Utilization of grape seeds in ruminant nutrition: effects of this by-product on health conditions, milk production and quality, and ruminal metabolism in Sarda dairy sheep

Grape seed is a by-product derived from winery and distillery industries, containing relevant concentrations of polyphenolic compounds. The use of this by-product in ruminant nutrition had not been evaluated yet. The present work studied the effects of dietary inclusion of grape seed, alone or in combination with linseed, as source of PUFA, on immune response, liver and kidney metabolic activity, ruminal metabolism, and milk yield, composition, fatty acid profile and oxidation stability in Sarda dairy sheep. It was demonstrated that grape seed and linseed can be included, alone or in combination, in dairy ewes diet without adverse effects on milk production traits and health status; in addition, an immunomodulatory effect of this residue was evidenced. Grape seed was not effective in reducing PUFA ruminal biohydrogenation; however, it increased the ruminal accumulation of CLA cis-9, trans-11 when used alone, and of vaccenic acid when combined with linseed, manly due to its high content in linoleic acid. Milk quality was improved, in term of FA composition, by the inclusion of grape seed and linseed, especially when used in combination. Moreover, dietary grape seed improved oxidative stability of milk, by reducing the accumulation and formation of lipid hydroperoxides and volatile secondary lipid oxidation products, i.e., hexanal and benzaldehyde, after light exposure. In conclusion, the inclusion of grape seeds in the diet of dairy ewes is an alternative use of this by-product

Use of multivariate factor analysis to characterize the fatty acid profile of buffalo milk

The suitability of multivariate factor analysis (MFA) to extract a small number of latent variables able to explain the correlation pattern among fatty acids (FA) in buffalo milk was evaluated. FA profile of milk samples from 214 Italian water buffaloes was analysed by gas chromatography. MFA, performed on the correlation matrix of 52 FA, was able to extract 10 latent factors with specific biological meaning related to a common metabolic origin for FA associated with the same factor. Scores of the factors were treated as new quantitative phenotypes to evaluate the effect of age, month of calving and lactation stage. MFA approach was effective in describing the FA profile of buffalo milk by using a low number of new latent variables that clustered FA having similar metabolic origin and function. The new variables were also useful to test the effect of environmental and individual animal factors on milk FA composition

Prediction of Milk Coagulation Properties and Individual Cheese Yield in Sheep Using Partial Least Squares Regression

The objectives of this study were (i) the prediction of sheep milk coagulation properties (MCP) and individual laboratory cheese yield (ILCY) from mid-infrared (MIR) spectra by using partial least squares (PLS) regression, and (ii) the comparison of different data pre-treatments on prediction accuracy. Individual milk samples of 970 Sarda breed ewes were analyzed for rennet coagulation time (RCT), curd-firming time (k20), and curd firmness (a30) using the Formagraph instrument; ILCY was measured by micro-manufacturing assays. An Furier-transform Infrared (FTIR) milk-analyzer was used for the estimation of the milk gross composition and the recording of MIR spectrum. The dataset (n = 859, after the exclusion of 111 noncoagulating samples) was divided into two sub-datasets: the data of 700 ewes were used to estimate prediction model parameters, and the data of 159 ewes were used to validate the model. Four prediction scenarios were compared in the validation, differing for the use of whole or reduced MIR spectrum and the use of raw or corrected data (locally weighted scatterplot smoothing). PLS prediction statistics were moderate. The use of the reduced MIR spectrum yielded the best results for the considered traits, whereas the data correction improved the prediction ability only when the whole MIR spectrum was used. In conclusion, PLS achieves good accuracy of prediction, in particular for ILCY and RCT, and it may enable increasing the number of traits to be included in breeding programs for dairy sheep without additional costs and logistics

The milk fingerprint of Sardinian dairy sheep: quality and yield of milk used for Pecorino Romano P.D.O. cheese production on population-based 5-year survey

The Pecorino Romano P.D.O. is the main sheep cheese produced in Italy and the first one among the sheep cheeses, in terms of quality and value, exported from the European Union. About half of the sheep milk produced in Italy is processed into this type of cheese by 36 dairies belonging to the Pecorino Romano Consortium. Eight million records of biweekly analyses of milk collected within a 5-year period from farms delivering their milk to the aforementioned consortium were analysed in this work. Monthly evolution curves were plotted for fat, protein, lactose, pH, NaCl, SCC, bacterial load and principal fatty acids (FAs). Due to the seasonal production systems of Sardinian sheep, monthly evolution of milk fat and protein contents and cheese yield are directly linked to the lactation curve pattern and the pastures quantity and quality. Also, the FA profile of milk is affected by grass availability and quality in both early and mid-lactation, whereas it is influenced by the energy balance of ewes in late lactation. Cheese yield equation was computed based on fat and protein contents and considering the variability among dairies in technological processes used in transforming Sarda sheep milk to Pecorino Romano P.D.O. These data could be a relevant basis to set-up future grids of milk payments based on quality standards. Moreover, they could be useful to formulate administrative policies on the dairy sector with the prospective to improve milk quality of Sardinian sheep destined to the Pecorino Romano production.Highlights The yield of Pecorino Romano P.D.O. (PR) is linked to fat and protein content of milk and it depends on the industrial processes adopted by each dairy Monthly variation of milk composition is of high interest for the PR producers to program the output of their milk-processing plans The content and monthly evolutions of principal fatty acids are important to determine the nutritional and technological properties of P

Genetic parameters of milk fatty acid profile in sheep: comparison between gas chromatographic measurements and Fourier-transform IR spectroscopy predictions.

Fatty acid (FA) composition is a key component of sheep milk nutritional quality. However, breeding for FA composition in dairy sheep is hampered by the logistic and phenotyping costs. This study was aimed at estimating genetic parameters for sheep milk FA and to test the feasibility of their routine measurement by using Fourier-transform IR (FTIR) spectroscopy. Milk FA composition of 989 Sarda ewes farmed in 48 flocks was measured by gas chromatography (FA GC ). Moreover, FTIR spectrum was collected for each sample, and it was used to predict FA composition (FA FTIR ) by partial least squares regression: 700 ewes were used for estimating model parameters, whereas the remaining 289 animals were used to validate the model. One hundred replicates were performed by randomly assigning animals to estimation and validation data set, respectively. Variance components for both measured and predicted traits were estimated with an animal model that included the fixed effects of parity, days in milking interval, lambing month, province, altitude of flock location, the random effects of flock-test-date and animal genetic additive. Genetic correlations among FA GC , and between corresponding FA GC and FA FTIR were estimated by bivariate analysis. Coefficients of determination between FA GC and FA FTIR ranged from moderate (about 0.50 for odd- and branched-chain FA) to high (about 0.90 for de novo FA) values. Low-to-moderate heritabilities were observed for individual FA (ranging from 0.01 to 0.47). The largest value was observed for GC measured C16:0. Low–to-moderate heritabilities were estimated for FA groups. In most of cases, heritabilites were slightly larger for FA GC than FA FTIR . Estimates of genetic correlations among FA GC showed a large variability in magnitude and sign. The genetic correlation between FA FTIR and FA GC was higher than 60% for all investigated traits. Results of the present study confirm the existence of genetic variability of the FA composition in sheep and suggest the feasibility of using FA FTIR as proxies for these traits in large scale breeding programs

Prenatal exposure to different diets influences programming of glucose and insulin metabolism in dairy ewes.

ABSTRACT Nutrition in fetal and postnatal life can influence the development of several biological systems, with permanent effects in adult life. The aim of this work was to investigate in dairy sheep whether diets rich in starch or fiber during intrauterine life (75 d before lambing) and postnatal life (from weaning to first pregnancy; growth phase) program glucose and insulin metabolism in the female offspring during their first pregnancy. Starting from intrauterine life, 20 nulliparous Sarda ewes were exposed to 4 dietary regimens (n = 5 per group) based on different dietary carbohydrates during their intrauterine life and their subsequent growth phase: (1) the fiber (FI) diet during both intrauterine and growth life, (2) the starch (ST) diet during both intrauterine and growth life, (3) the FI diet in intrauterine life followed by the ST diet in the growth phase, and (4) the ST diet in intrauterine life followed by the FI diet in the growth phase. After the end of the growth phase, all growing ewes were fed the same diet and naturally mated. When ewes were pregnant, on average at 124 ± 2 d of gestation they were challenged with an intravenous glucose tolerance test, and peripheral concentrations of glucose and insulin were determined. Basal insulin concentrations were higher in ewes exposed to the ST diet (0.97 μg/L) than in ewes exposed to the FI diet (0.52 μg/L) in intrauterine life. After glucose infusion, glucose and insulin concentrations were not affected by intrauterine diet. Insulin resistance, determined by the homeostasis model assessment, was affected by the intrauterine × growth phases interaction. Insulin sensitivity, assessed by the quantitative insulin check index, was lower in ewes exposed to the ST diet than in those exposed to the FI diet in intrauterine life (ST = 0.28; FI = 0.30). Diet in growth life had no effect on glucose and insulin metabolism. In conclusion, starchy diets offered during intrauterine life but not during postnatal life increased basal insulin level and lowered insulin sensitivity during the first pregnancy. Nutritional strategies of metabolic programming should consider that exposure to starchy diets in late fetal life might favor the programming of dietary nutrient partitioning toward organs with high requirements, such as the gravid uterus or the mammary gland

ProYoungStock: un progetto per promuovere il legame naturale tra vacca e vitello

This web article informs ruminant farmers and ruminant enthusiasts about the ProYoungStock project, with a brief insight into the main objectives and activities

Grape, Pomegranate, Olive, and Tomato By-Products Fed to Dairy Ruminants Improve Milk Fatty Acid Profile without Depressing Milk Production

The continuous increase in the cost of feeds and the need to improve the sustainability of animal production require the identification of alternative feeds, such as those derived from the agro-industrial sector, that can be effectively used for animal nutrition. Since these by-products (BP) are sources of bioactive substances, especially polyphenols, they may play an important role as a new resource for improving the nutritional value of animal-derived products, being effective in the modulation of the biohydrogenation process in the rumen, and, hence, in the composition of milk fatty acids (FA). The main objective of this work was to evaluate if the inclusion of BP in the diets of dairy ruminants, as a partial replacement of concentrates, could improve the nutritional quality of dairy products without having negative effects on animal production traits. To meet this goal, we summarized the effects of widespread agro-industrial by-products such as grape pomace or grape marc, pomegranate, olive cake, and tomato pomace on milk production, milk composition, and FA profile in dairy cows, sheep, and goats. The results evidenced that substitution of part of the ratio ingredients, mainly concentrates, in general, does not affect milk production and its main components, but at the highest tested doses, it can depress the yield within the range of 10–12%. However, the general positive effect on milk FA profile was evident by using almost all BP at different tested doses. The inclusion of these BP in the ration, from 5% up to 40% of dry matter (DM), did not depress milk yield, fat, or protein production, demonstrating positive features in terms of both economic and environmental sustainability and the reduction of human–animal competition for food. The general improvement of the nutritional quality of milk fat related to the inclusion of these BP in dairy ruminant diets is an important advantage for the commercial promotion of dairy products resulting from the recycling of agro-industrial by-products