大麦/箭筈豌豆混合日粮对绵羊营养物质消化率和温室气体排放的影响

为研究不同比例箭筈豌豆(Vicia sativa)日粮对绵羊消化代谢和温室气体排放的影响,本试验选用12只体况良好、体重为(30±1)kg的6月龄杂交代公羊,随机分为2组,分别饲喂不同箭筈豌豆添加水平的日粮。两组饲粮中,大麦(Hordeum vulgare)∶箭筈豌豆比例分别为8∶2和6∶4。预饲期为15 d,正式饲喂实验为6 d,试验羊转入代谢笼内采用全收粪尿法进行消化代谢试验。结果表明,2组间干物质采食量及营养物质消化率差异均不显著(P<0.05);6∶4组的单位代谢体重的氧气日消耗量有高于8∶2组的趋势(P=0.083),2组间甲烷、二氧化碳排放量各指标差异不显著(P<0.05)。综上可知,箭筈豌豆添加比例为20%和40%的日粮饲喂绵羊在营养物质消化代谢和温室气体排放的效果基本相同。     

The influence of lupin seed germination on the chemical composition and standardized ileal digestibility of protein and amino acids in pigs

The germination process can modify the chemical composition of nutrients in seeds, which can influence the digestibility and utilization of sprouts in animal diets compared to raw seeds. The aims of research were to provide controlled germination process of lupin seeds, monitor the changes in seed composition and determine the influence of the germination on the coefficients of standardized ileal digestibility (SID) of crude protein and amino acids in growing pigs, compared to raw lupin seeds. The seeds of two lupin species were used: yellow (RYL) (Lupinus luteus, cv. Lord) and blue (RBL) (Lupinus angustifolius, cv. Graf). Germination was provided in the dark at 24 °C for 4 days. Nutritional and antinutritional compositions of raw and germinated seeds (GYL and GBL, respectively) were analysed. Digestibility study was performed on pigs with an average body weight of 25 kg, and the pigs were surgically fitted with a T‐cannula in the distal ileum, with chromic oxide as an indicator. Seed germination increased the crude protein and fibre concentrations, but reduced the levels of the ether extract, nitrogen‐free extracts and all amino acids in protein. The content of alkaloids and raffinose family oligosaccharides decreased in both lupin species. Germination had no positive impact (p > 0.05) on the SID of crude protein and amino acids. Germination of lupin seeds negatively influenced the SID of lysine and methionine (p < 0.05). The results of the research revealed a decrease in the concentrations of antinutritional factors in the sprouts of yellow and blue lupins compared to raw seeds; however, no positive effect was observed on the coefficients of the standardized ileal apparent digestibility of protein and amino acids.     

Effects of toasting,inclusion levels and different enzyme supplementations of faba beans on growth performance of broiler chickens

Faba beans (Vicia faba) are an alternative protein source that likely can be used to a higher extent in broiler diets. White-flowered faba beans contain antinutritional substances (ANS) such as non-starch polysaccharides (NSP), trypsin inhibitors, and lectins, which might limit its inclusion level. Lectins and trypsin inhibitors are heat labile and previous studies have shown that steam-pelleting and enzyme treatment improves the nutritional value of faba beans. However, alternative to pelleting would facilitate for farmers to add faba beans on-farm. Currently, there are machines available for toasting faba beans on-farm, which might be used for broiler mash diets. The objective of this study was to investigate the effect of inclusion level (0, 10, 20 and 30%), toasting (140°C 5.5 min) and different enzymes (xylanase + phytase vs. xylanase, phytase, amylase, protease) of faba bean diets on growth performance and organ parameters in broilers. To test this, 2 experiments 34 and 35 days, using a total of 480 chickens were performed. Feed intake, body weight (BW) and feed conversion ratio were registered weekly, in addition, organ and carcass weights were registered at slaughter. The results showed that inclusion of 20% faba beans is possible in a pelleted diet with maintained broiler growth performance. When 20% was included in a mash diet, feed intake and BW decreased compared to chickens fed pelleted diets, irrespectively of pre-toasting of the beans. It can be concluded that toasting cannot replace pelleting. Supplementation of protease and amylase in addition to xylanase and phytase did not improve the nutritional value of faba beans.     

The effect of raw and roasted soybeans on intestinal health,diet digestibility,and pancreas weight of broilers

Soybeans have high protein and energy content; however, they also contain antinutritional factors that limit inclusion in feeds for nonruminant animals. Therefore, the aim of the present study was to evaluate the influence of feeding raw (RFFS), deactivated (DFFS), or over-heated (OFFS) full-fat soybeans on the intestinal health, diet digestibility, and pancreas weight of broilers. One hundred twenty broilers were fed diets containing 15% DFFS, 10% DFFS + 5% RFFS, 15% RFFS, or 10% DFFS + 5% OFFS; data were submitted to ANOVA and means were compared by Tukey's test. Broilers fed 15% RFFS presented higher goblet cell counts and sialic acid levels compared with those fed diets containing DFFS and OFFS. Intestinal villi were shorter in birds fed 15% RFFS than those fed 10% DFFS + 5% RFFS. The coefficient of apparent digestibility of nutrients was affected by the dietary treatments. The pancreas of the broilers fed the diets containing RFFS was significantly heavier of those fed DFFS or OFFS. The intestinal integrity, as well as pancreas structure, is impaired by the inclusion of RFFS in broiler diets. Conversely, soybean over-heating hinders nutrient utilization by broilers.     

Effects of dietary Tenebrio molitor meal inclusion in free‐range chickens

Insects are currently being considered as a novel protein source for animal feeds, because they contain a large amount of protein. The larvae of Tenebrio molitor (TM) have been shown to be an acceptable protein source for broiler chickens in terms of growth performance, but till now, no data on histological or intestinal morphometric features have been reported. This study has had the aim of evaluating the effects of dietary TM inclusion on the performance, welfare, intestinal morphology and histological features of free‐range chickens. A total of 140 medium‐growing hybrid female chickens were free‐range reared and randomly allotted to two dietary treatments: (i) a control group and (ii) a TM group, in which TM meal was included at 75 g/kg. Each group consisted of five pens as replicates, with 14 chicks per pen. Growth performance, haematological and serum parameters and welfare indicators were evaluated, and the animals were slaughtered at the age of 97 days. Two birds per pen (10 birds/treatment) were submitted to histological (liver, spleen, thymus, bursa of Fabricius, kidney, heart, glandular stomach and gut) and morphometric (duodenum, jejunum and ileum) investigations. The inclusion of TM did not affect the growth performance, haematological or serum parameters. The morphometric and histological features were not significantly affected either, thus suggesting no influence on nutrient metabolization, performance or animal health. Glandular stomach alterations (chronic flogosis with epithelial squamous metaplasia) were considered paraphysiological in relation to free‐range farming. The observed chronic intestinal flogosis, with concomitant activation of the lymphoid tissue, was probably due to previous parasitic infections, which are very frequently detected in free‐range chickens. In conclusion, the findings of this study show that yellow mealworm inclusion does not affect the welfare, productive performances or morphological features of free‐range chickens, thus confirming that TM can be used safely in poultry diets.     

The influence of dietary tannin supplementation on digestive performance in captive black rhinoceros (Diceros bicornis)

Free-ranging browsers such as the black rhinoceros (Diceros bicornis) consume a diet that contains tannins, whereas the diets offered to them in captivity consist mostly of items known to contain hardly any such secondary plant compounds. Tannins could have potentially beneficial effects, including the chelation of dietary iron (iron storage disease is a common problem in black rhinos). Here, we tested the acceptance, and the consequences on digestion variables, of a low-dose tannin supplementation in captive animals. Eight black rhinoceroses from three zoological institutions were used. Faecal output was quantified by total faecal collection. Diets fed were regular zoo diets supplemented with either tannic acid (T, hydrolysable tannin) or quebracho (Q, condensed tannins); overall tannin source intake increased at 5-15 g/kg dry matter (DM) in relation to regular zoo diets. Adaptation periods to the new diets were >2 months. Additional data were taken from one hitherto unpublished study. Data were compared to measurements in the same animals on their regular zoo diets. All animals accepted the new diets without hesitation. There was no influence of tannin supplementation on digestion coefficients of DM and its constituents, or faecal concentrations of short-chain fatty acids or lactate. Water intake did not increase during tannin supplementation. Should the inclusion of dietary tannin sources be an objective in the development of diets for captive rhinoceroses, moderate doses such as used in this study are unlikely to cause relevant depressions of digestive efficiency and will not interfere with bacterial fermentation in a relevant way.     

Phosphorus availability in feed phosphates determined by regression

Due to environmental concern a lot of effort has been dedicated to improve the utilisation of phytate phosphorus (P) in cereals and seeds. Consequently, microbial phytases are added to pig diets at the expense of feed phosphates. However, there is still a need for inclusion of feed phosphate, especially in diets for young piglets and lactating sows in order to meet their P requirement. This creates a demand for feed phosphates with a high P availability. Fourteen feed phosphates, including two newly developed monocalcium phosphates (MCP), were tested in this experiment. For each source, a series of 5 diets was prepared by inclusion of increasing amounts of either MCP or MSP. These diets were offered to pigs kept in metabolism crates (6 pigs on each of the 5 diets). After 5 days adaptation, total collection of faeces and urine was performed for 7 days. P availability in each source was determined by regression of the net absorption of P on P-intake. The experiment revealed that MSP had the highest availability (79%) and the availability of all the tested phosphates varied between 50 and 79%. The new MCPs proved to be 71 and 75% available.     

The impact of phytoestrogen source supplementation on reproductive performance,plasma profile,yolk fatty acids and antioxidative status in aged laying hens

The objectives of this study were to investigate the effects of flaxseeds and/or fenugreek seeds as a source of phytoestrogens in laying feed on productive performance, egg quality, yolk fatty acids, plasma profile and antioxidative status in aged laying hens. A total of 120 Bovans Brown hens at 65 weeks of age were housed individually in laying cages in an open‐sided building under a 16‐hr light: 8‐hr dark lighting schedule. Hens were randomly divided into four experimental treatments (n = 30 each): (a) control (basal diet without any supplementation); (b) 1 g/kg of flaxseeds; (c) 1 g/kg of fenugreek seeds; and (d) combination of 1 g/kg flaxseeds and 1 g/kg fenugreek seeds from 65 to 71 weeks of age. Hen‐day egg production and egg mass were significantly increased by dietary supplementation of flaxseeds and/or fenugreek seeds, while feed intake was not affected; thus, feed conversion ratio was improved (p < 0.05). Weights of egg, albumen, yolk and shell were increased by the dietary treatments. Shell thickness and yolk colour were improved by supplementation of flaxseeds and/or fenugreek seeds. Yolk crude protein was not significantly affected by treatments; however, crude fat and calcium contents in yolk were increased and egg yolk cholesterol content was decreased. Interestingly, dietary supplementation of flaxseeds, fenugreek seeds and their combination had a significant positive effect on plasma luteinizing hormone, follicle‐stimulating hormone, oestradiol‐17β and triglycerides. Inclusion of flaxseeds and/or fenugreek seeds in the diets enhanced the serum glutathione peroxidase and superoxide dismutase activities and reduced the malondialdehyde and total cholesterol concentrations in plasma. Dietary supplementation of flaxseeds and/or fenugreek seeds increased α‐linolenic and linoleic acids in egg yolk. It could be concluded that inclusion of mixed sources of phytoestrogens in diets improved laying performance, egg quality, the antioxidative status, hormonal profile and steroidogenesis in aged laying hens.     

饲料中抗营养因子消除方法研究进展

饲料抗营养因子是影响营养物质在动物体内消化利用和导致动物代谢性疾病的主要因素。为深入了解饲料抗营养因子消除方法,文章对饲料中抗营养因子的种类、抗营养作用机理及其消除方法的研究情况进行了综述。     

ORIGINAL ARTICLE: Nitrogen and energy utilization in lactating dairy goats fed diets with different legume seeds

The N and energy utilization of diets with different legume seeds was analysed in lactating goats. Four isonitrogenous and isoenergetic diets were used and in each case 30% of the protein was supplied by one of four different legume seeds: lupins (L), faba beans (FB), bitter vetch (BV) and vetch (V). A group of eight Granadina goats, allocated to a replicated 4 × 4 Latin Square, were used. The N and energy utilization of the different diets may be considered adequate; milk N/intake N was approximately 0.20, milk N/N balance was approximately 0.50 and milk energy/metabolizable energy was approximately 0.30. Under similar N and energy intakes, faecal and urinary excretion of N and the quantities in milk did not vary significantly. However, the partition of the N balance between milk production and deposit within the body varied depending on the diet. Although this N available to the metabolism was the highest for the FB diet, the quantity of this directed to milk was the lowest. Finally, the faecal and urinary excretion with respect to the quantity directed to milk production did not vary significantly among the different diets.     

Biochemical proximates of pumpkin (Cucurbitaeae spp.) and their beneficial effects on the general well‐being of poultry species

There is a growing need to increase productivity in poultry. Growth hormones and antibiotics have the ability to improve health, weight gain and feed efficiency in meat‐producing animals. The growth‐promoting antibiotics are administered to poultry to improve the general performance of the chicken. However, the use of the xenobiotic drugs in food‐producing animals has been a concern and a sensitive issue of debate for several decades in the EU and many other regional blocks of the world. Consequently, the use of hormones in animal production has been banned in Italy, Denmark and Germany for over 4–5 decades, while Belgium and Greece had never permitted its use for livestock fattening purposes. Bioactive phytochemicals exhibit antimicrobial, antioxidant, antiparasitic, antiprotozoal, antifungal and anti‐inflammatory properties and consequently have several beneficial effects on appetite, growth and the immune status of the animal. In South Africa, different species of pumpkin are produced for food due to their high nutrient content. The flesh serves as a traditional food, while the seeds and peels are commonly discarded. Pumpkin seed extract is reported to be useful for immunomodulation, reproductive health, therapeutics over a wide range of disease conditions and stimulates metabolism of accumulated fats. Studies have also shown that pumpkin seeds are a valuable source of protein and fat. Their complexity and extent of bioactivity offers sustainable prospects for natural control of pathogenic/parasitic organisms, stimulate nutrition or enhance resistance to disease infections, and reduce abdominal fat and serum levels of harmful lipids, while increasing serum levels of beneficial lipids.     

Peel meals as feed ingredients in poultry diets: Chemical composition,dietary recommendations and prospects

The increase demand for poultry products has had direct effect on the supply and price of feed. This has increased research interest into the potential of locally available, less competed and low cost materials as feed ingredients. Several peels from roots/tubers and fruits have been evaluated in poultry diets but recommendations have not been consistent. High fibre, low nutrient density and likely presence of antinutritional factors limit the efficient utilisation of peel meal by poultry. Plant cultivar, age, agronomic practices, method of peel processing, breed and age of poultry all affect the inclusion level of peel meal in poultry diets. The increase interest in breeding crops for low antinutrients, knowledge in processing technologies and availability of several additives such as enzyme products, amino acids and antinutrients binding agents in the feed market could improve the usefulness of peel meal in on‐farm poultry rations. This study reviews the potential of selected root/tuber and fruit peels as feed ingredients for poultry with regards their composition, dietary recommendation and prospects.     

Characteristics of lipids and their feeding value in swine diets

In livestock diets, energy is one of the most expensive nutritional components of feed formulation. Because lipids are a concentrated energy source, inclusion of lipids are known to affect growth rate and feed efficiency, but are also known to affect diet palatability, feed dustiness, and pellet quality. In reviewing the literature, the majority of research studies conducted on the subject of lipids have focused mainly on the effects of feeding presumably high quality lipids on growth performance, digestion, and metabolism in young animals. There is, however, the wide array of composition and quality differences among lipid sources available to the animal industry making it essential to understand differences in lipid composition and quality factors affecting their digestion and metabolism more fully. In addition there is often confusion in lipid nomenclature, measuring lipid content and composition, and evaluating quality factors necessary to understand the true feeding value to animals. Lastly, advances in understanding lipid digestion, post-absorption metabolism, and physiological processes(e.g., cell division and differentiation, immune function and inflammation); and in metabolic oxidative stress in the animal and lipid peroxidation, necessitates a more compressive assessment of factors affecting the value of lipid supplementation to livestock diets. The following review provides insight into lipid classification, digestion and absorption, lipid peroxidation indices, lipid quality and nutritional value, and antioxidants in growing pigs.     

Nutritive evaluation of legume seeds for ruminant feeding

Chemical composition, rumen degradability and the effect of particle losses, and intestinal digestibility of protein by using in situ‐in vitro and in vitro techniques were stated for beans (Vicia faba), lupin (Lupinus albus), vetch (Vicia sativa) and bitter vetch (Vicia ervilia) and four diets including those legume seeds. In addition, the apparent digestibility of experimental diets was determined in goats. The legume seeds showed high protein content (206–319 g/kg dry matter). Effective degradability of protein for legumes and diets varied from 0.80 to 0.87 and 0.76 to 0.82, respectively, decreasing to 0.53–0.76 and 0.61–0.67, respectively, when particle loss was taken into account. Different intestinal digestibility values were obtained with both methodologies without significant relationship between them (y = 1.058–0.463x; R² = 0.068; RSD = 0.140; p = 0.53). There were no differences in the apparent nutrients and energy digestibility among diets (p > 0.05). These legumes can supply rapidly degradable protein for microbial protein synthesis and contribute to the pool of amino acids available for the synthesis of milk protein and for retention in the body.     

Studies on the Use of Colocasia esculenta (Taro Cocoyam) in the Diets of Weaned Pigs

Sixty weanling Large White×Duroc pigs were allocated to five groups of 12 pigs per group and fed on one of five diets. The five diets comprised 0, 50% and 100% unboiled, sun-dried taro cocoyam cormels (Colocasia esculenta) and 50% and 100% boiled, sun-dried taro cocoyam cormels as replacements for maize. The levels of some antinutritional factors were also determined in both boiled and unboiled, sun-dried taro cocoyam. Boiling reduced (p<0.05) the amounts of the antinutritional factors in the taro cocoyam cormels. There were no significant differences (p>0.05) in feed intake, weight gain or feed efficiency between the diets containing boiled taro cocoyam cormels. However, for unboiled, sun-dried taro cocoyam cormels, there were significant differences (p<0.05) in weight gain and feed efficiency, these being depressed at more than 50% replacement of maize. This may be due to the relatively high amounts of antinutritional factors in the unboiled, sun-dried taro cormels. Boiled taro cocoyam cormels were comparable to maize as an energy source in the diets of weanling pigs.     

大豆中胰蛋白酶抑制因子的生化性质和抗营养作用

生大豆中含有许多抗营养因子影响其营养价值与利用效果,其中最主要的是胰蛋白酶抑制因子。本文总结了大豆中两大类胰蛋白酶抑制因子,即Kunitz类和Bowman-Birk类抑制因子的主要生化性质,以及含大豆胰蛋白酶抑制因子的日粮对不同种类动物的饲喂效果和生理反应。另外还介绍了胰腺分泌的蛋白酶与抑制因子的识别与反应机理,以及大豆胰蛋白酶抑制因子阻碍动物生长和引起胰腺增大的作用方式。最后讨论了在研究胰蛋白酶抑制因子的抗营养作用时,需要注意的几个问题。     

Evaluation of soy protein concentrates in nursery pig diets

Four experiments were conducted with 730 weanling pigs to determine the effects of soy protein concentrate (SPC) in diets for weanling pigs. Experimental diets were fed from d 0 to 14 postweaning and a common diet was fed from d 15 to 28 for Exp. 1, 2, and 3; experimental diets were fed from d 0 to 7 postweaning in Exp. 4. In Exp. 1, the 4 experimental diets included 1) a 0% soybean meal (SBM) diet containing animal protein sources; 2) a 40% SBM diet; or a 28.55% SPC (replacing the 40% SBM on a total Lys basis) diet from 3) source 1, or 4) source 2. Pigs fed diets containing either animal protein or 40% SBM had greater ADG and ADFI (P <0.05) than pigs fed either SPC source. In Exp. 2, the 5 experimental treatments included diets 2, 3, and 4 from Exp. 1, along with 14.28% SPC from each SPC source used in Exp. 1 (replacing half of the total Lys from the 40% SBM diet). From d 0 to 14 and d 0 to 28, the SPC source x level interaction was significant for ADG (P <0.01) and was a tendency for ADFI (P <0.07). Replacing SBM with SPC from source 1 did not affect pig performance. However, replacing SBM with SPC from source 2 resulted in an improvement (quadratic, P <0.05) in ADG for pigs fed the diet containing 14.3% SPC, but resulted in no benefit from replacing all the SBM with SPC. Replacing SBM with SPC from either source improved G:F (quadratic, P <0.01), with the greatest G:F observed for pigs fed the diets with 14.3% SPC. Experiment 3 evaluated increasing levels of source 2 SPC, with treatments consisting of 1) 0% (40% SBM); 2) 7.14%; 3) 14.28%; 4) 21.42%; and 5) 28.55% SPC. There was a tendency for increased ADG (quadratic, P <0.06) and increased ADFI (quadratic, P <0.04) as inclusion of SPC in the diet increased. The gain-to-feed ratio improved (linear, P <0.01) as the SPC level in the diet increased. Inclusion of approximately 14 to 21% SPC from source 2 maximized pig performance. In Exp. 4, pigs were offered a choice of consuming the diets containing 40% SBM or 28.6% SPC from source 2. Daily feed intake was greater (P <0.0001) for the SBM diet (186 g/d) than for the SPC diet (5 g/d). Our results suggest that replacing a portion, but not all, of the high-SBM diet with SPC from source 2, but not from source 1, improves pig performance. The poor intake of pigs fed high levels of SPC may indicate a palatability problem, thus limiting its inclusion in nursery pig diets.     

Common Vetch (Vicia sativa) for Improving the Nutrition of Working Equids in Campesino Systems on Hill Slopes in Central Mexico

Campesino systems on hill slopes in Central Mexico rely on equids for multiple activities and have a problem in adequately feeding them. A participatory trial was conducted to evaluate the inclusion of common vetch in the traditional forage oat crop to improve its feeding value. An agronomic evaluation was undertaken by intersowing common vetch at 40 kg seed/ha with oats at 80–100 kg/ha in small plots, recording the yield and the chemical composition of the fresh forage in ten plots at harvest. The data were analysed as a completely random design, taking each farmer/plot as a treatment. A feeding trial compared the live weight of 7 donkeys fed oats and vetch against 17 donkeys fed traditional forage. There were differences between farmers in forage yields (p<0.01) that could not be explained as due to soil types or management. The mean yield of 31.0 t/ha of fresh forage of oats–vetch was 20.5% higher than that from monoculture, and had a higher crude protein content. Donkeys fed the oats–vetch were heavier (p<0.001). The farmers evaluated the oats–vetch association positively, appreciating the higher yields and good condition of their equids. The combination is an appropriate technology for these campesino farming systems.     

BOARD-INVITED REVIEW: opportunities and challenges in using exogenous enzymes to improve nonruminant animal production

Diets fed to nonruminant animals are composed mainly of feed ingredients of plant origin. A variety of antinutritional factors such as phytin, nonstarch polysaccharides, and protease inhibitors may be present in these feed ingredients, which could limit nutrients that may be utilized by animals fed such diets. The primary nutrient utilization-limiting effect of phytin arises from the binding of 6 phosphate groups, thus making the P unavailable to the animal. The negative charges allow for formation of insoluble phytin-metal complexes with many divalent cations. Furthermore, phytin and protein can form binary complexes through electrostatic links of its charged phosphate groups with either the free amino group on AA on proteins or via formation of ternary complexes of phytin, Ca(2+), and protein. The form and extent of de novo formation of binary and ternary complexes of phytin and protein are likely to be important variables that influence the effectiveness of nutrient hydrolysis in plant-based diets. Nonstarch polysacharides reduce effective energy and nutrient utilization by nonruminant animals because of a lack of the enzymes needed for breaking down the complex cell wall structure that encapsulate other nutrients. Enzymes are used in nonruminant animal production to promote growth and efficiency of nutrient utilization and reduce nutrient excretion. The enzymes used include those that target phytin and nonstarch polysaccharides. Phytase improves growth and enhances P utilization, but positive effects on other nutrients are not always observed. Nonstarch polysaccharide-hydrolyzing enzymes are less consistent in their effects on growth and nutrient utilization, although they show promise and it is imperative to closely match both types and amounts of nonstarch polysaccharides with appropriate enzyme for beneficial effects. When used together with phytase, nonstarch polysaccharide-hydrolyzing enzymes may increase the accessibility of phytase to phytin encapsulated in cell walls. The future of enzymes in nonruminant animal production is promising and will likely include an understanding of the role of enzyme supplementation in promoting health as well as how enzymes may modulate gene functions. This review is an attempt to summarize current thinking in this area, provide some clarity in nomenclature and mechanisms, and suggest opportunities for expanded exploitation of this unique biotechnology.     

Evaluation of feeding value of forage soybean silage as a substitute for wheat bran in sheep

Twelve sheep were used in a 3 × 3 Latin square design to evaluate the effect of substituting wheat bran with forage soybean silage in the diet on apparent digestibility and nitrogen balance. Forage soybean (Glycine max (L.) Merrill) was cultivated in a no‐till, no‐herbicide cropping system with Italian ryegrass (Lolium multiflorum Lam.) as a living mulch. Forage soybean and Italian ryegrass were wilted and ensiled in round bales without additives, respectively. The experimental diets were based on corn silage supplemented with protein sources (tow silages or wheat bran). The crude protein and the acid detergent insoluble protein contents of forage soybean silage were the highest among the protein sources. The apparent digestibility of crude protein and the nitrogen balance did not significantly differ among the diets. In addition, the phytoestrogen content of forage soybean silage was below the level at which animal reproductive performance would be negatively affected. These results suggest that forage soybean silage has comparable feeding value to wheat bran, and can be given at an inclusion level of 17% (dry matter basis) as an alternative protein source to wheat bran without adverse effects on digestion or nitrogen balance in sheep fed a corn silage‐based diet.