Tedera is a valuable high-quality forage for sheep during summer–autumn. There is evidence that prior grazing experience of novel forages influences preference and haymaking of tedera improves preference by goats. In the first experiment, it was hypothesised that the voluntary feed intake (VFI) of fresh leaves and stems of tedera by sheep would be greater for experienced vs. naïve sheep. In the second experiment, it was hypothesised that the VFI of naïve sheep fed wilted leaves and stems of tedera would be greater than fresh leaves and stems of tedera. To test these hypotheses, adult Merino sheep were fed seven accessions of tedera, in two outdoor pen feeding experiments conducted consecutively. Each of six pens had 14 feeders, two for each accession, and two sheep. In experiment 1, three pens had sheep that had previously grazed tedera (experienced) and three pens had sheep with no experience (naïve), and all were fed fresh leaves and stems of the seven tedera accessions. Experiment 2 involved only naïve sheep, with three pens fed fresh leaves and stems and three pens fed wilted leaves and stems of the seven tedera accessions. Preference was measured each day for six days in experiment 1; and for five days in experiment 2 by calculating the average differences of feed offered and feed remaining from the feeders. In experiment 1, experienced sheep showed no difference in preference (average percentage eaten) in the first hour of each day compared to naïve sheep (70% vs. 56% DM intake (kg), p = 0.27). There was an increase in the amount eaten from the first to the last day for both groups, except for the intake of one accession that was reduced for the experienced sheep. In experiment 2, there was no statistical difference in preference between accessions. However, when the average percentage eaten by the experienced and naïve groups are combined, they are strongly correlated, with significant differences between accessions. Sheep did not eat more wilted tedera compared to fresh, which did not support our hypothesis. The only differences we found in sheep preference for tedera accessions occurred in experiment 1. Further studies to investigate seasonal differences in sheep preference between accessions is required and increased replication is needed to better determine the effect of prior grazing experience on the preference for tedera accessions.
Seasonal weight loss (SWL) is one of the major limitations in small ruminant production in drought-prone re-gions. The study of breeds with higher tolerance to the effects of SWL is particularly important to define breed selection strategies. In this work we evaluated the effect of SWL in the hepatic fatty acids profile in three ovine breeds with different levels of tolerance: the Merino (susceptible to SWL), the Dorper (intermediate tolerant to SWL), and Damara (tolerant to SWL). Animals from each breed were divided into two experimental groups: a growth group and a restricted fed group. The more representative fatty acids in the three breeds were stearic acid, oleic acid and palmitic acid. Univariate analysis revealed interaction between breed and feed-restriction in eighteen of the total fatty acids identified. Multivariate analysis showed separation between growth and restricted animals in each of the three breeds. Variations observed in the three breeds are in general related with fatty acid mobilization from the adipose tissue. Dorper and Damara breed showed exclusive variations, related with muscular tissue maintenance and hepatic adaptations respectively. Generally, Damara and Dorper breeds performed better under nutritional restriction, in accordance with results previously obtained following other approaches.
A remotely sensed pasture management technology, Pasture Growth Rate (PGR) has been developed by a research consortium of the Department of Agriculture Western Australia (DAWA), Commonwealth Scientific and Research Organisation (CSIRO), and Department of Land Information (DLI). A pilot study was funded by Australian Wool Innovation in 2003 to deliver the PGR information to a number of producers; four cooperative groups in the Great Southern and two groups in Dandaragan. Six producers from these groups were studied during the pasture growing season to determine how they used the technology and assess improvement in profitability, if any of their farming business. Key Findings • In all cases the use of PGR improved the profitability of the sheep enterprise.The increase in gross margin ranged from $23 to $334/per winter grazed hectare (WGHA). • The increased margin resulted from better utilisation of pasture, more effective feed budgeting and the introduction of new management techniques into the farming system. • The information on PGR provided timely information that was not discernible from observation of either the animals or pasture in the paddock until two to three weeks later. • The information on PGR improved confidence in decision making and helped reduce stress levels.
New Zealand’s average lambing percentage has increased from 100% in the 1980s to 130% today. There is no doubt that genetic improvements increased the potential in many flocks and overall animal health care has improved, but the single biggest contributor to the increase appears to have been better feeding. Improved feeding year-round is likely to be responsible rather than feeding at any particular time.
Seasonal weight loss (SWL) is a major constraint to extensive animal production systems. The Australian sheep production is based on merino sheep, a European breed not tolerant to SWL. Tolerant alternative breeds such as the fat-tailed Damara and the Dorper have been increasingly used in Australia and elsewhere, due to their robustness. The aim of this study was to understand the mineral profile of muscle and liver tissues of Australian Merino, Damara and Dorper, when subjected to SWL in order to understand SWL-tolerance physiology. Twenty-four lambs were divided randomly between growing (control) and nutritionally restricted groups for each breed. The trial lasted 42 days. Animals were weighed bi-weekly and at the end of the trial, lambs were slaughtered. Liver and muscle samples were taken immediately after slaughter. Mineral assessment was carried out using inductively coupled plasma-optical emission spectrometry. Analysis of variance showed mineral concentrations were generally increased in the muscle of restricted animals, mainly because of fat tissue mobilization. An increase in Zn and Fe concentrations indicates an increase of enzymatic activity in the liver of restricted sheep as well as differential abundance of Fe-containing proteins. High concentrations of Cu in the liver of Dorper indicate higher ability to accumulate this element, even under SWL.
Seasonal weight loss (SWL) is a major constraint in extensive animal production systems in the tropics and Mediterranean. The objective of this study was to characterize the amino acid profile of muscle and hepatic tissues of Australian Merino, Damara and Dorper lambs under restricted feeding to evaluate the impact of SWL at the metabolic and physiological levels. SWL induced generalized muscle protein breakdown among restricted groups of all breeds, with varying intensity. Dorper breed mobilized less muscle amino acids when under these conditions, with the Damara having frequent significant differences, namely by having lower amino acid concentrations in the muscle of restricted lambs. Damara lambs showed greater ability to catabolize branched-chain amino acids in the muscle tissue, which indicates yet another mechanism that provides the Damara with the necessary tools to endure harsh conditions. Overall, the Damara breed mobilized more muscle amino acids than the other breeds, with a better capacity to catabolize branched-chain amino acids in the muscle, while maintaining muscle structural integrity.
Seasonal weight loss (SWL) is a primary constraint for farmers in the Mediterranean and tropics. One cost-effective solution to SWL is utilizing breeds like the Damara sheep that have adapted to deal with nutritional stress. Previous studies concluded that one of the adaptation mechanisms of SWL is a specialized fatty acid metabolism. Accordingly, hepatic-mitochondrial proteomes were compared across two different breeds (24 sheep total, Merino, n = 12 and Damara, n = 12) and two different diets (restricted vs unrestricted diet, 6 per breed, per diet, 24 total). Mitochondrial-proteins were isolated and relatively quantified using Blue native PAGE / 2D-electrophoresis and then analyzed via mass spectrometry. The tool ReviGO summarized the proteomes' gene-ontology terms. A total of 50 proteins were identified with 7 changing significantly in abundance (ANOVA p-value<0.05). Specific abundance patterns of corticosteroid and inflammatory response-associated proteins such as annexin and glutamate dehydrogenase suggests that the Damara has an unusual inflammation response when subjected to SWL in addition to its unique metabolism. All significant proteins warrant further study; Annexin in particular shows promise as a potentially useful biomarker.
Tedera (Bituminaria bituminosa C.H Stirt. vars. albomarginata and crassiuscula) is a traditional forage species for goats in the Canary Islands, Spain. It has agronomic characteristics ideally suited to Mediterranean-like climates that allows it to provide high quality green forage for grazing animals during summer and autumn. It can be used to extend the growing season into late spring and early summer and/or to reduce or eliminate the need for expensive hand feeding of grain and hay to sheep to fill the ‘feed gap’ during the dry season in southern Australian farming systems. Three sheep grazing experiments were carried out with the objective to evaluate sheep production during summer and autumn with tedera as the sole diet. A 3-ha site at Dandaragan, Western Australia was grazed during the summer and autumn of 2014–2015 and 2016 and a 2.4-ha site was grazed at Kojonup, Western Australia during the same period in 2016. At each site, two grazing treatments were evaluated, continuous grazing and rotational grazing with six plots (14 days of grazing and 70 days of recovery). The first hypothesis tested was that tedera plants would not survive continuous grazing during summer and autumn. The second hypothesis tested was that without hand feeding, 10 dry sheep equivalents/ha would be able to at least maintain weight and condition score during summer and autumn. The third hypothesis tested was that rotational grazing would improve the production of the sheep (liveweight and condition score) compared with continuous grazing. The first hypothesis was rejected, the population of tedera plants did not significantly decline due to being continuously grazed during summer and autumn. The second hypothesis was confirmed, at the three experimental sites, 10 dry sheep equivalents/ha were able to at least maintain weight and condition score without any hand feeding. The third hypothesis was partially rejected; continuous grazing had a better performance of the sheep than rotational grazing. However, the rotational grazing plots had more tedera on offer in the remaining grazing plots in the rotation with the potential for a longer grazing time. These three experiments clearly demonstrate that tedera can be used to reduce or eliminate expensive hand feeding during summer and autumn using the simplest and least expensive grazing management; continuous grazing.
The effect of feed restriction on the liver protein profiles of two different breeds of sheep was studied. We compared Merino with the Damara, breeds with respectively low and high tolerance to nutritional stress. Each breed was grouped into two nutritional treatments: restricted (12-14% loss of live weight) and control (maintenance). The trial lasted 42 days. Animals were sacrificed and liver samples subjected to label free shotgun proteomics. The resultant proteins had both their fold change and statistical significance in an unpaired t-test calculated to identify differential protein abundance. The tool WebGestalt was utilized to perform an Overrepresentation Enrichment Analysis (ORA) for gene ontology terms associated with the significant proteins. We further validated shotgun proteomics findings using a selected reaction monitoring (SRM)-based targeted proteomics approach, where similar trends in regulation were obtained for a subset of relevant proteins across an independent cohort of animals. Results confirm that Damara has adapted to nutritional stress by mobilizing stored fatty acids within adipose tissue and converting them to energy more efficiently than Merino. Finally, Merino had an overabundance pattern primarily directed to protein synthesis pathways. Regulated proteins identified may be used as a basis for marker selection towards tolerance to nutritional stress. Biological significance: Sheep are one of the most important livestock animals. They remain however poorly understudied and described. Seasonal weight loss (SWL) due to pasture scarcity during the dry season is one of the most limiting conditions to ruminant production in the tropics. To counter SWL, farmers may use supple. mentation, expensive or difficult to implement. A more suitable long-term solution would be to use breeds that are naturally adapted to nutritional stress. This work contrasts two breeds with different levels of tolerance to SWL, the Damara and the Merino, respectively well and poorly adapted. Comparison is conducted at the level of the hepatic tissue and using label free proteomics. This work identifies a series of pathways in the liver of the Damara via label free proteomics that suggest a unique fatty acid metabolic process within this breed. Proteins that have increased abundance in the Damara in association with fatty acid metabolism may be used as potential markers of tolerance to nutritional stress. This research will pave the way for more viable, long-term solutions for farmers facing annual production problems due to drought in the tropics and the Mediterranean region.
Tedera ( Bituminaria bituminosa var. albomarginata) is a perennial legume native to Lanzarote, an island within the Canary Islands; known for its dry environment. It is a plant known as a grazing option within that island. Tedera was tested for its potential as an optional feed source for sheep grazing under Western Australian conditions, also known for its frequent periods of drought stress. Four sets each of 35 seasonal samples were taken from seven accessions of the legume, in an area known to have less than 600 mm of rain each year. Milled leaf – stem samples were analysed for a series of nutritive attributes and calibrations were developed using information in near infrared spectra. This paper presents findings, which demonstrate that some sound calibrations are possible for major nutritive attributes including acid detergent fibre, crude protein, calcium and chloride; for these attributes the ratio of performance to deviation exceeded a value of 4.5.
Seasonal Weight Loss (SWL) is one of the most pressing issues in animal production in the tropics and Mediterranean. This work aims to characterize muscle proteome changes as a consequence of SWL in meat producing sheep, using a label-free proteomics approach. We compare three breeds: the Australian Merino (SWL susceptible), the Damara (SWL tolerant) and the Dorper (SWL intermediate tolerance). We identified 668 proteins of the sheep proteome, 95 with differential regulation. Also we observe that the more vulnerable to SWL a breed is, the more differential abundance proteins we find. Protein binding was the most frequently altered molecular function identified. We suggest 6 putative markers for restricted nutritional conditions independently of breed: ferritin heavy-chain; immunoglobulin V lambda chain; transgelin; fatty acid synthase; glutathione S-transferase A2; dihydrodiol dehydrogenase 3-like. Moreover, we suggest as related to SWL tolerance: S100-A10 Serpin A3-5-like and Catalase, subject however to necessary validation assays. The identification of SWL-tolerance related proteins using proteomics will lead to increased stock productivity of relevant interest to animal production, particularly if identified at the muscle level, the tissue of economic importance in meat production. BIOLOGICAL SIGNIFICANCE:Seasonal Weight Loss (SWL) is the most pressing issue in animal production in the tropics and the Mediterranean. To counter SWL, farmers often use animal breeds that have a natural ability to withstand pasture scarcity. Here we study the sheep muscle proteome at the muscle level, the tissue of economic importance in meat production. Furthermore, the identification of proteins that change their abundance in response to SWL using proteomics can contribute to increased stock productivity of relevant interest to animal production. We identified 668 proteins of the sheep proteome. We demonstrate that the following proteins are affected by restricted nutritional conditions: ferritin heavy chain; immunoglobulin V lambda chain; transgelin; fatty acid synthase; glutathione S-transferase A2; dihydrodiol dehydrogenase 3-like. Furthermore, S100-A10, Serpin A3-5-like and Catalase are proteins that changed their abundance in response to SWL. Nevertheless, it is important to highlight that Catalase values for the merino breed were close to significance and therefore catalase validation is of utmost importance.
The nutritional requirements of twin-bearing ewes are ~25% greater than those of ewes with single fetuses during late pregnancy and nearly twice those of non-pregnant ewes. Underfeeding ewes, resulting in liveweight loss during late pregnancy, can have adverse effects on the production and survival of both the lamb and the ewe, and improving twin-lamb survival is critical to improving the overall reproductive performance of the National Merino flock. Scanning for pregnancy status and litter size allows for more precise management of the nutrition of the ewe flock according to the different nutritional needs of dry, single- and twin-bearing ewes. In the present paper, we tested the hypothesis that it is profitable to identify pregnancy status and litter size, and the optimum nutrition profiles are different for dry, single- and twin-bearing ewes. We tested this by examining a range of nutrition strategies for flocks where only the dry ewes were identified, or for flocks where the single- and twin-bearing ewes were identified. A MIDAS model set up for the Hamilton region in south-western Victoria was used for this analysis as it represents the whole flock and it includes a powerful feed-budgeting module that optimises animal and pasture management across the whole farm. The survival and production of the single- and twin-born progeny was adjusted on the basis of the liveweight profile of the single- and twin-bearing ewes. Our hypothesis was supported and profitability was increased by approximately AU$4630/farm or AU$0.80/ewe, by scanning ewes for pregnancy status and litter size, and the optimum liveweight profiles were different for dry, single- and twin-bearing ewes. The majority of the increase in profit was due to identifying litter size and being able to differentially manage the single- and twin-bearing ewes. When ewes are scanned for pregnancy status and litter size, the most profitable combination of profiles involves all ewes losing 4 kg in early pregnancy and single-bearing ewes regaining the 4 kg to lamb at their standard reference weight, twin-bearing ewes gaining 8 kg to lamb above their standard reference weight and dry ewes losing a further 4 kg to be 8 kg lighter than their standard reference weight at lambing time.
Seasonal Weight Loss (SWL) is an important constraint, limiting animal production in the Tropics and the Mediterranean. As a result, the study of physiological and biochemical mechanisms by which domestic animal breeds respond to SWL is important to those interested in animal breeding and the improvement thereof. To that end, the study of the proteome has been instrumental in gathering important information on physiological mechanisms, including those underlying SWL. In spite of that, little information is available concerning physiological mechanisms of SWL in production animals. The objective of this study was to determine differential protein expression in the muscle of three different breeds of sheep, the Australian Merino, the Dorper and the Damara, each showing different levels of tolerance to weight loss (low, medium and high, respectively). Per breed, two experimental groups were established, one labeled "Growth" and the other labeled "Restricted." After forty-two days of dietary treatment, all animals were euthanized. Muscle samples were then taken. Total protein was extracted from the muscle, then quantified and two-dimensional gel electrophoresis were conducted using 24 cm pH 3-10 immobiline dry strips and colloidal coomassie staining. Gels were analyzed using Samespots® software and spots of interest were in-gel digested with trypsin. The isolated proteins were identified using MALDI-TOF/TOF. Results indicated relevant differences between breeds; several proteins are suggested as putative biomarkers of tolerance to weight loss: Desmin, Troponin T, Phosphoglucomutase and the Histidine Triad nucleotide-binding protein 1. This information is of relevance to and of possible use in selection programs aiming towards ruminant animal production in regions prone to droughts and weight loss.
Sheep are a valuable resource for meat and wool production. During the dry summer, pastures are scarce and animals face Seasonal Weight Loss (SWL), which decreases production yields. The study of breeds tolerant to SWL is important to understand the physiological mechanisms of tolerance to nutritional scarcity, and define breeding strategies. Merino, Damara and Dorper sheep breeds have been described as having different levels of tolerance to SWL. In this work, we assess their liver and muscle metabolomes, and compare the responses to feed restriction. Ram lambs from each breed were divided into growth and feed restricted groups, over 42 days. Tissue metabolomes were assessed by 1H-NMR. The Dorper restricted group showed few changes in both tissues, suggesting higher tolerance to nutritional scarcity. The Merinos exhibited more differences between treatment groups. Major differences were related to fat and protein mobilization, and antioxidant activity. Between the Damara groups, the main differences were observed in amino acid composition in muscle and in energy-related pathways in the liver. Integration of present results and previous data on the same animals support the hypothesis that, Dorper and Damara breeds are more tolerant to SWL conditions and thus, more suitable breeds for harsh environmental conditions.
Seasonal weight loss is the major constraint to animal production in the tropics. To counter seasonal weight loss, the use of breeds better adapted to it is of major importance. Damara sheep are an important breed in tropical animal production, as they are not only able to tolerate seasonal weight loss, but also have a characteristic fat-tail adipose tissue, often discarded, but that may be of interest to the food industry. The objective of this work is to determine the effect of weight loss on mineral profiles (zinc, manganese, iron, potassium, sodium, magnesium and calcium) in the fat-tail of Damara sheep. The trial lasted 42 days and was conducted in Western Australia. Twenty-four Damara sheep lambs were randomly allocated to an underfed (growth rate –100 g/day) and a control group (growth rate 100 g/day). Upon slaughter, fat-tail adipose tissue was sampled and analysed by atomic absorption spectrophotometry for mineral content. The results showed no significant differences regarding minerals concentrations/quantities, with the exception of zinc and calcium concentrations that were higher in the restricted group, likely as a consequence of feed restriction and a decrease in fat tissue amount. In conclusion, we have quantified for the first time several minerals in Damara sheep fat-tail and demonstrated that reducing their bodyweight does not affect mineral quantity in fat-tails of Damara sheep.
BACKGROUND: Muscle fatty acid profile reflects the body condition of animals and has a noticeable effect on meat quality. Herein, longissimus dorsi muscle of three different sheep breeds, Damara (a fat-tailed breed), Dorper and Australian Merino sheep, was analysed for fatty acid composition. The three breeds were subjected to two distinctive feeding levels (ad libitum and restricted feeding) over 42 days.RESULTS: The Damara sheep revealed several differences compared to the other two breeds, namely a higher concentration of polyunsaturated fatty acids, which can be related to being a fat-tailed breed. Even in restricted feeding conditions, this breed revealed the highest levels compared to Merino and Dorper sheep respectively, of linoleic acid (+31% and +28%), linolenic acid (+97% and +51%), eicosapentaenoic acid (EPA) (+65% and +37%), docosapentanenoic acid (DPA) (+31% Merino) and dodosahexanenoic acid (DHA) (+63% and +77%). EPA, DPA and DHA are three omega-3 fatty acids, with described beneficial characteristics.CONCLUSION: With this work we show other qualities (higher levels of the omega-3 fatty acids, EPA, DPA and DHA) of Damara meat that might present this breed as an interesting alternative for animal production in semi-arid climates. (C) 2015 Society of Chemical Industry
Bituminaria bituminosa is a drought-tolerant, perennial legume that has been used for centuries as a part of the mixed sward in grazing systems around the Mediterranean sea and cut and carried' to feed as hay to dairy goats in the Canary Islands; varieties albomarginata and crassiuscula, commonly known as tedera, are native only to the Canary Islands. In south-western Australia, tedera will likely be directly grazed as green plants to help fill the feed gap in summer-autumn, due to its drought tolerance and capacity to retain green leaves. There are no reports of ill-effects of grazing tedera in its native environment; however, tedera is never the sole diet there. Hence, before proceeding to grazing trials it was important to conduct pen feeding studies with a sole diet of tedera. Sheep fed fresh tedera exclusively for 34 days readily consumed the forage and remained in good health, as reflected by a standard set of blood chemistry parameters. Furthermore, while the intake of the sheep fed tedera may not have been ad libitum (similar to 1.0 kg DM/head.day), they maintained their liveweight (42.5 kg) and body condition (condition score 3) throughout the experiment. This is the first experiment to measure the in vivo digestibility and nitrogen balance of sheep fed fresh' tedera forage. During the metabolism study, the in vivo digestibility of organic matter in the dry matter of the fresh tedera was similar to that of lucerne chaff (59% vs 55%) when the sheep fed lucerne chaff had their intake restricted to that of those fed tedera.
The objective of this study was to investigate the effects of the forage shrub tedera (Bituminaria bituminosa) on nutrient digestibility, rumen microbial fermentation and furanocoumarins degradation in the rusitec. The variables were measured in fermentation liquid on Days 13 and 17 and were compared with a control (lucerne hay). Overall, tedera had greater (P < 0.05) neutral detergent fibre and acid detergent fibre digestibility than lucerne hay on both days of the experiment, but on Day 17 it had lower (P < 0.01) dry matter and crude protein digestibility than lucerne hay. There were no significant differences in concentration of NH3-N and pH between treatments, but NH3-N concentrations in both treatments were lower (P < 0.05) on Day 17 than on Day 13. The concentration of total volatile fatty acids in vessels were not affected by treatments, but the concentration of acetate was lower and acetate-to-propionate ratio higher (P < 0.05) in tedera than lucerne hay on Day 13 of the experiment. Furanocoumarins were detected in the tedera treatment only. Their concentration in the fermentation liquid increased immediately after the addition of the plant material to the fermenter, reaching highest concentrations after 2 h. These concentrations gradually declined over the next two sampling times, but 6 h after the 'feeding', they were still detectable in the fermentation liquid. It was concluded that (i) tedera had in vitro digestibility and fermentability variables comparable to lucerne; (ii) furanocoumarins were degraded in the fermentation fluid, and (iii) furanocoumarins from tedera did not seem to impede microbial fermentation. Tedera may provide an alternative feed source to hay and grain for filling the summer-autumn feed gap without negatively affecting nutrient digestibility and rumen microbial fermentation.