159 research outputs found
Manic-like reaction to sleep deprivation in mice follows a cyclical pattern and a dose-response effect
No full text
Manic-like reaction to sleep deprivation in mice follows a cyclical pattern and a dose-response effect
No full textGenetic parameters of weeping teats in Italian Saanen and Alpine dairy goats and their relationship with milk production and somatic cell score
No full textThis paper reports a quantitative genetics analysis of weeping teats (WT), an abnormality of the mammary gland in goats. Weeping teats are characterized by milk oozing out of the teat or by the presence of multiple cysts near its base. This abnormality has been routinely recorded in Italian Alpine and Saanen goats since 2000 using a score of 0 or 1 (0 = defect not present, 1 = defect present). No information is available on the genetic background of WT or its relationship with production or other udder-related traits. Data obtained by the Italian National Sheep and Goat Breeders Association (Rome, Italy) were used to estimate both heritability of WT and its genetic correlation with milk yield, somatic cell score, and udder traits. The final data set used in the analysis included 2,178 Saanen and 2,309 Alpine primiparous goats kidding from 2009 to 2014. The pedigree data included 7,333 Saanen and 7,421 Alpines, respectively. A threshold-linear multivariate animal model was used to estimate variance and covari- ance components. A genealogical data analysis was also implemented, including genealogical data completeness, inbreeding, and identification of possible most recent common ancestors. On average, around 4 and 13% of primiparous Saanen and Alpine females kidding from 2009 to 2014 showed mammary gland abnormality, respectively. Weeping teats heritability was 0.27 and 0.26 for Saanen and Alpine, respectively. Genetic cor- relations between milk production or somatic cell score ranged from -0.16 in Saanen to 0.43 in Alpine, but the standard error of the estimates was very large. Positive genetic correlations were observed among WT and teat characteristics in both Saanen and Alpine. The average inbreeding of abnormality carriers was 2.4 and 5.1 for Saanen and Alpine, respectively. The genealogical data analysis identified 4 common ancestors of affected does in Saanen and 2 in Alpine. These results indicate that WT have a possible genetic background. A genome-wide association study might help in understanding the polygenic or monogenic determination of this abnormality
Associations between candidate gene polymorphisms and milk production traits in Alpine goats farmed in Italy
No full textMilk fat yield and composition have a great economic importance in the goat industry being most of milk destined to cheese processing. The identification of genes associated with these traits could provide useful indications for breeding programs. In this work, an association study between 11 SNP polymorphisms at 3 candidate genes (acetyl-coenzyme A carboxylase, ACACA; stearoyl-CoA desaturase, SCD; lipoprotein lipase, LPL) was carried out on 59 Alpine bucks. Data from 13,331 daily records, for milk, fat, and protein yields (kg/d) and fat and protein contents (%) of 2,220 lactations were recorded on 946 goats, daughters
of the 59 bucks. Associations were tested with a mixed linear model that included the fixed effects of flock, date of the test, lactation stage, kidding season, age of the goat at kidding, SNP genotype of the sire and the random effect of the goat. Four SNPs were found to be significantly associated to milk production traits (Bonferroni gene-wide adjusted significance P < 0.01). The GC substitution at exon 1 of the LPL locus had the highest effect on milk yield (difference of about 0.6 kg/day between the 2 homozygotes CC and GG, respectively, P < 0.01). The CT substitution at exon 45 of the ACACA locus affected milk yield and fat percentage. The deletion at the 3′ untranslated region of the SCD locus affected milk, and protein (undeleted homozygotes produced about 16 g/d more than deleted ones) yield and fat percentage. Finally, the CT mutation at exon 5 of the SCD gene was associated to milk yield.
These interesting associations should be obviously validated on a larger sample. Moreover, effect on other traits as milk fatty acid composition could be considered in future analyses
Effetto di polimorfismi in geni candidati sulle caratteristiche qualitative del latte ovino
No full textPower Optimization for Intensity and Time Jitter Characterization in Optical Frequency Multiplication and Time Multiplexing
No full textA comparison of genetic and genomic breeding values in Saanen and Alpine goats
No full textNowadays, several countries are developing or adopting genomic selection in the dairy goat sector. The most used method to estimate breeding values is Single-Step Genomic Best Linear Unbiased Prediction (ssGBLUP) which offers several advantages in terms of computational process and accuracy of the estimated breeding values (EBVs). Saanen and Alpine are the predominant dairy goat breeds in Italy, and both have similar breeding programs where EBVs for productive traits are currently calculated using BLUP. This work describes the implementation of genomic selection for these two breeds in Italy, aligning with the selection practices already carried out in the international landscape. The available dataset included 3 611 genotyped animals, 11 470 lactation records, five traits (milk, protein and fat yields, and fat and protein percentages), and three-generation pedigrees. EBVs were estimated using BLUP, GBLUP, and ssGBLUP both with single and multiple trait approaches. The methods were compared in terms of correlation between EBVs and genetic trends. Results were also validated with the linear regression method excluding part of the phenotypic data. In both breeds, EBVs and GEBVs were strongly correlated and the trend of each trait was similar comparing the three methods. The average increase in accuracy across traits and methods amounted to +13 and +10% from BLUP to ssGBLUP for Alpine and Saanen breeds, respectively. Results indicated higher prediction accuracy and correlation for GBLUP and ssGBLUP compared to BLUP, implying that the use of genotypes increases the accuracy of EBVs, particularly in the absence of phenotypic data. Therefore, ssGBLUP is likely to be the most effective method to enhance genetic gain in Italian Saanen and Alpine goats
Genetic parameters of weeping teats in Italian Saanen and Alpine dairy goats and their relationship with milk production and somatic cell score
No full textThis paper reports a quantitative genetics analysis of weeping teats (WT), an abnormality of the mammary gland in goats. Weeping teats are characterized by milk oozing out of the teat or by the presence of multiple cysts near its base. This abnormality has been routinely recorded in Italian Alpine and Saanen goats since 2000 using a score of 0 or 1 (0 = defect not present, 1 = defect present). No information is available on the genetic background of WT or its relationship with production or other udder-related traits. Data obtained by the Italian National Sheep and Goat Breeders Association (Rome, Italy) were used to estimate both heritability of WT and its genetic correlation with milk yield, somatic cell score, and udder traits. The final data set used in the analysis included 2,178 Saanen and 2,309 Alpine primiparous goats kidding from 2009 to 2014. The pedigree data included 7,333 Saanen and 7,421 Alpines, respectively. A threshold–linear multivariate animal model was used to estimate variance and covariance components. A genealogical data analysis was also implemented, including genealogical data completeness, inbreeding, and identification of possible most recent common ancestors. On average, around 4 and 13% of primiparous Saanen and Alpine females kidding from 2009 to 2014 showed mammary gland abnormality, respectively. Weeping teats heritability was 0.27 and 0.26 for Saanen and Alpine, respectively. Genetic correlations between milk production or somatic cell score ranged from −0.16 in Saanen to 0.43 in Alpine, but the standard error of the estimates was very large. Positive genetic correlations were observed among WT and teat characteristics in both Saanen and Alpine. The average inbreeding of abnormality carriers was 2.4 and 5.1 for Saanen and Alpine, respectively. The genealogical data analysis identified 4 common ancestors of affected does in Saanen and 2 in Alpine. These results indicate that WT have a possible genetic background. A genome-wide association study might help in understanding the polygenic or monogenic determination of this abnormality
Preliminary association studies between EBVs and SNPs in 5 candidate genes for milk fat in goats
No full textFat yield and content play a major role in the technological and nutritional quality of goat milk, influencing nutritional, aromatic and technological characteristics, like firmness, color and flavor, of milk and milk-derived products (Delacroix-Buchet and Lamberet 2000). These traits are relevant factors for the market value of dairy goat products and make milk fat a considerable component of the economic efficiency of goat production. Moreover, fatty acid composition of milk is of great interest, considering the implications for human health (Garcìa-Fernandez et al. 2009).
This work aims to present some preliminary results of the association studies between a panel of SNPs identified in candidate genes for milk fat and estimated breeding values for fat yield (kg) and fat content (%), calculated by the National Breeders Association (ASSONAPA) on a sample of 80 Alpine and Saanen bucks reared in Italy.
The five candidate genes investigated are well known for their role. Acetyl-coenzyme A carboxylase alpha (ACACA) is part of a multifunctional complex enzyme system which catalyzes the rate-limiting step in fatty acid synthesis. Badaoui et al. (2007a) observed in ACACA gene a polymorphism associated with fat yield, lactose content and somatic cell count in 4 Spanish goat breeds. Diacilglycerol acyl transferase 1 (DGAT1) is a key enzyme in triacylglycerol synthesis in the mammary gland, well known in cattle for its effects on fat and protein yield (Grisart et al. 2004), whereas in goat Angiolillo et al. (2007) identified only a SNP. Fatty acid synthase (FASN) encodes a multifunctional protein catalyzing the synthesis of palmitate into long-chain saturated fatty acids. In cattle SNP on FASN gene showed a significant association with milk fat yield and content (Roy et al. 2006).
Lipoprotein lipase (LPL) encodes homonymous lipase with the dual functions of triglyceride hydrolase and ligand/binding factor for receptor-mediated lipoprotein uptake. In this gene Badaoui et al. (2007) observed one SNP associated with fat content in 4 Spanish goat breeds.
Stearoyl-CoA desaturase (SCD) is the key enzyme involved in the endogenous synthesis of conjugated linoleic acid (CLA) in ruminants. It is well studied in cattle whereas in goat only some SNPs are known (Badaoui et al. 2007b; Moioli et al. 2007)
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