Joaquín Angulo

Effects of polyunsaturated fatty acids from plant oils and algae on milk fat yield and composition are associated with mammary lipogenic and SREBF1 gene expression

The main aim of the present study was to examine the effects of long-term supplementing diets with saturated or unprotected polyunsaturated fatty acids from two different plant oils rich in either n-3 or n-6 fatty acids (FAs) plus docosahexaenoic acid (DHA)-rich algae on mammary gene expression and milk fat composition in lactating dairy cows. Gene expression was determined from mammary tissue and milk epithelial cells. Eighteen primiparous German Holstein dairy cows in mid-lactation were randomly assigned into three dietary treatments that consist of silage-based diets supplemented with rumen-stable fractionated palm fat (SAT; 3.1% of the basal diet dry matter, DM), or a mixture of linseed oil (2.7% of the basal diet DM) plus DHA-rich algae (LINA; 0.4% of the basal diet DM) or a mixture of sunflower oil (2.7% of the basal diet DM) plus DHA-rich algae (SUNA; 0.4% of the basal diet DM), for a period of 10 weeks. At the end of the experimental period, the cows were slaughtered and mammary tissues were collected to study the gene expression of lipogenic enzymes. During the last week, the milk yield and composition were determined, and milk was collected for FA measurements and the isolation of milk purified mammary epithelial cells (MECs). Supplementation with plant oils and DHA-rich algae resulted in milk fat depression (MFD; yield and percentage). The secretion of de novo FAs in the milk was reduced, whereas the secretion of trans-10,cis-12-CLA and DHA were increased. These changes in FA secretions were associated in mammary tissue with a joint down-regulation of mammary lipogenic enzyme gene expression (stearoyl-CoA desaturase, SCD1; FA synthase, FASN) and expression of the regulatory element binding transcription factor (SREBF1), whereas no effect was observed on lipoprotein lipase (LPL) and glycerol-3-phosphate acyltransferase 1, mitochondrial (GPAM). A positive relationship between mammary SCD1 and SREBF1 mRNA abundances was observed, suggesting a similar regulation for these genes. Such data on mammary gene expression in lactating cows presenting MFD contribute to strengthen the molecular mechanisms that govern milk fat synthesis in the mammary glands. In purified MEC, the dietary treatments had no effect on gene expressions. Differences between mammary tissue and milk purified MEC gene expression were attributed to the effect of lipid supplements on the number of milk purified MEC and its RNA quality, which are determinant factors for the analysis of gene expression using milk cells.

Dietary fatty acid intervention of lactating cows simultaneously affects lipid profiles of meat and milk.

BACKGROUND The present study investigated tissue-specific responses of muscle and mammary gland to a 10 week intervention of German Holstein cows (n = 18) with three different dietary fat supplements (saturated fat; linseed oil or sunflower oil plus docosahexaenoic acid-rich algae) by analysing fatty acid profiles and quality parameters of meat and milk. RESULTS Plant oil/algae intervention affected neither fat content nor quality parameters of meat but decreased fat content and saturated fatty acid amounts of milk. Linseed oil/algae intervention caused significantly higher concentrations of C18:3n-3 (meat, 1.0 g per 100 g; milk, 1.2 g per 100 g) and C22:6n-3 (meat, 0.3 g per 100 g; milk, 0.14 g per 100 g). Sunflower oil/algae intervention increased n-6 fatty acid contents in milk (4.0 g per 100 g) but not in meat. Elevated amounts of C18:1trans isomers and C18:1trans-11 were found in meat and especially in milk of plant oil/algae-fed cows. C18:1cis-9 amounts were found to be increased in milk but decreased in meat after plant oil/algae intervention. CONCLUSION The present study demonstrated that dietary fatty acid manipulation substantially shifted the fatty acid profiles of milk and to a lesser extent of meat, whereas meat quality traits were not affected. Indications of tissue-specific responses of mammary gland and muscle were identified.

Quantitative and nutritional characterization of fruit and vegetable waste from marketplace: A potential use as bovine feedstuff?

There are different sources for the generation of solid waste, and marketplaces are considered one of them. Fruit and vegetable waste (FV) from a marketplace in Colombia was quantitatively and nutritionally characterized to contribute to its use in bovine feeding and to contribute minimizing its environmental impact. The evaluation was carried out 7 days per week during 4 periods of the year. FV was grouped by cluster analysis using SAS(®) 2006. FV was composed of 43% fruit, 30% vegetables and 27% stems, leaves, leaf wrappers, corncobs, roots, refuse and others. FV was defined in four main groups. On average, FV contained 10% crude protein (CP), 36.6% neutral detergent fiber (NDF), 29.6% acid detergent fiber (ADF), 87.8% ruminal degradability at 24 h, 3657 kcal/kg, 0.59% calcium (Ca(+2)), and 0.21% phosphorous (P). There were no statistical differences between days or between periods of evaluation (p > 0.05) for CP or for Ca(+2). As for NDF and ADF, there were statistically significant differences between periods but not between days. The microbiological parameters only increased when the humidity was up to 12%. FV represents a potential feedstuff for bovine feeding, and its recycling could avoid the discharge of a large amount of waste to landfills, which would minimize its environmental impact.

Nutritional evaluation of fruit and vegetable waste as feedstuff for diets of lactating Holstein cows

Organic waste from markets represents about 10-20% of the total waste of a city. A large proportion comes from the overproduction of fruit and vegetables, turning them into potential pollutant. The nutritional value found for fruit and vegetable waste (FV) from a marketplace, in a previous work, showed that this product might be considered as a potential alternative for animal feeding. This study evaluated the use of FV as feedstuff for diets of lactating Holstein cows with an emphasis on milk yield and quality. FV was included in 0, 6, 8, 12, and 18% of the concentrate. A 4 x 4 Latin squares model was used to analyze data (4 animal groups, 4 periods of evaluation, and 4 treatments). No statistical differences in milk yield per kilogram of eaten concentrate or concentrate intake were recorded between groups fed FV and the control group. There was a significant effect of the treatment on cis-9,trans-11 CLA and α-linolenic acid content in milk. These results showed that FV can be used as a dietary ingredient for high-yield lactating cows without detriment in the milk yield and with improvement in the milk quality. FV could be included at proportions of between 6% and 18% in the concentrate, as long as the animals dietary requirements are covered. The main impact of these results is the alternative generated for the improvement of the environment.

Nutrient Management in Silvopastoral Systems for Economically and Environmentally Sustainable Cattle Production: A Case Study from Colombia

In recent years, livestock production has received negative publicity due to environmental degradation. Critics charge that the expansion of cattle production around the world has destroyed the forest, increased soil erosion, and has contaminated the environment. These negative effects have been caused by poor decisions in the production system. Nevertheless, there are possible solutions. Given ongoing climate change, fears of environmental contamination, and global market competition, silvopastoral systems emerge as a valuable alternative to develop an economic, productive, and environmentally-friendly system for livestock raising in the world. The purpose of this chapter is to give a general description of the silvopastoral systems and to provide a synopsis of the main productive and environmental benefits obtained by using them for dairy and beef cattle production. Most of information in this chapter is inspired by the Colombian experience during the past 20 years.