Analisi dei polimorfismi del gene della miostatina (MSTN) e loro associazione con le performance del cavallo anglo arabo da corsa

The Anglo Arabian horse breed is spread all over the world. The aim of this study was to investigate polymorphisms of the myostatin gene (MSTN) in Anglo Arabian racehorses. Blood samples were collected from 180 horses and DNA was extracted. Data concerning the sport career were achieved. MSTN gene was entirely sequenced from two subjects and 14 polymorphic sites were detected. Resequencing of the fragments 3 and 6 in all the 180 horses was later performed. The only SNP that showed a significant effect on sport performance (arrival and success indexes) was g.66,493,737, which showed three genotypes, CC, CT and TT. Heterozygotes CT were characterized by the best performances considering the arrival index. As regard the success index, no difference was registered between homozygous and heterozygous for short distances, but the latter are always the best on medium and long distances. Orthogonal contrasts showed that heterozygous horses attained the highest cash prize in the medium distances while CC homozygotes have better performances in the short distances. CT and TT showed the same results on long and short distances. In conclusion, flexibility of the Anglo Arabian racehorse was evidenced. Selection led to particularly resistant horses, easily and indifferently adapted for race distances ranging from 1400 to 2400 meters. These findings should be useful both to bring higher value to the genotyped animals and for better selection schemes

Milk yield, quality, and coagulation properties of 6 breeds of goats: Environmental and individual variability.

ABSTRACT Goat milk and cheese production is continuously increasing and milk composition and coagulation properties (MCP) are useful tools to predict cheesemaking aptitude. The present study was planned to investigate the extension of lactodynamographic analysis up to 60 min in goat milk, to measure the farm and individual factors, and to investigate differences among 6 goat breeds. Daily milk yield (dMY) was recorded and milk samples collected from 1,272 goats reared in 35 farms. Goats were of 6 different breeds: Saanen and Camosciata delle Alpi for the Alpine type, and Murciano-Granadina, Maltese, Sarda, and Sarda Primitiva for the Mediterranean type. Milk composition (fat, protein, lactose, pH; somatic cell score; logarithmic bacterial count) and MCP [rennet coagulation time (RCT, min), curd-firming time (k20, min), curd firmness at 30, 45, and 60 min after rennet addition (a30, a45, and a60, mm)] were recorded, and daily fat and protein yield (dFPY g/d) was calculated as the sum of fat and protein concentration multiplied by the dMY. Data were analyzed using different statistical models to measure the effects of farm, parity, stage of lactation and breed; lastly, the direct and the indirect effect of breed were quantified by comparing the variance of breed from models with or without the inclusion of linear regression of fat, protein, lactose, pH, bacterial, somatic cell counts, and dMY. Orthogonal contrasts were performed to compare least squares means. Almost all traits exhibited high variability, with coefficients of variation between 32 (for RCT) and 63% (for a30). The proportion of variance regarding dMY, dFPY, and milk composition due to the farm was moderate, whereas for MCP it was low, except for a60, at 69%. Parity affected both yield and quality traits of milk, with least squares means of dMY and dFPY showing an increase and RCT and curd firmness traits a decrease from the first to the last parity class. All milk quality traits, excluding fat, were affected by the stage of lactation; RCT and k20 decreased rapidly and a30 was higher from the first to the last part of lactation. Alpine breeds showed the highest dMY and dFPY but Mediterranean the best percentage of protein, fat, and lactose and a shorter k20 and a greater a30. Among the Mediterranean goats, Murciano-Granadina goats had the highest milk yield, fat, and protein contents, whereas Maltese, Sarda, and Sarda Primitiva were characterized by much more favorable technological properties in terms of k20, a30, and a45. In conclusion, as both the farm and individual factors highly influenced milk composition and MCP traits, improvements of these traits should be based both on modifying management and individual goat factors. As expected, several differences were attributable to the breed effect, with the best milk production for the Alpines and milk quality and coagulation for the Mediterranean goats

Polymorphism of Caprine SLC11A1 Gene and Relationships with Hygienic Characteristics of Milk

The solute carrier family 11 member A1 (SLC11A1) gene is associated with resistance to infectious diseases. Genetic variability at the 3’ untranslated region (3’-UTR) of this gene is due to the presence of a polymorphic microsatellites that contain a (GT) n dinucleotide repeat. The microsatellite variability and relationships with milk yield and composition, somatic cell count (SCC) and total microbic count (TMC) were investigated in 260 goats of Sarda breed. Genotyping of the upstream guanine-thymine repeat (GT)n revealed twenty different genotypes and eight alleles (GT11, GT12, GT14, GT15, GT16, GT17, GT18 and GT19). The present study confirmed the high genetic variability of the Sarda goat and that the genotype of the microsatellite at 3’-UTR SLC11A1 affected many chemical and hygienic characteristics of milk as fat, protein and SCC

Polymorphism of Caprine SLC11A1 Gene and Relationships with Hygienic Characteristics of Milk

The solute carrier family 11 member A1 (SLC11A1) gene is associated with resistance to infectious diseases. Genetic variability at the 3’ untranslated region (3’-UTR) of this gene is due to the presence of a polymorphic microsatellites that contain a (GT) n dinucleotide repeat. The microsatellite variability and relationships with milk yield and composition, somatic cell count (SCC) and total microbic count (TMC) were investigated in 260 goats of Sarda breed. Genotyping of the upstream guanine-thymine repeat (GT)n revealed twenty different genotypes and eight alleles (GT11, GT12, GT14, GT15, GT16, GT17, GT18 and GT19). The present study confirmed the high genetic variability of the Sarda goat and that the genotype of the microsatellite at 3’-UTR SLC11A1 affected many chemical and hygienic characteristics of milk as fat, protein and SCC

The Effect of Long-term Freezing on Renneting Properties of Sarda Sheep Milk

Cold storage is a well-known strategy to limit concerns about seasonality for sheep dairy productions. The aim of this study was to investigate the effect of long-term freezing on milk renneting properties from the Sarda sheep, an autochthonous breed from Italy. Two-hundred milk samples from 50 pluriparous Sarda ewes were collected at monthly intervals throughout the lactation from April to July. Each sample of fresh milk was analysed for composition and subsamples were obtained and frozen for one, three and five months. Renneting properties, both from the fresh and frozen subsamples, were achieved using the Formagraph instrument and results were submitted to a mixed model statistical analysis. The storage effect significantly affected (P<0.01) the renneting parameters. A large amount of non coagulating subsamples was registered after a long-term frozen storage. Furthermore, milk clotting time was longer in frozen subsamples and curd firmness diminished after a freezing period of five months. In conclusion, the remarkable decreasing of sheep milk renneting characteristics after frozen storage can predict a worse yield and quality of cheese-making and suggests that freezing of Sarda raw milk should be limited to shorter periods

The Sheep growth hormone gene polymorphism and its effects on milk traits

Growth hormone (GH) is encoded by the GH gene, which may be single copy or duplicate in sheep. The two copies of the sheep GH gene (GH1/GH2-N and GH2-Z) were entirely sequenced in one 106 ewes of Sarda breed, in order to highlight sequence polymorphisms and investigate possible association between genetic variants and milk traits. Milk traits included milk yield, fat, protein, casein and lactose percentage. We evidenced 75 nucleotide changes. Transcription factor binding site prediction revealed two sequences potentially recognised by the pituitary-specific transcription factor POU1FI at the GH1/GH2-N gene, which were lost at the promoter of GH2-Z, which might explain the different tissues of expression of GH1/GH2-N (pituitary) and GH2-Z (placenta). Significant differences in milk traits were observed among genotypes at polymorphic loci only for the GH2-Z gene. Sheep with homozygote genotype ss748770547 CC had higher fat percentage (P &#60; 0&#183;01) than TT. SNP ss748770547 was part of a potential transcription factor binding site for C/EBP alpha (CCAAT/Enhancer Binding Protein), which is involved in the regulation of adipogenesis and adipoblast differentiation. SNP ss748770547, located in the GH2-Z gene 5&#8242; flanking region, may be a causal mutation affecting milk fat content. These findings might contribute to the knowledge of the sheep GH locus and might be useful in selection processes in sheep

The Effect of cold acidified milk replacer on productive performance of suckling kids reared in an extensive farming system

This study was conducted, in an extensive farm, to assess the effects of artificial feeding with an acidified milk replacer on productive performance of goat kids. Thirty-two Sarda kids, randomly divided into two feeding groups of 16 kids, (NM, naturally milk fed by their dams, and AR, artificially bottle-fed with an acidified milk replacer) were weighed at weekly intervals until slaughtering, at 42 days of age. A blood sample was collected from each goat kid before slaughter for the assessment of the metabolic status. Post-mortem data were registered: carcass characteristics; percentages of commercial cuts; muscle, separable fat and bone + tendons percentage. Results were analysed by a General Linear Model procedure. The two feeding groups showed similar live weights, except for the period between 7 and 21 days of age. As regards slaughter data, AR kids had a reduced fat deposition and carcasses with shorter diameters and a longer leg. Measurements after dissection showed that the muscle/fat ratio was more favourable in AR kids. Although there were some differences between the groups, haematochemical parameters of both NM and AR were in the range reported for goat kids. On the basis of the results of this trial, artificial feeding with an acidified milk replacer can provide carcasses similar to those obtained with natural milk feeding and can be used both for goat kid meat production and eradication schemes of diseases transmitted by milk-feeding

Effect of polymorphisms at the casein gene cluster on milk renneting properties of the Sarda goat

This study investigated the influence of casein genes polymorphism on renneting properties of milk from Sarda goats. Milk yield and composition, and renneting properties (rennet coagulation time RCT, firming time k20 and curd firmness a30) were evaluated in 200 multiparous goats from three farms, at monthly intervals from March to July. Animals were genotyped at CSN1S1, CSN2, CSN1S2 and CSN3. Statistical analysis was performed by a repeated measures General Linear Model. CSN1S1 significantly affected milk traits with a lower fat content registered for goats carrying the F allele. The highest protein concentration was recorded for the CSN1S1 AB goats. Milk from CSN1S1 FF homozygote goats was characterized by a delayed k20 and the CSN1S1 AB showed a higher a30. All the parameters were influenced by the CSN2 locus, except milk yield. Polymorphism at CSN1S2 influenced only daily milk yield and a30. The CSN1S2 0 null allele was detected for the first time in this breed. The influence of genotype effect was particularly marked for CSN3; RCT and k20 were delayed in CSN3 BB goats and the highest level of a30, 47.88 mm registered for CSN3 AA goats, could be considered remarkable when compared to other goat breeds or populations. In conclusion, this study improved knowledge on the effects of goat casein genes on milk renneting parameters, and could be useful in the future planning of breeding programs and specific dairy products linked to the Sarda breed (PDO/PGI)

Polymorphism of caprine <i>SLC11A1</i> gene and relationships with hygienic characteristics of milk

The solute carrier family 11 member A1 (SLC11A1) gene is associated with resistance to infectious diseases. Genetic variability at the 3’ untranslated region (3’-UTR) of this gene is due to the presence of a polymorphic microsatellites that contain a (GT) n dinucleotide repeat. The microsatellite variability and relationships with milk yield and composition, somatic cell count (SCC) and total microbic count (TMC) were investigated in 260 goats of Sarda breed. Genotyping of the upstream guanine-thymine repeat (GT)n revealed twenty different genotypes and eight alleles (GT11, GT12, GT14, GT15, GT16, GT17, GT18 and GT19). The present study confirmed the high genetic variability of the Sarda goat and that the genotype of the microsatellite at 3’-UTR SLC11A1 affected many chemical and hygienic characteristics of milk as fat, protein and SCC