Advancing mastitis assessment in dairy bovines via short milking tube thermography: A seasonal perspective.

In India, where dairy production leads globally, infrared thermography (IRT) and short milking tube thermography specifically are vital for managing mastitis. Therefore, the present study focuses on thermal imaging of the udder and short milking tube (SMT) of the milking machine during the peak milking process of Sahiwal cows and Murrah buffaloes during winter, summer, rainy and autumn seasons to identify sub-clinical (SCM) and clinical mastitis (CM) cases using the Darvi DTL007 camera. The udder health was assessed using the California Mastitis Test, Somatic Cell Count (SCC) and IRT throughout the year. Log10SCC and thermogram analysis revealed a difference (p < 0.01) between healthy, SCM, and CM cases during different seasons in both breeds. Further results showed an increase (p < 0.01) in SMT thermograms of SCM and CM cases compared to healthy quarters in Sahiwal cows during winter, summer, rainy, and autumn were 4.26 and 7.51, 2.37 and 4.47, 2.20 and 3.64, 2.90 and 4.94 ºC, respectively and for Murrah buffaloes were 3.56 and 5.55, 2.70 and 3.81, 1.72 and 3.10, 3.14 and 4.42ºC, respectively. The highest degree of increase in milking udder skin surface temperature and SMT of SCM and CM cases compared to healthy quarters was observed during the winter and the least during the rainy season. Thus, regardless of the seasons examined in this study, SMT thermograms effectively assessed SCM and CM.

Deciphering the immune responses in late gestation Sahiwal cows under different microclimate and its carryover effect on progenies.

The current investigation aimed to comprehend the inflammatory and related immune responses in intrauterine calves subjected to heat stress (HS) during late gestation. For this purpose, 48 Sahiwal cows in late gestation were chosen and categorized into four equal groups: naturally heat stressed (NHS), cooling-treated (CLT), spring, and winter, and likewise their neonate calves born in summer (IUHS - intrauterine heat stressed and IUCL - intrauterine cooled), spring, and winter seasons. Environmental parameters were recorded, and the temperature-humidity index (THI) was calculated daily throughout the study period. The average THI values ranged between 84.18 (summer-NHS), 73.88 (summer-CLT), 78.92 (spring), and 64.91 (winter). NHS and spring groups exhibited thermal stress based on THI (> 76.00). Various treatments significantly (P < 0.01) impacted parameters like rectal temperature (RT), respiratory rate (RR), pulse rate (PR), and skin temperature (ST) in Sahiwal cows and their calves during the study, except for heart rate (HR). Blood samples collected during different seasons and from cows housed in a climatic chamber were used to extract plasma. Plasma cortisol, interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), and thiobarbituric acid reactive substances (TBARS) levels were notably higher (P < 0.05) in the NHS compared to the CLT group. Conversely, total antioxidant capacity (TAC) and immunoglobulin G (IgG) levels were higher (P < 0.05) in the CLT and winter groups. IUHS calves exhibited significantly (P < 0.05) lower overall mean plasma TAC and IgG levels but higher inflammatory and oxidative biomarkers, such as IL-6, TNF-α, and TBARS. Additionally, significant impacts on body weight were observed for factors such as interval (P < 0.01) and the interaction between treatment and interval (P < 0.05), exhibiting consistently lower body weight in IUHS calves throughout the study period. These findings suggest that late gestation heat stress may lead to physiological alterations in future calves. Strategies aimed at mitigating heat stress during late gestation should be considered not only for the productivity and well-being of the pregnant dam but also for the development and future performance of the calf.

Economic viability of using OvSynch and fixed timed artificial insemination protocol in breeding improvement of pastoral herds in the rangelands.

Though using Assisted Reproductive Technologies (ARTs) can improve oestrus detection, conception and pregnancy success, thus benefit breeding program implementation, empirical evidence of their economic viability is lacking to inform investment decisions in pastoral herds. This study assessed economic viability of using OvSynch and fixed Timed Artificial Insemination (TAI) protocol in Sahiwal upgrading breeding program under two hypothetical cases of best and worst in activity-based money allocations when pastoral herds deploy either optimal or low input husbandry practices. From herd owners' assessment of milk production, best-case scenarios attain on average 10 L/cow/day with optimal husbandry and 5 L/cow/day with low input husbandry. The worst-case scenarios attain 5 L/cow/day with optimal husbandry and 1 L/cow/day with low input husbandry. Benefit- Cost Analysis (BCA) estimated Net Present Value (NPV), Benefit-Cost ratio (BCR) and Internal Rate of Return (IRR) to establish economic viability of using OvSynch and TAI Protocol in pastoral breeding programs. Both best-case scenarios retuned positive NPVs (82,028 and 6,912), BCR values (1.68 and 1.08) and IRR (27.46% and 8.08%) while worst-case scenarios returned negative NPVs (-135,855 and -141,025), BCR values of below 1 (0.87 and 0.66) and IRR values below the minimum rate of returns. These economic parameters were sensitive to price changes in inputs and outputs, under both optimal and low input husbandry practices. Results indicate that using OvSynch and TAI Protocol is a profitable and economically viable investment under optimal husbandry practices but not under low input husbandry practices. By implications, use of OvSynch and TAI Protocol in Sahiwal upgrading breeding programs need be accompanied with improved husbandry practices and de-risking pastoral herd owners from price changes in input and output markets.

Attention module incorporated transfer learning empowered deep learning-based models for classification of phenotypically similar tropical cattle breeds (Bos indicus).

Accurate breed identification in dairy cattle is essential for optimizing herd management and improving genetic standards. A smart method for correctly identifying phenotypically similar breeds can empower farmers to enhance herd productivity. A convolutional neural network (CNN) based model was developed for the identification of Sahiwal and Red Sindhi cows. To increase the classification accuracy, first, cows's pixels were segmented from the background using CNN model. Using this segmented image, a masked image was produced by retaining cows' pixels from the original image while eliminating the background. To improve the classification accuracy, models were trained on four different images of each cow: front view, side view, grayscale front view, and grayscale side view. The masked images of these views were fed to the multi-input CNN model which predicts the class of input images. The segmentation model achieved intersection-over-union (IoU) and F1-score values of 81.75% and 85.26%, respectively with an inference time of 296 ms. For the classification task, multiple variants of MobileNet and EfficientNet models were used as the backbone along with pre-trained weights. The MobileNet model achieved 80.0% accuracy for both breeds, while MobileNetV2 and MobileNetV3 reached 82.0% accuracy. CNN models with EfficientNet as backbones outperformed MobileNet models, with accuracy ranging from 84.0% to 86.0%. The F1-scores for these models were found to be above 83.0%, indicating effective breed classification with fewer false positives and negatives. Thus, the present study demonstrates that deep learning models can be used effectively to identify phenotypically similar-looking cattle breeds. To accurately identify zebu breeds, this study will reduce the dependence of farmers on experts.

Investigation of milk microbiota of healthy and mastitic Sahiwal cattle.

BACKGROUND: Sahiwal cattle is an indigenous cattle breed of Pakistan and mastitis is one of the major problems faced by Sahiwal cattle which hinders its production potential. The study was designed to investigate the milk microbiota of healthy and mastitic Sahiwal cattle as part of a multistep project to develop probiotics for the mitigation and control of mastitis. Milk samples of Sahiwal cattle (healthy clinical mastitis and subclinical mastitis) reared under similar husbandry and management practices were processed for 16S rRNA gene base metagenomics analysis. RESULTS: Results revealed that Proteobacteria were dominant in the healthy group and subclinical mastitis group (56.48% and 48.77%, respectively) as compared to the clinical mastitis group (2.68%). In contrast, Firmicutes were abundant in the clinical mastitis group (64%) as compared to the healthy and subclinical mastitis groups (15.87% and 38.98%, respectively). Dominant species assigned in the healthy group were Ignavibacterium album, Novosphingobium capsulatum, Akkermansia muciniphila and Lactobacillus fermentum.The clinical mastitis group was dominated by Streptococcus dysgalactiae and Corynebacterium bovis, while subclinical mastitis group included Lactobacillus fermentum and uncultured acidobacteriales and Akkermansia muciniphila as dominant species. Alpha diversity indices showed higher microbial diversity in the healthy group compared to the clinical and sub-clinical mastitis groups. CONCLUSION: It is concluded that the milk microbiota of healthy sahiwal cattle has higher diversity and dominant taxa in the different groups may be used as signature microbes for mastitis susceptibility. Akkermansia muciniphila is one of candidate specie that was identified and may be used for development of probiotics.

Genome wide mining of SNPs and INDELs through ddRAD sequencing in Sahiwal cattle.

The study was conducted in Sahiwal cattle for genome wide identification and annotation of single nucleotide polymorphisms (SNPs) and insertions and deletions (INDELs) in Sahiwal cattle. The double digest restriction-site associated DNA (ddRAD) sequencing, a reduced representation method was used for the identification of variants at nucleotide level. A total of 1,615,211 variants were identified at RD10 and Q30 consisting of 1,480,930 SNPs and 134,281 INDELs with respect to the Bos taurus reference genome. The SNPs were annotated for their location, impact and functional class. The SNPs identified in Sahiwal cattle were found to be associated with a total of 26,229 genes. A total of 1819 SNPs were annotated for 209 candidate genes associated with different production and reproduction traits. The variants identified in the present study may be useful to strengthen the existing bovine SNP chips for reducing the biasness over the taurine cattle breeds. The diversity analysis provides the insight of the genetic architecture of the Sahiwal population Studied. The large genetic variations identified at the nucleotide level provide ample scope for implementing an effective and efficient breed improvement programme for increasing the productivity of Sahiwal cattle.

Effect of BsaA I genotyped intronic SNP of leptin gene on production and reproduction traits in Indian dairy cattle.

In the present study, candidate single nucleotide polymorphism (SNP) g.92450765 G > A of leptin gene was explored for Bos indicus cattle with an aim to explore its possible effect on production and reproduction traits. The genotypic and allelic frequencies of BsaA 1 genotyped SNP g.92450765 G > A indicated the predominance of AG (0.65) genotyped Sahiwal cows in our studied population. The least-squares analysis showed a significant association (p < 0.05) of identified genetic variants with total milk yield (TMY) and 305 days milk yield (MY) (p < 0.05). The GG genotyped cows were found to be associated with higher milk yields. However, for reproduction traits under study AA genotype was found to be more favorable with respect to service period and calving interval (p < 0.05). Computational analysis was also performed to predict changes if any in the transcription factor binding sites (TFBS) caused due to the identified SNP in the intronic region of the leptin gene. TFBS analysis predicted that the targeted SNP at g.92450765G > A may lead to the disappearance of TFBS such as Hypermethylated in cancer 2 protein (HIC2), Max-binding protein MNT (MNT), Cyclic AMP-dependent transcription factor -3 (ATF3), Myc-associated factor X (MAX) and Microphthalmia-associated transcription factor (MITF). It may lead to changes in transcriptional regulation.

Novel insights into genome-wide associations in Bos indicus reveal genetic linkages between fertility and growth.

Bos indicus breed Sahiwal, famous for its optimum performance, has so far been genetically improved for performance traits based on phenotypic records and the genomic knowhow regarding genes, regions and biological processes underlying the complex quantitative traits is lacking. In this context, a Genome-wide Association Study was performed for fertility and growth traits in Sahiwal cattle to shed light on its genomic profile. A total of 46 SNPs were found associated with the traits at genome-wide suggestive threshold of P ≤ 10-4. USP32, LRPPRC, PLA2G10, RRN3 and ASAP1 were identified as putative candidate genes for body weight at different ages. However, several genes mapped for growth traits like GREB1, PLA2G10, RAD51C, BIRC6, TEX14 and PEBP4 had significant physiological underpinnings in determining fertility of the animals. Moreover, Quantitative trait loci (QTL) identification revealed potential overlaps with the already reported QTLs for both fertility and growth for most of the traits. Further, candidate SNP enrichment analysis revealed an enriched biological process for birth weight with a significant reproductive role. Based on the findings, genetic linkages underlying fertility and growth could be discerned in Sahiwal population and may be utilized for improving fertility traits in future.

Candidate K232A mutation of DGAT1 gene associated with production and reproduction traits in Indian Dairy cattle.

The present study was conducted on Hardhenu and Sahiwal cows to evaluate the genetic diversity and the effect of candidate K232A mutation of diacylglycerol O-acyltransferase (DGAT1) gene on performance traits. PCR product of 413 bp size targeting K232A mutation of DGAT 1 gene was genotyped by Eae1 restriction enzyme and further confirmed by sequencing. The PCR-RFLP analysis for K232A showed that the frequencies of alleles K and A were 0.80 and 0.20 in Hardhenu and 0.98 and 0.02 in Sahiwal cattle, respectively. The frequencies of genotypes for KK and KA genotype were estimated as 0.60 and 0.40 in Hardhenu and 0.96 and 0.04 in Sahiwal cattle, respectively. Chi-square test showed that K232A SNP did not meet with the Hardy-Weinberg equilibrium (p < .01) in Hardhenu cattle. Association analysis revealed that KA genotype was significantly associated with total milk yield (p < .01) and 305 days milk yield (p < .01)in Hardhenu cattle. Hardhenu cows having KA genotype comparatively revealed favorable mean values for AFS (880.31 ± 26.65), AFC (1166.36 ± 19.94), SP (157.46 ± 22.80), CI (441.41 ± 44.28) and AI/Conception (1.80 ± 0.17), indicating that KA genotype can be used as a candidate marker for simultaneous improvement of both production and reproduction traits.

Association of udder type traits with single nucleotide polymorphisms in Sahiwal (Bos indicus) and Karan Fries (Bos taurus × Bos indicus) cattle.

Udder structure of milking cows is not merely vital to display the visual characteristics, but also important for high milk output and low mastitis risk incidence as well. The present study measured different udder type traits in Sahiwal (Bos indicus) and Karan Fries (Bos taurus × Bos indicus) and investigated their association with single nucleotide polymorphisms in Vitamin D Receptor and Protein Tyrosine Phosphatase, Receptor Type, R genes. GG genotype of SNP rs454303072 was found to have wider rear udder, larger udder circumference, longer distance between fore-rear teats and left-right teats in Karan Fries cattle. Whereas, in Sahiwal cattle, AA genotype of this SNP was found to be associated with the higher and wider rear udder, larger udder circumference and wider udder. AA genotype of SNP rs382671389 was found to be associated with longer fore teat in Karan Fries cattle. The TT and CC genotype of SNP rs435289107 was associated with udder type traits in Karan Fries and Sahiwal cattle respectively. These results suggest that BTA 5 harbors genomic regions associated with udder traits in Bos indicus and Bos indicus x Bos taurus cattle.

Genome-wide in silico analysis leads to identification of deleterious L290V mutation in RBBP5 gene in Bos indicus.

Genome-wide deleterious mutations were identified in zebu cattle (Bos indicus) using in silico approach. The ddRAD sequence data of Sahiwal cattle were annotated and aligned with the cattle reference genome (ARS-UCD1.2). A total of 279,383 SNPs were identified at Read Depth10, which were further filtered to 692 missense SNPs. These SNPs were further analyzed, for functional consequences, by using Variant Effect Predictor, PolyPhen, PROVEAN, and PANTHER tools. A total of 18 SNPs, were finally identified as deleterious, and among these, 12 SNPs were mapped on nine different genes. ERRAT, ProSA-web, Project HOPE, TM-Align, and YASSARA tools, further confirmed the protein malfunctioning of one missense (L290V) mutation of Retinoblastoma binding protein-5 (RBBP5) gene, transcribing a cell cycle regulatory protein and associated with Retinoblastoma in human. This derived bioinformatics pipeline may be useful for preliminarily identifying the deleterious DNA mutations in livestock, specifically in absence of any genetic disease records.

Comparative RNA isolation methods from fresh ejaculated spermatozoa in Sahiwal cattle (Bos indicus) and Murrah buffalo (Bubalus bubalis) bulls for high quality and enhanced RNA yield.

Sperm mRNA transcriptional profiling can be used to evaluate the fertility of breeding bulls. The aim of the study was to compare the modified RNA isolation methods for higher RNA yield and quality from freshly ejaculated sperm of cattle and buffalo bulls. Ten fresh ejaculates from each Sahiwal (n = 10 bulls × 10 ejaculates) and Murrah bulls (n = 10 bulls x 10 ejaculates) were used for RNA isolation. From the recovered live sperm, total sperm RNA was isolated by conventional methods (TRIzol, Double TRIzol), membrane-based methods combined with TRIzol (RNeasy + TRIzol) with the addition of ß-mercaptoethanol (BME) and Kit (RNeasy mini) methods in fresh semen. Among different isolation methods; the membrane-based modified methods combined with TRIzol (RNeasy + TRIzol) with the addition of ß-mercaptoethanol (BME) resulted significantly (p < .05) higher total RNA quantity (300-340 ng/µL) and better purity in different concentrations of spermatozoa viz., 30-40 million, 70-80 million and 300-400 million sperm. The study concluded that the inclusion of BME to the combined membrane-based methods with somatic cell lysis buffer solution was best for constant increased yield and purity of RNA isolation from Sahiwal cattle and Murrah buffalo bull sperm.

Effect of non-genetic factors on linear type traits in Karan fries (Bos taurus × Bos indicus) and Sahiwal (Bos indicus) cows in sub-tropical climatic conditions of India.

The focus of present study was to find out the effect of non-genetic factors on linear type traits in Karan Fries and Sahiwal cows reared at an organized farm of northern India. The present study was conducted on Lactating Karan Fries (N = 123) and Sahiwal (N = 133) cows maintained at Livestock Research Center of ICAR- National Dairy Research Institute, Karnal, India during the period of 2017-2019. Total eight udder morphometric traits and seven teat morphometric traits were measured. The linear model including fixed effects of season, parity and stage of lactation was used for the analysis. In Karan Fries cows, linear type traits were significantly affected by parity and stage of lactation, while in Sahiwal cows linear type traits were significantly affected by season, parity and stage of lactation. Udder depth (UD) and udder circumference (UC) were significantly (p < 0.05) affected by season, parity and stage of lactation in Sahiwal cattle, while in Karan Fries cattle udder length (UL) and shortest distance from rear teat ends to floor (SDR) were significantly (p < 0.01) affected by parity and stage of lactation. The results pertaining to present study indicated that season, parity and stages of lactation were important sources of variation for most of linear type traits. Adjustment of data for these effects is necessary to reduce known differences between animals and to obtain reliable estimates of the traits.

Influence of endometritis on the follicular dynamics, recovery, quality, gene expression, nuclear maturation and in-vitro developmental competence of oocytes in Sahiwal cattle.

Uterine infections often lead to culling of valuable animals from a herd, resulting in genetic drain. The genetic potential of problematic females could be harvested by in-vitro embryo production. The objective of this study was to evaluate the effect of clinical endometritis on follicular dynamics, recovery, quality, gene expression, nuclear maturation and in-vitro developmental competence of oocytes in Sahiwal cattle. The B-mode ultrasonography was performed to examine the uterus for the presence of pus. Based on the history and reproductive examination of cows, a total of twelve (n = 12) Sahiwal cattle were selected for the experiment: (1) healthy group (n = 6) and (2) clinical endometritis group (n = 6). The 1st ovum pick-up (OPU) was conducted on day 165 postpartum. The collected cumulus oocytes complexes (COCs) were graded into A, B, C and D grades depending on the number of layers of cumulus cells and homogeneous nature of cytoplasm. Nuclear maturation was assessed by staining the oocytes with Hoechst 33,342. The results revealed that the number of medium-sized follicle (1.3 ± 0.1 versus 0.6 ± 0.1) and total number of follicles (9.1 ± 0.7 versus 6.6 ± 0.7) were higher (p < .05) in the healthy group as compared to clinical endometritis group, respectively. Similarly, the number of oocytes recovered (5.0 ± 0.4 versus 2.8 ± 0.4), oocytes with grade A, B and C (2.9 ± 0.3 versus 1.5 ± 0.3), proportion of oocytes with grade A or B (33 ± 0.0 versus 20 ± 0.1) and nuclear maturation (68 ± 0.1 versus 55 ± 0.1) were also higher (p < .05) in the healthy group as compared to clinical endometritis group, respectively. Perhaps, cleavage rate (55.1 ± 0.1 versus 46.2 ± 0.1) and blastocyst rate (29.7 ± 0.0 versus 26.3 ± 0.1) did not differ (p > .05) between the groups. Likewise, the expression level of growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) in immature oocytes did not differ (p > .05) between both the groups. In conclusion, clinical endometritis has a negative effect on follicular dynamics, oocyte recovery, oocyte quality and nuclear maturation; furthermore, the developmental competence of COCs is not compromised by it.

Tinospora cordifolia modulates the seminal parameters, leakage of intracellular enzymes and seminal antioxidants in equilibrated and cryopreserved semen of Sahiwal bulls.

The present study was undertaken to assess the effects of stem extract of Tinospora cordifolia (Giloy or Guduchi) in the semen extender on seminal parameters, leakage of intracellular enzymes and antioxidants in semen of Sahiwal bull. A total of 48 ejaculates from four bulls were selected for the study. Spermatozoa of 25 × 106 were incubated in 100, 300 and 500 µg of stem extract of Guduchi as Gr II, III and IV, respectively, and pre-freeze and post-thaw semen samples were analysed for seminal parameters [motility, viability, total sperm abnormality (TSA), plasma membrane integrity (PMI) and acrosomal integrity (AcI)], intracellular enzymes [aspartate aminotransferase (AST) and lactate dehydrogenase (LDH)] and seminal antioxidants [superoxide dismutase (SOD) and catalase] in comparison with an untreated control group (Gr I). The results revealed that stem extract-treated semen had significantly (p < .05) higher motility, viability, PMI, AcI, SOD and catalase and had significantly (p < .05) lower TSA, AST and LDH compared to those in untreated control group at pre-freeze and post-thaw stages. Semen treated with 100 µg stem extract/25 × 106 spermatozoa had significantly (p < .05) higher motility, viability, PMI, AcI, SOD and catalase and had significantly (p < .05) lower TSA, AST and LDH compared to those in control, 300- and 500-µg-treated groups at pre-freeze and post-thaw stages. Further, these seminal parameters and antioxidants were showing decreasing trend and TSA and leakage of intracellular enzymes were showing increasing trend from Gr II to Gr IV at pre-freeze and post-thaw stages. Thus, 100 µg/25 × 106 spermatozoa were optimum or suitable dose for cryopreservation of Sahiwal bull semen. The study concluded that T. cordifolia stem extract 100 µg/25 × 106 spermatozoa in the semen extender can be effectively utilized to reduce the oxidative stress and improve the pre-freeze and post-thaw seminal parameters in Sahiwal bull. However, further studies on effects of different concentrations of stem extract on in vitro or in vivo fertility trials are to be conducted to assess the impact of the stem extract supplementation in the semen extender on field pregnancy outcomes in bovine species.

Moringa oleifera leaf meal supplementation improves nutrient digestibility, milk yield, and reproductive performances in dairy cows during early lactation.

The study aimed to evaluate the effects of Moringa oleifera leaf meal (MOLM) supplementation on nutrient utilization, milk yield, and reproductive performance of early lactating Sahiwal cows. Control cows (GC) received a basal diet, while the treatment cows (GM) were supplemented with concentrate comprising 12% MOLM. Ovarian activity and uterine involution were monitored by trans-rectal ultrasonography on the 21st, 28th, 35th, and 42nd days postpartum. The result indicated that MOLM-supplemented cows required fewer days (P ≤ 0.05) to complete uterine involution. As lactation progresses, there was a significant reduction (P ≤ 0.05) in the diameter of the cervix and uterine horns in GM than GC. There was a significant increase in the number of follicles on the 21st day and average milk yield in GM than GC. The incidence of endometritis and cystic ovarian disease was less in MOLM supplemented group. The use of MOLM in the diet reduced the total cost per cow per successful service. It is concluded that MOLM can be safely included at 12% in the diet of early lactating cows to modulate the reproductive performances of dairy cows. Dairy farmers can use moringa leaf meal to feed their dairy cows, which is cheaper and improves production and reproduction performance.

Response to hormonal treatment and conception rates of Sahiwal cows subjected to fixed time artificial insemination in pastoral dairy systems.

This study aimed at determining factors influencing response of Sahiwal cows/heifers to fixed time artificial insemination protocol in pastoral systems in Kenya. Available cows/heifers were inspected for conformity to Sahiwal breed characteristics, parity, body condition score, and subsequently rectal palpation to determine pregnancy status, ovarian structures, and estimated ovarian diameter. Consequently, these animals were injected with 100 µg of gonadotrophin-releasing hormone. On days 7 and 9, only responsive cows/heifers were injected with 500 µg of cloprostenol and 100 µg of gonadorelin Acetate, respectively. On day 10, animals were inseminated and separated from bulls for 45 days and pregnancy diagnosis done after 90 days. Analysis of variance was performed to determine the effects of production system, parity, and ovarian structures on ovary diameters pre- and post-hormonal treatment. Logistic regression was used fitting a logit function to account for the binomial distribution of conception. Overall, 56.2%, 23.1%, and 20.7% of the animals had follicles (F), corpus luteum (CL), and corpus albicans (CA), respectively, at day 0, and 16.6%, 68.6%, and 14.8%, respectively, at day 7. Human and environmental factors had no influence on conception. Among the animal factors, only the ovarian structures at day 7 had a significant effect on conception. Ovaries with CL at this time were about 6 times significantly more likely to conceive than those with F. For higher conception rates, animals with ovaries with CL should be recruited into the FTAI program as they are significantly more likely to conceive than those with other ovarian structures.

Effect of seasons and photoperiods on seminal attributes and sperm morphology in Holstein Friesian × Sahiwal crossbred dairy bulls.

Cattle being non-seasonal breeding species, effects of photoperiods on sperm traits and morphology had been reported inadequately in breeding bulls. To elucidate the plausible existence of effects of photoperiods and seasons, seminal traits of Holstein Friesian × Sahiwal crossbred dairy bulls (N = 557) were analysed using different statistical models. A present study revealed that the biological rhythm of reproduction oscillated almost in parallel to the annual changes of natural photoperiods even in non-seasonal breeding species like cattle bulls. Semen traits diminished to the lowest in winter solstice (WS ± 45 days), progressively increased with the rising day length of spring (vernal equinox ± 45 days), reached a peak in summer solstice (SS ± 45 days), and then gradually reduced with decreasing photoperiod of the autumn equinox (AE ± 45 days). From summer solstice to winter solstice, sperm concentration reduced by 90.53 million/ml (8.85%), total sperm count/ejaculate decreased by 785 million (13.87%), total motile sperm count/ejaculate reduced by 17.59%, and total post-thaw motile sperm counts/ejaculates diminished by 38.64%. In short-duration photoperiods (≤ 12 h), bulls had a significantly (P < 0.01) higher incidence of major, minor, tail abnormality and total aberrant sperm% compared to that of long-duration photoperiods (> 12 h). Solstice equinox-based seasonal classification provided better insight into photoperiodicity on bulls' semen quality and sperm traits as compared to conventional meteorological classification of seasons. It was concluded that photoperiods affect sperm productivity, semen quality, and sperm morphology in non-seasonal breeding species like dairy bulls, maintained at transitional latitude (29° N) tropical climate. Bulls' reproductive ability was more influenced by the phases of increasing/decreasing day length duly primed by climax/trough of photoperiods, compared to mere long/short duration of photoperiods.

Evaluation of candidate genotype of GH gene associated with growth, production and reproduction traits in Dairy Cows.

Growth hormone (GH) is a major regulator of postnatal growth and metabolism in mammals and plays a critical role in growth, production and fertility in cattle. The present study was conducted in dairy cattle to find the association of g.48769565 C > T mutation with growth, production and reproduction traits in Sahiwal and Hardhenu cattle. PCR-RFLP was performed to genotype g.48769565 C > T mutation using the MspI restriction enzyme in our resource cattle population. In Hardhenu cattle, the frequencies of C and T alleles were 0.59 and 0.41, respectively, while genotypic frequencies were 0.33, 0.53 and 0.14 for CC, CT and TT respectively. The frequencies of the C and T alleles were 0.24 and 0.76, respectively, in Sahiwal cattle and it was observed that the highest frequency was for the TT genotype (0.58) and the lowest was for the CC genotype (0.06). Chi-square analysis showed that g.48769565C>T SNP loci meet with the Hardy-Weinberg equilibrium in Sahiwal and Hardhenu cattle. From the least-squares analysis, it was observed that CC genotype was significantly associated with total milk yield (TMY), 300 days milk yield (300D MY), lactation length (LL), dry period (DP) and artificial insemination (AI)/conception (p < .05). We also observed a significant association (p < .05) of genotype CT with 3-month calves body weight. Cows with TT genotype revealed comparatively favourable service period (SP) and calving interval (CI) in our resource population. These observed differences in their allelic and genotypic frequencies in association with the traits underlying production and fertility can be utilized for genetic improvement in dairy cattle.

Effect of three schemes of ovum pick-up on the follicular dynamics, gene expression, and in-vitro developmental competence of oocytes in Sahiwal cattle.

This study aimed to compare the effect of three schemes of ovum pick-up (OPU) on follicular dynamics, oocytes recovery, oocytes quality, gene expression, nuclear maturation and in-vitro developmental competence of oocytes in Sahiwal cattle. Considering the follicle population, all the cows were divided equally in a 3 × 3 cross over design, and each cow received one of the three treatments: (a) twice weekly (TW; n = 6), (b) once weekly (OW; n = 6) and (c) bi-weekly OPU (BW; n = 6) in three periods, with the first OPU conducted on 4, 7 and 14 days after second dominant follicle puncture (DFP) in the TW, OW and BW OPU interval groups, respectively. The collected cumulus oocytes complexes (COCs) were graded into A, B, C and D grades depending on the number of layers of cumulus cells and homogeneous nature of cytoplasm. Nuclear maturation was assessed by staining the oocytes with Hoechst 33342. The growth rate (mm/day) of dominant follicle (DF) (F1) (0.49 ± 0.21 vs. 0.71 ± 0.26 vs. 1.30 ± 0.27) and first subordinate follicle (F2) (0.85 ± 0.27 vs. 0.71 ± 0.25 vs. 1.06 ± 0.29) did not differ (p > .05) among all the three groups. The proportion of animals bearing a corpus luteum (CL) in the BW OPU interval group (53.3%) was significantly higher (p < .05) as compared to TW (13.3%) and OW (18.3%) OPU interval groups. The number of medium-sized follicles and oocyte with grade A and B were significantly higher (p < .05) in the TW (1.16 ± 0.21 and 33.88 ± 0.03) OPU interval group as compared to the OW (0.88 ± 0.22 and 21.54 ± 0.03) and BW (0.55 ± 0.21 and 21.89 ± 0.02) OPU interval groups. However, the number of degenerated oocytes in BW (0.85 ± 0.16) OPU interval group was significantly higher (p < .05) as compared to the TW (0.16 ± 0.15) and OW (0.44 ± 0.16) OPU interval groups. Expression level of growth differentiation factor 9 in TW OPU interval group was significantly higher (p < .05) as compared to the OW and BW OPU interval groups. Likewise, expression level of bone morphogenetic protein 15 (BMP15) in the TW and BW OPU interval groups was significantly higher (p < .05) as compared to the OW OPU interval group. The nuclear maturation rate was significantly higher in the TW (63.64 ± 0.07) and BW (59.26 ± 0.08) OPU groups as compared to OW (51.43 ± 0.06) OPU interval group. However, the cleavage rate (59.30 ± 0.06 vs. 44.29 ± 0.06 vs. 56.67 ± 0.06) did not differ (p > .05) among the three groups. Whereas, the blastocyst rate tended to be higher (p = .06) in the TW (29.07 ± 0.05) and BW (28.33 ± 0.04) OPU interval groups as compared to OW (18.57 ± 0.05) OPU interval group. Taken together, it can be concluded that TW OPU interval scheme enhances the medium-sized follicles resulting in good quality oocytes, regulates the oocyte-derived paracrine factors, leading to higher nuclear maturation rates and improved embryonic development in-vitro.