Traceability of pasture feeding using some fatty acids and spectrophotometric parameters in milk

Seventy-three cow milk individual samples deriving from seven farms with different feeding system (pasture, P vs. stall, S), were collected with the aim to trace pasture feeding from different milk characteristics. Samples were analyzed for: linoleic and linolenic acids, colour parameters (L*, b*, a* C and H) using a Minolta CM-2002 spectrophotometer; the integral value of reflectance spectrum between 530 and 450 nm was also calculated. The linoleic/linolenic acids ratio resulted significantly lower in P group (P<0.001), whereas yellowness (b*) and the absolute integral value resulted significantly higher in P group (P<0.001). Linoleic/linolenic acids ratio allowed the complete discrimination between feeding groups, whereas the integral value and yellowness allowed only a partial discrimination (respectively 90.4% and 79.5% of cases). However, a milk fatty acid composition is strongly dependent on fat intake, any additional fat inclusion in the ration can modify it, apart from pasture presence in the diet. On the contrary integral value and yellowness are strongly related to carotenoids pigments, recognized as biomarkers of fresh herbage in the diet. For these reasons, integrating linoleic/linolenic ratio and colour parameters in a principal components analysis, a complete discrimination between pasture and stall feeding was obtained, with a greater reliability of results due to the combination of milk characteristics associated to different sources of variation (fats intake and carotenoids intake)

The role of polymorphism at αs1-casein locus on milk fatty acid composition in Girgentana goat

Sixteen lactating Girgentana goats were used to evaluate the effect of polymorphism at αs1-casein locus on milk fatty acids composition. Animals, homogeneous for milk production, days of lactation and body weight, were divided into two groups: eight homozygous for strong allele (AA group) and eight homozygous for weak allele (FF group). The experimental diet, identical for the two groups, consisted of alfalfa hay (1.5 kg), whole barley, whole maize, pelleted sunflower and whole faba bean (0.5 kg each). In spite of identical selected diets, also in terms of fatty acids, milk fatty acid composition resulted different between the two groups. In particular, except for C8:0, short and medium chain fatty acids and odd chain fatty acids resulted in higher percentage in the AA group. Taking in account that the difference reported in our experiment concerns above all de novo synthesized fatty acids, our results seem to confirm the hypothesis that polymorphism at αs1-casein locus can influence milk fatty acid composition in goats

Effect of the αs1-casein genotype and its interaction with diet degradability on milk production, milk quality, metabolic and endocrinal response of Girgentana goats

We studied interaction between diet degradability and genotype at CSN1S1 locus in lactating goats.•We evaluated productive, metabolic and hormonal response of goats at different αs1-casein genotype.•Little effect of diet degradability and interaction with genotype on production and quality.•Higher milk yield, casein percentage and lower urea in goats with strong alleles at CSN1S1 locus.•Higher tyroid hormones in goats with strong alleles

Effect of morning vs. afternoon grazing on intramuscular fatty acid composition in lamb

The aim of this study was to assess whether different grazing management affect animal performance and meat fatty acid composition. Thirty-five lambs were divided into three groups: 12 lambs grazed from 9 am to 5 pm (8h group); 11 lambs grazed from 9 am to 1 pm (4hAM group) and 12 lambs grazed from 1 pm to 5 pm (4hPM group). The trial was conducted over 72 days. The 8h lambs had greater DMI (P < 0.0005) and final body weight (P < 0.05) than the 4hPM and 4hAM lambs while carcass weight was not different between the three groups. The meat of the 4hPM lambs contained greater (P < 0.05) percentages of polyunsaturated fatty acids, C18:2 cis-9 trans-11 and lower saturated fatty acids and C18:0 than the meat of the 8h and 4hAM lambs. It is concluded that allowing lambs to graze during the afternoon rather than during 8 h does not compromise the carcass yield and results in a healthier meat fatty acid profile. Summary This paper was written in the framework of the LowInputBreeds project: “Development of integrated livestock breeding and management strategies to improve animal health, product quality and performance in European organic and ‘low input’ milk, meat and egg production”. The LowInputBreeds project unites 21 partners from Europe and further afield and will develop integrated breeding and management strategies to tackle the issue of improved animal health and food quality. It will run until 2014 and is co-funded by the European Union’s Seventh Framework Programme for Research and Technological Development