Effects of dietary sources of vegetable fats on performance of dairy ewes and conjugated linoleic acid (CLA) in milk.

Two experiments were carried out to study the effects of supplementing the ration of lactating ewes with vegetable fats (sunflower oil, SO or hydrogenated palm oil, HPO; HIDROPALM (R)) on diet digestibility, milk yield and milk composition, and on the concentration of the conjugated linoleic acid (CIA) C18:2 cis-9 trans-11 and C18:1 trans-11 (vaccenic acid, VA) and other main fatty acids in milk fat. Treatments involved a control diet, without added oil, and 2 diets supplemented with either 12 g/kg SO or 12 g/kg HPO on a dry matter (DM) basis. In the first experiment, 6 non-pregnant, non-lactating Lacaune ewes were used following a 3 x 3 replicated Latin Square design. Addition of vegetable fat supplement to the diet increased digestibility of DM, organic matter (OM) and crude protein (CP), but did not affect that of the ether extract (EE), neutral detergent fibre (NDF) or acid detergent fibre (ADF). In the second experiment, 60 Lacaune dairy ewes mid-way through lactation (120 +/- 12 days in milk, 0.98 +/- 0.03 kg/day average milk yield) were divided into three equal-sized groups each of which was assigned to one of the three experimental diets for 4 weeks. Compared with the control treatment, supplementation with H PO increased milk yield and energy-corrected milk. But neither vegetable fat supplement modified percentages of fat and protein in milk. Supplementation with HPO increased C14:1, C16:1 and C16:0 content and reduced C18:0 and C18:1 cis-9 content in milk fat. Supplementation with SO increased the VA content in milk fat by 36% and that of cis-9 trans-11 CLA by 29% in comparison with the control diet. Supplementation with HPO led to milk fat with 15% more cis-9 trans-11 CLA than control milk. In conclusion, adding a moderate dose of HPO or SO to the diets increased CIA concentration in milk fat. Nevertheless, supplementation with SO was more effective than HPO in increasing CLA concentration in milk fat and reducing the atherogenicity index, improving milk quality from the human health standpoint

Características y gestión de los recursos nutritivos utilizados en la alimentación del ganado ovino explotado en zonas de regadío

Durante la última década se ha producido un desplazamiento de las explotaciones de ganado ovino, fundamentalmente de aquellas dedicadas a la producción de leche, desde las zonas más desfavorecidas hacia las de regadío, más productivas. Simultáneamente, el sistema de producción se ha intensificado. Estos cambios se han reflejado en la alimentación del ganado, si bien la evolución no ha sido la misma en todas las explotaciones. En el presente capítulo se describen las características bromatológicas y las formas de obtención y de utilización de los recursos nutritivos empleados en estas explotaciones y las formas de obtención y de utilización de los recursos nutritivos empleados en estas explotaciones

Effect of time of supplementary feeding on intake, apparent digestibility and rumen fermentation of grass hay by sheep

Effects of time of supplementation on forage intake, nutrient apparent digestibility and rumen fermentation were studied with 12 mature castrated male sheep (wethers) offered grass hay from 16.30 h to 09.30 h and supplemented with a cereal-based concentrate given at either 09.30 or 16.00 h. Voluntary intake of hay organic matter (OM) was decreased by feeding the concentrate (P < 0.01). Offering concentrate at 09.30 h after hay was available, increased intake of hay and total OM compared with offering it at 16.00 h before hay was available (P < 0.05). Daily pattern of hay intake was not changed when concentrate was offered at 09.30 h compared with feeding hay alone, but concentrate given at 16.00 h resulted in a lower hay intake between 16.30 and 18.00 h. Sheep offered concentrate at 09.30 h had higher rumen ammonia levels than those offered concentrate at 16.00 h, but there were no differences in the apparent digestibility of the nutrients, rumen pH and molar proportions of the main volatile fatty acids. There were also no differences between groups in the blood plasma concentrations of 3-hydroxybutyrate (3OHB), nonesterified fatty acids (NEFA) and glucose. It is concluded that feeding supplement after rather than before a period of intake of forage or a bout of grazing may offer a means of minimizing reduction of forage intake as a consequence of feeding concentrate

Características y gestión de los recursos nutritivos utilizados en la alimentación del ganado ovino explotado en zonas de regadío

Durante la última década se ha producido un desplazamiento de las explotaciones de ganado ovino, fundamentalmente de aquellas dedicadas a la producción de leche, desde las zonas más desfavorecidas hacia las de regadío, más productivas. Simultáneamente, el sistema de producción se ha intensificado. Estos cambios se han reflejado en la alimentación del ganado, si bien la evolución no ha sido la misma en todas las explotaciones. En el presente capítulo se describen las características bromatológicas y las formas de obtención y de utilización de los recursos nutritivos empleados en estas explotaciones y las formas de obtención y de utilización de los recursos nutritivos empleados en estas explotaciones

Fattening lamb nutrition. Approaches and strategies in feedlot

[EN] Several kinds of lamb are currently being produced in the Iberian market and all of them require different feeding strategies. Gender, season of the year, genotype, fattening score and priorities should be kept in mind when planning farm management to achieve not only a good product but also good profitability. Despite the great variability in fattening lamb trials, we can predict technical and economic performance from the initial and final body weight, depending on the sex, genotype and season.The authors acknowledge the support of NANTA S.A. and NUTRECO (economical and technical) CSIC of Leon (statistical studies and technical support) and FRANCO Y NAVARRO (farmer and figure of reference in the lamb industry in Spain).Bello, J.; Mantecón, A.; Rodríguez Garcia, M.; Cuestas, R.; Beltrán, J.; González, J. (2016). Fattening lamb nutrition. Approaches and strategies in feedlot. Small Ruminant Research. 142:78-82. https://doi.org/10.1016/j.smallrumres.2016.04.006S788214