Effect of weather conditions on somatic cell score in Sicilian Valle del Belice ewes

Mastitis susceptibility of Valle del Belice ewes from the south of Sicily to temperature, humidity, precipitation, solar radiation, sun hours, air pressure, wind-speed and wind-direction measured by a public weather station was investigated using 65,848 test-day somatic cell score (SCS) records of 5,237 ewes. All weather parameters had an effect on SCS in a regression approach. Extreme values of maximum and minimum temperaturehumidity indices resulted in increased SCS. Higher precipitation, solar radiation and sun hours resulted in increased SCS, whereas higher air pressure and wind speed resulted in reduced SCS

Beta-lactoglobulin polymorphism in Girgentana goat breed

Beta-lactoglobulin (b-lg) is a globular protein belonging to the lipocalin family. It is the major whey protein in the milk of ruminants. It is also present in the milk of most mammals but is lacking in rodents, lagomorphs and humans. A large number of variants have been reported for cow and sheep milk. Several studies have shown association between b-lg variants and milk production and composition, even if the results are not always concordant. In goat, no b-lg variants related with amino acid change have been characterized at DNA level, but some authors described the presence of polymorphisms in the 3’UTR and in the proximal promoter region. Mutations in the promoter region could be those most likely responsible for different level of gene expression. The aim of this work was to study the genetic polymorphism at DNA level of b-lg gene in Girgentana goat breed. A total of 238 genomic DNA samples of Girgentana breed were genotyped. A fragment of 709 bp, including 588 bp of proximal promoter region and 121 bp of exon 1, was amplified using primers GOAPF3 and GoatE1R2. PCR-RFLP procedure was used for fast detection of two single nucleotide substitutions as described by Graziano et al. (2003). The base substitutions originating the polymorphic sites consist of: 1. a transition T›C at position -341 and 2. a transition C›T at position -60. A FspBI PCR-RFLP protocol was used to detect the mutation -341 (T/C) and a SmaI PCR-RFLP protocol for the mutation -60 (C/T) of the proximal promoter region. The allelic frequencies and the Hardy-Weinberg equilibrium were estimated using the GENEPOP software. Girgentana goat breed shows no significant deviation from Hardy- Weinberg equilibrium for the allele frequencies found in both polymorphic sites considered. The genotypic frequencies for both mutations resulted in 0.65 (T/T), 0.33 (T/C) and 0.02 (C/C) for the position -341, and 0.82 (C/C), 0.17 (C/T) and 0.01 (T/T) for the position -60. These results are in agreement with the previous obtained by Graziano et al. (2003) in the same breed. Further analysis are in progress to investigate the possible effect of these variants on the expression of b-lg gene, on the milk protein composition and on milk production traits

Feed efficiency of Italian Holstein dairy heifers in the genomic era – preliminary results

Genetic selection of dairy cattle has classically been based on fertility and productivity (kilograms of milk, protein, fat). In recent years a growing interest in characters related to health and efficiency of the animals has taken hold. The selection of animals with a high feed efficiency can bring benefits in terms of health, productivity and environmental impact. A first batch of 16 Holstein heifers (mean age 12.63 ± 2.90 months) was selected and housed in a tie-stall of the Centro Zootecnico Didattico Sperimentale (CZDS) of Lodi for the whole length of the trial (35 days). Blood samples were collected and sent to the lab to perform genotyping of the animals. Heifers were fed a composed ration of sorghum silage and total mixed ration, delivered daily on individual feeders to ensure each animal continuous access to the feed. Animals had free access to the water. Feed intake was obtained weighing the supplied ration and the residual the day after. Individual body weight (BW), body condition score (BCS), hearth girth (HG) and height at the wither (W) were measured weekly. Feed Conversion Ratio (FCR) and Residual Feed Intake (RFI) were calculated using Dry Matter Intake (DMI) data. Fecal samples were collected weekly to assess any relation between feed efficiency and acidic profile of the feces. Preliminary results show an average daily gain of  941 ± 206 grams, an increase of mean BW from 374.63 ± 17.06 (day 0) to 407.56 ± 17.06 kilograms (day 34), an increase of mean BCS from 3.97 ± 0.11 (day 0) to 4.19 ± 0.11 (day 34), an increase of mean HG from 169.25 ± 2.83 (day 0) to 177.41 ± 2.83 centimeters (day 34), an increase of mean W from 127.28 ± 1.23 (day 0) to 132.69 ± 1.23 centimeters (day 34)

Demographic characterization and genetic variability of the Girgentana goat breed by the analysis of genealogical data

The aim of this paper is to present an overview of the actual Sicilian Girgentana population structure by the analysis ofgenealogical data. Statistics show that in 1983 the population consisted of 30,000 Girgentana goats; ten years lateralmost 98% of the entire Girgentana population disappeared. The remaining population consists of 461 individuals (134males and 327 females), with 368 living animals. The effective population size is 380 individuals. The inbreeding rate pergeneration was equal to 0.13%. The average estimated inbreeding level within the living male population was equal to0.8% (0-15%); and the average inbreeding level within the living female population was equal to 0.7% (0-31%). Theaverage relationship between males and females estimated on 27,772 possible matings was equal to 0.5% (0-8.7%).The estimated inbreeding level was not high due to the lack of pedigree information. This is resulting in a ratio betweenthe number of founder equivalents (ƒe = 22,94) and the number of absolute founders (ƒa = 93) equal to 25%

Validation of genomic breeding values for feed efficiency using field data: experience from UNIBO experimental herd

A strategy to maximize genetic gain in dairy farming is to identify genetically elite females through genomic testing. Indeed, direct genomic values (DGV) are early accessible at a cost-effective also in young stock and are subsequently blended to estimated breeding values (GEBV) once prediction of genetic merit is undertaken when phenotypes are available. These criteria can be used by farmers to rank females and service the best ones with (sexsorted) semen of elite bulls to achieve greater gain while simultaneously reducing the number of non-productive animals. Feed efficiency is nowadays the most popular issue for animal scientists working with ruminants. The purpose of the current research was to validate feed efficiency breeding values using real dry matter intake (DMI) data. For this purpose, we quantified the association between DGV/GEBV of predicted feed efficiency (PFE) and on-field feed intake data. Up to date, the total number of genotyped subjects at the UNIBO experimental herd is 279. Cows are routinely enrolled into experimental nutritional trials in which individual DMI (kg/d) information are collected on a daily basis. DGV/GEBV for PFE are calculated by ANAFIBJ within the national genetic and genomic evaluation; proofs are standardized to a mean of 100 and standard deviation of 5. Data were analysed with a linear mixed model, separately for primiparae and pluriparae, by adjusting the dependant variable DMI for the fixed effects of daily milk yield (linear covariate), PFE DGV/GEBV (two classes: <100 or ≥100), and days-post-calving (<120 or ≥120); random terms were cow nested within experimental trial and contemporary group (experimental trial-test date). Mean PFE was 99.50 (±1.48) while daily individual DMI averaged 23.48 (±3.44) and 26.91 (±3.14) kg/d for primiparae and pluriparae, respectively. The Pearson’s correlation coefficient between PFE and feed intake was −0.14, suggesting that cows with higher genetic merit have lower DMI. Differences between least squares means of the two PFE levels were −0.23 (±1.10; p > 0.05) and −0.26 (±0.75; p > 0.05) kg DMI/d in first- and later-parity cows, respectively. Although not significantly different, estimates indicated that, irrespective of systematic effects, cows with higher genetic merit for PFE have a lower individual daily intake compared to those with a lower genetic merit. Future efforts should be pursued to augment the sample size in order to increase the robustness of these estimates

Study of fertility traits in Italian Jersey Cattle

Selection Index of Italian Jersey cattle is composed by breeding values (BVs) of production traits, type traits and somatic cell score. Knowing selection for milk yield has been proved to deteriorate fertility performances, aim of the Italian Holstein, Brown and Jersey Breeders Association (ANAFIBJ) is to develop a fertility index inspired to the model they use for Italian Holstein breed. The model used considers different phenotypes for heifer and cow evaluation, but while for Holstein only the first three parities are considered, for Jersey all parities are considered to overcome the lower size of the population. Starting from two different datasets, containing data on inseminations and lactations we derived several fertility traits. From the inseminations dataset we harvested information on the dates of services, which we grouped in baches of a maximum length of 300 days. The groups of inseminations have then been attached to the calvings happened in an interval of 260–300 days from at least one of the services in the group. Phenotypes estimated for both heifers and cows are Non-Return Rate at 56 days (NRR56) and Interval from First to Last service (IFL); Age at First Insemination (AFI) has been computed only for heifers, while Days from delivery To First Service (DTFS) and Equivalent Milk Yield 305 (EMY305) only for cows. The values of the phenotypes have been filtered to be in line with biological and economic criteria of cattle farming. The final dataset is composed of 35081 records for heifers and 100285 records for cows. Correlations and Co-Variances between the phenotypes have been calculated. For Heifers we observe a slight positive correlation between AFI and NRR56 (ρxy = −0.061) and a negative correlation between NRR56 and IFL (ρxy = −0.349); IFL and AFI are negatively correlated (ρxy = −0.048). For cow fertility traits NRR56 resulted to be positively correlated with DTFS (ρxy = 0.088) and negatively correlated with EMY305 (ρxy = −0.092) and IFL (ρxy = −0.293); DTFS resulted negatively correlated to IFL (ρxy = −0.015) and EMY305 (ρxy = −0.045), while IFL and EMY305 resulted positively correlated (ρxy = 0.083). The next step is to calculate genetic parameters and EBVs for fertility traits for Italian Jersey

The hairless (hr) gene is involved in the congenital hypotrichosis of Valle del Belice sheep

Congenital hypotrichosis in mammalian species consists of partial or complete absence of hair at birth. The hairless gene is often responsible for this disorder in men, mice and rats. Recent experimental data on Valle del Belice sheep reared in Sicily for milk production, support the genetic control of the ovine hypotrichosis as a Mendelian recessive trait. The ovine hairless gene was chosen as the candidate gene involved in this disorder. Blood samples were collected from Valle del Belice sheep with the normal and hypotrichotic phenotypes. Almost the entire hairless gene was successfully amplified using the long PCR technique. Unrelated sheep with differing phenotypes were randomly chosen for sequencing the amplified products. Different mutations related to the hypotrichotic phenotype were found in exon 3. In fact, sequencing revealed an A/T transversion at position 739, a G/A transition at position 823, and a C/T transition at position 1312. From these nucleotide exchanges, three substitutions of the processed mature protein were deduced at the amino acid positions 247 (Thr/Ser), 275 (Ala/Thr), and 438 (Gln/Stop). A PCR-SSCP based test was developed in order to detect the last mutation, which is responsible for the hypotrichotic phenotype

Chromosomal assignment of the ovine hairless (hr) gene by fluorescence in situ hybridization.

Congenital hypotrichosis in mammalian species consists of partial or complete absence of a hair coat at birth. Affected individuals having a partial hair coat at birth may loose it subsequently.The aim of this paper was to physically map the ovine hr gene using fluorescence in situ hybridization (FISH).A preliminary study on an internet data bank (http://www.informatics.jax.org) showed that the regions of the hr gene on murine chromosome 14 and human chromosome 8 present homology with ovine chromosome 2

Phenotypic analysis of milk composition, milk urea nitrogen and somatic cell score of Italian Jersey cattle breed

The present study aimed to assess the phenotypic variation of milk yield (MY) and quality traits in Italian Jersey (IJ) breed. Sources of variation were investigated through a linear mixed model, including the fixed effects of days in milk (DIM), parity, calving season, milking frequency, recording type, the interaction between DIM and parity, and the random effects of herd-test-day (HTD), cow and the residual. Results highlighted the high contents of milk fat (5.18%), protein (4.08%) and casein (3.16%) of IJ cows. Somatic cell score, averaging 3.35 units, should be lowered through specific managerial actions. Phenotypic variances of MY and milk quality traits were mainly due to cow effect, whereas phenotypic variance of milk urea nitrogen (MUN) content was mainly due to HTD effect, meaning that managerial conditions, especially feeding, are very important to explain the variation of MUN. In conclusion, the present study allowed to characterise milk of IJ cows at population level and to identify environmental factors associated with variation of MY and quality traits, which will be useful to adjust phenotypic records in genetic evaluation of Jersey breed.Highlights Factors affecting milk quality traits of Italian Jersey cows have been investigated. Phenotypic variance of milk composition and SCS was mainly due to cow effect, and that of MUN was mainly driven by herd-test-day effect. Significant environmental factors identified in the present study will be used to adjust phenotypic records in genetic analysis