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9 páginas, 3 figuras, 2 tablas., This study evaluated the influence of a temporary nutritional protein restriction (NPR) performed, under commercial conditions, in prepubertal female lambs on first lactation milk production traits and the inflammatory response triggered by an inflammatory challenge of the. From 40 Assaf female lambs, we defined a control group (C n = 20), which received a standard diet for replacement lambs and the NPR group (n = 20), which received the same diet but without soybean meal between 3 and 5 months of age. About 150 days after lambing, 24 of these ewes (13 NPR, 11C) were subjected to an intramammary infusion of E. coli lipopolysaccharide (LPS). Our dynamic study identified indicator traits of local (SCC) and systemic (rectal Ta, IL-6, CXCL8, IL-10, IL-36RA, VEGF-A) response to the LPS challenge. The NPR did not show significant effects on milk production traits and did not affect the SCC and rectal Ta after the LPS challenge. However, the NPR had a significant influence on 8 of the 14 plasma biomarkers analysed, in all the cases with higher relative values in the C group. The effects observed on VEGF-A (involved in vasculogenesis during mammary gland development and vascular permeability) and IL-10 (a regulatory cytokine classically known by its anti-inflammatory action) are the most remarkable to explain the differences found between groups. Whereas further studies should be undertaken to confirm these results, our findings are of interest considering the current concern about the future world's demand for protein and the need for animal production systems to evolve toward sustainability., The nutritional and inflammatory challenge experiments and the sample collection described in this study were funded by the SMARTER project through the Horizon 2020 research and innovation program of the European Commission (Grant Agreement No. 772787). The cytokine/interleukine panel analyses were funded by the Spanish national project EPIMILKSHEEP (Ref. RTI2018–093535-B-I00), funded by the Spanish Ministry of Science and Innovation.

14 páginas, 5 tablas, 2 figuras., The causative relationship between ruminal biohydrogenation alterations known as the trans-10 shift and marine lipid-induced milk fat depression (MFD) has been questioned in dairy ewes, but the large intra- and inter-experiment differences in the levels of trans-10 shift indicators precludes firm conclusions. This meta-analysis was conducted to quantify the relationship between trans-10 shift milk indicators [i.e., trans-10,cis-12 conjugated linoleic acid (CLA), trans-10 18:1 or trans-10:trans-11 18:1 ratio] and lactation performance, mainly milk fat traits, in Assaf dairy ewes. A database comprising of 17 experiments including 50 dietary treatments was compiled. The diets were grouped into 2 dietary conditions: (1) non-MFD condition, which included 14 diets supplemented with plant oils and tannins that modified the milk fatty acid profile without lowering milk fat concentration and yield, and 12 respective control diets, and (2) MFD condition, which included 15 diets supplemented with marine lipids that induced the low fat-milk syndrome, and 9 respective control diets. The overall levels of milk trans-10 shift indicators did not differ between dietary conditions, but significant increments were found in the supplemented diets relative to their respective controls. A similar linear and negative (slope: −7.28 ± 2.816) relationship between milk fat concentration and trans-10,cis-12 CLA was found in both dietary conditions. However, the quadratic negative response of milk fat content to trans-10 18:1 concentration was greater in MFD than in non-MFD conditions. In the two dietary conditions, the relationship between milk trans-10,cis-12 CLA or trans-10 18:1 and de novo fatty acid concentration in milk was negative, whereas the relationship with preformed fatty acid proportion was positive. The magnitude of changes in both milk fatty acid groups in response to changes in these trans-10 shift indicators were greater in non-MFD compared with MFD conditions. Milk fat yield and trans-10 shift indicators were only negatively related in ewes that were fed marine lipid supplements, because reductions in de novo fatty acid yield with increased shift indicator levels were not counteracted by concomitant increments in preformed fatty acid secretion. The best-fit (lower root mean squared error, higher R2 and no prediction biases) equations of milk fat or major milk fatty acid groups, as concentration or yield, were based on milk trans-10 18:1 concentration. In conclusion, different responses between the two conditions to similar shift indicator levels support that the trans-10 shift would not be a major factor explaining the diet-induced low-fat milk syndrome in dairy ewes., This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO; AGL2017-87812-R), co-funded by the European Regional Development Fund. P. G. Toral benefited from a Ramón y Cajal research contract from the MINECO (RYC-2015-17230), co-funded by the European Social Fund, and a researcher mobility grant from the University of León.

14 páginas, 6 tablas., This study was funded by the Instituto de Ganadería de Montaña (CSIC-University of León, Spain) and the University of Perugia (Department DSA3; project “Ricerca di Base – 2015”). P. G. Toral benefits from a ‘Ramón y Cajal’ research contract (MINECO-European Regional Development Fund).

10 páginas, 2 tablas., Growth in demand for foods with potentially beneficial effects on consumer health has motivated increased interest in developing strategies for improving the nutritional quality of ruminant-derived products. Manipulation of the rumen environment offers the opportunity to modify the lipid composition of milk and meat by changing the availability of fatty acids (FA) for mammary and intramuscular lipid uptake. Dietary supplementation with marine lipids, plant secondary compounds and direct-fed microbials has shown promising results. In this review, we have compiled information about their effects on the concentration of putative desirable FA (e.g. c9t11-CLA and vaccenic, oleic, linoleic and linolenic acids) in ruminal digesta, milk and intramuscular fat. Marine lipids rich in very long-chain n-3 polyunsaturated fatty acids (PUFA) efficiently inhibit the last step of C18 FA biohydrogenation (BH) in the bovine, ovine and caprine, increasing the outflow of t11-18:1 from the rumen and improving the concentration of c9t11-CLA in the final products, but increments in t10-18:1 are also often found due to shifts toward alternative BH pathways. Direct-fed microbials appear to favourably modify rumen lipid metabolism but information is still very limited, whereas a wide variety of plant secondary compounds, including tannins, polyphenol oxidase, essential oils, oxygenated FA and saponins, has been examined with varying success. For example, the effectiveness of tannins and essential oils is as yet controversial, with some studies showing no effects and others a positive impact on inhibiting the first step of BH of PUFA or, less commonly, the final step. Further investigation is required to unravel the causes of inconsistent results, which may be due to the diversity in active components, ruminant species, dosage, basal diet composition and time on treatments. Likewise, research must continue to address ways to mitigate negative side-effects of some supplements on animal performance (particularly, milk fat depression) and product quality (e.g. altered oxidative stability and shelf-life)., This work was conducted within the framework of the research projects AGL2014-54587 and AGL2017-87812 (Spanish Ministry of Economy and Competitiveness, MINECO). P.G.T. benefited from a Ramón y Cajal research contract (RYC-2015-17230, MINECO).

8 páginas, 3 tablas., Despite the benefits of adding marine lipids rich in n-3 polyunsaturated fatty acids (PUFA) to ruminant diets to improve milk fatty acid (FA) composition, this strategy induces milk fat depression (MFD), precluding its application under practical conditions. The MFD elicited by marine lipids has tentatively been explained by a shortage of available ruminal 18:0 for mammary uptake and Δ9-desaturation to cis-9 18:1, which might increase milk fat melting point and impair fat secretion. This hypothesis was challenged in a recent experiment in dairy ewes, as diet supplementation with 2% DM of 18:0 did not prove useful to alleviate fish oil-induced MFD. However, further research with higher levels of 18:0 inclusion seemed advisable. Therefore, in this study, 16 lactating ewes were allocated to 4 treatments lasting 27 days: a total mixed ration containing no additional lipid (control) or 2% DM of fish oil alone (FO) or in combination with 3% (FOSA3) or 4% (FOSA4) of stearic acid. Fish oil supplementation induced MFD, but addition of 18:0, regardless of the dose, was not able to mitigate it: decreases in milk fat content reached 19% in FO, 20% in FOSA3 and 27% in FOSA4. The reduction in milk 18:0 concentration due to FO (−81%) was completely reverted neither by FOSA3 (−41%) nor by FOSA4 (−25%), and something similar occurred with cis-9 18:1 concentrations (12.53, 5.91, 9.50 and 11.28 g/100 FA, in control, FO, FOSA3 and FOSA4, respectively). Increases in some candidate milk fat inhibitors in FO and FOSA diets (e.g., cis-9 16:1, cis-11 18:1, trans-10 18:1, 10-oxo-18:0, or trans-10 cis-15 18:2) might account for the absence of a positive effect of dietary 18:0. The estimated milk fat melting point was lower in the three supplemented diets (on average, −2.6 °C compared with the control). In conclusion, addition of high doses of stearic acid to the diet (at 3 and 4% DM) was not able to alleviate the MFD caused by the concomitant supplementation with fish oil. This lack of response would further challenge the hypothesis suggesting that fish oil-induced MFD is mainly explained by decreased ruminal production of 18:0 and subsequent problems of milk fat fluidity, but further research would be still needed., This work was supported by the Council of Castile and Leon (CSI023U13). The authors thank D. Carreño, A. G. Mendoza and L. Rodríguez for their help with experimental animals and fatty acid analysis. Pablo G. Toral benefits from a Ramón y Cajal research contract from the Spanish Ministry of Economy, Industry and Competitiveness (RYC-2015-17230), co-funded by the European Regional Development Fund.

10 páginas, 5 tablas, 1 figura., The ability of tannins to interfere with ruminal biohydrogenation (BH) and modulate the fatty acid (FA) profile of ruminant-derived products is highly controversial, which is probably related to the type of tannin and the dosage rate. Therefore, this in vitro study was conducted to analyse the effect of four commercial extracts of tannins (from chestnut, oak, quebracho and grape) at four doses (20, 40, 60 and 80 g/kg diet DM) with the aim of selecting an effective treatment to modulate the BH of unsaturated FA. Two in vitro assays with batch cultures of rumen microorganisms, using cannulated ewes as donors of rumen inocula, were performed. The incubated substrate (a total mixed ration similar to that fed to the animals) was supplemented with 20 g of sunflower oil/kg DM. The first experiment followed a 4×4 + 1 design (i.e., 4 types of tannins×4 doses of each one, and a control), and treatment effects on the FA composition of the ruminal digesta were examined by gas chromatography. On the basis of these results, the second experiment was conducted to make sure that the selected dose and type of tannin would not impair rumen fermentation. To this end, gas production kinetic parameters, extent of degradation, in vitro true substrate digestibility, pH, and ammonia and volatile FA concentrations, as well as the bacterial community (by terminal restriction fragment length polymorphism, T-RFLP) were examined. All tannin extracts were able to modulate the in vitro BH of unsaturated FA. However, the high dose required in many cases suggests that their efficacy would be rather limited in terms of animal feeding. On the other hand, the oak tannin extract, at a dose of 20 g/kg diet DM, increased total polyunsaturated FA, 18:3n-3, 18:2n-6 and trans-11 18:1, and decreased trans-10 18:1 and 18:0 rumen concentrations without eliciting any negative response in ruminal fermentation. Although this treatment had no discernible effects on the bacterial community structure and diversity, a few fragments compatible with uncultured Lachnospiraceae species were affected., D. Carre˜no and P. G. Toral gratefully acknowledge receipt of an FPI predoctoral grant and a Juan de la Cierva research contract, respectively, from the Spanish Ministry of Economy and Competitiveness (MINECO). This work was supported by the MINECO (AGL2011-23700).

9 páginas, 3 tablas, 1 figura., Supplementation of a linoleic acid-rich diet with marine algae reduces milk fat content while impacting milk fatty acid profile in dairy sheep. Unlike other ruminant species, in ovine there are limited data on the molecular mechanisms that may regulate adipose, liver, and mammary responses to dietary marine lipids. This study was conducted to investigate changes in mRNA expression and relative mRNA abundance of key enzymes involved in lipid metabolism in mammary, subcutaneous adipose and liver tissue in response to long-term milk fat depression induced by marine algae. Eleven Assaf ewes were randomly assigned to 2 experimental diets consisting of a TMR based on alfalfa hay and concentrate (40:60) supplemented with 25 g of sunflower oil/kg DM plus 0 (SO; control diet) or 8 g of marine algae/kg of DM (SOMA diet) for 54 d. Quantitative reverse transcription-PCR was used to study expression of target genes in tissues harvested at slaughter at the end of the feeding period (54 d). There was no effect of SOMA on mammary and adipose tissue expression of genes encoding proteins required for fatty acid uptake and activation (ACSS2, LPL), intracellular fatty acid transport (FABP3, FABP4), de novo fatty acid synthesis (ACACA, FASN), esterification (DGAT1, DGAT2, LPIN1), desaturation (SCD), elongation (ELOVL6), trans-criptional regulation (INSIG1, MED1, PPARG, RXRA, SCAP, SREBF1, THRSP) and lipid droplet formation (ADFP, BTN1A1, XDH). Abundance of PPARG (0.04%) and INSIG1 (2.22%) in mammary tissue was markedly greater than that of SREBF1 (0.002%), suggesting that they may play a more important role in milk fat synthesis regulation. Addition of marine algae did not affect the expression of-hydroxybutyrate, NEFA, glucose,triacylglycerol, growth hormone, insulin-like growth factor 1, insulin, and leptin was not different between groups at d 54. Taken together with the milk fat responses and previous data from bovine fed similar diets, results suggest that transcriptional control mechanisms regulating fat synthesis in mammary secretory tissue were likely established during earlier stages of the feeding period., This work was supported in part by the Spanish Ministry of Economy and Competitiveness (MINECO; AGL2011-23700) and by the 2011 International Seed Grants Program College of Agricultural, Consumer and Environmental Sciences, University of Illinois (Urbana). E. Bichi gratefully acknowledges receipt of a predoctoral grant from the Spanish National Research Council (CSIC; JAE Program) supported by European Social Fund. The authors thank the staff from the Instituto de Ganadería de Montaña (León, Spain) for their help in the field work and laboratory analysis.

9 páginas, 5 figuras, 1 tabla., The aim of the present study was to evaluate the in vitro effects of heather (Ericaceae) phenolic extracts on the abomasal nematodes Teladorsagia circumcincta and Haemonchus contortus. Extracts of three heather species (Calluna vulgaris, Erica cinerea, Erica umbellata and a balanced mixture of all three) were tested in vitro on different development stages of T. circumcincta (eggs, infective larvae and adult worms) and H. contortus (eggs and infective larvae) using an egg hatching assay (EHA), a larval exsheathment inhibition assay (LEIA) and an adult motility inhibition assay (AMIA). The egg hatching rate was measured after incubation with heather extracts for 48 h at 25 °C. Ensheathed infective larvae were incubated for 3 h at 20 °C with heather extracts. Artificial exsheathment was induced in vitro by adding hypochloride solution to the larval suspension. The progress of exsheathment over time was measured by repeated observations at 10-min (T. circumcincta) and 20-min (H. contortus) intervals for 60 min. Adult T. circumcincta worms were obtained from two donor goats and incubated with the extracts at 37 °C for 3 days in 48-well multiwell plates. Worm motility was measured at 0, 19, 24, 43, 48, 67 and 72 h. The extracts were tested at concentrations of 75, 150, 300, 600 and 1200 μg/mL. Incubation with E. cinerea, E. umbellata and mixed heather extracts had a significant (P < 0.01) dose-dependent effect on T. circumcincta egg hatching. H. contortus egg hatching was significantly (P < 0.01) inhibited only by the E. cinerea extract. All extracts had a significant (P < 0.01) dose-dependent effect on the exsheathment of T. circumcincta and H. contortus infective larvae. The incubation with all heather extracts induced a reduction in adult T. circumcincta motility compared to the control, although significant (P < 0.05) differences were only found at the highest concentration (1200 μg/mL). The effect of the mixed extract was significant at all concentrations and significant effects were also observed for C. vulgaris and E. umbellata at 600 μg/mL. These results show anthelmintic properties of heather phenolic extracts against T. circumcincta and H. contort, thus confirming observations from previous in vivo studies., This work was supported by the Spanish National Institute for Agrarian and Food Research and Technology (INIA, Project RTA2007-00098) and was also part of the EU research collaboration COST Action FA0805 CAPARA. Javier Moreno-Gonzalo was financed by INIA.

9 páginas, 1 figura, 1 tabla., In the last decade, numerous studies have been carried out to evaluate the potential anthelmintic benefit of the consumption of bioactive plants in small ruminants, in order to reduce the dependence on conventional chemotherapy and supporting a sustainable control of gastrointestinal (GI) parasitism. This review summarizes the anthelmintic and nutritional effects of heather (shrub species belonging to the Ericaceae family, such as Erica spp. or Calluna vulgaris) supplementation in grazing goats naturally infected by GI nematodes. The experiments were carried out in a mountain area in north-western Spain where shrubby heather-gorse vegetation is dominant. Some plots were established, in which the vegetation had been improved by soil ploughed and dressing and sowing perennial ryegrass (Lolium perenne) and white clover (Trifolium repens), and removing any heather that was present. Cashmere goats reared outdoors under pasture conditions were used in the experiments. The trials compared the response to GI nematode infections, animal performance and nutrition in goats supplemented or not with heather. Interactions between heather availability and other alternative methods to control GI nematode infections based on grazing management (stocking rate) or nutrition (energy supply) as well as the potential adaptation of the rumen microbiota to the consumption of tannins, were also studied. The results suggest that (i) heather supplementation in grazing goats significantly reduces the level of GI nematode egg excretion, (ii) the faecal nematode egg count reduction could be associated with a decrease in worm fertility and/or reduction in the establishment of incoming third-stage larvae, (iii) consumption of heather is associated with an apparent greater resilience of goats to GI nematode infections, and (iv) the amount of tannins consumed by the goats supplemented with heather does not seem to be associated to anti-nutritional effects which eventually resulted in a better animal performance in the animals incorporating these shrubs in their diet. Practical application of this knowledge in temperate areas would support the management of plots integrating improved pastures with high nutritive value (ryegrass-white clover) with natural vegetation communities., This work was supported by the Spanish National Institute for Agrarian and Food Research and Technology (INIA, Project RTA2007-00098) and was also part of the EU research collaboration COST FA0805.

8 páginas, 4 tablas., In vitro studies have suggested that feeding tannins to ruminants can favourably alter ruminal biohydrogenation of dietary linoleic acid, enhancing accumulation of trans-11 18:1 (VA, vaccenic acid) in the rumen and thereby the content of some human health promoting fatty acids, such as VA and cis-9 trans-11 18:2 (rumenic acid, RA), in dairy or meat products. However, reports on impacts of these phenolic compounds on milk fatty acid (FA) profile are very limited and inconsistent. Therefore, fourteen Assaf ewes in mid lactation were used to examine effects of addition of a mixture (1:1, w/w) of two commercial oenological extracts of quebracho condensed tannins (CT) and chestnut hydrolysable tannins (HT) to a diet containing sunflower oil (SO) on animal performance, milk yield and composition, and ruminal fermentation. All sheep received a total mixed ration based on alfalfa hay and a concentrate (400:600), supplemented with 20 g of SO/kg dry matter (DM) plus 0 (Control; n = 7) or 10 (TAN; n = 7)g of tannins/kg DM. Milk production and composition was analyzed on days 0, 3, 6, 9, 12, 15, 18, 21, 24 and 27 on treatments, and milk FA profile on days 0, 3, 6, 12, 18 and 27. Neither DM intake nor milk, or its component, yield was affected by TAN treatment. Similarly, addition of the extract of tannins to a SO containing ration did not alter concentrations of the major FA classes in milk (i.e., saturates, monounsaturates, and polyunsaturates), had very limited effects on the proportion of particular FA, and was not able to enhance milk VA and RA enrichment above that achieved with SO supplementation. Temporal changes in milk FA composition were characterized by an increase in unsaturated FA with 18 carbons, mainly cis and trans 18:1, and a concomitant reduction in most short and medium chain saturates (6:0 to 12:0 and 16:0; P, The authors thank the research farm staff for their help in the field work and C. Delavaud (INRA, Clermont-Ferrand-Theix, France) for useful discussion during the identification of milk fatty acids. They also thank Prof. K.J. Shingfield (MTT Agrifood Research Finland) for helpful comments and revision of the manuscript. P.G. Toral and E. Bichi were granted fellowships from the CSIC (I3P and JAE Programmes, respectively).

9 páginas, 9 figuras., Three experiments were conducted to study the clinical and pathological findings associated with poisoning in cattle due to ingestion of young oak leaves (OL) and the main factors responsible for toxicosis. In Experiment 1, six 1.4 year-old bulls were fed up to 5 kg of young OL per animal per day and showed no signs of toxicity, apart from a slight proteinuria. In Experiment 2, another six 1.4 year-old bulls were first subjected to severe feed restriction for eight days and then fed a higher amount of OL (approx. 10 kg) daily. A marked increase of serum creatinine and blood urea (BUN) was detected in urine as well as clinical signs consistent with renal failure. At necropsy, animals showed gastrointestinal ulcers and kidney tubular necrosis. Since these results suggested a crucial role of the feed restricting period, a third experiment was conducted administering the same amount of young OL as in Experiment 1, but adding the severe feed restricting period as in Experiment 2. There was a wide variation in clinical signs, with one bull showing clinical signs and lesions, another recovering after showing mild clinical signs and high levels of creatinine and BUN, and the third appearing clinically normal. The relevance of restriction access to food in the development of OL toxicosis appears to be critical because the intoxication was only elicited when the OL administration was preceded by a severe feed restricting period., The Ministry of Education and Science (MEC, Spain) supported this work (Project AGL2004-06076).

11 pages, 3 tables, 2 figures.-- Available online 24 Sep 2008., Previously published as proceeding at the VII International Symposium on the Nutrition of Herbivores (Beijing, China Sep 17-22, 2007).--Journal of Animal and Feed Sciences, 16, Suppl.2:13-18 (2007). https://digital.csic.es/handle/10261/13148, Two experiments were conducted to study the effects of feeding young Pyrenean oak leaves (OLs) to beef cattle on in vitro ruminal fermentation. A total of 12 ruminally cannulated Brown Swiss bullswere divided into experimental groups thatwere fed different quantities of OLs via the ruminal cannula (on average 0, 2.5, 5.2 and almost 10 kg fresh matter/animal per day; the treatments designated control, L-OL, H-OL and VH-OL, respectively). Batch cultures of rumen microorganisms and the in vitro gas production technique were used to study ruminal fermentation of two substrates (grass hay and OL) incubated with rumen inocula derived fromeach bull. Results showed not only a dose-dependent negative effect of feeding tannin-containing OL on ruminal fermentation of conventional feeds, such as the grass hay, but also improved fermentation of tannin-containing feeds, such as the OLs, in bulls fed moderate quantities of OLs (i.e., L-OL and H-OL), which suggests adaptation of the rumen microbial population. Detrimental effects of the VH-OL treatment indicate that the high level of tannins in the rumen of bulls on the highest dose of OLs would have exceeded the capacity of the microorganisms to resist or detoxify them., This work was supported by the MEC (project AGL2004-06076-C02-01).

12 pages, 5 tables.-- Available online Jun 6, 2005., Use of preserved rumen fluid (RF) as microbial inoculum for in vitro gas production techniques (IVGPT) would be of practical importance when access to ruminally cannulated animals is limited. This experiment was designed to study effects of RF preservation on its subsequent fermentative activity. Four substrates being: alfalfa hay (AH), barley straw NDF (BS-NDF), cellulose and starch were incubated with rumen inoculum obtained from 12 rumen cannulated grazing sheep, of which six (G) received no supplement and the other 6 (G+S) received 500 g/day of a concentrate. Sub-samples of RF were processed without delay (i.e., control) or stored at approximately 0°C in a chest with crushed ice for 3, 6 and 24 h (treatments 3, 6 and 24 h, respectively) or at −18 °C for 24 h in a freezer (treatment 24 F). An IVGPT was used to determine the rate and extent of gas production and DM disappearance. Average fermentation rate (AFR) and extent of degradation in the rumen (ED) were estimated. Incubations with inoculum derived from supplemented sheep (G+S) resulted in faster rates of gas production (with differences, as proportionate increases, of 0.77 for the barley straw NDF; P < 0.01), lower lag times (e.g., 13.2 versus 4.0 h for the starch; P < 0.05), and higher ED values (e.g., 229 versus 331 g/kg for the barley straw NDF or 173 versus 409 g/kg for the cellulose; P < 0.05). Storing RF in ice for 3 or 6 h had no effect on any fermentation parameter. Treatment 24 h did not affect IVGPT parameters when starch and cellulose were fermented, but estimates of rates and ED were lower (P < 0.05) with BS-NDF and AH. Fermentative activity of rumen inoculum was, in general, reduced by freezing (24 F). However, incubations of starch and cellulose were less affected by frozen inoculum than those of AH or BS-NDF. Preservation of RF for up to 6 h in crushed ice may be a practical alternative, when necessary, to use fresh RF as microbial inoculum., G. Hervás and M.J. Mora gratefully acknowledge receipt of a research contract and a predoctoral grant, respectively, from the Spanish Council for Scientific Research (CSIC, Spain) supported by the European Social Fund.

13 pages, 1 figure, 4 tables.-- PMID: 15826684 [PubMed].-- Online version available Nov 26, 2004., Previously published as proceeding: XXXI Jornadas de Estudio AIDA(VIII Jornadas sobre Producción Animal). ITEA Vol. Extra 20, Tomo II, 594-596 (Zaragoza, Spain, May 11-13, 1999). https://digital.csic.es/handle/10261/14911, Previously published as proceeding at the XXXI Jornadas de Estudio AIDA (VIII Jornadas sobre Producción Animal). ITEA Vol. Extra 20, Tomo II, 591-593 (Zaragoza, Spain, May 11-13, 1999). https://digital.csic.es/handle/14914, Twenty-four growing Assaf lambs, divided into four groups of six animals, were used to study the effect of the undegradable protein content of the post-weaning diet on feed intake, body growth and reproductive development. From week 1 to week 21, the four groups were fed ad libitum as follows: group LL was given barley straw and low protein concentrate (LP); group HH was given barley straw and high protein concentrate (HP); group LH was given barley straw and LP concentrate from week 1 to 11 (period 1) and barley straw and HP concentrate from week 12 to 21 (period 2); group HL was given barley straw and HP concentrate in period 1 and barley straw and LP concentrate in period 2. From week 22 to week 26 (period 3), all animals received the same amount of hay and LP concentrate. Barley straw intake was not significantly (P > 0.05) affected by dietary treatments. In the 1st period, average concentrate intake and live body weight gain (LWG) were greater in lambs fed HP than LP supplement. In the 2nd period, concentrate intake was not significantly (P>0.05) affected by type of supplement, but LWG was greater for lambs fed HP than LP supplement. Scrotal circumference in week 11 was significantly (P0.05) due to dietary treatments were observed on scrotal circumference in weeks 21 and 25. Dietary treatments had no significant (P>0.05) effect on either circulating concentration of testosterone or ejaculate characteristics. In conclusion, results from this study suggest that supplementing diets with undegradable protein enhanced performance throughout the breeding period and accelerated testis growth. Nevertheless, final testis size, pattern of circulating testosterone and sperm output were unaffected by dietary treatments., M. Fernández is grateful to the Spanish "Ministerio de Educación y Ciencia (MEC)" for financial assistance under a pre-doctoral grant. The authors wish to thank the "Station de Physiologie de la Reproduction des Mammifères Domestiques" (INRA, Tours, France) for plasma testosterone analyses. This research was supported by the project PTR 95-0020-OP.

http://dx.doi.org/10.1016/S0377-8401(01)00323-6, The condensed tannin (CT) content of eight shrub species (Cytisus purgans, Cytisus scoparius, Genista florida, Genista occidentalis, Calluna vulgaris, Erica arborea, Erica australis and Juniperus communis) from a grazing mountain area of northern Spain was analysed and related to various indicators of nutritive value. Chemical composition, in vitro gas production, OM degradation and true DM digestibility were evaluated in samples collected in January and June. With the exception of two samples comprised of considerable amounts of flowers, the shrub legumes examined had low contents of CT (less than 6.51 g quebracho tannin equivalents/kg DM) which would generally be considered unlikely to affect digestion of nutrients in the gastrointestinal tract of animals. However, Ericaceae species and J. communis, which are evergreen species, showed a high CT content (higher than 176 g quebracho tannin equivalents/kg DM) throughout the year. CT were negatively correlated (P, This work was supported by the Junta de Castilla y León (Projects CSI 3/99).