Identification of Polymorphism within Exon 8 of Bovine HSP90AA1 Gene using PCR-SSCP Technique

Heat shock proteins (HSPs) are a type of molecular chaperones that aid in the recovery of stressed cells and serve as a major system for intracellular self-defense. A study was conducted during the year 2018–19 at College of Veterinary Science Rajendranagar, Hyderabad, Telengana State, India to find polymorphisms in exon 8 of the bovine HSP90AA1 gene in Sahiwal (n=50) and crossbred (n=50) cows. Blood samples were collected from the experimental animals and genomic DNA was isolated. Physiological parameters like body temperature and respiration rate for each animal were taken during the experimental period and the heat tolerance coefficient was calculated. The data on production and reproduction traits were obtained from the history sheets of the animals. To detect the polymorphism, a 539 bp fragment of the HSP90AA1 gene covering exon 8 was subjected to the Polymerase Chain Reaction-Single-Strand Conformation Polymorphism (PCR-SSCP) technique.The PCR-SSCP of exon 8 of HSP90AA1 gene yielded two genotypic patterns AA and AB corresponding to two allelic variants with frequencies of 0.85, 0.15, 0.81 and 0.19 in Sahiwal and crossbred cows, respectively. The PCR-SSCP patterns obtained were correlated with the physiological, productive, and reproductive traits in both Sahiwal and crossbred cows. The association analysis of SSCP patterns of the exon 8 of HSP90AA1 gene revealed non-significant effect in Sahiwal cows, although the AB genotype had a significantly longer service period in crossbred cows.

Association of Lameness with Body Condition Score, Udder Health and Milk Quality in Sahiwal Dairy Cows

Background: Bovine lameness predominantly due to foot disorders is a severe herd health concern instigating substantial influence on dairy economics owing to increased odds of mastitis and reduced fertility. Timely diagnosis and treatment of lameness can save these economic losses. The current study was aimed to evaluate lameness and its effect on animal health in terms of body condition score and on udder health in Sahiwal cows. Methods: 204 lactating Sahiwal dairy cows in different lactation lengths and parities, from local Sahiwal farms in Punjab were evaluated for lameness. Cows were scored for body condition and lameness. Quarter foremilk used to determine the quarter health status of the cows by California mastitis test (CMT) and bacteriological culture and cow composite milk samples for estimation of somatic cell count (SCC), electrical conductivity, pH and milk composition, in terms of fat, solids not fat, protein and lactose were collected maintaining aseptic conditions. Result: 34 per cent had asymmetry in gait or mild lame, 5 per cent had moderate lameness and 1 per cent had severe lameness. Lameness had no significant effect on the body condition scores of Sahiwal cows. Subclinical mastitis was found in 40.2 per cent of Sahiwal dairy cows. It was concluded that incidence of mastitis was higher in the lame group as revealed by CMT and bacteriological culture and the lame group had significantly (P less than 0.05) more SCC and electrical conductivity than healthy cows. However, milk composition was not affected by lameness.

Association of SSCP Polymorphisms of HSP70 Gene with Physiological, Production and Reproduction Performance in Sahiwal and Crossbred Cows

Background: Cellular tolerance to heat stress is mediated by heat shock proteins (HSPs). The HSPs act as molecular chaperones and are transcribed in response to stress. Among different families of these proteins, HSP70 is considered to be related to the development of temperature tolerance. Unraveling polymorphism in heat shock protein genes could be a step towards the identification of genetic markers for selecting heat-tolerant cattle. Methods: The present study was carried out in Sahiwal (n=50) and Crossbred cows (n=50) with the objective to identify polymorphisms in HSP70 gene. Two fragments (295 and 220 bp) of HSP70 gene were subjected to Polymerase Chain Reaction-Single-Strand Conformation Polymorphism (PCR-SSCP) technique. Statistical analysis was performed to study the association of each SSCP genotype on physiological, production and reproduction traits in Sahiwal and crossbred cows using the univariate GLM model of SPSS 25. Result: The PCR-SSCP of 295 bp fragment of HSP70 gene revealed two genotypes AA and AB in Sahiwal cows and two genotypes AA and AC in crossbred cows. The association analysis revealed that genotype AA had higher peak milk yield in Sahiwal cows while the same genotype had higher total lactation milk yield, lower service period and calving interval in crossbred cows. The 220 bp fragment was found to be monomorphic in both Sahiwal and crossbred cows.

Genetic Profiling of PHKA2 Gene and its Association with Udder Type Traits in Indian Dairy Cattle

Background: The experiment aimed to investigate polymorphisms in exon 2 of the PHKA2 gene and investigate the relationship between identified single nucleotide polymorphism and udder type traits in Sahiwal cows. Udder morphometry is being used as a forecaster of production performance in cows since older times. Finding the variants associated with these traits in largely variable region of PHKA2 gene can prove to be highly beneficial. Methods: DNA isolated from Sahiwal cows was analysed by DNA sequencing. Nine udder type and five teat types were measured for each animal according to procedure followed by International committee of animal recording (2012). Result: Three SNPs g.124497381C greater than T, X:124497248 G greater than A and X:124497189 C greater than T were identified. Recessive homozygotes were negligible as mutant allele exhibited very low ranging frequency (from 0.02 to 0.08) for the targeted loci. Identified point mutation g.124497381C greater than T was found to be significantly (p less than 0.05) associated with distance between teats and central ligament, SNP X: 124497248G greater than A with rear udder width, fore udder attachment, udder depth, udder length and teat length (p less than 0.05) and SNP X: 124497189 C greater than T with udder length and rear udder height (p less than 0.05). Interaction of identified SNPs and udder traits highlighted the gene’s potential as a candidate gene for selecting for conformation traits in Indian Sahiwal cattle.

Insights Into The Effect of Shelter Modification On Key Biochemical Aspects vis-a-vis the Performance of Sahiwal Zebu Cows Reared in Hot Arid Ambience

This study was undertaken to evaluate the effect of shelter modifications in the form of floor alteration and heat stress amelioration aids on the biochemical aspects and productive performance of Sahiwal zebu cows. 24 healthy Sahiwal cows in their second or third parity were randomly assigned to four groups (G1, G2, G3, and G4) having 6 cows each and were studied for duration of 150 days from June to November. G1 acted as control without any shelter modification, while G2 cows were housed in stalls with rubber mat covered floors, G3 cows were provided with cooling fans along with water sprinkling twice a day, and G4 cows were housed in stalls combining rubber mat floors with cooling fans and water sprinkling twice a day. This study revealed a significant (p<0.05) effect of shelter modification on milk yield, though no significant effect on milk composition was found. Among blood biochemical parameters, serum cholesterol and cortisol levels registered a significant (p<0.05) effect of shelter modification. The use of heat amelioration aids with, and without rubber mat floors positively influenced the productive and biochemical aspects of Sahiwal cows. Such strategies can be utilized to reduce stress on animals and help in maintaining their production.

Effect of Seasons on Physiological Responses in Sahiwal and Crossbred Cows

Background: Growing demand for improving milk production and rising temperatures due to global warming has increased the thermal load on dairy animals. Physiological parameters such as respiration rate and body temperature mainly determine the adaptability of animals to climate stress. During genetic adaptation, Bos indicus cattle have acquired thermo tolerant genes and when exposed to heat stress conditions, the Bos indicus cattle have lower respiration rates and rectal temperatures than Bos taurus animals. The present study was aimed to study the effect of seasons on the physiological responses in Sahiwal and crossbred cows. Methods: A total of 50 crossbred cows maintained at Military dairy Farm, Secunderabad and 50 Sahiwal cows maintained at Livestock Farm Complex, College of Veterinary Science, Rajendranagar, PVNRTVU were utilized for the present investigation. The study was conducted during summer (THI = 83.71±0.01), rainy (THI = 71.37±0.01) and winter (THI = 66.69±0.01) seasons. Changes in respiration rate (RR), rectal temperature (RT) and heat tolerance coefficient (HTC) were observed in different seasons in Sahiwal and crossbred cows. Result: RR (breaths/ min) in Sahiwal cows during summer, rainy and winter were 28.56±0.38, 23.38±0.38 and 20.54±0.38 respectively whereas RR (breaths/ min) in crossbred cows were 44.58±0.38, 25.94±0.38 and 21.90±0.38 respectively. In Sahiwal cows RT (°C) during summer, rainy and winter were 38.52±0.03, 38.23±0.03 and 38.13±0.03 respectively whereas RT (°C) in crossbred cows were 39.22±0.02, 38.72±0.03 and 37.80±0.03 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 crossbred cows. It was observed that Sahiwal cows are less sensitive to heat stress and are better able to regulate their body temperature than crossbred cows when environmental temperature increases during summer. The HTC values were lower in Sahiwal cows in all the seasons studied indicating better thermo tolerance when compared to the crossbred cows.

Production and Reproduction Performance of Sahiwal and HF × Sahiwal Cows

Background: Milk production is one of the most important economic traits in dairy cattle. Crossing of zebu cattle (Bos indicus) with temperate cattle breeds (Bos taurus) was undertaken to improve the milk production in India. Crossbreeding has resulted in improved production performance of the dairy animlas over the past few decades. Methods: Data on 50 purebred Sahiwal cows from the Livestock Farm Complex, College of Veterinary Science, Rajendranagar, Hyderabad and 50 Holstein Friesian × Sahiwal crossbred cows maintained at the Military Dairy Farm, Secunderabad were utilized to study the influence of breed and parity on various production and reproduction traits. The various traits studied were: Total lactation milk yield (TLMY) Lactation length (LL), Peak yield (PY), Age at first service (AFS), Age at first calving (AFC), Gestation period (GP), Service period (SP), Dry period (DP) and Calving interval (Cl). Result: In the present study, significant effect of breed was found on the TLMY and PY with the crossbreds recording higher values for both the traits. The means for TLMY, PY, LL, GP, SP, DP and CI were 1768.32±109.67 kg, 10.17±0.50 kg, 304.41±13.00 days, 277.71±2.24 days, 182.60±15.51 days, 167.47±10.68 days and 430.23±13.46 days in Sahiwal and 2983.45±78.32 kg, 14.92±0.36 kg, 324.71±9.29 days, 275.34 days, 181.09±10.91 days, 127.01±7.51, 413.61±9.47 days in crossbred cows respectively. It may be concluded that the productive performance of crossbred cows was better than that of indigenous cows.

Ovarian dynamics, hormone profiles, and characterization of ovarian and uterine blood flow in cycling Sahiwal cows

The objectives were to investigate the ovarian dynamics and hormonal profiles during the oestrus cycle, and to characterize the ovarian and uterine blood flow (OBF versus UBF) indices on the extent of vascular perfusion towards the dominant follicle (DF) or corpus luteum (CL) during the peri-ovulatory follicular wave in Sahiwal cows. In experiment 1, cyclic cows (n = 21) were selected at their spontaneous oestrus (day 0) and subjected to B-mode ultrasonography throughout the oestrus cycle. In experiment 2, cyclic cows (n = 9) were randomly selected at day 0, and categorized according to the intra-ovarian patterns as ovaries with DF (n = 3), CL (n = 3) or both (DF+CL; n = 3) to characterize the OBF and UBF indices using Doppler ultrasonography. The length of the oestrus cycle (days), number of follicular waves (n) and size (mm) of DF and CL were 20.1 ± 0.9, 2.1 ± 0.2, 14.7 ± 0.7 and 15.9 ± 2.5, respectively. The concentrations (ng/mL) of plasma progesterone increased linearly, and a peak was attained at day 12.2 ± 1.0. However, it reduced linearly with the onset of luteolysis at day 16.4 ± 0.3 of the oestrus cycle. The plasma progesterone (P4) concentrations and the diameter of CL correlated throughout the oestrus cycle. The mean OBF and UBF indices did not differ between intraovarian patterns. Taken together, this information on reproductive physiological parameters could be used to develop synchronization protocols to improve reproductive management in Sahiwal cows.

Detection of Subclinical Ketosis in Urine of Cattle and Buffaloes

Background: Subclinical ketosis (SCK) in dairy cows is a common metabolic disorder and a strong determinant of the health and performance of cows throughout lactation. Considerable amount of milk loss takes place with SCK incidence in dairy animals. Greater benefits are to be gained by monitoring the cows for SCK. The current study was aimed to find out incidence of SCK by urine test strip (Keto-Diastix). Methods: The present investigation was carried out on crossbred and Sahiwal cows and Murrah buffaloes (n=180) of the institute herd and rural dairy farms (n=97) around Karnal. The urine samples were tested for subclinical ketosis (SCK) 5-60 days postpartum from August 2019 to March 2020. Meteriological data on wet and dry bulb temperature and ambient temperature was collected and THI was calculated. Data of SCK incidence was classified based on stages of early lactation (5-20, 21-40 and 41-60d), parity (I, II, III and above), seasons (hot-humid, autumn, winter and spring) and milk production level ( less than 10kg, 10-20 kg and greater than 20 kg/d). Milk yield and environment variables were recorded during the experiment. Urine ketone and glucose level was detected by keto-Diastix to find out incidence of SCK. Result: Mean level of ketone bodies in urine was higher (P less than 0.01) in high yielding cows as compared to the medium yielders; however it did not vary in buffaloes. Ketone bodies in urine were high (P less than 0.01) in crossbred cows than that of buffaloes and Sahiwal cows. Urine glucose level did not vary among cows and buffaloes. It is concluded that high producing crossbred cows are more vulnerable to SCK between 41-60d of lactation and in III parity and above due to peak milk production. Sahiwal cows and buffaloes suffer less from SCK probably due to medium level of milk production. Factors like high milk yield, higher parity and hot-humid stress makes the animal more vulnerable to SCK. The screening of urine samples of animals at monthly intervals may be practiced by the farmers to monitor the incidence of SCK.

Studies on Ovarian Follicular Dynamics and Steroid Profiles in Sahiwal Cattle

Background: Understanding of ovarian follicular dynamics and endocrine regulation is essential to design and use interventions to optimize reproductive efficiency. Bos indicus and Bos taurus cows have some differences in their follicular dynamics and ovarian steroidal hormones. The present study was planned to understand follicular dynamics vis-a-vis ovarian steroids profiles in Sahiwal cattle. Methods: The study was conducted in normal cyclic, pluriparous, non-lactating Sahiwal cows (n=7). Trans-rectal ultrasonography was performed to record the location, size, number of follicles and size of corpus luteum (CL) from the beginning, till the end of experiment. The dataset was used to characterize the follicular wave emergence, growth, regression, time of selection and ovulation of the dominant follicle in each cow. Result: Three Sahiwal cows showed two wave and four cows showed three wave estrous cycles with mean interovulatory length of 20.33±0.33 and 22.50±0.28 days, respectively. No significant difference was recorded in the maximum diameter of corpus luteum, P4 and E2 plasma levels between 2-wave and 3-wave estrous cycles. The peak progesterone values of 6.00±0.91 and 6.2±1.2 ng/ml and peak estradiol values of 15.83±0.60 and 14.31±0.44 ng/ml were recorded in 2-wave and 3-wave estrous cycle, respectively. The results showed that Sahiwal cows had 2-wave and 3-wave estrous cycle and the 3-wave estrous cycle had comparatively longer inter-ovulatory period and smaller maximum diameter of second wave dominant follicle than 2-wave estrous cycle.