**Effect of Rumen-Inert Fat Enriched with High Levels of Poly-Unsaturated Fatty Acids on the Productive and Reproductive Response in Ruminants**

Alejandro Salvador, Rolando Hernandez, Thais Diaz and Ricardo Betancourt

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/50879

## **1. Introduction**

86 Milk Production – An Up-to-Date Overview of Animal Nutrition, Management and Health

*Journal of Nutrition*, Vol. 125, No. 12, pp. 3049-3054, ISSN 0022-3166

Zeisel, S. H.; Mar, M., Zhou, Z. & Da Costa, K. A. (1995). Pregnancy and lactation are associated with diminished concentrations of choline and its metabolites in rat liver.

> The chapter will discuss the effect of rumen-inert fat enriched with high levels of polyunsaturated fatty acids (PUFA) on the productive and reproductive responses in ruminants. The discussion will include characteristics of the milk and its derivatives such as goat cheese. The expertise presented in the chapter will cover the authors' experience about the interrelationship between nutrition and reproduction in ruminants from the College of Veterinary Sciences at the Central University of Venezuela.

> The success of milk and meat production systems with ruminants depends largely on an efficient reproductive performance of the herd. Thus, numerous researchers have tried to identify the different factors affecting the productive and reproductive behavior of these herds, being the nutritional component one of the factors that has the highest impact on tropical livestock. Marked shortcomings of forage quality and quantity generate undernourished animals, originating low production parameters in our livestock, far below the desired levels. In countries located in the tropical region of the world the reproductive efficiency in beef and dairy cattle is low, no more than 40-45% (Diaz, 2009). In addition, the pregnancy rate in first calf cows is around 30%, post-partum anestrous period for cattle ranges from 150 to 210 days (Montaño and Ruiz, 2005) and early embryonic mortality in lactating dairy cows, is around 30% (Bach, 2003).

> Furthermore, during the early postpartum period the lactating cow (dairy, beef and dual purpose cows), as well as the dairy goats, show a gap between the consumption and the amount of energy needed, especially during the time of maximum requirements, when the cow and the goat do not meet their nutritional requirements, which leads to the massive

© 2012 Salvador et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2012 Salvador et al., licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

mobilization of its body reserves, particularly energy, generating a state known as the Negative Energy Balance (NEB), which can cause deleterious effects on milk production, health and reproductive performance.

A practical way to control this NEB is through the increase of the food consumption by animals and/or the increase of the energy density of the diet. Thus, various food technologies have been developed for this purpose: energy banks, the use of strategic crops such as sugar cane, liquid diets with high levels of energy, multi-nutritional blocks and energy supplementation with rumen-inert fat. Increasing the fat content of the ration is a way to decrease the NEB, because of fats have double the energy than sugars. However, there are limitations on their use, particularly if the fat is not a rumen-inert fat.

If rumen-inert fat is used to feed ruminants, some undesirable effects of active fats at ruminal level, would be avoided, and higher amount of fat could be used.

On the other hand, if the fat is rich in polyunsaturated faty acids (PUFA; linoleic, linolenic, docosahexanoic [DHA], or eicosapentaenoic acid [EPA]), the rumen-inert fat enriched not only supplies energy, but allows the incorporation of the beneficial effects that these fatty acids have on the animal body and in the productive and reproductive response, therefore having a nutraceutical effect, i.e., producing meat and milk with high levels of these fatty acids, which may have a beneficial effect on human health.
