Determination of the best non-linear function to describe the growth of Kajli sheep

The aim of the present study was to determine the best non-linear growth function to describe the growth of Kajli sheep. For this aim, the Brody, von Bertalanffy, Logistic, and Gompertz models were used to describe the sigmoidal relationship between bodyweight and age of the Kajli sheep. The records obtained from the Livestock Experiment Station, Khushab, were collected between 2007 and 2018. The records comprised 9864 age-weight observations (300 for male, 9564 for female, 7392 for single, 2388 for twin, and 84 for triplet lambs), which extended from birth to 12 months old. Candidate non-linear functions were fitted and the curve parameters were estimated by nlsfit (fit non-linear models) function in R statistical package, version 3.6.1. Goodness of fit criteria that were used to evaluate predictive performances of candidate models were adjusted coefficient of determination (R2adj), Akaike’s information criterion (AIC), Bayesian information criterion (BIC) and root means square error (RMSE). The Brody model was the best non-linear function that described the biological growth pattern of all, male, female, single, twin, and triplet lambs. Differences in curve parameter estimates between male and female suggested a definite pattern of sexual dimorphism. Moreover, a higher estimate of rate of maturity in female lambs reflects their early maturity compared with male Kajli lambs. Similarly, the single-born Kajli animals with highest maturity rate were maturing at an earlier age than twins and triplets. This is the first report on the non-linear pattern of visible changes in bodyweight of Kajli sheep from birth to 12 months old.Key words: age, bodyweight, growth curves, regression, shee

Analysis of non-genetic and genetic influences underlying the growth of Kajli lambs

Data on 2931 Kajli lambs, born from 2007 to 2018, were used to quantify environmental and genetic effects on growth performance of Kajli sheep. Traits considered for evaluation were birth weight (BWT), 120-day adjusted weight (120DWT), 180-day adjusted weight (180DWT), 270-day adjusted weight (270DWT), and 365-day adjusted weight (365DWT). Fixed effects of year of birth, season of birth, sex, birth type, and dam age on these traits were evaluated using linear procedures of SAS, 9.1. Similarly, BWT, 120DWT, 180DWT, and 270DWT were used as fixed effects mixed model analyses. Variance components, heritability and breeding values were estimated by restricted maximum likelihood. The genetic trend for each trait was obtained by regression of the estimated breeding values (EBV) on year of birth. Analyses revealed substantial influence of birth year on all traits. Sex and birth type were the significant sources of variation for BWT and 120DWT. Season of birth did not influence birth weight meaningfully, but had a significant role in the expression of 120DWT, 180DWT, and 270DWT. Heritability estimates were generally low (0.003 ± 0.018 to 0.099 ± 0.067) for all traits. With the exception of the genetic correlation of 180DWT and 365DWT, the genetic correlations between trait were strong and positive. Only 365DWT had a positive genetic trend. Although the heritability estimates for almost all weight traits were low, high and positive genetic correlations between BWT and other weight traits suggest that selection based on BWT would result in the improvement of other weight traits as a correlated response.Keywords: bodyweight, breeding value, genetic correlation, shee

Phytic acid: How far have we come?

Phytic acid is a major storage form of phosphorous. Obvious reasons are there to favor its reduced concentration in organisms. However, certain justifications can also be settled, in order to support its increased natural concentration. In both cases, there are questions to be answered to favor one side while alleviating the harm of neglecting the other. This article reviews our current state of understanding of phytic acid - focusing on the topics of current and future interests in the field

PCR-RFLP-based identification of polymorphisms in BMPR1B, GDF9 and BMP15 genes associated with litter size in Beetal and Teddy goats

The genes BMPR1B, GDF9 and BMP15 are oocyte-derived members of the transforming growth factor-β superfamily, which is essential for follicular growth and ovulation. The aim of the current study was to determine the incidence of reported mutations in exon 3 of BMPR1B gene, exon 1 of GDF9 gene, and exon 2 of BMP15 gene and their association with litter size in three parities of Beetal and Teddy goats. Based on the known mutations in these genes, PCR primers were designed to find out the polymorphism through the PCR-RFLP technique in 120 randomly selected animals of the two breeds, which vary in their prolificacy. The current results show that there were significant differences in litter size [1.708 ± 0.060 in Beetal (B) and 2.167 ± 0.056 in Teddy (T) goats] in both breeds. The results of breed x parity interaction showed significant differences in litter size in first [1.158 ± 0.061 (B); 1.861 ± 0.057 (T)], third [2.062 ± 0.078 (B); 2.583 ± 0.073 (T)] and average parity [708 ± 0.060 (B); 2.167 ± 0.056 (T)] in both breeds. All three loci in both breeds were found to be polymorphic and the results of breed x parity x genotype analysis showed that genotypes of all the three genes were significantly associated with litter size in all parities in both breeds. For the BMPR1B gene, heterozygous (CT) animals of Beetal and Teddy goats had the largest litter size in all three parities and the average (parity) litter size, showing the overdominance of the heterozygotes. Similarly, for GDF9 gene, heterozygous animals (AG) had the largest litter size in both breeds. For BMP15 gene homozygous carrier animals (CC) of both breeds had the highest number of kids, followed by the heterozygous (AC) genotypes. The current results show the importance of BMPR1B, GDF9 and BMP15 as the major genes that influence prolificacy in both Beetal and Teddy goats. It is suggested that these polymorphisms can be used as molecular markers to select the prolific animals in these breeds.Keywords: Beetal goats, Teddy goats, molecular markers, prolificacy, polymorphis

Metabolic engineering and thermodynamic characterization of an extracellular β-glucosidase produced by Aspergillus niger

The production of an extracellular β-glucosidase by Aspergillus niger NRRL 599 was optimized using submerged fermentation technique. Effect of different media, different carbon sources, initial pH of the fermentation medium, temperature, incubation period and inoculum size on the production of β- glucosidase enzyme was investigated. A. niger NRRL 599 produced maximum extracellular β- glucosidase (4.48 U/mg) in Eggins and Pugh medium with 1% wheat bran (w/v) at pH 5.5 inoculated with 4% conidial suspension after 96 h of incubation at 30°C. Purified β-glucosidase gave Km and Vmax values of 3.11 mM and 20.83 U/mg respectively for pNPG hydrolysis. The enzyme was optimally active at pH 4.8 and at temperature of 60°C. Thermodynamic parameters, Ea, ΔH and ΔS were found to be 52.17 KJ/mol, 49.90 J/mol.K and -71.69 KJ/mol, respectively. The pKa1 and pKa2 of ionizable groups of active site residues involved in Vmax were calculated to be 4.1 and 6.0 respectively.Key words: β-Glucosidase, Aspergillus niger, kinetics, thermodynamics

PREPARATION OF CONJUGATE FOR USE IN AN ELISA FOR HUMORAL IMMUNE RESPONSE AGAINST EGG DROP SYNDROME VIRUS IN LAYER CHICKS

An indirect enzyme-linked immunosorbent assay (ELISA) was performed for the detection of antibodies against Egg Drop Syndrome (EDS) virus. Virus identification was done through haemaggluti- nation inhibition (HI) test using known antisera. Antichicken immunoglobulins were raised in goats and purified by ammonium sulphate precipitation technique. These goat-antichicken immunoglobulins were conjugated with horseradish peroxidase. Twenty-seven serum samples were collected from a layers flock vaccinated against EDS and specific antibodies were determined by using a horseradish conjugate

Experimental investigation of long-term performance of fiber-reinforced epoxy and polyurethane polymer composites

The primary challenge encountered by polymers and their composites when exposed to saline water is their inadequate ability to withstand wear and tear over time. With a potential to replace conventional materials the long-term performance of FRP composites is still a novice area. This manuscript thus, reports an experimental investigation and prediction of the durability of fiber-reinforced polymer composites exposed to seawater at different temperatures. E-glass/epoxy and E-glass/polyurethane samples were exposed to 23 °C, 45 °C and 65 °C seawater for up to 2700 days (90 months). Tensile tests evaluated the mechanical performance of the composite as a function of exposure time, and strength-based technique was used to assess the durability. The experimental results revealed that the tensile strength of E-glass/epoxy composite decreased by 6.3% and 48.9% after 90 months in seawater at 23 and 65 °C, respectively, whereas it declined by 37.6% and 63.6% respectively for E-glass/Polyurethane composite. The prolonged immersion in seawater results in plasticization and swelling in the composite material, which accelerates the fiber/matrix debonding. SEM micrographs indicate fiber/matrix debonding, potholing, fiber pull-out, river line marks, and matrix cracking which showcases deterioration in the tensile properties of both composites

Analysis of chemical constituents in medicinal plants of selected districts of Pakhtoonkhwa, Pakistan

Alkaloids, flavonoids and saponins were determined in the Teraxacam officinale, Cichorium intybus and Figonia tritica. Quantative determinations of crude alkaloids, flavonoids and saponins (g kg-1) and their percentages (%) were determined in C. intybus, T. officinale and F. critica collected from Kohat, Mardan, Nowshera and Peshawar regions. Thin layer chromatography (TLC) study of the alkaloids, flavonoids and saponins were carried out with different solvent systems and color of the spot and Rf value of each constituent was determined. Among the samples of C. intybus, relatively higher contents of alkaloids (14 g kg-1) were found in the sample collected from Mardan region, followed by the sample gathered from Nowshera which is equal to 13.8g kg-1. Higher contents of flavonoids were found in C. intybus collected from Kohat region which was 23.48 g kg-1. The other remaining samples of C. intybus ranged in the decreasing order of 19.7, 17.2 and 10.0 g kg-1 for the ones collected from Nowshera, Mardan and Peshawar, respectively. The overall saponin contents remained almost low as compared to the alkaloid and flavonoid contents.Key words: Alkaloids, flavonoids, saponins, TLC study, medicinal plants