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Abstract

The experiments reported in this research paper were aimed at assessing the genetic responses of a Holstein cow population, as a response to the variations in environmental temperature, through the analysis of the effects resulting from the genotype by environment interaction (GEI), based on reaction norms. Therefore, milk production data was collected from the database of the Paraná Holstein Breeders Association in Brazil for 67,360 primiparous cows born between 1990 and 2015, with the purpose of evaluating the temperature effect, considered as an environmental variable, distinguished under six gradients (17 ºC to 19.5 ºC) over the region. A random regression model was adopted, utilizing the fourth order under the Legendre polynomials, applying the mixed models of analysis by the REML method, and using the WOMBAT software. Additionally, the breeding value of the 15 most representative bulls was assessed, in response to the changes in the temperature gradient. The total milk production on average was estimated at 8,412.83 ± 2,012.08 kg. The heritabilities estimates were found in the low to moderate range, from 0.18 to 0.23, displaying a decline with a rise in the temperature, highlighting the influence it exerted on the heritabilities. Variations in the genetic expression of some bulls were noted to show differences of up to 289 kg of milk in response to the increase in the temperature from 17 ºC to 19.5 ºC. However, all the genetic correlations between the gradients for milk yield were above 0.80, in the range of 0.873 to 0.998, revealing no remarkable interaction between the genotype and environment. This result indicates that the application of the temperature variable in the models of genetic analysis in southern Brazil is not required.

Abstract

The aim of this study was to determine the effect of Virginia fanpetals (Sida hermaphrodita) silage on carcass and beef quality characteristics. Forty Polish Holstein-Friesian bulls aged 16 months were assigned to 4 dietary treatments (n=10) and were fed different types of silage during a 7-month fattening period. The proportion (g/kg dry matter) of silage in the diets was as follows: (1) grass silage (GS) (600); (2) Sida silage (SS) (600); (3) SS (300) and GS (300); and (4) SS (300) and maize silage (MS) (300). Silage was supplemented with concentrate at 400 g/kg DM in each diet. The animals were slaughtered at the end of the fattening period. Silage type had no significant effect on BWG or feed to gain ratio. The carcasses of bulls fed Sida silage and maize silage received higher scores for conformation than the carcasses of bulls fed grass silage (P<0.05). The meat of bulls fed Sida silage had the lowest value of Warner-Bratzler shear force. Meat from SS+MS group bulls had the highest intramuscular fat (IMF) content and was lightest in color, whereas meat from bulls fed Sida silage and grass silage received the highest scores for color uniformity, aroma, taste and overall acceptability.

Abstract

Recent studies have demonstrated a significant role of mitochondrial DNA (mtDNA) defects in the pathogenesis of many human and some canine tumours. The aim of this study was to identify mutations in the ND2 and ND4 mitochondrial genes in canine mast cell tumours and determine their association with the process of neoplastic transformation and the phenotypic traits of dogs. In total, 136 gene sequences from 68 biological samples, including blood and neoplastic tissue samples from 34 dogs with diagnosed MCTs, were analysed. The study consisted in DNA sequencing of the ND2 and ND4 genes as well as bioinformatics and statistical analyses. For the first time, mutations in NADH-dehydrogenase genes were detected in dogs with MCTs. In total, 22 polymorphic loci and 19 mutations in the ND2 and ND4 genes were identified. The majority of the identified mutations were homoplasmic, and tumour heteroplasmy was detected in eight nucleotide positions in three dogs. Seven of the ND2 mutations and two of the ND4 mutations caused an amino acid change. The changes in non-synonymous protein-coding SNPs did not exert an adverse effect on proteins. A statistically significant correlation of the presence of mutations/polymorphisms with the sex, age, and size of the dogs and the tumour location was demonstrated. Polymorphisms and mutations in NADH-dehydrogenase genes, including mastocyte-specific changes, in canine mast cell tumours that had not been reported earlier in the literature were identified. Some of these changes may imply that these are the hotspot mutations in canine mast cell tumours. It cannot be excluded that the molecular changes are directly associated with the development of mast cell tumours, and further investigations are needed to verify whether they can become molecular markers of MCTs in the future.

Abstract

The aim of the study was to determine the effect of the method of fragmentation of hybrid rye and maize grain on digestibility parameters for ruminants. Varying degrees of fragmentation – none (whole grains; WG), crushed (CG) or ground to pass through a 4.0 (GG4.0) or 1.5 mm (GG1.5) screen – were estimated by the in sacco nylon bag technique, in vitro true digestibility (IVTD), and the in vitro gas production (GP) technique. WG, CG, GG4.0 and GG1.5 were categorized as none, slight, moderate and extensive fragmentation of the grain kernel, respectively. Three non-lactating cows fitted with ruminal and duodenal cannulas were used to determine the effective rumen degradability (ERD) and intestinal and total tract digestibility (ID and TTD, respectively) of dry matter (DM), crude protein (CP) and starch. IVTD was determined with an ANKOM DaisyII Incubator, and GP and in vitro organic matter digestibility were determined with an ANKOMRF Gas Production System. Dry matter, CP and starch of hybrid rye grain were rapidly degraded in the rumen, and this degradability as well as ID and TTD was only marginally affected by the method of kernel fragmentation; however, among the methods used, the ERD of GG4.0 rye was the lowest. On the other hand, the greater the degree of kernel fragmentation, the higher ERD, ID and TTD were obtained for the DM, CP and starch of maize grain. In summary, rye grain is more susceptible to fermentation in the rumen than maize grain, but the means of grain processing may alter the rate, extent and site of their digestion, particularly for maize grain.

Abstract

Female fertility is an important trait that contributes to cow’s profitability and it can be improved by genomic information. The objective of this study was to detect genomic regions and variants affecting fertility traits in Iranian Holstein cattle. A data set comprised of female fertility records and 3,452,730 pedigree information from Iranian Holstein cattle were used to predict the breeding values, which were then employed to estimate the de-regressed proofs (DRP) of genotyped animals. A total of 878 animals with DRP records and 54k SNP markers were utilized in the genome-wide association study (GWAS). The GWAS was performed using a linear regression model with SNP genotype as a linear covariate. The results showed that an SNP on BTA19, ARS-BFGL-NGS-33473, was the most significant SNP associated with days from calving to first service. In total, [69] significant SNPs were located within 27 candidate genes. Novel potential candidate genes include OSTN, DPP6, EphA5, CADPS2, Rfc1, ADGRB3, Myo3a, C10H14orf93, KIAA1217, RBPJL, SLC18A2, GARNL3, NCALD, ASPH, ASIC2, OR3A1, CHRNB4, CACNA2D2, DLGAP1, GRIN2A and ME3. These genes are involved in different pathways relevant to female fertility and other characteristics in mammals. Gene set enrichment analysis showed that thirteen GO terms had significant overrepresentation of genes statistically associated with female fertility traits. The results of network analysis identified CCNB1 gene as a hub gene in the progesterone-mediated oocyte maturation pathway, significantly associated with age at first calving. The candidate genes identified in this study can be utilized in genomic tests to improve reproductive performance in Holstein cattle.

Abstract

This study has been designed to optimize the semen freezing protocol in rabbits, in this regard we compared a Tris-citrate-glucose (TCG) extender with a commercial one (Cortalap®), that to the best of our knowledge has never been used up to now on the in vitro freezability and fertilizing ability of cryopreserved rabbit semen. Two different inseminating semen doses were considered. Five pooled semen samples were divided into two subsamples and each of them were diluted to a ratio 1:1 (v:v) with a freezing extender composed of TCG or Cortalap® containing 16% of dimethylsulfoxide and 0.1 mol/L of sucrose. The extended semen was filled into 0.25 mL plastic straws and frozen above a liquid nitrogen surface. After thawing (50°C/10 seconds) we determined sperm motility, viability, membrane functionality, acrosome and DNA integrity. Our results showed that the Cortalap® extender significantly improved the in vitro post-thaw sperm quality, in comparison to TCG. When we compared the extenders in vivo, no significant differences in the reproductive performances were observed independently by inseminating doses used. In this study we demonstrated that Cortalap® extender can be used as an alternative to TCG. Thus, the Cortalap® being a ready to use extender, implies a reduction of time, mistakes and microbial contaminations during its preparation. This discovery results as significant because it provides beyond an important contribution to the creation of the first Italian semen cryobank of rabbit breeds and also for livestock rabbit farms based on artificial insemination (AI) program.

Abstract

This study was conducted to investigate the in vitro and in vivo antioxidant effect of Artemisia argyi powder (AAP). 240 mixed-sex one-day-old Arbor Acres broilers were randomly divided into five treatment groups, each consisting of six replicates (one replicate per cage) with eight broilers per replicate. Broilers were fed basal diets supplemented with 0, 2.5, 5, 10 and 20 g AAP per kg feed, respectively. The hepatic and intestinal samples were collected on d 21 and 42 for analysis of antioxidant indices and antioxidative enzyme gene expression. The in vitro results showed that the scavenging activity of Artemisia argyi against •OH and DPPH were 34.99±1.11% and 74.12±0.50%, respectively; the ferric reducing power was 2.58±0.03%. The in vivo results showed that dietary 20 g/kg of AAP significantly enhanced the hepatic total antioxidant capacity (T-AOC), catalase (CAT) activity, and glutathione peroxidase (GSH-Px) activity, also decreased the malondialdehyde (MDA) content; dietary10 g/kg of AAP significantly increased the gene expression of superoxide dismutase (SOD) and CAT on d 42. For the duodenum, 10 g/kg of AAP increased SOD activity (P<0.05), and reduced MDA level (P<0.05) on d 21; the gene expression of CAT and SOD were increased in the 20 g/kg of AAP treatment compared with the control group on d 42. For the jejunum, on d 21, the T-AOC level was increased by inclusion of 10 g/kg of AAP, and CAT activity was enhanced significantly at 5, 10, and 20 g/kg of AAP group; dietary AAP significantly decreased MDA level at the concentration of 2.5, 5, 10 and 20 g/kg in contrast with control group on d 42; 5 and 20 g/kg of AAP increased the gene expression of SOD on d 21, and the gene expression of GSH-Px was increased (P<0.05) in 10 g/kg of AAP group on d 42. For the ileum, compared to the control group, 2.5 and 20 g/kg of AAP increased SOD activity (P<0.05); and dietary 10 and 20 g/kg of AAP significantly reduced MDA level; dietary 10 g/kg of AAP increased the gene expression of SOD, CAT and GSH-Px in broilers on d 42. In conclusion, dietary AAP could improve the antioxidant defenses of liver and small intestine, and the best concentration of the AAP improving hepatic and small intestinal antioxidant status was 20 g/kg and 10 g/kg, respectively.

Abstract

This paper presents the current possibilities, state of knowledge and prospects of in vitro production (IVP) of pig embryos, which consists of in vitro oocyte maturation, in vitro fertilization and in vitro embryo culture. In pigs, oocyte maturation is one of the most important stages in the embryo IVP process. It determines the oocyte’s fertilization ability as well as its embryonic development. Through many research studies of the proper selection of oocytes and appropriate maturation medium composition (especially the addition of various supplements), the in vitro maturation of pig oocytes has been significantly improved. Recent studies have demonstrated that modifications of the diluents and in vitro fertilization media can reduce polyspermy. Furthermore, several adjustments of the porcine culture media with the addition of some supplements have enhanced the embryo quality and developmental competence. These updates show the progress of IVP in pigs that has been achieved; however, many problems remain unsolved.

Abstract

Considerable variation in embryo transfer (ET) catheter types, diverging opinions on their quality and functionality, complications following the insertion of catheters, low efficiency of the application of ET methods in humans, and their widely varying efficiency in animals demonstrate the need to improve ET methods and to look for new types of catheters. Such an opportunity is offered by the introduction of catheters made of new-generation biomaterials. This study was aimed to introduce a new generation of biomaterials into reproductive biotechnology. New-generation materials were compared with materials that have been used for many years, and the functionality of newly produced catheters was compared in vivo. Five types of biomaterials were tested: polycaprolactone (PCL), dibutyryl chitin (DBC), polypropylene (PP), polyethylene (PE) and polylactide (PLA). The study was carried out in two stages. Firstly, the basic utility parameters such as geometric stability, surface structure and catheter resistance were evaluated. Subsequently, the biocompatibility of selected biomaterials in embryo cultures was examined, and the development potential of the obtained blastocysts was evaluated. In the second stage, in in vivo with live animals, the biomaterials were tested for biocompatibility and the obtained catheters were examined for their ET functionality. Efficiency with the use of the newly produced catheters was determined, the quality of the blastocysts obtained after embryo culture in the uterus was assessed, and oviducts were subjected to histopathological examination after embryo transfer. Of the tested biomaterials, only polyethylene (PE) showed adequate biological and material properties and proved suitable for production of ET catheters.

Abstract

Β-hydroxy-β-methylbutyrate (HMB) is one of the leucine metabolites with protein anabolic effects which makes it very popular among athletes. Previously, it was shown that HMB administered during the prenatal period reduced the pool of primordial follicles and increased the proportion of developing follicles in newborn piglets. This work is a further step to understand these morphological alterations. Therefore, the aim of this study was to examine the effect of prenatal HMB treatment on the expression of the Kit ligand, BMP-4, bFGF, and the IGF-1/IGF-1R system which are the main growth factors controlling follicular development. Excised ovaries from 12 newborn piglets, originated from the control (n=6) and HMB-treated (n=6) sows were used for immunohistochemical and western-blot analysis. The tested proteins were localized within egg nests and ovarian follicles. Furthermore, the western-blot assay indicated higher BMP-4, Kit ligand, and IGF-1R expression, while the level of bFGF and IGF-1 proteins decreased after HMB dietary treatment. These findings show that HMB included into sow diet can modulate the expression of growth factors and thereby alter ovarian morphology in offspring. Therefore, this study opens a discussion about the benefits and risks of the diet supplemented with HMB and its potential application in medicine and animal husbandry, and further research is necessary in this area.