Quercetin, a naturally occurring flavonoid, has received attention for its potential benefits in chicken nutrition due to its antioxidant, anti-inflammatory, and gut-health-promoting qualities. This review summarizes current research on quercetin supplementation in broiler chickens, focusing on its implications on growth performance, immunological response, gut health, and meat quality. Quercetin has been shown in studies to improve body weight increase, feed conversion efficiency, and nutrient absorption while also reducing oxidative stress by upregulating antioxidant enzymes like superoxide dismutase and glutathione peroxidase. Furthermore, it aids immunological regulation by lowering inflammatory cytokines and increasing disease resistance. Quercetin also improves gut microbiota composition and shape, resulting in greater digestive health. Furthermore, it enhances meat quality by lowering lipid peroxidation, improving texture, and increasing shelf life. Findings indicate quercetin as a possible natural alternative to antibiotics in broiler diets, which aligns with the growing need for sustainable, antibiotic-free poultry production. However, additional research is needed to enhance its bioavailability, administration approaches, and long-term effects in commercial applications. Future research should focus on improving its bioavailability and determining its economic viability in large-scale commercial applications.

Antimicrobial utilisation in livestock production has emerged as a critical concern due to its direct association with antimicrobial resistance and irrational drug-use practices in food animals. The present study was conducted to assess the utilisation pattern of antibiotics among semi-intensive pig farmers in Assam and to identify the influence of service providers on treatment success along with behavioural patterns associated with antibiotic use. An exploratory ex-post facto research design was adopted covering 240 pig farmers selected through multistage stratified sampling from six agro-climatic zones of Assam. Primary data were collected using a modified AMUSE Livestock Version 2.0 interview schedule. Descriptive statistics, Fisher’s exact test, binary logistic regression and multiple correspondence analysis were employed for data analysis. The findings revealed that veterinarians were the principal drug administrators, followed by veterinary field assistants/paravets and unlicensed practitioners (quacks). Government hospitals/dispensaries and animal health workers (AHW) were the major sources of drug procurement. Reported treatment success was significantly higher under veterinarian-administered therapy, and logistic regression indicated that veterinarian-administered treatment had 18.80 times greater odds of complete treatment success than treatment administered by informal providers. Behavioural patterns associated with service-provider dependence and treatment outcomes were identified. Although respondents reported seeking external advice prior to drug administration, substantial dependence on non-veterinarian service providers persisted. The findings highlight the need to strengthen professional veterinary outreach and antimicrobial stewardship interventions for sustainable pig health management in Assam.

INTRODUCTION:Cryopreservation of semen is commonly linked to reduced sperm movement, compromised membrane integrity, and reduced functional capacity due to excessive production of reactive oxygen species (ROS). Moringa oleifera leaf extract is recognized for its powerful antioxidant capabilities, which can neutralize ROS directly or boost the function of natural antioxidant enzymes. OBJECTIVE:This research was undertaken to assess the impact of incorporating moringa leaf extract into a TRIS-citrate-yolk extender on antioxidant enzyme activity, post-thaw sperm quality, and in vitro fertility in Barbari bucks. METHODS:Semen samples were obtained from eight healthy bucks and divided into four treatment groups based on the concentration of moringa extract in the extender 0 mg/100 mL (Group I), 50 mg/100 mL (Group II), 100 mg/100 mL (Group III), and 200 mg/100 mL (Group IV). Following cryopreservation and thawing, the sperm samples were assessed for various quality parameters, antioxidant enzyme activity, and zona binding capacity. RESULTS:The results indicated that adding moringa extract significantly reduced (p < 0.01) ROS generation and lipid peroxidation in all treatment groups compared with the control. Moreover, sperm motility, membrane integrity, and functional quality were better preserved in the extract-supplemented groups, with Group III showing the most notable improvement. The zona binding assay further confirmed enhanced sperm-egg interaction in the treated groups. CONCLUSION:The addition of moringa leaf extract to the extender effectively mitigates oxidative stress-related damage during cryopreservation and thawing, thereby improving sperm viability and fertility potential in Barbari buck semen. This method shows potential for enhancing reproductive outcomes in artificial insemination programs.

Background: Uterine infections are a leading cause of infertility and economic loss in dairy cattle, often resulting from complex polymicrobial infections. Rapid and accurate detection of the causative pathogens is essential for effective management. This study focuses on assessing the prevalence of uterine infections and developing a multiplex PCR assay for simultaneous detection of key bacterial pathogens in cattle. Methods: A total of 1,905 cattle from the Vindhyan region were screened for uterine discharge and categorized as clear with tiny flakes, cloudy, mucopurulent, purulent, or haemorrhagic. Sixty uterine samples were aseptically collected for molecular analysis. Conventional PCR was employed to detect Escherichia coli, Fusobacterium necrophorum, Trueperella pyogenes, Clostridium tertium and Histophilus somni. A multiplex PCR (mPCR) assay was subsequently developed for simultaneous detection of E. coli, C. tertium and H. somni and its sensitivity, specificity and accuracy were assessed to evaluate diagnostic performance. Result: The overall prevalence of uterine infections was 10.44%, consisting of 60.80% subclinical endometritis, 26.63% clinical endometritis and 12.56% metritis. The prevalence rates of E. coli, C. tertium and H. somni were 85%, 92.9% and 73.33%, respectively. Conventional PCR detected E. coli in 54, F. necrophorum in 01, T. pyogenes in 70, C. tertium in 44 and H. somni in 12 of the 60 uterine samples. Using mPCR, 51 samples were positive for E. coli, 44 for C. tertium and 15 for H. somni. The sensitivity, specificity and accuracy of the mPCR were 100%, 66.6% and 95% for E. coli; 100% each for C. tertium; and 80%, 100% and 95% for H. somni, respectively, indicating its high diagnostic efficiency.

This study focused on the development and characterization of a bioactive film of chitosan (1.5%, w/v) integrated with a thyme (Thymus vulgaris) essential oil nanoemulsion (TNEO). The biopolymer was applied on raw chicken drumsticks to assess its effectiveness in preserving the quality and safety of meat under refrigeration. Gas chromatography-mass spectrometry (GC-MS/MS) analysis of the thyme essential oil identified key bioactive components, viz. carvacrol (60.18%), mcymene (22.93%) and thymol (3.24%). The dynamic light scattering (DLS) assay and transmission electron microscopy (TEM) ensured the successful encapsulation and stability of the nanoemulsion. The infusion of thyme nanoemulsion significantly enhanced the morphological features, UV barrier properties, moisture vapor barrier properties, and flexibility of chitosan film-critical properties, fulfilling the requirements for effective meat packaging. Further, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) were performed to analyze the active biopolymers, which ensured the compatibility between nanoemulsion and chitosan matrix. Notably, the film with 2% TNEO exhibited significant antimicrobial activity against Staphylococcus aureus (14.67 +/- 0.33 mm) and Escherichia coli (12.67 +/- 0.33 mm), as measured through zones of inhibition (ZOI), and also antioxidant properties (40.05 +/- 1.19% reactive scavenging activity). When applied to chicken drumsticks, the 2% TNEO film significantly delayed microbial spoilage, inhibited lipid oxidation, and preserved the color attributes of the meat over a 15-day refrigerated storage period compared to no chitosan and TNEO film. From this study, it is concluded that chitosan-thyme nanoemulsion film can be utilized as a highly promising, green active-packaging solution for extending the shelf-life of raw poultry.

Linear type traits are important for animal breeders for making selection decision in dairy cattle because of their significant influence on production and close association with mastitis. The objective of this study was to identify and evaluate the effects of SNPs in the bovine candidate genes, Interleukin 22 (IL22) and Complement component 4 (C4A), with milk production as well as linear type traits in Karan Fries (Bos taurus × Bos indicus) and Sahiwal (Bos indicus) cows. Four SNPs i.e. rs482793551, rs458036541, rs482793664 and rs455271937 in IL22 gene and two SNPs i.e. rs137485678 and rs132741478 in C4A gene were identified. Interestingly, SNPs rs458036541, rs482793551, and rs455271937 were detected exclusively in Sahiwal cattle, whereas SNP rs482793664 and rs132741478 were uniquely observed in Karan Fries cattle, indicating breed-specific genetic variations. The AA genotype of rs482793664 was found to have deeper central ligament, thicker teats and larger teat diameter, shorter distance from rear teat end to floor and shorter distance from fore teat end to floor in Karan Fries cattle. In Sahiwal cattle, SNPs rs458036541, rs482793551 and rs455271937 were found to be associated with fore udder attachment. The CC genotype of SNP rs455271937 had deeper udder and longer fore teats in Sahiwal. The panel of identified and verified SNPs from this study for both indigenous and crossbred cattle will be useful for marker assisted selection in dairy breeding programs in these breeds.

BACKGROUND: In the quest for sustainable nutritional security, small ruminants play a crucial role, yet many producers face a common stumbling block: insufficient fertile bucks in their herds. This often results in disappointing production outcomes. A simple yet powerful solution lies in the supplementation with minerals and vitamins, thereby enhancing fertility and ensuring that small ruminant herds thrive and contribute to a more secure and productive agriculture. OBJECTIVE: To determine the effects of vitamin E and Se on semen quality and freezability, antioxidant activity, testosterone level, and fertility of Jakhrana bucks. MATERIALS AND METHODS: Eighteen Jakhrana bucks were classified as subfertile bucks based on their semen characters and fertility test. The bucks were randomly allocated into three equal groups and subjected to the following treatments: G1, control; G2, injected with Vit E 250IU/head + Se 0.1 mg/kg body weight.; G3, injected with Vit E 500 IU/head + Se 0.2 mg/kg body weight once weekly for 8 weeks. Semen and blood samples were collected twice weekly for all bucks to assess semen quality and semen was frozen and the post-thaw semen quality parameters (such as progressive motility, viability, abnormality and acrosomal integrity) were evaluated. Serum testosterone level and antioxidant capacity were also measured. At the 8th week of the study, 60 multiparous estrus does (20 does for each group) were exposed for mating to assess the fertility of buck after treatment. RESULTS: Fresh and post-thaw semen quality parameters were significantly (p <0.05) higher in G3 in comparison with G2 and G1, respectively. Also, testosterone level was significantly (p <0.05) increased at the 3rd week (W3) in the G2 and G3 groups in comparison with control group. Fertility and kidding rates were significantly (p <0.05) higher in does who were mated with bucks of G3. CONCLUSION: Injection of vitamin E and selenium improved the semen quality parameters and most importantly the fertility of bucks.

The present study was aimed to study the morphologic, morphometric, production and reproductive traits of the unexplored native goats from Vindhyan region of Eastern Uttar Pradesh. The data of 308 male and 590 female goats were collected from 45 villages and 449 farmers. The goats are managed under an extensive zero input production system by the poor and marginal farmers for their livelihood security since the time immemorial. These are small sized, black or brown coloured, and primarily raised for meat production. Head is straight to slightly convex, ears are flat, leafy and pendulous, and tail is bunchy and curved upward. Muzzle, eyelids and hooves are predominantly black and the horns are flat, curved and spiral with upward-backward-outward orientation. The average adult body weight was 31.34±0.38 kg in males and 28.78±0.12 kg in females. The means (cm) for body length, height at withers and chest girth were 66.41±0.34, 72.65±0.42 and 77.77±0.58, respectively, in adult males and 65.08±0.14, 69.22±0.24 and 74.35±0.16, respectively, in adult females. These goats are seasonal breeder with major breeding season from May to July and bred through natural service. Age at first estrus was ~9 months and age at first kidding was ~15 months. Twinning was common from second parity onwards. Milk production was found to be very low. The morphological appearance and morphometric measurement indicate that these indigenous goats are phenotypically distinct from the other goats of the adjoining area and can be registered as unique breed for better genetic management.

In growing plant population, effect of stress is a perturb issue affecting its physiological, biochemical, yield loss and developmental growth. Protein-L-isoaspartate-O-methyltransferase (PIMT) is a broadly distributed protein repair enzyme which actuate under stressful environment or aging. Stress can mediate damage converting protein bound aspartate (Asp) residues to isoaspartate (iso-Asp). This spontaneous and deleterious conversion occurs at an elevated state of stress and aging. Iso-Asp formation is associated with protein inactivation and compromised cellular survival. PIMT can convert iso-Asp back to Asp, thus repairing and contributing to cellular survival. The present work describes the isolation, cloning, sequencing and expression of PIMT genes of Carica papaya (Cp pimt) and Ricinus communis (Rc pimt) Using gene specific primers, both the pimts were amplified from their respective cDNAs and subsequently cloned in prokaryotic expression vector pProEXHTa. BL21(DE3) strain of E. coli cells were used as expression host. The expression kinetics of both the PIMTs were studied with various concentrations of IPTG and at different time points. Finally, the PIMT supplemented BL21(DE3) cells were evaluated against different stresses in comparison to their counterparts with the empty vector control.

Importance of Study: Semen cryopreservation results in sperm damage due to lipid peroxidation or oxidative stress, leading to a decrease in conception rate. The sperm damage during cryopreservation can be minimized with the use of suitable antioxidant supplements in semen diluent. Some herbs have potent antioxidant potential and can be used in semen diluent to protect the spermatozoa. Objective: Hence, the investigation was planned to evaluate the effect of Asparagus racemosus (A. racemosus) aqueous extract on buck semen quality during cryopreservation. Methodology: In the current study, semen was collected from eight Sirohi bucks, and from each buck, 8 ejaculates were collected. Good-quality semen samples were pooled during each collection. Pooled semen samples were then divided into four equal parts and diluted in TRIS buffer containing different concentrations of A. racemosus aqueous extract (different groups, i.e., G I -5 mg, G II -2.5 mg, G III -1.25 mg, and G IV -0 mg of A. racemosus aqueous extract in 1 mL TRIS buffer). All the diluted semen samples were kept at equilibration temperature (5 degrees C) for 2 hours and then cryopreserved by the manual method. Semen samples were evaluated for various sperm characteristics and antioxidant status before and after cryopreservation. Results: Asparagus racemosus aqueous extract showed significant (p < 0.05) enhancement of sperm viability, sperm motility, acrosomal integrity, and plasma membrane integrity, whereas it reduced sperm abnormality. Furthermore, in the experimental groups, the antioxidant gene expression was found to be increased compared to that of the treatment group. G III (p < 0.05) showed significantly better results in terms of sperm viability, sperm motility, acrosomal integrity, and plasma membrane integrity. Conclusion: Asparagus racemosus aqueous extract has the antioxidant potential to protect buck spermatozoa during semen cryopreservation.

Abstract Lack of knowledge on genetic and phenotypic diversity of goats and its adaptation in local environment impede the implementation of strategies for breeding and management. Hence, the present study was undertaken to characterize the local goats of Vindhyan region of India based on their morphology and morphometry. The study conducted in 308 males and 590 females indicates that the goats of studied population is small in size with black or brown coat colouration, grey skin and horns, black eyelids and hooves, black or brown muzzle and characteristics flat, curved and spiral or straight horns oriented either upward-backward-outward (93.24%) or upward-backward (6.76%). Forehead was straight to slightly convex, ears were flat, leafy and pendulous and tail was bunchy and curved upward. Beard was present on 36.14% of goat. Milk production was very low whereas dressing percentage was recorded as 47.6 ± 0.31%. The major breeding season was found to be May-July whereas litter size was recorded as 1.37. The morphological appearance and morphometric measurement of body length, height at wither, chest-girth, length of ear, horn and tail and body weight at birth, 3, 6, 9, 12 months as well as adult body weight (6 teeth) indicated that the studied goat population is phenotypically distinct from the other goats of the adjoining area and are important genetic resource of India.

Tick-borne diseases (TBDs) of livestock are endemic across various parts of tropical countries. Theileriosis is one such economically important TBD, caused by the Theileriidae family of organisms, which is transmitted by ticks. Theileria annulata, the causative agent of tropical theileriosis, contributes a significant loss to the dairy sector by causing anorexia, high fever, anemia, inflammatory changes in vital organs and icterus, thus, a loss in milk yield. Though vaccines are available, their protective efficacy is not absolute, and treatment is limited to early diagnosis of the causative agent. Routinely, microscopic identification of piroplasms in the erythrocytes (Giemsa-stained) of infected animals or schizonts in lymph node biopsies are practiced for diagnosis. PCR-based techniques (multiplex, uniplex, nested and real-time) have been reported to perform well in diagnosing active infection. Several attempts have been made using serological assays like Dot blot, ELISA and ICT, but the results were of variable sensitivity and specificity. Recombinant proteins like the Theileria annulata merozoite surface antigen (Tams1) and Theileria annulata surface protein (TaSP) have been explored as antigenic candidates for these assays. In the present study, we predicted an immunogenic peptide, i.e., TaSP-34, from the TaSP using various computational tools. The predicted peptide was custom synthesized. The diagnostic potential of the peptide was assessed by indirect plate ELISA to detect the bovine-IgM against Theileria annulata. Alongside, a recombinant truncated TaSP (rTaSP(tr)) was expressed and purified, which was used to compare the performance of the peptide as a diagnostic candidate. The IgM-based peptide ELISA was 100% sensitive and 92.77% specific as compared to PCR (Tams1 targeting), while 98.04% sensitivity and 97.44% specificity were observed in comparison with rTaSP(tr) ELISA. Almost perfect agreement between peptide ELISA and Tams1 PCR was observed with a Cohen’s kappa coefficient (κ-value) of 0.901 and agreement of 95.31%. Further, the κ-value between the peptide ELISA and rTaSP(tr) ELISA was found to be 0.95, and the agreement was 97.65%, which shows a good correlation between the two tests. The findings suggest that the TaSP-34 peptide can be an efficient and new-generation diagnostic candidate for the diagnosis of T. annulata. Furthermore, the peptide can be synthesized commercially at a larger scale and can be a cost-effective alternative for the protein-based diagnostic candidates for T. annulata.

Cholesterol deficiency is a new monogenic autosomal recessive inherited defect in Holstein cattle and is associated with chronic and recurrent diarrhea followed by death of calves during the first six months of life. We have successfully screened the causative mutation for cholesterol deficiency in indigenous, exotic and crossbred cattle of India. This is the first report about the presence of APOB mutation causing calf mortality in the Indian Holstein Friesian population. The mutation associated with cholesterol deficiency was not detected in any of indigenous breeds of cattle suggesting that the mutation could be specific to Holstein Friesian breed only. The occurrence of causal mutation for cholesterol deficiency in one of the Holstein Friesian bull under study (with carrier frequency of 1.67%) clearly indicates that mutation has already been transmitted into Indian Holstein-Friesian population. In our opinion it is the right time to take stringent actions in order to check its further spread. Further, this study accentuates the need for regular screening of existing as well as importing breeding bulls, especially of Holstein-Friesian lineage, for CDH genetic defect before introduction of bulls into genetic improvement programs. It is also highly recommended that the screening for CDH mutation must be made mandatory for all the semen producing/importing agencies under the minimum standards for production of bovine semen.

The invasion of the male urogenital tract by microorganisms, and its subsequent effects on sperm fertilising ability, has not been well discussed in bucks. The present study was conducted to assess the bacterial load in fresh semen of the 2-6 years old bucks. For conducting the experiment, semen ejaculates from 18 bucks (6 from each breed namely Jakhrana, Jamunapari and Barbari) were used. We collected 5 ejaculates from each buck in each season (Summer-April to June, Rainy-July to Sept and Winter-November to January). Semen was collected with the artificial vagina (AV) method, and separate AV was used for each buck every time. The semen collection frequency was once in a week. Immediately after initial evaluation, collected semen samples were transferred to the microbiology laboratory of the institute. Thereafter, the semen samples were subjected to bacteriological examination to assess the microbial load. The results of the current study indicate that the microbial load in the semen was significantly (p < 0.05) higher in the Jamunapari bucks and in aged bucks. Bacteriospermia in different seasons was not significantly varied; however, nonsignificant increase in microbial load during the rainy season was observed. Overall, the average bacterial load in the semen of Jamunapari, Barbari and Jakhrana bucks was found 540.50 ± 55.88 CFU/ml, 391.81 ± 46.33CFU/ml and 388.93 ± 44.71 CFU/ml respectively. No significant difference in bacterial counts in the subsequent ejaculates among bucks was observed. Moreover, correlation analysis revealed that the proportions of motility, viability, plasma membrane integrity and acrosomal integrity were negatively influenced by the increased bacterial contamination of buck semen.

Jersey haplotype (JH) 1, a stop-gain lethal mutation in the CWC15 gene, causes embryonic losses in Jersey cattle. Two PCR based assays using Amplification Refractory Mutation System (T-ARMS-PCR) and restriction fragment length polymorphism (PCR-RFLP) were developed for screening of the JH1 in cattle. During the screening, seven among 30 Indian Jersey bulls were identified as carriers of the mutant JH1 allele, the first time in the country. These PCR assays are economical, rapid and accurate; and can be used separately or in combination for screening and cross-validation of the JH1 carriers in Jersey cattle.

The main objective of this study was to determine the association of production traits with genetic variants in exon 5 and intron 3 of bovine growth hormone (bGH) gene in Sahiwal cattle. The analyses were based on the detection of single nucleotide polymorphisms (SNPs) in GH-AluI (exon 5) and GH-MspI (intron 3) using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The frequency of AluI (L/V) and MspI (T/C) alleles were 86.20/13.70 and 89.80/ 9.50, respectively. The distribution of the frequency of GH genotypes for LL, LV, and VV were 73.4, 25.5, and 1.0 and for TT, TC, and CC genotypes were 80.9, 17.7, and 13.0, respectively. Season of calving had none but period of calving had significant effect on the studied production traits. The phenotypic data was adjusted for non-genetic factors and regression analysis was done. There was detectable significant effect of the GH-AluI and GH-MspI on the analyzed production traits. The cows with LL genotype had significantly higher milk yield traits than the LV genotype. Similarly, the productive performance of the studied cows with TT genotype was also significantly higher than TC and CC genotypes. Results revealed that the Sahiwal cows with LL and TT genotypes of the bGH locus can be considered to be a favourable genotype for production traits, although these findings need to be confirmed by further research before SNPs can be used in a marker assisted selection program by the animal breeder.

The study was conducted to understand the effect of season, parity and stage of lactation on productive performance of Sahiwal cattle. The data of productive traits of 133 Sahiwal cattle from 2016 to 2018 maintained at the Livestock Research Center, Karnal, Haryana, were used for this study. The production data were analyzed using least-square procedures based on season, parity and stage of lactation. Results indicated that the parity had significant (p less than 0.05) influence on monthly milk yield (MMY) whereas, the stage of lactation had highly significant (P less than 0.01) influence on monthly milk yield (MMY) and test day milk yield (TDMY). However, there was no significant effect of season on different productive performance traits in Sahiwal cattle. The phenotypic parameter estimates indicated that the parity and stage of lactation of cattle can be used as a selection tool for improvement of productive traits considering its high positive phenotypic correlations with succeeding productive traits in Sahiwal cows.

The present study was conducted on 1,002 reproductive records of 430 Jersey crossbred cattle, descended from 57 sires and 198 dams, maintained at the Eastern Regional Station of ICAR-National Dairy Research Institute, Kalyani, Nadia, West Bengal, India to investigate the influence of direct genetic, maternal genetic and maternal permanent environmental effect on three most important reproductive traits viz., number of service per conception (NSPC), days open (DO) and calving interval (CI) of Jersey crossbred cattle. Six single-trait animal models (including or excluding maternal genetic or permanent environmental effects) were fitted to analyse these traits, and the best model was chosen after testing the significant increase in the log-likelihood values when additional parameters were added in the model. Direct heritability estimates for NSPC, DO and CI from the best model were 0.10, 0.14 and 0.20, respectively. The maternal permanent environmental (c(2)) effects on reproductive traits accounted for almost negligible fraction of the total phenotypic variance in this study. The maternal genetic effects (m(2)) also contributed very little (0%-3%) to the total phenotypic variance except for CI where it was important and accounted for 20% of phenotypic variance. A significantly large negative genetic correlation was observed between direct and maternal genetic effects for all traits, suggesting the presence of antagonistic relationship between dam's direct additive component and daughter's additive genetic component. Results suggest that both direct and maternal effects were important only for CI but not for other traits. Therefore, both direct additive effects and maternal genetic effect need to be considered for improving this trait by selection.

The aim of this study was to determine the associations of persistency with genetic variants of bovine growth hormone (bGH) gene in Indian Sahiwal cows. The data pertaining to the monthly test day milk yield (MTDMY) and first lactation length (FLL) of 305 lactating Sahiwal cows over a period of 23 years (1993–2016) were subjected to analysis. Persistency of milk yield was estimated by using test day based ratio method and Wilmink b function. Mean LL was 220.06±8.15 days in all studied Sahiwal cows, however, 276.67±10.25 days in cows with ≥100 days of LL and having 500 kg MY. The peak of milk yields was achieved at third TD of the first lactation. Macrophage stimulating protein 1 (MspI) and Arthrobacter luteus1 (AluI) restriction endonucleases were used to digest the amplified regions in intron 3 and exon 5, respectively of bGHgene. The bGHMspI restriction fragment length polymorphism (RFLP) yielded TT, CT and CC genotypes, whereas bGH-AluIRFLP yielded CC, CG and GG genotypes. Significant association was found between first lactation persistency estimated using test day based ratio method and bGH-MspI polymorphism. No significant association was found between first lactation persistency and bGH-AluI polymorphism. In summary, results of present study revealed that the TT genotype of bGH–MspI gene in Sahiwal cows has better lactation persistency than other genotypes.