Organic zinc and copper supplementation on antioxidant protective mechanism and their correlation with sperm functional characteristics in goats

Trace minerals feeding had significant effects on sperm production and fertility with better absorption and proper utilization within the body for optimum reproductive function. Several studies have shown that more influenced trace elements in the diets of animals are copper (Cu) and zinc (Zn). Bucks showing deficiency of this mineral might affect the quality of semen production which in turn would affect the fertility. This experiment was thus designed to test the effects of organic Cu and Zn supplementation on antioxidants enzyme activities and sperm functional attributes in fresh semen of bucks. Forty bucks (n = 40, Aged 5 months) were assigned to ten groups of four animals in each group, supplemented (for a period of 8 months) with different levels of organic Zn: 20 mg (T2), 40 mg (T3) and 60 mg (T4), organic Cu: 12.5 mg (T5), 25 mg (T6), 37.5 mg (T7) and combined organic Zn and Cu: 20 + 12.5 mg (T8), 40 + 25 mg (T9), 60 + 37.5 mg (T10), respectively, per kg dry matter and no additional mineral diet (control; T1). One hundred and sixty semen samples were collected through electro‐ejaculator and analysed for sperm quantity, quality, acrosome intactness and plasma membrane integrity and correlated with the catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase enzyme activities in seminal plasma. The results indicated organic Cu and zinc supplemented bucks produced more sperm cells, had higher sperm concentrations, maintained higher (p < .01) sperm livability, plasma membrane and acrosome integrities, more motility and velocity. The increased antioxidant enzyme activities, reduced oxidative stress and lowered lipid peroxidation were positively correlated (p < .05) with the sperm functional attributes. In conclusion, organic Cu and Zn supplement to male goats showed protective roles against oxidative damage and maintained better fresh semen characteristics.     

Effect of Supplementation of Taurine or Trehalose in Extender on Immunolocalization of Tyrosine Phosphoproteins in Buffalo and Cattle (Karan Fries) Cryopreserved Spermatozoa

The present study assessed the effects of incorporation of Taurine or Trehalose in extender on immunolocalization of tyrosine phosphoproteins, Cryocapacitation and other sperm quality parameters (motility, viability and membrane integrity) in post‐thawed sperm from Buffalo (Murrah) and Cattle (Karan Fries). Six ejaculates from six individual bulls from both species were chosen at random and split into four aliquots: one aliquot without dilution (fresh sample), another diluted in egg yolk tris‐citrate (EYTC) extender and the rest of aliquots with EYTC dilution supplemented with taurine (50 mm ) or trehalose (100 mm ), respectively, and cryopreserved. Following cryopreservation, semen were thawed and assessed for standard semen quality parameters. Extent of capacitation in cryopreserved spermatozoa was measured by inducing in vitro acrosome reaction followed by dual staining. Immunolocalization of tyrosine phosphoproteins was carried out by immunocytochemistry using primary antibody clone pT‐154 (anti‐phosphotyrosine antibody) and FITC‐conjugated secondary antibody. Immunofluorescent signals were analysed for level of protein tyrosine phosphorylation in spermatozoa. Post‐thaw semen evaluation showed supplementation of taurine or trehalose to EYTC extender significantly (p < 0.05) increased motility, viability and membrane integrity of spermatozoa in both species. Percentage of cryocapacitated spermatozoa was significantly (p < 0.05) higher in cattle as compared to buffalo and degree of cryocapacitaion of spermatozoa decreased significantly (p < 0.05) upon supplementation of additives in both the species. It was also found that tyrosine phosphoproteins were localized differentially in fresh and cryopreserved spermatozoa. Supplementation of taurine or trehalose to freezing extender changed the localization of tyrosine phosphoproteins in cryopreserved spermatozoa similar to fresh in both the species. The results obtained clearly indicated that supplementation of taurine or trehalose to EYTC prior to cryopreservation improves Buffalo and Cattle sperm quality in terms of cryocapacitation and immunolocalization of tyrosine phosphoproteins during freezing–thawing process.     

The effectiveness of a single dose of doramectin pour-on in the control of gastrointestinal nematodes in yearling stocker cattle

Three field studies were conducted to determine the efficacy of a single dose of doramectin pour-on in the control of gastrointestinal nematode infections in yearling stocker calves on pasture. These 140-day studies were carried out between October 1995 and March 1996 in Tennessee (TN), between January and June 1997 in Louisiana (LA), and between May and September 1997 in Wisconsin (WI). Calves with patent nematode infections were equally allocated to treatments (doramectin pour-on, at 500 microg/kg body weight or untreated control) and pastures as randomized complete-block designs (LA and TN studies) or completely at random (WI study). There were six pasture replicates per treatment at each site, with each pasture replicate accommodating six calves at the TN site (36 calves per treatment), five calves at the LA site (30 calves per treatment), and seven calves at the WI site (42 calves per treatment). Fecal samples for nematode egg counts were collected on Day 0, and at 28-day intervals thereafter. Body weights were recorded on Day 0 and at 28-day intervals until study termination. Nematode egg output of the doramectin-treated groups was reduced over the entire grazing period compared to those in the untreated control groups, resulting in average daily weight-gain advantages of 0.055 kg (p < or = 0.05) for the TN study, 0.208 kg (p < or = 0.05) for the LA study, and 0.116 kg (p < or = 0.05) for the WI study.     

The persistent efficacy of doramectin pour-on against biting and sucking louse infestations of cattle

A repeated-exposure challenge model was used to evaluate the pour-on formulation of doramectin in preventing the establishment of louse infestations in cattle. Twenty calves cleared of preexisting biting and sucking louse infestations were randomly and equally allocated to either a doramectin-treated or untreated control group, with five replicates per group. Doramectin pour-on was administered topically at a dose rate of 500 microg/kg body weight. Every 14 days, from a pool of seeder calves with infestations of at least 50 biting and 50 sucking lice each, 10 calves were selected and 1 was placed in each replicate pen. Every week during the 112-day study, 9 predilection sites on the doramectin-treated and untreated calves were examined to estimate the louse population density. A calf met the infestation criterion for a louse species when two or more live lice were counted on two or more body regions for two consecutive count days. Because only 4 of 10 untreated calves acquired Solenopotes capillatus infestations, the persistent efficacy of doramectin against S. capillatus was not evaluated. Bovicola bovis and Linognathus vituli infestations in the untreated calves developed shortly after exposure to infested seeder calves. The acquisition of B. bovis and L. vituli infestations in the doramectin-treated group was delayed for 77 days and 105 days, respectively.     

Assessment of Genetic Variability in the Coding Sequence of Melatonin Receptor Gene (MTNR1A) in Tropical Arid Sheep Breeds of India

Seasonal behaviour in sheep, which varies in tropical and temperate environmental conditions, is a matter of study, because it can provide a clue to address the problem of seasonality in sheep. Melatonin receptor is the membrane‐bound G‐coupled receptor, sensing the message of photoperiodic cues thorough melatonin. Restriction fragment length polymorphism (RFLP) studies were carried out to assess the variability of gene at G612A and C606T SNPs in MTNR1A gene, which have been studied to be markers for out‐of‐season breeding. Allelic frequency distribution corresponded to higher frequency of GG and CC genotype, in tropical arid sheep breed in comparison with temperate region sheep breed. PCR amplification of MTNR1A gene of 30 animals was performed and single nucleotide polymorphisms (SNPs) identification was carried out using Lasergene software. Seven SNPs/mutations were identified, but most of them were synonymous, except the one G706A, leading to substitution of valine by isoleucine. Polyphen‐2 analysis of G706A mutation revealed that it is a benign mutation. Two important SNPs C426T and G555A, which were identified in temperate sheep breeds, could not be traced in Magra and Marwari breeds of sheep. Thus, the Magra and Marwari breeds of tropical, arid region demonstrated the presence of both polymorphic SNPs markers G612A and C606T, associated with out‐of‐season breeding. GG and CC genotypes were having a higher prevalence in the studied population.     

Crystal and molecular structure of a thymine phototrimer

Thymine trimer was isolated from a frozen aqueous solution of thymine which was irradiated with ultraviolet light and was presumably formed through the rearrangement of an initial oxetane photoproduct. X-ray diffraction analysis of a single crystal has confirmed the trimeric diol structure and has established the stereoconfiguration of the molecule. The possible importance of the diol structure in photobiology is pointed out.     

Crystalline ordering in silica and germania glasses

The diffraction patterns of both silica and germania glasses are consistent with a structure in which nearly all of the atoms belong to tridymite-like regions of up to about 20 angstroms or more that are bonded efficiently together in a manner analogous to that found in twinned crystals.     

Effect of <Emphasis Type="Italic">Vachellia tortilis</Emphasis> on understory vegetation,herbaceous biomass and soil nutrients along a grazing gradient in a semi-arid African savanna

The spatial pattern and abundance of herbaceous vegetation in semi-arid savannas are dictated by a complex and dynamic interaction between trees and grasses. Scattered trees alter the composition and spatial distribution of herbaceous vegetation under their canopies. Therefore, we studied the effect of Vachellia tortilis on herbaceous vegetation composition, biomass and basal area, and soil nutrients on sites with varying grazing intensities in the central rift valley of Ethiopia. Data were collected on species composition, cover and biomass of herbs and grasses, and soil moisture and nutrient contents under light, medium, and heavy grazing pressures, both under the inside and outside of V. tortilis canopies. Species richness was similar in both locations but decreased with increased grazing. Only the overall biomass and herb cover were significantly greater under the canopy than outside, and overall biomass showed significant unchanging decline with increased grazing. However, vegetation cover was significantly greater on moderately grazed sites compared to low and heavily grazed sites. All soil variables were significantly higher under V. tortilis canopies than outside. Our findings suggest that V. tortilis has more effect on composition and diversity of herbaceous vegetation than on species richness, and that V. tortilis promotes the herbaceous layer biomass by reducing soil moisture loss and increasing soil fertility under the inside than outside the canopies. Therefore, we suggest that management practices should be directed on reducing pressure on V. tortilis by regulating grazing. Low to moderate grazing levels (i.e., a stocking rate less than 39.6 TLU ha^?1 yr^?1) seems to be tolerable to ensure sustainable conservation of the species in the study area in particular and in semi-arid savannas in general.