Wether Sheep Research Articles

A Comparison of Growth Performance, Blood Parameters, Rumen Fermentation, and Bacterial Community of Tibetan Sheep When Fattened by Pasture Grazing versus Stall Feeding

Traditionally, Tibetan sheep only graze pastures without any supplementary feed. However, in recent years, feedlots are being used for fattening Tibetan sheep. The present study compared the growth rates, blood parameters, rumen fermentation, and bacterial communities in Tibetan sheep fattened by pasture grazing (PG) versus those fattened by stall feeding (SF). Twenty 18-month-old Tibetan sheep wethers (42.6 ± 2.11 kg) were divided randomly into PG (n = 10) and SF (n = 10) groups. The PG sheep grazed the grasslands without any supplementary feed, while the SF sheep were offered a commercial total mixed ration (TMR) at a crude protein content of 16.2% DM and an ME of 10.59 MJ/kg. The sheep were on their treatments for 70 days, which included 10 days for adaptation and 60 days for measurements. The average daily gain, white blood cell and lymphocyte counts were greater (p < 0.05), while the platelet count was lower (p < 0.05) in the SF group than in the PG group. The serum glutathione peroxidase activity, and concentrations of total proteins and albumin were greater (p < 0.05), while glucose was lower (p < 0.01) in the PG group compared to the SF group. The concentrations of ruminal ammonia–N and total volatile fatty acids (VFAs) were greater (p < 0.05), while the pH was lower (p < 0.05) in the SF group compared to the PG group. The molar proportion of acetate and the ratio of acetate to propionate were greater (p < 0.01) in the PG sheep than in the SF sheep, but the molar proportion of propionate and iso-VFAs did not differ (p > 0.05) between the groups. Based on the PCoA, the ruminal bacterial communities were distinct between groups, and the alpha diversity was greater (p < 0.001) in the PG sheep than in the SF sheep. The dominant phyla of the rumen bacteria were Firmicutes and Bacteroidetes, while the Firmicutes to Bacteroidetes ratio was greater (p < 0.001) in the SF group than in the PG group. At the genus level, the relative abundance of Ruminococcus was greater (p < 0.05) in the SF group, while the abundances of Prevotella, the Rikenellaceae_RC9_gut_group, Butyrivibrio, and unclassified_f_Lachnospiraceae were greater (p < 0.05) in the PG group. It was concluded that the Tibetan sheep adopted a short-term intensive fattening strategy when stall fed which altered the rumen bacterial community and blood parameters, enhanced rumen fermentation, and, ultimately, improved their average daily gain.

PSI-3 Effects of a Retinoid X Receptor agonist on primary ovine satellite cells

Abstract Sheep producers are typically paid based on body weight, so understanding the mechanisms of postnatal skeletal muscle growth is vital. Satellite cells are responsible for the capacity for postnatal skeletal muscle growth. Satellite cells proliferate and then differentiate into myoblasts before fusing with existing myotubes. The retinoid X receptor (RXR) is a transcription factor that enhances myogenic differentiation 1 (MyoD) expression, which increases differentiation and fusion of myoblasts in sheep. LG 100268 is an RXR agonist, which activates the RXR. The objective of this project is to measure the effect of LG 100268 on primary ovine satellite cell (OSC) proliferation and protein synthesis rates. Primary OSC were isolated from the hind legs of 9-mo old commercial hair sheep wethers (n = 3). For proliferation, cultures were grown to approximately 70% confluency, followed by treatment with 5% fetal bovine serum (FBS) or 300 nM of LG 100268 in 5% FBS. For protein synthesis, cultures were grown to approximately 80% confluency, at which point cultures were induced to differentiate and treated 48-h later with serum free media (SFM) or 300 nM LG 100268 in SFM. Proliferation rates were measured at 24-h post-treatment, and protein synthesis rates were measured at 6-h post-treatment. Treatment with 300 nM LG 100268 increased (P = 0.004) OSC proliferation rates compared with control cultures. Preliminary protein synthesis results suggest that LG 100268 does not alter (P = 0.22) protein synthesis rates of fused OSC. However, more research is warranted to clarify the role of the RXR in sheep skeletal muscle growth.

114 The efficacy of a natural fungus (Duddingtonia flagrans) in reducing gastrointestinal nematode indicators in lambs

Abstract Sustainable and profitable small ruminant production in the US is affected by infections with gastrointestinal nematodes (GIN), especially the blood sucking GIN, Haemonchus contortus. The overuse and misuse of available drug classes has led to multi-drug resistant GIN that pose significant challenges to parasite control on many farms. The objective of this study was to evaluate the effectiveness of a natural fungus (Duddingtonia flagrans; Bioworma, International Animal Health) in reducing GIN larval counts and other GIN indicators in hair sheep wethers. Eighteen St. Croix (n = 9) and Barbados Blackbelly (n = 9) wethers (227 ± 1.4 days of age and 29.7 ± 0.6 kg BW) were dewormed (d 0) with a combination of levamisol (Prohibit; 8 mg/kg BW) moxidectin (Cydectin; 0.2 mg/kg BW) and albendazole (Valbazen; 7.5 mg/kg BW) prior to the start of feeding according to the manufacturer’s recommendations for feeding BioWorma. At this time, lambs were separated into two treatment groups (n = 9/group), split into 3 replications per treatment group and placed on six pasture paddocks (0.06 ha; n = 3 per paddock) after accounting for breed, initial fecal egg count (FEC) and BW. Lambs were then fed daily either a grain supplement ration (corn and soybean meal) with Livamol with Bioworma (LIV) or without (CON) at 2% of their BW for 98 d. LIV was added to the ration based on total lamb BW/paddock. To evaluate the effect of LIV treatment, BW and body condition scores (BCS) were recorded every 2 wk for 98 d. Blood and fecal samples were also collected for determination of packed cell volume (PCV) and FEC. Pooled treatment group feces (d 0 – 98) were collected and cultured to determine GIN genera. A subset of animals/treatment (n = 3) will be harvested to determine abomasal worm counts. Data were analyzed using repeated measures in a mixed model, and FEC were log transformed before analysis. Following deworming (d 0), FEC were reduced by 100% by d 14. There was a mixed population of GIN at the start of the study (averaging 54%, 42%, 1.2% and 1.8% for H. contortus, Tricostrongylus spp., Oesphagostomum spp. and Nematodirus spp., respectively). LIV with Bioworma supplementation had no impact on BW, BCS, PCV or FEC in this study averaging 34.2 ± 0.3 kg, 2.5 ± 0.04, 34.7 ± 0.5% and 150.9 eggs per gram, respectively. Under the conditions of this study, Bioworma® supplementation had no influence on GIN indicators measured up to 100 d of grazing. This research will be continued during subsequent grazing seasons to determine the effect of continued supplementation on lamb parasite load and performance as well as pasture infestation levels.

Exogenous fibrolytic enzymes promoted energy and nitrogen utilization and decreased CH4 emission per unit dry matter intake of tan sheep grazed a typical steppe by enhancing nutrient digestibility on China loess plateau.

Exogenous fibrolytic enzyme (EFE) products in ruminant nutrition may be an important alternative to meet the increased demands for animal products in the future with reduced environmental impacts. This study aimed to evaluate the dose-response of EFE supplementation on the nutrient digestibility, nitrogen and energy utilization, and methane (CH4) emissions of Tan sheep grazed in summer and winter. A total of 20 Tan wether sheep with an initial body weight of 23.17 ± 0.24 kg were used in a randomized complete block design and categorized into two groups. Animals fed orally with 1 g of EFE (10,000 U/g) mixed with 30 mL of water using a drencher constituted the EFE group. For experimental accuracy, the control (CON) group was orally administered with 30 mL of normal saline daily before grazing. The following results were obtained: EFE in the diet increased dry matter intake (DMI) (P < 0.05), average daily gain (ADG) (P < 0.05), and digestibility (P < 0.05) compared with CON in summer and winter. DMI increased but ADG and digestibility decreased in winter compared with those in summer. Sheep fed with the EFE diet increased the concentrations of rumen ammonia nitrogen (P < 0.05) and total volatile fatty acids (P > 0.05), but reduced pH (P > 0.05), compared with CON in summer and winter. EFE increased nitrogen (N) intake, digestible N, retained N, and retained N/digestible N (P < 0.05) but reduced fecal N/N intake, urinary N/N intake, and excretion N/N intake in summer and winter (P < 0.05), compared with CON. Retained N/N intake was reduced and excretion N/N intake increased in winter relative to those in summer. In winter, gross energy (GE), manure E/GE, CH4 emissions, CH4/DMI, and CH4/GE increased but digestion energy and metabolic energy decreased compared with those in summer. Sheep fed with the EFE diet had a greater GE intake than those fed with the CON diet (P < 0.05) but had lesser CH4/DMI and CH4E/GE (P < 0.05) than those fed with the CON diet in both summer and winter. In conclusion, EFE supplementation increased DMI, apparent digestibility, and N deposition rate. These effects were beneficial for animal production. The CH4 emission per unit DMI of grazing Tan sheep was lesser and conducive for augmenting the environmental benefits.

Effect of Rye Grain Derived from Different Cultivars or Maize Grain Use in the Diet on Ruminal Fermentation Parameters and Nutrient Digestibility in Sheep

Abstract Six wether sheep with ruminal and duodenal cannulas were used in a replicated 3 × 3 Latin square to determine the effect of rye grain (from an open-pollinated or a hybrid cultivar) and maize grain from hybrid cultivar inclusion in the diet on ruminal fermentation parameters and nutrient digestion in different gastrointestinal tract compartments. The experimental diets consisted of meadow hay (800 g/day) and a concentrate mixture (300 g/day) that contained rye grain from an openpollinated cultivar (OPRG), rye grain from a hybrid cultivar (HRG), or maize grain from a hybrid cultivar (MG) as a main energy source. Each experimental period lasted 17 days and consisted of 10 days for diet adaptation and 7 days for data and sample collection. Ruminal fermentation (pH, short-chain fatty acids, and ammonia concentration) and nutrient digestion up to the duodenum (in reticulorumen, omasum, and abomasum), in the intestine, as well as in the total digestive tract was investigated. Mean ruminal pH was higher for MG compared to HRG and OPRG (P&lt;0.01) but did not differ between HRG and OPRG (6.45, 6.35, and 6.29 for MG, HRG, and OPRG, respectively). Treatment did not affect short-chain fatty acid concentration in the rumen, except for the molar proportions of valeric acid and of isovaleric acid of the total short-chain fatty acids, which was or tended to be higher (P≤0.06) for MG compared to HRG and OPRG. Less starch was digested in the gastrointestinal tract up to the duodenum and more in the intestine for MG compared to HRG and OPRG (P=0.01); however, total tract nutrient digestibility did not differ between treatments. In conclusion, usage of rye grain in sheep diets resulted in a lower ruminal pH compared to maize grain usage. No differences for ruminal fermentation, nutrient digestion up to the duodenum, in the intestine, as well as in the total digestive tract between rye grain from open-pollinated and hybrid cultivar usage in sheep diets were found.

A garlic and citrus extract: Impacts on behavior, feed intake, rumen fermentation, and digestibility in sheep

There is global interest in decreasing methane (CH4) emissions from ruminants due to their negative impacts on the efficiency of the livestock industry and the environment. The present study was conducted to evaluate the effects of a natural combination of garlic and citrus, Mootral, as a novel feed supplement on behavior, feed intake (FI), rumen fermentation, digestibility, growth performance, and CH4 reduction in sheep. Four Corriedale wether sheep, kept in individual metabolic cages and used in a 4 × 4 Latin square design, were fed a 50 : 50 grass hay : concentrate ratio diet at 55 g dry matter/kg BW0.75/day. Mootral was supplemented at four concentrations: 0 (control), 1, 5, and 10 g/kg on a dry matter (DM) basis. The experiment was performed over four 21-day periods, each consisting of 14 days for the adaptation period and 7 days for sample collection. Health status was checked daily, while body weight was recorded weekly. Refusal feed, fecal, and urine samples were collected for 5 days. Behavioral observations were performed for 2 continuous days. CH4 and carbon dioxide (CO2) emissions were quantified by an open-circuit respiratory system on days 19 and 20, while rumen fluid was collected three times, both before (0 h) and after (3 and 6 h) morning feeding on day 21. The results of the current study showed that animals supplemented with Mootral dedicated more time to eating (P < 0.05) and had a higher frequency of lying around feeding time (P < 0.001) than non-supplemented animals. Continuous observation revealed that Mootral supplementation decreased the incidence of oral non-nutritive behaviors (P < 0.001) and abnormal behavior (P = 0.016) of the sheep around feeding times compared with the control group. Moreover, rumination activity was observed to be higher for supplemented animals through instantaneous scan sampling data (P < 0.001). Mootral supplementation did not affect total FI or any rumen fermentation parameters, digestibility, or growth performance. Compared with the control group, 5 and 10 g Mootral/kg DM decreased the CH4 emission yield per digestible DM intake up to 7 % (P < 0.05) and 12.8 % (P < 0.01), respectively, while no effect on CO2 emissions was observed. In conclusion, Mootral, a combination of garlic and citrus, is a promising natural feed supplement that can be used to reduce CH4 emissions from ruminants without causing any negative impact on FI, rumen fermentation, or digestibility, thereby leading to improved animal welfare.

Comparison of sheep and dairy cows for in vivo digestibility of perennial ryegrass

Sheep are often used as a proxy for dairy cows when measuring the digestibility of a feed. In recent years grassland management guidelines for ruminant animals have been re-evaluated in accordance with the progression in animal genetics and the acknowledgement that genetic potential has an influence on both feed intake and digestibility. Recommended pre-grazing herbage mass (HM) targets are now much lower with improved perennial ryegrass varieties available for grazing swards. The objective of this study was to compare the in vivo digestibility of perennial ryegrass in wether sheep and lactating dairy cows. The experimental design was selected to measure the effect of animal species (cows, sheep), sward HM measured cutting herbage at 4 cm above ground level (low: 1 700 kg DM/ha and high: 4 000 kg DM/ha) and season (Spring: Apr–May, Summer: Jul–Aug) on the digestibility of perennial ryegrass. Each HM treatment was offered to each animal within species and season for 12 d using a 2 HM × 2 period changeover Latin square design. There were eight cows and eight sheep, so there were four 2 × 2 Latin squares for each animal species (two) at each season (two), giving 64 observations. During each 12 d experimental period, the first 6 d were used for adaptation (adaptation phase) and the final 6 d were used for measurement (measurement phase). In vivo organic matter digestibility (OMD) in spring did not differ between animal species but in summer sheep had higher in vivo OMD than cows. The results described herein highlight the suitability of wether sheep as an alternative to dairy cows for determining the digestibility of perennial ryegrass in spring but not in summer. Stage of growth of the plant, which is intrinsically linked to season, should be considered as results show that digestibility in the ruminant was affected by season but not differentially affected by changing sward HM.

Dry Matter Intake and In Vivo Digestibility of Grass-Only and Grass-White Clover in Individually Housed Sheep in Spring, Summer and Autumn.

Simple SummaryFeed intake and the digestibility of that feed are key drivers of animal production from grazed forage. This study compared the digestibility and voluntary dry matter (DM) intake of grass-only and grass-white clover (grass-clover) forage in individually housed sheep. The study was a Latin square design, repeated in spring, summer and autumn in 2017. Grass-clover and grass-only forage was harvested daily and offered ad libitum to 6 individually housed wether sheep per treatment. Digestibility of the forage DM, organic matter (OM), neutral detergent fibre (NDF) and acid detergent fibre (ADF) was determined using the total faecal collection method. Dry matter intake was similar on both forage types. White clover inclusion increased forage crude protein concentration in autumn and reduced NDF concentration in the offered forage, resulting in increased nitrogen intake in autumn and reduced NDF intake in all seasons. Grass-clover swards had a significantly greater OM and DM digestibility compared to grass-only swards. This could potentially result in increased animal production from grass-clover swards compared to grass-only swards.Intake and digestibility are key drivers of animal production from grazed forage. The objective of this study was to compare the in vivo digestibility and voluntary dry matter (DM) intake of grass-only and grass-white clover (grass-clover) forage in individually housed sheep. This study was a Latin square design, repeated on three occasions in 2017: Spring (27 March–29 April), summer (19 June–22 July) and autumn (4 September–29 September). Grass-clover and grass-only swards were harvested daily and offered ad libitum to 6 individually housed wether sheep per treatment per period. Digestibility of DM, organic matter (OM), neutral detergent fibre (NDF) and acid detergent fibre (ADF) were determined using the total faecal collection method. Dry matter intake was not significantly different between treatments. White clover inclusion increased forage crude protein concentration in autumn (p < 0.001) and reduced NDF concentration in the offered forage (p < 0.001), increasing nitrogen intake per sheep in autumn (p < 0.001) and decreasing NDF intake per sheep in autumn (p < 0.001). Grass-clover swards had a significantly greater OM and DM digestibility compared to grass-only swards (p < 0.05). This could potentially result in increased animal production from grass-clover swards compared to grass-only swards.

GRAIN REPLACEMENT VALUE OF CASSAVA AND SWEET POTATOES IN RATIONS FOR GROWING LAMBS.

27 LAMBS made up of 24 West African Dwarf (WAD)X Yankasa crosses aged 6 to 7 months old of 11 to 14kg weight and 3 WAD wether sheep, about 3 years old and weighing 34 to 39kg were used in this experiment designed to evaluate the maize replacement value of sweet potato and cassava tubers in sheep diet through energy and protein utilization. Each of the wether sheep carried permanent rumen cannula. The results showed that the maize, sweet potato and cassava based concentrates fed as supplement to grass (Cynodon nlemfuensis) improved the digestibilities of crude fibre, crude protein, organic matter, NFE and N-balance. The treatment effect was significant (P&lt;0.05) with the highest coefficients and N-retention values recorded for Animals fed sweet potato based concentrate. The ruminal VFA's production, ammonia and blood urea levels followed the same trend for all the three energy sources but the treatment effect was not significant. All the parameters so obtained on energy and protein utilization, however, indicated that the dried milled sweet potato and cassava tubers can successfully replace maize grains in sheep diet.

The effect of fermented corn grain supplementation to alfalfa on water intake and water balance by wether sheep

Cilj ovog rada bio je utvrditi utjecaj dodatka vlažnog zrna kukuruza (VZK) sjenaži lucerne (SL) na ad libitum konzumaciju i balans vode kastriranih ovnova. Istraživanje se sastojalo od 3 hranidbena tretmana: (i) hranidba samo SL, (ii) hranidba SL uz dodatak 5 g VZK kg-1 tjelesne mase kastriranih ovnova (SL5) i (iii) hranidba SL uz dodatak 10 g VZK kg-1 tjelesne mase kastriranih ovnova (SL10). Pokus je bio postavljen kao 3x3 latinski kvadrat. Životinje su hranjene 2x dnevno, cijelo su vrijeme imale na raspolaganju vodu ad libitum. Kod tretmana SL5 i SL10 je utvrđena niža konzumacija vode napajanjem (P&amp;lt;0,05) i niža konzumacija vode hranom (P&amp;lt;0,05) u usporedbi s tretmanom SL. Dodatak VZK SL je smanjio lučenje vode urinom (P&amp;lt;0,05), a povećao lučenje vode fecesom (P&amp;lt;0,05) u usporedbi s tretmanom SL. Kod tretmana SL5 je izlučeno više urina (P&amp;lt;0,05) u usporedbi s tretmanom SL10. Dodatak VZK SL je smanjio balans vode kastriranih ovnova (P&amp;lt;0,05) u usporedbi s balansom vode kastrata hranjenih samo sjenažom lucerne. Zaključeno je da dodatak VZK obroku baziranom na SL utječe na konzumaciju i lučenje vode iz organizma te balans vode kastriranih ovnova.

PSX-13 Effects of supplementing sugar-based byproducts on ingestive behavior and ruminal fermentation parameters in small ruminants

Abstract A duplicated 4 × 4 Latin square design evaluated the effects of replacing ground corn grain (GCG) by sugar-based byproducts plus corn gluten feed (SBB-CGF) on ingestive behavior and ruminal fermentation parameters in small ruminants. Four ruminally cannulated wether sheep and four wether goats (72 and 65 ± 2.3 kg BW, respectively) were individually allocated to 8 pens, over 4 periods of 19-d each (12 d adaptation plus 7 d of sample collection) to receive a diet containing 50% roughage (bermudagrass hay; Cynodon sp.) and 50% concentrate (80% GCG, 16% soybean meal, and 4% premix) with 4 levels of inclusion of SBB-CGF in replacement of GCG (0, 33, 66, and 100%, DM basis). Corn gluten feed was used with SBB to maintain the diets isonitrogenous. Ruminal fluid was collected at 0, 2, 4, and 6 h after the morning feeding, whereas ingestive behavior was assessed on the d 12 of each period for 24 h. Resting time linearly increased with greater inclusion levels of SBB-GCF (P = 0.04; 15.6, 15.7, 16.0, 16.8 h/d). Rumination time was greater (P = 0.001), whereas resting time was lower (P = 0.002) for wether sheep vs. goats (6.5 vs. 4.3 h/d and 15 vs. 17 h/d, respectively). Ruminal concentrations of ammonia-N (P = 0.05; 13.3, 13.2, 10.4, and 10.4 mg dL-1), acetate (P = 0.001; 58.9, 49.6, 48.5, and 43.1 mM), and acetate:propionate ratio (P &amp;lt; 0.001; 3.6, 2.4, 2.0, and 1.9 mM) linearly decreased, whereas propionate concentrations (P = 0.01; 17.9, 23.0, 30.6, and 28.8 mM) linearly increased with greater levels of SBB-GCF in the diet. In conclusion, sugar-based byproducts plus corn gluten feed can replace ground corn grain up to 100% in the diets of goats and sheep consuming a 50:50 roughage:concentrate diet without compromising the ingestive behavior and ruminal fermentation parameters.

How does herbage mass effect voluntary dry matter intake and in vivo organic matter digestibility in sheep and the in vitro gas production of perennial ryegrass?

It is essential to have accurate data relating sward herbage mass (HM) to voluntary dry matter intake (VDMI) and in vivo organic matter digestibility (OMDIV) across the year. This will ensure that the production performance of animals grazing differing HM swards can be accurately predicted using in vitro and in situ methods. The objectives of this experiment were to (i) determine the OMDIV and VDMI of sheep offered perennial ryegrass differing in HM throughout the growing season and (ii) evaluate in vitro gas production (IVGP) and in situ indigestible neutral detergent fibre (iNDFIS) as methods of predicting OMDIV. A 3 × 3 Latin square design was used to investigate three HM treatments. The target HM (measured > 4 cm) of perennial ryegrass for the three HM treatments was 1200 kg dry matter (DM)/ha (Low), 2500 kg DM/ha (Medium) and 4000 kg DM/ha (High). The experiment was a Latin square design repeated in three time stages (TS) in 2013 (TS1, TS2 and TS3). A 3 × 2 incomplete Latin square design was used in early spring 2014 (TS4). In TS4 the HM were lower than in the previous TS at 1000 kg DM/ha (Low), 1800 kg DM/ha (Medium) and 2500 kg DM/ha (High). Each experimental period within each TS consisted of a 6 day adaptation phase and 6 day measurement phase; with 12 Texel wether sheep used. Sheep were fed ad libitum to ensure a 10% refusal rate. The interaction between TS and HM treatment had the greatest effect on chemical composition, VDMI and OMDIV. Low HM swards had the greatest VDMI and OMDIV. For each 1000 kg DM/ha increase in HM, OMDIV was reduced by 2.3% on average. This varied from 0.9% in TS4 to 2.7% in TS3. There was no difference between HM treatments in the rate of digestion of digestible NDF using the IVGP technique. In situ indigestible NDF concentration and OMD derived from IVGP (OMDGP) were highly correlated with OMDIV (r2 = 0.901 and 0.895 respectively) and moderately correlated with digestible organic matter intake (DOMI) (r2 = 0.633 and 0.652 respectively). It can be concluded that the interaction between HM and TS will greatly affect OMDIV and VDMI. Secondly OMDIV can be predicted by both iNDFIS and OMDGP with acceptable accuracy to allow for their use in future feed evaluations.

Effects of perennial ryegrass variety and ploidy on voluntary dry matter intake and in vivo digestibility in sheep

Two tetraploid varieties, Astonenergy and Delphin, and two diploid varieties of perennial ryegrass (Lolium perenne), Tyrella and Glenroyal, were evaluated for voluntary dry matter intake (VDMI) and in vivo organic matter digestibility (OMD) using Texel wether sheep housed in digestibility stalls. The structural profile and leaf, stem, dead proportions of the sward were also measured. The experiment was repeated on three occasions (Time Stage (TS)): May/June 2013 (TS1), August/September 2013 (TS2) and September/October 2014 (TS3). Data from both years were analysed separately. There was no variety effect on VDMI during TS1 (1481 ± 44.4 g/day), TS2 (1621 ± 41.7 g/day) or TS3 (1223 ± 86 g/day). There was a significant interaction between TS and variety for OMD (P<0.05) in 2013. OMD declined from TS1 to TS2 for all varieties (P<0.001). This was associated with an increased content of dead material in the sward in TS2 (P<0.001). There was a significant interaction (P<0.05) between TS and ploidy for VDMI as a percentage of bodyweight (VDMI % BW) and OMD in TS1 and TS2, as diploid varieties had higher values in TS1 and lower values than in TS2. In TS3, tetraploid varieties had higher VDMI (% BW) (P<0.05) and a tendency towards higher OMD (P=0.07) when compared to diploid varieties. These results indicate that there is a season by variety (and ploidy) interaction for VDMI and OMD. Future work should use an increased number of varieties to investigate the causes and timing of this interaction.

Partition of dietary energy by sheep fed fresh ryegrass (Lolium perenne) with a wide-ranging composition and quality

Context Perennial ryegrass (Lolium perenne L.) is an important forage in temperate ruminant agricultural systems, but its quality and composition is highly variable and can become dominated by senescent material during summer and dry periods. Nutritive value is often predicted on the basis of chemical composition and calculated metabolisable energy (ME), which is rarely measured. Aim To measure the partition of energy from ryegrasses with widely varying proportions of leaf and senescent material, among faeces, urine and methane (CH4) in sheep. Methods Three experiments were undertaken with two groups of young wether sheep, fed seven diets of freshly cut ryegrass, at maintenance levels of intake to measure the partition of dietary energy among faeces, urine and CH4, enabling ME to be calculated. Across the seven diets, green leaf accounted for 16.0–87.6% of feed offered, whereas senescent material ranged from 2.8% to 65.0% and nitrogen (N) ranged between 8.6 and 31.2 g/kg DM. Measured ME was compared with predicted values based on digestible energy. Methane emissions were determined by both open-circuit respiration chambers and sulfur hexafluoride marker dilution. Key results Apparent digestibility (g/100 g) of DM ranged from 51.8 to 75.3 and N from 26.7 to 73.9. The percentage of the gross energy of feeds partitioned to CH4 (chamber) was 6.01–7.42, and 1.77–5.69 to urine. Effects of digestibility on CH4 yields (g/kg DM intake) were minor and the sum of energy losses to CH4 and urine were 13.5–17.6% of digestible energy (DE) intake, suggesting an underestimation of ME when predicted from DE. Use of sulfur hexafluoride substantially overestimated CH4 emissions when the permeation tubes had been in the sheep for 80 days. Conclusions A high proportion of senescent material in ryegrass had little effect on CH4 yields from sheep and energy losses to urine were mostly less than 3% of energy intake and were related to dietary N concentration. Implications Dietary ME calculated from DE is likely to be underestimated when ryegrass contains a high proportion of senescent material, due to reduced urinary energy losses, as CH4 yields are largely unaffected by maturity or senescence.

Effects of level of intake of a 50% concentrate pelleted diet on metabolizability by mature Katahdin wethers

Ten adult Katahdin sheep wethers (74.3 ± 2.03 kg initial BW), approximately 3 yr of age, were used in a crossover experiment to study effects of a restricted feeding regime on digestibility, metabolizability, and heat energy. A 50% concentrate pelleted diet was fed near the ME requirement for maintenance (Control; DM intake = 44.4 g/kg BW0.75) and at 55% of this level (Restricted; DM intake = 24.4 g/kg BW0.75). Periods were 4 wk in length, with 3 wk for adaptation, measures in the final week when animals were situated in metabolism cages, and 2 days for gas exchange quantification via a head-box respiration calorimetry system. Apparent total tract digestibilities of DM (68.9 and 76.1%; SEM = 1.08), OM (78.3 and 83.3%; SEM = 1.57), CP (74.6 and 80.7%; SEM = 1.68), NDF (50.9 and 61.9%; SEM = 3.23), and gross energy (77.9 and 83.0%; SEM = 1.59) were greater (P < 0.05) for Restricted than for Control. Expressed in MJ/day, energy in urine (1.03 and 0.67; SEM = 0.294) and ruminally emitted methane (1.03 and 0.77; SEM = 0.076) were greater for Control vs. Restricted (P < 0.05), but as a percentage of gross energy were at least numerically greater for Restricted (urine: 5.63 and 6.48%, SEM = 2.218 and P = 0.594; methane: 5.46 and 7.16% for Control and Restricted, respectively, SEM = 0.579 and P = 0.030). As a consequence, ME intake as a percentage of gross energy intake did not differ (P = 0.354) between treatments (66.8 and 69.4% for Control and Restricted, respectively; SEM = 2.89). The treatment difference in heat energy (11.05 and 9.29 MJ/day; SEM = 0.563) was less than in ME intake (12.67 and 7.30 MJ/day for Control and Restricted, respectively; SEM = 0.508); thus, recovered energy differed from 0 (P < 0.05) and was greater for Control vs. Restricted (1.62 and −1.99 MJ/day; SEM = 0.661). In conclusion, restricted feed intake had marked influence on digestibility, although energy losses in urine and methane energy compensated so that metabolizability did not differ between treatments. With a diet of this nature a similar ME concentration could be assumed for studies with hair sheep fed near the standard maintenance requirement and restricted in intake.

Effect of substituting soybean meal with euglena (Euglena gracilis) on methane emission and nitrogen efficiency in sheep.

This study evaluated methane (CH 4) emission, intake, digestibility, and nitrogen efficiency in sheep fed diets containing replacement levels (0%, 33%, 50%, and 67% of soybean meal with euglena). In this experiment, four Corriedale wether sheep with an initial body weight of 53.8 ± 4.6 were arranged in a 4 × 4 Latin square design. This experiment lasted 84 days, divided into four experimental periods. Each period lasted 21 days, which consists of 14 days of adaptation to the diets, 5 days to collect samples, and 2 days to collect gas emission from sheep. Methane emission expressed as L/kg DM intake or g/kg DM intake reduced by up to 37% and the energy loss via CH 4 (% of GE intake) reduced by up to 34%. No differences (p > 0.05) were observed in DM and OM intake and whole tract apparent DM digestibility due to substitution of soybean meal with euglena. The total CP loss reduced significantly (linear, p < 0.001) and CP efficiency increased linearly (p = 0.03) with increasing concentration of euglena. As a result, nitrogen balance and average daily weight gain remained unchanged despite higher nitrogen concentration in soybean supplemented group. In conclusion, substitution of soybean meal with euglena reduced methane emission without affecting the performance of animals.

Effects of level of brackish water and salinity on feed intake, digestion, heat energy, ruminal fluid characteristics, and blood constituent levels in growing Boer goat wethers and mature Boer goat and Katahdin sheep wethers

A study was conducted to evaluate effects of the level of a brackish water source (5596 mg/l total dissolve salts; TDS) and higher levels of TDS through addition of NaCl on feed intake, digestion, and heat energy in growing Boer goat wethers (GRO-G) and mature Boer (MAT-G) and Katahdin sheep wethers (MAT-S). Five GRO-G (22.1 ± 2.50 kg; 0.76 ± 0.121 yr of age), five MAT-G (52.2 ± 4.99 kg), and five MAT-S (65.5 ± 4.17 kg) were assigned to three simultaneous 5 × 5 Latin squares with 3-wk periods. Treatments within squares were ad libitum intake of fresh water (0-BRW), 50% fresh water and 50% brackish water (50-BRW), 100% brackish water (100-BRW), 100-BRW plus 3450 mg/l NaCl (Low-SLW), and 100-BRW plus 6900 mg/l NaCl (Mod-SLW). Total water intake was not influenced by TDS level with GRO-G or MAT-S but increased linearly with increasing TDS (P = 0.004) for MAT-G (952, 1087, 1284, 1192, and 1372 g/day for 0-BRW, 50-BRW, 100-BRW, Low-SLW, and Mod-SLW, respectively; SEM = 147.7). Organic matter (OM) intake was not influenced by water treatment with GRO-G but changed quadratically as TDS increased (P = 0.049) with MAT-G (744, 749, 785, 732, and 703; SEM = 76.3) and linearly (P = 0.065) with MAT-S (870, 867, 835, 788, and 694 g/day for 0-BRW, 50-BRW, 100-BRW, Low-SLW, and Mod-SLW, respectively; SEM = 80.0). Total tract OM digestion in MAT-G and MAT-S was not influenced by water TDS level but decreased linearly (P = 0.004) and tended to change quadratically (P = 0.054) in GRO-G (59.3, 55.5, 47.8, 47.0, and 49.5% for 0-BRW, 50-BRW, 100-BRW, Low-SLW, and Mod-SLW, respectively; SEM = 4.67). Intake of metabolizable energy (ME) decreased linearly with increasing TDS for MAT-G (P = 0.014; 458, 458, 441, 449, and 381; SEM = 34.2) and MAT-S (P = 0.045; 384, 361, 328, 317, and 289; SEM = 33.2) and increased linearly and changed quadratically (P ≤ 0.031) for GRO-G (519, 402, 321, 319, and 363 kJ/kg BW0.75 for 0-BRW, 50-BRW, 100-BRW, Low-SLW, and Mod-SLW, respectively; SEM = 54.5). In conclusion, increasing TDS concentration in drinking water had effects on intake and digestion that differed among animal types, with ME intake of growing goats more adversely affected by increasing brackish water level compared with mature small ruminants because of decreased digestibility. Conversely, decreases in ME intake for MAT-S with increasing TDS primarily related to decreasing feed intake, with relatively small effects for MAT-G associated with the Mod-SLW treatment.

128 Effects of Level of Brackish Water and Salinity on Feed Intake, Digestion, and Heat Energy in Growing Boer Goat Wethers and Mature Boer Goat and Katahdin Sheep Wethers.

128 Effects of Level of Brackish Water and Salinity on Feed Intake, Digestion, and Heat Energy in Growing Boer Goat Wethers and Mature Boer Goat and Katahdin Sheep Wethers.

Intake and Digestibility of Sheep-fed Alfalfa Haylage Supplemented with Corn

The objective of this study was to determine the effect of dry corn (DC) and fermented corn (FC) supplemented to alfalfa haylage (AH) (Medicago sativa L.) on feed intake, digestibility, and nitrogen (N) balance in wether sheep. The study consisted of five feeding treatments incorporating AH alone and AH supplemented with 5 or 10 g of DC (DC5 and DC10, respectively) or FC (FC5 and FC10, respectively) kg−1 body weight (BW) d−1 to Suffolk wethers. The DC5 and FC5 treatments were higher in acid detergent fibre (ADF) intake (P < 0.001), neutral detergent fibre (NDF) intake (P < 0.001), and N intake (P < 0.05) compared with the DC10 and FC10 treatments. Both energy sources (DC and FC) and supplemental levels (5 and 10 g kg−1 BW d−1) increased (P < 0.05) the digestibility of dry matter (DM) and organic matter (OM), and the digestibility of OM in DM (D value), and decreased the digestibility of ADF (P < 0.05). The DC10 and FC10 treatments had higher D values (P < 0.05) and reduced ADF digestibility values (P < 0....

Evaluation of different types of calcined magnesites as feed supplement in small ruminant

Magnesium (Mg) deficiency in ruminants can be avoided by the inclusion of magnesium oxide (MgO) supplements in their diets. However, the behaviour of MgO supplements in the rumen depends on various factors such as ore-origin, calcination conditions, particle size distribution etc. Moreover, in most cases the solubility of MgO supplements (both in vitro and in vivo) is not related with their apparent bioavailability, so their quality should be evaluated primarily by using both in vitro and in vivo tests before using them in practice. Thus, the objectives of this study were: to determine: (a) the particle size distribution of four MgO supplements (Δ1, Δ2, Δ3 and Δ4) with different chemical composition and their both in vitro and in vivo solubility and (b) their apparent bioavailability. The solubility of MgO supplements was tested in an aqueous NH4NO3 solution (in vitro) and in sheep (in vivo). Five fistulated wether sheep of Karaguniko breed were used in a Latin-square (5×5) design to determine the in vivo solubility. The sheep were kept in metabolism cages and were given a basal diet (800g alfalfa hay and 600g concentrates). The same diet plus 2g of each MgO supplement was given to each sheep respectively during a 17-days period in order to determine their apparent bioavailability. The results showed that the solubility was depended on both the amounts of fine particles and the reactivity of the MgO supplements (P<0.05). A decrease in the solubility of the MgO supplements was found by increasing Fe2O3 and Al2O3 content. Despite the fact that for the most MgO supplements (Δ2, Δ3 and Δ4) a close relationship was found between solubility (both in vitro and in vivo) with apparent bioavailability this did not occur in the case of Δ1 MgO supplement. Moreover, the Δ4 MgO supplement was evaluated as the best candidate for feed supplement in ruminant’s diets, not only due to its better particle size distribution, but also to its significantly high solubility (both in vitro and in vivo) and bioavailability which was due to its high purity (>90%) and reactivity (49s) and lower content in Fe2O3 and Al2O3 compounds compared to the others. In conclusion, the properties of MgO supplements should be tested both in vitro and in vivo before their use in practice since they are affected by various factors.