**6. Final considerations**

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

(1994), González and Bas (2002) and Sanz Sampelayo *et al*. (2002a).

production decreased.

during lactation.

no differences (P > 0.05) in terms of consumption of hay of Bermuda grass (*Cynodon dactylon*) offered ad libitum between groups (0.85 ± 0.02 kg and 0.83 ± 0.02 kg for treatment and control group respectively). These results are consistent with those reported by Teh *et al*.

Figure 4 shows that there was a significant effect (P < 0.05) of days in milk on the consumption of hay, showing that hay consumption increased immediately after the peak of lactation and decreased as the milk production reduces, coinciding with results reported by Jimeno *et al*. (2003) who pointes out that the lowest level of consumption is just one week before calving. On the other hand, the voluntary consumption increased after calving up to the maximum consumption between 6 to 10 weeks; However, it was not linear increase. Then, subsequent to the peak of milk the consumption declined linearly as the milk

**Figure 4.** Effect of rumen-inert fat on the voluntary consumption of hay in crossbreed Canarian goats

Supplementation with rumen-inert fat enriched with high levels of PUFA, should start enough time before parturition, to promote energy reserves of the animal (to improve body condition score) and to maintain body condition during the early postpartum period, in order to reduce the negative effects that has NEB on the production and reproduction in ruminants. Diaz *et al*. (2009) recommend that this type of fat supplementation, should begin between 21-40 days before calving, with doses between 100 and 400 g/cow/day, according to the type of cow (dairy or dual purpose cows). The time that the supplementation will be given varies according to the farm, the basal diet, the level of production, the type of animal, etc., but in general it is recommended to keep it during 90 days postpartum, period in which requirements of the cows are higher because they reach the peak of milk production.

Salvador *et al*. (2009) y Zamora (2010) recommend in dairy goats, that supplementation with this type of fat, would be given during the same way and time but with lower levels (45 and 80 g/goat/d) depending on the weight and the level of production of the goat.

Although the rumen-inert fat is not the solution to all problems of our farms, it is a food resource of great potential, that contains high levels of polyunsaturated fatty acids that allows the incorporation of beneficial effects that essential, fatty acids (ω-6 and ω-3) may have on the reproductive and productive activity of our herds and at the same time generating meat, milk and other derivatives with better nutritional quality.
