A Comparative Study of Simple Regression Models to Estimate Fibre Length Growth in Chios Sheep from Common Meteorological Variables

Chios sheep is a promising sheep breed, with wool, one of its products, to be of special interest to genetic improvement programs. Recently, it has been reported significant linear correlation between the fibre length growth (FLG) of Chios sheep, an important component of its wool quality, and each of the meteorological variables air temperature (T) and sunshine (SUNS), but nothing is known about the prediction of FLG from T and SUNS. Thus, this work aims to investigate the effectiveness of five simple regression models (linear, quadratic, cubic, logarithmic and inverse), concerning the aforementioned prediction, using visual examination and two widely accepted statistical measures, the adjusted coefficient of determination (R2adj) and the root mean square error (RMSE). Results showed that the applied nonlinear regression models were characterized by higher R2adj and lower RMSE in comparison to the linear one, irrespective of input variable. The inverse model presented the greatest effectiveness to predict FLG from T and SUNS, separately (maximum R2adj and minimum RMSE), followed by the logarithmic and the linear ones, under visual examination and applied statistical measures. Air temperature was superior to SUNS in all cases (higher R2adj and lower RMSE), when comparing the regression models of the same type to check their effectiveness for predicting FLG. The findings of our study could be a decisive step towards a better exploitation of the examined meteorological variables for the sustainable production of Chios sheep.

ACAA2 and FASN polymorphisms affect the fatty acid profile of Chios sheep milk

The objective of the research reported in this research communication was the identification and association of single nucleotide polymorphisms (SNP) in the ovine DGAT1, FASN, SCD1 and ACAA2 genes with milk fat percentage and fatty acid (FA) content. Three consecutive monthly milk samplings were obtained from a total of 429 purebred Chios ewes during mid-lactation. Genotypic data were jointly analyzed with 1184 fat content and 37 718 FA percentage records using mixed models. The 3′ untranslated region (UTR) of the DGAT1 gene and the 5′ and 3′UTRs of the SCD1 gene appeared to be monomorphic. The FASN g.14777C>T SNP on exon 31 was associated with C13:0 and the ACAA2 g.2982T>C SNP on the 3′UTR was associated with C9:0, C11:0, C12:1 cis-9, C13:0 and the ω6/ω3 index, while fat percentage was not affected by the identified SNPs. The results could be useful for breeding programs aiming to improve the quality and nutritional value of ovine milk.

Seasonal variation of wool fibre length in Karagouniko and Chios sheep in relation to meteorological factors

Karagouniko and Chios sheep breeds present a lot of advantages on the implementation of sheep farming in Greece, a country with diverse relief resulting in a microclimatic variety, but nothing is known about the impact of season, as the outcome of important meteorological variables, on the fibre length growth (FLG) of the aforementioned breeds. Thus, the effect of season (Winter, Spring, Summer, Autumn) on the FLG of these breeds (by using analysis of variance) was studied in the Artificial Insemination Center of Karditsa (39021΄18΄΄N, 21054΄19΄΄E), Periphery of Thessaly, Greece, combined with a correlation analysis between FLG of each examined sheep breed and each of the studied meteorological variables, air temperature (AIRT), relative humidity (RH), sunshine (SUNS) and rainfall (R) for a two-year period. It was found that the FLG of Karagouniko sheep was significantly higher than the respective growth of Chios sheep, for each examined season, while the descending order of seasonal FLG for both breeds was Winter>Spring>Autumn>Summer. Fibre length growth of Karagouniko and Chios breeds correlated negatively with AIRT and SUNS and positively with RH, implying a better FLG in cooler, more overcast and wetter time periods. Our study adds new knowledge concerning the effect of season, and particularly, the effect of the aforementioned meteorological variables on the wool growth of two considerable sheep breeds in Greece, Karagouniko and Chios, opening up new horizons for their exploitation.

Farm conditions and production methods in Chios sheep flocks

The objective was to describe farm conditions and production methods in intensively reared flocks of Chios sheep in Greece. The total of 66 farms of the Chios sheep Breeders Cooperative "Macedonia" were included in the study that was carried out using a purpose-built questionnaire and farm visits for onsite assessment by an experienced veterinarian. A detailed databasewas constructed using the information obtained from individual farms. Thereafter, four parameters concerning structural and management components were selected (flock size, sheep breeding experience, pasture use and application of three milkings daily) and their effect on milk production was estimated using one-way ANOVA. The results showed that the average flock comprisedof 314 sheep (16 rams, 210 ewes and 88 lamb ewes), whereas flock size was positively correlated to milk production (P<0.05). Inaddition, large flocks had more personnel and practiced three milkings per day (P<0.05). The majority of farms (83.3%) had milking parlours and the average milk yield per ewe was 276.6±55.6. The majority of farmers were relatively young (41.2±8.9years old) with limited experience in sheep production. However, they had a good level of education and showed increased interest in intensification and specialization of production methods. The acreage of private land was generally small (7.6 hectares) and was used mainly for production of feedstuffs; grazing was a secondary objective. In most farms, the feeding management wasinappropriate; overfeeding of concentrates and unbalanced rations was the dominant practice. Preventive measures included vaccinations (100% of farms vaccinated for clostridial diseases) and anthelminthic treatments (at least once a year in all flocks). In conclusion, farm conditions and production methods in studied flocks were considered satisfactory and revealed the potential for further improvements that are discussed here.

Laparoscopie collection and transfer of Chios sheep embryos

The efficiency of two different laparoscopic techniques for embryo collection was examined. Two groups (A and B) of 12 Chios breed ewes were used as donors and 20 crossbred Chios ewes as recipients. Oestrus was synchronised by intravaginal sponges, the donors were supervoulated by 8,8 mg of ovine FSH and laparoscopic intrauterine artificial insemination was conducted with extended fresh ram semen. Embryo collection was carried out the 6th day after AI. The uteri of the animals of group A were flushed after catheterisation of the ipsilateral oviduct. In the animals of group Β a flushing catheter was inserted close to the tip of the horn. Fifty nine and 46 embryos were collected from groups A and Β corresponding to recovery rate of 51.75% and 39% respectively (P>0.05). Laparoscopic transfer of 43 fresh embryos resulted to 11 (55%) pregnancies with (39.5%) surviving fetuses.

Production of transgenic sheep: Microinjection of the bovine P77 gene construct in Chios sheep breed zygotes

The feasibility of integration of the bovine P77 construct into zygotes and two cell embryos of Chios sheep breed was examined. The P77 gene construct comprised bovine as l casein promoter regulatory sequence fused to the fragment between exons 2 and 9 of the bovine chymosin gene. One of the two pronuclei of the zygote or a nucleus of a blastomere of a two cell embryo was microinjected with 1 pi of DNA solution containing approximately 1000 copies of the gene construct. In total 193 zygotes and 87 two cell embryos collected from 49 donor ewes were used. After 1 - 5 h culture microinjected zygotes (n=175) and two cell embryos (n=76) were transferred by a laparoscopic technique to the oviducts of 68 recipients. 22 recipients (32.4%) gave birth to 29 lambs which correspond to 11.6% of the total number of zygotes - embryos transferred. PCR analysis performed in skin samples of these lambs revealed that in one ewe lamb the P77 construct has been integrated in its genome. The growth and puberty of this lamb was physiological and is currently pregnant. This is the first transgenic farm animal born in Greece.

Haematology values and effect of age and reproductive stage on haematological parameters of Chios sheep

The main aim of the present study was to determine the values of the haematological parameters of dairy sheep reared under intensive and semi-intensive conditions, as well as to test for the effects of age and reproductive stage of the animals on the values of these parameters. In total, 200 clinically healthy Chios sheep from 10 farms of Central Macedonia were used in the study. For the determination of the effect of age 150 sheep were assigned in three groups. Group A consisted of 50 lambs aged 3-6 months (meantSD: 4.45±1.22 months), group Β of 50 non-pregnant ewes into lactation aged 1-3 years (meantSD: 2.18±0.74 years) and group C of 50 non-pregnant ewes into lactation aged more than 3 years (meantSD: 5.88±1.87 years). For evaluating the effect of reproductive status 50 pregnant ewes in dry period were used, 15-30 days before the expected day of lambing (group D), along with the 100 non-pregnant ewes into lactation of groups Β and C (group E). Blood sampling was performed once, in dry ewes from December to January, and in lambs and lactating ewes from March to May. The mean values of the determined haematological parameters were within the range provided by the literature, except for red blood cells count of ewes. The results also showed that haematocrit, haemoglobin concentration and red blood cells, white blood cells, neutrophils, lymphocytes, eosinophils and platelets count were significantly affected by the age; only monocytes and eosinophils count by the reproductive stage of the animals.