Validazione di un test rapido per la rilevazione di antibiotici nel latte ovino

The study was designed to achieve evaluation and validation of a rapid screening test in ewe milk. Betastar® Combo 3.0 reveals antibiotics of betalactams and tetracyclines classes. Antibiotics-free milk samples from Sarda ewes, throughout three sampling trials, were commingled with Penicillin, Amoxicillin, Cefazolin and Oxytetracycline. Spiking concentrations were set on the European Union maximum residue limits (MRLs). Betastar® Combo 3.0 has thee lines of detection on the dipstick: the first for betalactams, the second as control line and the third for tetracyclines. Test is negative when the ratio between intensities of test lines and control line is higher than 1.0 while it is positive when it is lower or equal than 1.0. Results were achieved and analysed with a statistical software. A total amount of 180 negative control samples were tested and they were always negative according to antibiotics, trials and ewes. Results for Penicillin showed a satisfactory detection limit from 2 to 3 μg/kg (MRL is 4 μg/kg). As regards Amoxicillin and Oxytetracycline, results were almost always lower than the MRLs (4 and 100 μg/kg, respectively) but in one case out of nine detecting concentration was slightly higher. Detection limit for Cefazolin was higher than its specific MRL (50 μg/kg). In conclusion, Betastar® Combo 3.0 could be a suitable method in order to achieve a rapid detection of some antibiotics residues in ewe milk at farm and industrial levels

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

Goat casein genotypes are associated with milk production traits in the Sarda breed

The aim of the current work was to analyze, in the Sarda breed goat, genetic polymorphism within the casein genes and to assess their influence on milk traits. Genetic variants at the CSN1S1, CSN2, CSN1S2 and CSN3 gene loci were investigated using PCR-based methods, cloning and sequencing. Strong alleles prevailed at the CSN1S1 gene locus and defective alleles also were revealed. Null alleles were evidenced at each calcium-sensitive gene locus. At the CSN3 gene locus, we observed a prevalence of the CSN3 A and B alleles; the occurrence of rare alleles such as CSN3 B&#8243;, C, C', D, E and M; and the CSN3 S allele (GenBank KF644565) described here for the first time in Capra hircus. Statistical analysis showed that all genes, except CSN3, significantly influenced milk traits. The CSN1S1 BB and AB genotypes were associated with the highest percentages of protein (4.41 and 4.40 respectively) and fat (5.26 and 5.34 respectively) (P &lt; 0.001). A relevant finding was that CSN2 and CSN1S2 genotypes affected milk protein content and yield. The polymorphism of the CSN2 gene affected milk protein percentage with the highest values recorded in the CSN2 AA goats (4.35, at P &lt; 0.001). The CSN1S2 AC goats provided the highest fat (51.02 g/day) and protein (41.42 g/day) (P &lt; 0.01) production. This information can be incorporated into selection schemes for the Sarda breed goat

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