at the first, second and third month of lactation for the animals in group II and I did not differ significantly. The mineral content in serum and milk in both groups were within the normal range reported for the species. Results with respect to balance of P and Zn did not differ significantly whereas that for Ca, and Mg differed significantly (P<0.05) between the two groups. Higher retention values were recorded in group II for Ca and group I for Mg. The average retention percent of Ca and Mg differed significantly (P<0.05) the higher values recorded in group I for Mg and in group II for Ca. There was no incidence of metabolic disorders like hypocalcaemia, hypomagnesaemia and ketosis in both groups of animals. An overall critical evaluation of the results obtained in the present study helps to infer that different levels of calcium followed in the present study has a major effect on improving the Ca balance of early lactating cows. The results suggest that levels of Ca in compounded cattle feed at one per cent is better than 0.5 per cent to avoid negative balance of calcium during early lactation when paddy straw is the sole roughage source. The study also indicates that with high levels of dietary Ca there is a need for Mg supplementation to avoid negative balance arising due to interaction of the two elements.

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