Diel feeding activity and intensity in the European eel Anguilla anguilla (L.) during an annual cycle in a Cantabrian stream

Diel and seasonal shifts in the feeding activity and intensity of a riverine stock of European eels, Anguilla anguilla (L.), were assessed in the Río LLorín, a right-side tributary of the Río Esva drainage (northwestern Spain). No consistent diel cycles were detected in either season (eels feed with similar intensity in the day and at night), but increased feeding activity was evidenced during the warmer months relative to weaker but still significant activity in winter. Heterogeneity in both feeding activity and intensity may stem from the high rates of secondary production in the form of benthic food available for eels, and mild temperatures all year round

Use of visible and near infrared reflectance spectra to predict lipid peroxidation of light lamb meat and discriminate dam's feeding systems

Measurement of thiobarbituric acid reactive substances (TBARS) is a well-established method for determine lipid oxidation in meat. This assay, however, is time-consuming and generates undesired chemical waste. Dam''s milk is the principal source of vitamins and provitamins that delay lipid oxidation of light lamb meat; these compounds are stored in the lamb''s muscle tissue. Hence, lamb meat could be used to determine the origin of the dam''s diet. The aim of this study is to evaluate Near-infrared reflectance spectroscopy (NIRS) as a tool for determining the lipid peroxidation of light lamb meat and differentiate the meat of light lambs according the diet of their dams during lactation (grazing alfalfa, lucerne, or fed a total mixed ration). NIRS using select wavelengths was able to detect the lipid oxidation of meat (TBARS method). NIRS can detect analytes at concentrations of parts per million. Moreover, the feed diets were discriminated successfully

The interplay between exposure and preference for unpalatable foods by lambs

Herbivores satiate on single foods ingested too frequently or in excess. We hypothesized that exposure to the same unpalatable food too frequently or in excess causes satiety, which in turn would reduce subsequent use and preference for this food when alternatives become available. In each of three experiments, twenty-four lambs were randomly assigned to three treatment groups (8 lambs/group), where they received high (Ad libitum), intermediate (100–200 g/d) or low exposure (20–40 g/d) to three unpalatable foods: The invasive weed medusahead (Experiment 1), an alfalfa:quebracho tannin ration (70:30; QT) (Experiment 2), or wheat straw (Experiment 3). After exposure, all groups in Experiments 1 and 3 received a simultaneous offer of the unpalatable food and a novel food that changed across four consecutive preference tests: Grape pomace (Test 1), barley straw (Test 2), tall fescue hay (Test 3), and beet pulp (Test 4). Lambs in Experiment 2 received a simultaneous offer of each of these novel foods and the same novel food containing 30% quebracho tannins. During exposure, lambs in Experiment 1 showed a low and cyclic pattern of medusahead intake, and the group with intermediate level of medusahead exposure showed greater intake values than the Ad libitum group, followed by the group with the lowest level of exposure (P intermediate > low level of exposure (P < 0.05). During preference tests, lambs with the least level of exposure to the unpalatable foods tended to consume more medusahead (35% to 37%; P = 0.11) or wheat straw (15 to 30%; P = 0.10) than lambs that received greater levels of exposure. In contrast, differential exposure to QT did not influence subsequent preference for tannin-containing foods (P = 0.33), but animals with the greatest level of exposure to QT consumed 24% more alternatives (i.e., non-tannin containing foods) than lambs that had received the lowest level of QT exposure (P < 0.05). Intake of alternative novel foods during preference tests increased with increments in nutritional quality from grape pomace and barley straw to tall fescue hay and beet pulp (P < 0.05), suggesting that lambs discriminated the nutritional value of the novel foods. In conclusion, repeated exposure to unpalatable foods has the potential to further reduce their utilization when alternatives –even when novel– become available. This effect appeared to be influenced by the chemical characteristics of the unpalatable food and it has implications for the coexistence of plant species in grazed communities

Carotenoids and liposoluble vitamins in the plasma and tissues of light lambs given different maternal feedings and fattening concentrates

The carotenoids and liposoluble vitamins in the plasma and tissues of the lambs under different maternal feedings and fattening concentrates was studied. During lactation, 21 lambs were housed with their dams, that received a total mixed ration (intensive); 21 ewe–lamb pairs grazed on alfalfa; and 21 pairs grazed on sainfoin. After weaning, half of the lambs in each maternal feeding group received a commercial concentrate (control) and the other half a concentrate with quebracho (Schinopsis balansae), as a source of condensed tannins, until they were slaughtered (23 kg). The analyte concentrations in the plasma of lambs at weaning reflected the content in the feedstuffs. Grazing during suckling more than doubled the contents of lutein in the liver and retinol in the tissues compared to the intensive feeding. The content of a-tocopherol in the tissues was greatest in sainfoin lambs, intermediate in alfalfa lambs, and lowest in the intensive lambs. The quebracho concentrate decreased a-tocopherol (by 41–81%) and ¿-tocopherol (by 65–89%) contents in the lamb tissues. The use of the analytes in the plasma at weaning correctly classified 100% of the lambs into the maternal feeding (intensive vs. grazing (alfalfa + sainfoin)) but has to be improved in the carcass and tissues separately

Meat quality of light lambs is more affected by the dam’s feeding system during lactation than by the inclusion of quebracho in the fattening concentrate

The inclusion of natural antioxidants in the diet, through fresh forages or condensed tannins, might prolong meat shelf life and modify the meat quality. The aim of this study was to evaluate the effect of the dam’s feeding system during lactation and the inclusion of quebracho in the fattening concentrate of male lambs on meat color, chemical composition, and lipid oxidation. Dams and their suckling lambs were fed indoors or allowed to graze on alfalfa or sainfoin until lambs reached 42 d old. Thereafter, the weaned lambs were fed concentrates with 5% quebracho or without quebracho until reaching 22 to 24 kg BW. Meat of suckling lambs from dam’s fed indoors (Indoor lambs) presented greater intramuscular fat content and lower a-tocopherol content than meat of suckling lambs from dam’s fed Alfalfa (Alfalfa lambs) and Sainfoin (Sainfoin lambs; P < 0.01), independent of the fattening diet. Regarding meat color of longissimus thoracis et lumborum muscle, on average, Indoor lambs’ meat presented greater lightness, yellowness, and hue angle values than Alfalfa and Sainfoin lambs’ meat (P < 0.05). The redness was affected by the interaction between the feeding system during lactation and the time of storage, but, on average, Alfalfa and Sainfoin lambs had greater redness than Indoor lambs (P < 0.05). The lipid oxidation from 5 to 14 d of meat display time observed for Sainfoin lambs was lower than that for Indoor lambs (P < 0.05). The intramuscular fatty acid profile of meat from the Sainfoin and Alfalfa lambs met particularly well the Food and Agriculture Organization of the United Nations recommendation for human health, compared that of meat from the Indoor lambs. The dietary inclusion of quebracho during fattening modified meat a-tocopherol content, oxymyoglobin levels after 8 d of storage, and fatty acid profiles. In conclusion, the results indicate higher importance of the diet during suckling than during the subsequent fattening period on meat quality parameters such as color, lipid oxidation, and fatty acid profile. Dams grazing Sainfoin provide a more stable lamb meat, and it would be cheaper to feed the dams with fresh forages with a high a-tocopherol content than supplementing the concentrate of the lambs with synthetic a-tocopherol

Effects of feeding sainfoin proanthocyanidins to lactating ewes on intake, milk production and plasma metabolites; 34996024

There is increasing interest in using sainfoin (Onobrychis viciifolia) to feed sheep, but it contains proanthocyanidins (PACs), and the associated effects of PAC on sheep production are not well-known. The aim of the study was to assess the effect of the presence of PAC from sainfoin, through the inclusion of polyethylene glycol (PEG), on the intake and productive parameters of local ewes bearing one male lamb. For the experiment, 20 ewes and their newborn male lambs were placed in individual indoor cages. All ewes were fed ad libitum fresh sainfoin plus 200 g/d barley. Twice daily, half of the ewes were orally dosed with only water (Sainfoin Group; n = 10), and the other half were orally dosed with 100 g/d PEG 4000 per ewe (Sainfoin + PEG Group; n = 10). Sucking lambs were permanently housed with their dams until they reached 10–12 kg BW. The intake of sainfoin was recorded daily, and its chemical composition was analysed. Weekly, the BW, body condition score (BCS), milk yields and individual milk and blood samples were recorded. At the beginning and end of the experiment, faecal samples were collected from ewes and analysed for the anthelmintic role of PAC. The chemical composition, polyphenol content and antioxidant capacity of the diet and milk were analysed. The presence of PAC did not affect the intake, BW, BCS or milk yield of the dams (P > 0.05); however, all parameters were affected by the week of lactation (P 0.05). The presence of PAC had no effect on parasitism (P > 0.05). In conclusion, the presence of PAC had no relevant effects on milk production, although it affected protein metabolism, as indicated by the urea contents in milk and plasma. © 2021 The Author

Alfalfa but not milk in lamb's diet improves meat fatty acid profile and a-tocopherol content

To establish animal feeding recommendations, it is required to quantify whether the effects of combining dietary alfalfa and milk on meat composition of light lambs are overlapped or independent. This experiment aimed to evaluate the separate effects of dietary alfalfa and milk access on the light lamb carcass quality (10–11 kg), meat colour, chemical composition, fatty acid profile and a-tocopherol content. Thirty-two lambs were assigned to one of four treatments in a 2 × 2 factorial design. The factors were the inclusion of dietary forage (grazed alfalfa vs. concentrate-fed indoors) and lactation length (weaning at a target live-weight of 13 kg vs. suckling until slaughter at 22–24 kg). Dietary alfalfa but not milk supply improved conjugated linoleic acid isomers (CLA), omega-3 fatty acids and a-tocopherol contents in lamb meat without affecting meat colour attributes. Milk supply affected more the fatty acid profile (more saturated) than the a-tocopherol content of meat. Thus, dietary alfalfa improved CLA, omega-3 fatty acids and a-tocopherol content in light lamb without affecting the meat colour, whereas lengthening the lactation period did not provide benefits in terms of meat colour or healthy nutrient composition

Effects of using rosemary residues as a cereal substitute in concentrate on vitamin e, antioxidant activity, color, lipid oxidation, and fatty acid profile of barbarine lamb meat

The shortage of some ingredients and, consequently, the continuous increase in the price of feed encourage the search for other alternatives to maintain animal production and enhance its products. In this line, the use of aromatic plant by-products in animal diet has been recently and widely considered, given their richness in bioactive compounds. Therefore, the aim of this study was to investigate the effects of the inclusion of rosemary residues (RR) and protein sources on lamb meat quality. The experiment was carried out on 24 male Barbarine lambs (3 months old) with an average body weight (BW) of 17.8 ± 2.6 kg, which were divided into three homogeneous groups according to BW. The diet comprised 600 g of oat hay and 600 g of concentrate. Three types of concentrate were evaluated: commercial concentrate as the control group (C); rosemary residues (RR) plus soybean meal as the RRS group, and RR plus faba bean as the RRF group. After an experimental period of 65 days, lambs were slaughtered. The inclusion of RR in both concentrates increased the a-tocopherol and total polyphenol content in meat and protected meat against discoloration (high red index and chroma after 9 days of storage) but did not affect meat lipid oxidation, which was similar for all groups. The FA profile was affected by the inclusion of RR, with no effect from the source of protein (faba bean or soybean). The inclusion of RR in the concentrate increased the C18:2 n-6, C18:3n-3, C20:4 n-6, C20:5 n-3, and C22:5 n-3 content (p < 0.05). Consequently, the inclusion of RR also increased the total polyunsaturated FA (p < 0.05) and the ratio of polyunsaturated FA to saturated FA (p < 0.05). The results of this study demonstrate that concentrate based on RR could be useful for lamb meat production by improving the nutritional quality of meat, especially the fatty acid profile. In addition, soybean meal can be replaced by faba bean in lamb concentrate without affecting meat quality. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Efecto del tipo de forraje y la inclusión de quebracho en la dieta de ovejas lactantes sobre sus rendimientos productivos

Se estudió el efecto del tipo de forraje y el uso de quebracho en la dieta de ovejas sobre sus rendimientos y los de sus corderos lechales. Para ello, se utilizaron 39 ovejas con sus corderos distribuidos en 4 lotes según un diseño factorial de 2x2, con dos tipos de forraje (Pastoreo de pradera vs . Heno de pradera) y dos tipos de concentrado [concentrado comercial (Control) vs . concentrado con quebracho (QUE)]. El ensayo se prolongó desde el nacimiento hasta el sacrificio de los corderos a un peso vivo de 10-12 kg. La producción de leche y su contenido proteico fueron superiores en las ovejas Pastoreo que en las de Heno, con un contenido de grasa similar. Las ovejas de Pastoreo presentaron mayor concentración plasmática de urea y proteína total, y menor de ácidos grasos no esterificados. Los corderos de Pastoreo fueron más pesados al sacrificio y presentaron mayor rendimiento canal que los corderos de Heno a la misma edad. La inclusión de quebracho en el concentrado de ovejas no afectó al peso, producción lechera o concentración de metabolitos plasmáticos de las ovejas; únicamente redujo el contenido proteico de la leche en un 4% y aumentó el peso vivo del cordero en la tercera y cuarta semana de lactación, que tendió a alcanzar el peso de sacrificio 3, 5 días antes que el resto de corderos. En nuestras condiciones de trabajo, las ovejas lactantes en pastoreo y sus corderos lechales obtuvieron mejores rendimientos que las ovejas estabuladas con heno. La inclusión de quebracho no presentó efectos consistentes

Efecto de la inclusión de aceite de murta en la dieta de cabritos sobre la calidad sensorial de la carne

Los autores agradecen a Zina Taghouti, técnica en el laboratorio de Producción Animal del INRAT por la asistencia técnicaPublishe