Dairy Research Institute Research Articles

Effect of Non-Genetic Factors on Disposal Pattern in Tharparkar Cows

Data on 166 Tharparkar cows, maintained at Dairy cattle breeding division of ICAR-National Dairy Research Institute, Karnal (Haryana) during 1991 to 2013 were collected and classified into four period viz., P1 (1991-1995), P2 (1996-2000), P3 (2001-2005) and P4 (2006-2013) of calving and four season viz. Winter, Summer, Rainy and Autumn of calving to study the disposal pattern. Out of total lifetime milk yield, 83.39% in Tharparkar cows was completed upto 5th parity and due to which the analysis upto 5th parity was conducted. Descriptive statistics were computed for analysis of disposal pattern, whereas effect of non-genetic factors on disposal pattern was analyzed using Chi square statistic. The overall disposal in adult cow per lactations basis was (Mortality: 3.33% and culling: 27.78%) but overall disposal upto fifth parity was 29.88% (culling rate: 26.5% and mortality rate: 3.32%). The overall disposal in adult cows was higher in third parity (33.3%) and lowest in fifth parity (24.3%). The effect of calving season on overall disposal rate in third lactation was significant (P

Prediction of lifetime performance traits by principal component analysis in Jersey crossbred cattle at an organized farm of eastern India

Data on first lactation traits viz. peak yield, 305 days milk yield, milk yield per day of lactation length and total milk yield per day of calving interval were used for prediction of lifetime milk yield (LTMY) upto 4th lactation in Jersey crossbred animals maintained at the organized herd of the Eastern Regional Station, ICAR-National Dairy Research Institute, Kalyani, Nadia, West Bengal using principal component analysis (PCA). The evolved equation, LTMY4 = 2400.56** + 0.698**PC could explain 48.8% variation in the estimated values with adjusted R2 = 48.5%. Early selection of Jersey crossbred cattle based on first lactation records can be done with the help of predicted equation. The study also revealed that factor extracted could be used in breeding programs with sufficient reduction in the number of first lactation traits to be recorded for explanation of maximum variability for prediction of lifetime performance traits in Jersey crossbred cattle.

Seasonal variation of mitochondria activity related and heat shock protein genes in spermatozoa of Karan Fries bulls in tropical climate

The study was conducted the seasonal effect on mitochondria activity-related genes [Succinate dehydrogenase (SDH), Citrate synthase (CS) and mitochondrial transcription factor-A (TFAM)] and heat shock protein (HSP) genes in spermatozoa of Karan Fries (Tharparkar X Holstein Friesian) bulls. Five (n = 5) adult healthy bulls were selected from Artificial Breeding Research Centre of National Dairy Research Institute, Karnal. Thirty (30) ejaculates were collected during summer and winter using artificial vagina (42–45 °C). The ambient temperature, relative humidity, dry and wet bulb temperatures were recorded during the study. Total RNA was isolated by Trizol method. The mRNA expression of SDH, CS and TFAM was lower during summer compared to winter season. The expression of HSP70.1, HSP70.2, HSP90 and HSP105 was higher (p < 0.05) during summer than winter season. However, the expression of HSP70.8 was non-significantly higher during summer season. The physical analysis of semen (volume, motility, live spermatozoa, hypo-osmotic swelling test, concentration, acrosome integrity, total sperm out, major abnormalities) was affected significantly (p < 0.05) by the summer season. The antioxidant enzymes (glutathione peroxidase, superoxide dismutase, glutathione reductase and total antioxidant capacity) and malondialdehyde (product of lipid peroxidation) concentration were estimated higher (p < 0.05) during the summer season than winter. The semen quality of Karan Fries bulls is affected considerably during summer season in tropical climatic conditions.

Genetic analysis of fertility traits in Jersey crossbred cows

The present study was carried out to evaluate the genetic and non-genetic factors affecting fertility traits viz., number of service per conception (NSPC), service period (SP) and calving interval (CI) and genetic and phenotypic parameters of these traits in Jersey crossbred cattle, maintained at Eastern Regional Station of ICAR-National Dairy Research Institute, Kalyani, West Bengal over a period of 39 years (1976-2014). The least squares means for the NSPC, SP and CI were 1.73±0.08 inseminations, 156.37±7.47 days and 458.32±9.56 days respectively. The study revealed that all the traits were decreasing significantly with parity number. Season was important in determining service period, whereas period of calving influenced calving interval in this study. NSPC, SP and CI did not differ significantly among different genetic groups; but, half-breds of Jersey and Tharparkar (½ Jersey-½ Tharparkar) showed comparatively lower NSPC, SP and CI than half-breds of Jersey and Red Sindhi and other crosses in this study. The random effect of sire was highly significant on all the fertility traits considered in this study. Heritability estimates for NSPC, SP and CI were 0.08±0.06, 0.18±0.08 and 0.16±0.08 respectively. All the three analyzed traits had close genetic relationships. Low to moderate heritability of reproductive traits indicates slow genetic progress through selection and further improvement in reproductive performance can be made either by better management practices or including large number of polymorphic markers associated with fertility in the population to assist animal selection

Gender Disparity in Access to Information and Extension Services in Dairy Farming

A study on the role of men and women in accessing different communication sources and extension services in dairy farming was undertaken during 2016-17 in Haryana, India with 120 randomly selected women farmers. Personal interview and PRA (Participatory Rural Appraisal) methods were used for data collection and analyzed using frequency and percentage. Majority of males had land ownership, livestock and credit. Majority of the women respondents had occasional contact with veterinary surgeons & ICAR-National Dairy Research Institute and animal feed dealers. However in case of informal sources, majority of the males had contact with relatives/ friends. Women’s role is highly reflected in fodder collection, feed preparation, cleaning of animal shed, milking and taking care of animals. This gender disparity brings urgent need to sensitize the dairy farmers/farm women and enable them to have equal access of resources, input and opportunities through appropriately designed extension models for ultimate empowerment of farm women and the progress of the country.

Effect of saline water on rumen fermentation and serum profile in Murrah male calves

Twenty growing male Murrah calves, with average body weight (kg) 220±5, were randomly assigned to five treatments of water containing total dissolved solids (TDS; ppm) viz CON=500; T1=2,000; T2=4,000; T3=6,000 and T4=8,000 at National Dairy Research Institute (NDRI), Karnal India. Animals were arranged in a randomized block design with 120-day experimental period. Feed and water intake were measured daily, rumen fermentation parameters and blood profile were evaluated at monthly interval. Water intake was apparently higher in T1 (17.46 l/day) and T2 (16.77 l/day) as compared to CON (control; 14.07 l/day) but did not differ significantly. However, water intake was lower (P less than 0.05) in T3 (10.40 l/day) and T4 (8.18 l/day) as compared to group T1, T2 and T3CON. Except ammonia nitrogen which was decreased with increasing TDS of water, all other rumen liquor parameters were found similar. In blood parameters, there was significant decrease (P less than 0.05) in plasma glucose, total protein, and albumin while there was significant increase (P less than 0.05), in AST and ALT with increasing TDS of water. Blood Urea Nitrogen, creatinine, uric acid were not affected. On the basis of above results it was inferred that water intake was decreased at higher TDS (above 4000 ppm)

Effect of vitamin E supplementation on semen and blood profile of vaccinated crossbred bulls

Vaccination is one of the major stress factors that affects the semen productivity of the breeding bulls who showed consistent higher body temperature for several days. Therefore, a study was planned to assess the ameliorative strategy of vaccination stress by Vitamin E supplementation on twelve Holstein-Friesian crossbred bulls (432 ejaculates) maintained at Artificial Breeding Research Centre, ICAR-National Dairy Research Institute, Karnal. The bulls were vaccinated for FMD @ 3 ml by SC injections. In treatment group (6 bulls), Vitamin E was supplemented @ 4000 I.U./bull/day, ten weeks before and nine weeks after vaccination and another group without Vitamin E supplementation served as control. Vitamin E supplementation resulted in significantly reduced sperm abnormalities and improved sperm concentration, total motile spermatozoa (106), total live spermatozoa per ml (106), total sperm (106), live sperm/ml and total dose harvested in treated group as compared to control. Individual motility (%), mass motility, NEC (%), HOST (%) and IA (%) were higher in the treatment group, but it was not significant. Better blood biochemical profile of bull was evident in Vitamin E supplemented group though it was not significant statistically. It can be concluded that Vitamin E supplementation in vaccinated bulls was effective in ameliorating vaccination stress to some extent.

Demographic parameters and disposal pattern in Sahiwal cattle herd

The knowledge of disposal rate, its causes and factors affecting it at various ages are very essential in a given herd for producing replacement stock to maintain proper herd structure. The relevant data for the present study on Sahiwal cows and their calves from 1994 to 2013 (20 years) were collected and recorded at ICAR-National Dairy Research Institute (ICAR-NDRI), Karnal. The analysis of influence of various non-genetic factors on disposal pattern was carried out by Chi-square method using the SPSS software. The age specific disposal of Sahiwal cattle at various age groups i.e. 0–1 month, 1–3 month, 3–6 month, 6–12 month, 12–18 months and 18 month to AFC were 13.79, 4.95, 2.80, 4.53, 1.29 and 3.21%, respectively. The mortality of female from birth to AFC in respective age groups was 13.79, 4.95, 2.00, 2.47, 0.72 and 1.90%, respectively. The incidence of mortality was decreased, while culling increased as the age advanced. Maximum mortality was observed mainly due to pneumonia and enteritis while poor growth and late maturity were the major reasons for culling. It was also observed that about 15.86% of the cows died while they were in the herd and the rest 84.13% were culled from the herd. The expected herd life at first lactation was found to be 2.52 lactations which showed the decreasing trend along the parity. The present study concluded that the first three months of age is more critical period for the survival of calves. Therefore there is need of intensive feeding and healthcare management to minimize involuntary disposal.

Relationship between Solid Food Introduction and Picky Eating in the STRONG Kids 2 Cohort

Picky eating is prevalent in toddlers and has been linked to infant feeding practices. Early introduction of solid food is associated with picky eating; however, the relationship with specific types of complementary food is unknown. The objective of this study was to examine associations between types of solid food introduced during infancy and picky eating behavior in children 18‐months of age. Participants were drawn from an ongoing STRONG Kids 2 birth cohort of mother‐infant dyads (current study n = 259, full sample n = 440). Mothers responded to survey questions about the type and amount of solid food introduced during infancy, the perception of their child's picky eating behaviors at 18‐months, and whether they breastfed or formula‐fed their child during the introduction to solids. Ordinal logistic regression (i.e., proportional odds model) was used to determine associations between types of solid food introduced and odds of picky eating, while controlling for child sex, race/ethnicity, age of introduction to solids, and mode of milk feeding. The introduction of sweets (e.g., ice cream and pudding), cereal, pureed fruit, and egg yolk were positively associated with parental perception of picky eating at 18‐months (all p&lt;0.05). There was no association between parental perception of picky eating and the introduction of vegetables, meat, or dairy. Overall, our findings suggest that early exposure to various tastes and textures may influence the development of picky eating later in childhood. Further research is needed to determine the influence of the timing and type of solid food introduction on children's long‐term dietary variety and eating behavior.Support or Funding InformationSupported by National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2011‐67001‐30101 and the Dairy Research Institute.

Culling pattern and effect of selection on milk production over the periods in Sahiwal cattle at an organised farm

The investigation was carried out on 1,629 calving records of 462 Sahiwal cows calved between 1988 and 2013 at National Dairy Research Institute, Karnal, Haryana, India to study culling pattern as well as the effect of selection on milk production. Average culling and mortality rate per lactation of Sahiwal cows were 23.82 and 4.54%, respectively. The culling was found due to teat and udder problems (32.47%), followed by reproductive problems (22.73%) and low milk production (10.82%) in the herd. Most of the voluntary culling (based on the low milk yield) was observed during second and third lactations. Stage of lactation and milk yield had significant influence on culling during first lactation whereas, period had significant influence on culling during second lactation. Sahiwal cows yielding more than 8 kg of milk/day were less likely to cull and the probability of culling of cows increased after the completion of 360 days of first lactation. Most probable producing ability of per day milk yield [MPPA (PDMY)] was estimated for selected and culled cows. There is an intense need to minimize the involuntary culling of cows by providing better feeding and management so that more of cows can be saved in herd, which will in turn facilitate in increasing selection intensity and selection differential in the herd and ultimately help in faster genetic improvement of Sahiwal cows.

Extraction of chitosan and its oligomers from shrimp shell waste, their characterization and antimicrobial effect.

Aim:The present study was performed to utilize the shrimp shell waste for chitin and chitosan production, characterization by Fourier transform infrared (FT-IR) technique and to evaluate the antimicrobial effects of chitosan oligomers produced by depolymerization of chitosan by nitrous acid.Materials and Methods:Chitosan was extracted from the shrimp shell waste by the chemical method and characterized by FT-IR. Chitooligomers were produced by depolymerising chitosan using nitrous acid, and the chitooligomers were tested for antimicrobial effect against four gut pathogenic organisms, i.e., Enterobacter aerogen (National Collection of Dairy Culture [NCDC] 106), Enterococcus faecalis (NCDC 119), Escherichia coli (NCDC 134), and Staphylococcus aureus (NCDC 109) by well diffusion method using Muller-Hinton agar. A pure culture of pathogenic organisms was collected from NCDC, ICAR-National Dairy Research Institute, Karnal.Results:Extracted chitosan characterized by FT-IR and chitooligomers demonstrated antimicrobial effect against four gut pathogenic organisms used in this study. Zone of inhibitions (mm) were observed in E. faecalis (13±0.20), E. coli (11.5±0.4), S. aureus (10.7±0.2), and E. aerogen (10.7±0.3). E. faecalis showed larger inhibition zone as compared to all other organisms and inhibitions zones of E. aerogen and S. aureus were comparable to each other.Conclusion:Shrimp waste can be utilized for chitosan production, and the chitooligomers can be used as feed additive for gut health enhancement and have potential to replace antibiotics from the feed. Along with value addition pollutant load could be reduced by waste utilization.

Identification of single nucleotide polymorphism in protein phosphatase 1 regulatory subunit 11 gene in Murrah bulls.

Aim:This study was conducted with the objective to identify single nucleotide polymorphism (SNP) in protein phosphatase 1 regulatory subunit 11 (PPP1R11) gene in Murrah bulls.Materials and Methods:Genomic DNA was isolated by phenol–chloroform extraction method from the frozen semen samples of 65 Murrah bulls maintained at Artificial Breeding Research Centre, ICAR-National Dairy Research Institute, Karnal. The quality and concentration of DNA was checked by spectrophotometer reading and agarose gel electrophoresis. The target region of PPP1R11 gene was amplified using four sets of primer designed based on Bos taurus reference sequence. The amplified products were sequenced and aligned using Clustal Omega for identification of SNPs. Animals were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using EcoNI restriction enzyme.Results:The sequences in the NCBI accession number NW_005785016.1 for Bubalus bubalis were compared and aligned with the edited sequences of Murrah bulls with Clustal Omega software. A total of 10 SNPs were found, out of which 1 at 5’UTR, 3 at intron 1, and 6 at intron 2 region. PCR-RFLP using restriction enzyme EcoNI revealed only AA genotype indicating monomorphism in PPP1R11 gene of all Murrah animals included in the study.Conclusion:A total of 10 SNPs were found. PCR-RFLP revealed only AA genotype indicating monomorphism in PPP1R11 gene of all Murrah animals included in the study, due to which association analysis with conception rate was not feasible.

Physiological Response to Thermal Stress in Sahiwal and Karan Fries Cows

The study was conducted to observe the effect of season on thermoregulation responses. A total of 100 cows including 50 Sahiwal and 50 Karan Fries cows were selected from Livestock Research Centre of ICAR-National Dairy Research Institute, Karnal, India. The study was conducted during winter (THI=49.67±1.18), spring (THI=64.65±0.41) and summer (THI=87.28±1.26) seasons. The fluctuations were observed in RR, RT and HTC of Sahiwal and Karan Fries cattle in different seasons. In Sahiwal cows RT (°C) during winter, spring and summer were 37.300±0.095c, 38.178±0.095b and 38.810±0.095a respectively whereas RT (°C) in Karan Fries were 37.492±0.115c, 38.398±0.115b and 39.186±0.115a during winter, spring and summer respectively. RR (breaths min-1) in Sahiwal cows during winter, spring and summer were 15.738±0.795c, 18.158±0.795b and 29.818±0.795a respectively whereas RR in Karan Fries during winter, spring and summer were 15.779±1.136c, 22.979±1.136b and 47.299±1.136a respectively. The magnitude of increase in RR, RT and HTC were found to be higher during summer compared to other seasons in both Sahiwal and Karan Fries cattle. It was observed that Sahiwal cows are less sensitive and are better able to regulate body temperature in response to heat stress than Karan Fries cows.

Genetic analysis of first lactation production and fertility traits in Karan Fries cattle

The present investigation encompasses the genetic analysis of first lactation production and fertility performance of Karan Fries cattle. Data were collected on 1,988 cows maintained at National Dairy Research Institute (NDRI), Karnal, Haryana over a period of 34 years (1978 to 2012). Least squares analysis was carried out to study the effect of non-genetic factors, viz. season of first calving (SC), period of first calving (PC), genetic group (GG) and age at first calving group (AFCG) on first lactation fertility and production traits. Least squares means of age at first calving (AFC), first calving to first service (FCFS), first service period (FSP), first lactation length (FLL), first calving interval (FCI), first lactation 305 day or less milk yield (F305MY), first lactation total milk yield (FTMY), milk yield per day of first lactation length (MY/FLL), milk yield per day of first calving interval (MY/FCI) and first lactation daughter pregnancy rate (FDPR) were 957.48±6.54 days, 79.46±3.58 days, 130.03±4.43 days, 347.02±5.51 days, 415.47±5.21 days, 3,213.91±47.61 kg, 3,760.49±74.27 kg, 10.49±0.12 kg/day, 9.14±0.13 kg/ day and 0.33±1.42, respectively. Overview of least squares analysis regarding first lactation traits indicated that most of the non-genetic factors excepting AFC group, significantly affected the performance of the animal. Results revealed the superiority of F1 over other GG of Karan Fries cows indicating a significant effect of heterosis. Heritability estimated by both analysis of variance and average information restricted maximum likelihood methods indicated that the fertility traits were less affected by additive gene action; the estimates for production traits indicated higher role of additive gene action. Both phenotypic and genetic correlation estimates indicated antagonistic association between fertility and production traits.

Effect of genetic and non-genetic factors on milk yield and milkcomposition traits in Murrah buffaloes

The objective of the present study was to investigate the effect of genetic and non-genetic factors and to estimate genetic parameters of first lactation 305 days milk yield (FLMY305), 305 days fat yield (LFY), 305 days solid not fat yield (LSNFY), 305 days total solid yield (LTSY), 305 days fat percentage (FAT%), 305 days solid not fat percentage (SNF%) and 305 days total solid percentage (TS%) in Murrah buffaloes. The data of 315 Murrah buffaloes calved from 1993 to 2013 and sired by 47 bulls maintained in an organized farm at ICAR-National Dairy Research Institute, Karnal was analyzed to study the effect of genetic and non-genetic factors. Least squares analysis was done to estimate the effect of genetic and non-genetic factors on FLMY305, LFY, LSNFY, LTSY, FAT%, SNF% and TS%. Heritability estimates were obtained by using paternal half-sib correlation method. The heritability estimates for FLMY305, LFY, LSNFY, LTSY, FAT%, SNF% and TS% traits were found to be 0.30, 0.29, 0.30, 0.30, 0.05, 0.02 and 0.06, respectively. Very high and positive genetic and phenotypic correlations of FLMY305 with milk constituents’ yield traits implied that selection based on FLMY305 would result in correlated response in milk constituents yield traits and therefore need not to be considered separately for their improvement.

Random regression model with heterogeneous residual variance reduces polynomial order fitted for permanent environmental effect but does not affect genetic parameters for milk production in Sahiwal cattle

The random regression test-day models can accelerate the genetic improvement of Sahiwal cattle as test-day milk yield models offer a faster, accurate and economical approach of genetic evaluation. First three lactation monthly test-day records of Sahiwal cows calved between 1961 and 2012 at ICAR-National Dairy Research Institute, Karnal were used to fit random regression model (RRM) with various order of legendre polynomial, and a constant (RRM-HOM) or heterogeneous residual variance (RRM-HET). For both RRM-HOM and RRM-HET third order legendre polynomial for modelling additive genetic effects were found best. There was reduction in order of fit for modelling permanent environmental effects due to assumption of heterogeneous residual variance, as legendre polynomial of sixth order for RRM-HOM and fourth or fifth order for RRM-HET was found to be best, for modelling the permanent environmental effect. First two eigenvalues of additive genetic random regression coefficient matrix explained more than 99% of the additive genetic variation, whereas four eigenvalues explained ~98% of the permanent environment variations. First eigenfunction from both the models did not show any large change along lactation, suggesting most variation can be explained by genes that act in same way during lactation. The heritability estimates were generally low but moderate for some test-day milk yields, and it ranged from 0.007 to 0.088 for first, 0.044 to 0.279 for second, and 0.089 to 0.129 for third lactation from RRM-HOM. The values of genetic correlation between test-day milk yields ranged from 0.06 to 0.99 for first, 0.77 to 0.99 for second, and 0.07 to 0.99 for third lactation, from RRM-HOM. The value of permanent environment correlation ranged from 0.30 to 0.98 for first, 0.07 to 0.99 for second, and 0.16 to 0.98 for third lactation. The genetic correlations between two adjacent test-days were high (≥0.90). RRM-HET also gave similar heritability and correlation estimates. The rank correlation between sire breeding values for first, second, and third lactation, estimated using two models were 0.98, 1.00, and 0.99, respectively, indicating there was no difference in the ranking of animals using two models. Thus the random regression model with lower order of polynomial for modelling additive genetic effect and higher order polynomial for modelling animal permanent environmental effect was found suitable for genetic evaluation and both RRM-HOM and RRM-HET can be used for modelling test-day milk yield and breeding value prediction in Sahiwal cattle.

Evaluation of bull fertility of Sahiwal breeding bulls

In the present investigation, bull fertility of Sahiwal breeding bulls has been studied. The study was conducted on records of 43 Sahiwal bulls maintained under 8 sets of Sahiwal breeding project at ICAR- National Dairy Research Institute, Karnal (India). The data on bull fertility of Sahiwal breeding bulls during 27 years (1987-2013) were analysed. The presented study revealed that the average conception rate based on first AI and overall conception rate of Sahiwal breeding bulls were estimated as 45.95% and 46.38 %. Average sire conception rate of Sahiwal breeding bulls range from – 2% to + 3% and – 2% to + 4 % for conception rate based on first AI and overall conception rate. It has been observed that the average conception rate based on first AI was lower as compare to overall conception rate and higher conception rate of Sahiwal breeding bulls is having higher sire conception rate.

Genetic evaluation of reproductive traits in Jersey crossbred heifersat an organized farm of eastern India

The present study was conducted on data of reproductive traits (viz., age at first service and age at first calving) in Jersey crossbred heifers, maintained at the Eastern Regional Station of ICAR-National Dairy Research Institute, Kalyani, West Bengal over a period of 38 years (1977-2014) to determine the effects of genetic and non-genetic factors. The data were classified according to season of birth, period of birth of animals and distributed in eight genetic groups having different level of Jersey inheritance. The least square mean of age at first service (AFS) and age at first calving (AFC) were 750.61±12.35 and 1089.36±13.99 days respectively. Sire had highly significant (P&lt;0.01) influence on both AFS and AFC in the present study whereas, the genetic group had only significant effect on age at first calving. The half-bred of Jersey and Tharparkar crosses (1/2 Jersey-1/2 Tharparkar) had significantly lower AFC (987.47±43.21 days) than half-bred of Jersey and Red Sindhi and other crosses in this study. Moreover, the animals having less than 50 % and more than 62.5 % Jersey inheritance had highest AFC than other crosses. On the other hand, period of birth had significant effect on both AFS and AFC; however, season of birth only influenced AFC. Heritability estimates of AFS and AFC were observed 0.46±0.19 and 0.30±0.19 respectively. Strong genetic correlation (0.81±0.19) was estimated between these traits. Since, these traits have moderate to high heritability, it indicates faster improvement of these traits through selection.

Molecular characterization and combined genotype association study of bovine cluster of differentiation 14 gene with clinical mastitis in crossbred dairy cattle.

Aim:The present study was undertaken with the objectives to characterize and to analyze combined genotypes of cluster of differentiation 14 (CD14) gene to explore its association with clinical mastitis in Karan Fries (KF) cows maintained in the National Dairy Research Institute herd, Karnal.Materials and Methods:Genomic DNA was extracted using blood of randomly selected 94 KF lactating cattle by phenol-chloroform method. After checking its quality and quantity, polymerase chain reaction (PCR) was carried out using six sets of reported gene-specific primers to amplify complete KF CD14 gene. The forward and reverse sequences for each PCR fragments were assembled to form complete sequence for the respective region of KF CD14 gene. The multiple sequence alignments of the edited sequence with the corresponding reference with reported Bos taurus sequence (EU148610.1) were performed with ClustalW software to identify single nucleotide polymorphisms (SNPs). Basic Local Alignment Search Tool analysis was performed to compare the sequence identity of KF CD14 gene with other species. The restriction fragment length polymorphism (RFLP) analysis was carried out in all KF cows using Helicobacter pylori 188I (Hpy188I) (contig 2) and Haemophilus influenzae I (HinfI) (contig 4) restriction enzyme (RE). Cows were assigned genotypes obtained by PCR-RFLP analysis, and association study was done using Chi-square (χ2) test. The genotypes of both contigs (loci) number 2 and 4 were combined with respect to each animal to construct combined genotype patterns.Results:Two types of sequences of KF were obtained: One with 2630 bp having one insertion at 616 nucleotide (nt) position and one deletion at 1117 nt position, and the another sequence was of 2629 bp having only one deletion at 615 nt position. ClustalW, multiple alignments of KF CD14 gene sequence with B. taurus cattle sequence (EU148610.1), revealed 24 nt changes (SNPs). Cows were also screened using PCR-RFLP with Hpy188I (contig 2) and HinfI (contig 4) RE, which revealed three genotypes each that differed significantly regarding mastitis incidence. The maximum possible combination of these two loci shown nine combined genotype patterns and it was observed only eight combined genotypes out of nine: AACC, AACD, AADD, ABCD, ABDD, BBCC, BBCD, and BBDD. The combined genotype ABCC was not observed in the studied population of KF cows. Out of 94 animals, AACD combined genotype animals (10.63%) were found to be not affected with mastitis, and ABDD combined genotyped animals was observed having the highest mastitis incidence of 15.96%.Conclusion:AACD typed cows were found to be least susceptible to mastitis incidence as compared to other combined genotypes.

Optimization of dry period in Karan Fries cow.

Aim:The objective of this study was to optimize dry period (DP) length that can maximize the production across adjacent lactations and overall lifetime yield.Materials and Methods:Performance records with respect to DP spread over a period of 15-year in Karan Fries (KF) cattle maintained at Livestock Research Centre (National Dairy Research Institute), were collected for the study. Data of 681 KF cows were analyzed by least square technique to examine the effect of non-genetic factors on DP. Season of calving was classified into four seasons: Winter season (December-March), summer season (April-June), rainy season (July-September), and autumn season (October-November); period of calving into five periods: 1998-2000 (1-period), 2001-2003 (II-period), 2004-2006 (III-period), 2007-2009 (IV-period), and 2010-2012 (V-period), and parity into six parities, i.e., 1st, 2nd, 3rd, 4th, 5th, and >6th parities to see the effect of non-genetic factors on DP.Results:Period of calving, season of calving, and parity did not affect the DP significantly (p<0.05). The overall least square mean of DP was 67.93±2.12 days. For the optimization of DP with regard to milk productivity, analysis was carried out by class interval method. DP was classified into eight classes (<22, 23-45, 46-67, 68-89, 90-111, 112-133, 134-155, and >156 days), and optimum level was obtained at 46-67 days (3rd class) with the following respective milk yield (MY) of 305 daily MY (4016.44±43.68 kg), total MY (4704.21±61.51 kg), MY per day of lactation length (13.03±0.13 kg), and MY per day of calving interval (11.68±0.41 kg).Conclusion:From the study, it was concluded that this optimal DP length (46-67 days) is suitable for maximizing the production. Hence, one should aim to dry off pregnant cows to achieve a DP of appropriate length to enhance productivity in the next lactation, as very short and very long DP reduces the economic profitability in dairy animals.