Author/s : H. G. Helal / Department of Animal & Poultry Nutrition, Desert Research Center, Cairo, Egypt.
This study was conducted to investigate the effect of sprouted barley (Hordeum vulgare) on Acacia saligna (As), rice straw (Rs) and mixture of them on performance of growing lambs. Thirty five growing female Barki lambs (initial weight of 16.4 ± 0.8 kg), about four months age were divided by weight into five groups (7 animals each) for 180 days. To receive one of the following experimental roughages: G1: rice straw (Rs) ad-lib (untreated) as control; G2: dried Acacia ad-lib (As) as control; G3: sprouted barley grains on rice straw ad-lib (SRs); G4: sprouted barley grains on dried Acacia adlib (SAs); G5: sprouted barley grains on 50 % Rs + 50 % As adlib (SRs+ SAs). All animals were fed 60% of total energy requirements as concentrate feed mixture (CFM). At the end of the growing trial five digestibility trials were conducted to evaluate the digestibility of the experimental roughages. Results showed that the treatments with sprouted barely increased CP, Ash and NFE contents while DM, OM, EE, CF, NDF, ADF and ADL contents, were decreased. Sprouted barely on Acacia (SAs) or rice straw (SRs) revealed a significant (P≤0.05) improvement in OM, CP, EE, CF, NFE, NDF, ADF and hemicellulose digestibilities. Nutritive values expressed as TDNg/Kg B.W. and DCP% increased significantly (P≤0.05) in treated groups G4, G3 and G5 than untreated G1 (Rs) and G2 (As). Also, lambs fed the treated roughages retained higher (P≤0.05) nitrogen values than untreated treatments. Na and K balance (g/kg BW) of G4 had highest (P≤0.05) significant values as compared with other tested roughages in present study. lambs fed sprouted barely had significantly higher (P≤0.05) values of total volatile fatty acids (VFA), ruminal ammonia (NH3- N) concentration, serum total proteins. Albumin, globulin, urea and creatinine were increased (P≤0.05) compared with untreated roughages. The highest (P≤0.05) value of average daily gain, feed conversion (g feed/ g gain) and economical feed efficiency were recorded for G4. However, the lowest (P≤0.05) values were recorded for G1. In conclusion, we can produce green fodder by utilizing dried Acacia and rice straw by simple methodology using crop sprouts barley without any harmful effect on growing female Barki lambs.
Key words: Acacia, rice straw, sprouted barley, sheep, growth, rumen and blood parameters.
In Egypt, there is a gap between the available feedstuffs and farm animal requirements. This was estimated as a shortage of 3.1 million tons of TDN per year. Nontraditional by-products must search in order to decrease the relay on traditional resources to fill the gap and to decrease feeding costs (Zaza, G.H., 2005). Feed shortage will be increased in the next decades due to the expected global climate changes which will lead to increase desertification in many arid and semi-arid aeries of the world that leads to; accelerate soil erosion by wind and water; increasing salinity in water wells and soil with rain drop. These phenomena will lead to despair the natural range plant cover (Shawket, et al., 2010). Halophytes are widely distributed in high density in these aeries under harsh conditions. Acacia saligna is the most successful species of Acacia due to its tolerance to drought, ability to grow in salty soil, higher production of green biomass, higher crude protein content and good nutritive value; but, it cannot serve as a sole feed for sheep due to its high content of condensed tannins (Degan et al., 1997) which form precipitates with proteins, resulting in the formation of indigestible tannin-protein complexes (Makkar, 1993; Degen et al., 1995) and also form complexes with soluble carbohydrates, cellulose, hemicelluloses and amino acids reducing their digestibilities (Barry, 1985). Fibrous crop by-products or farm wastes are characterized by extensive lignification of the cellulose and the hemicellulose, and by low levels of protein, soluble carbohydrates and minerals (Van Hao and Ledin, 2001). One of these wastes is rice straw which produced in an average of 3.5 million ton on year (Khattab et al., 2009). A big amount of rice straw is disposed by burning, so, air pollution increased which reflect on human health. Few attempts were tried to improve nutritive value of rice straw (Ibrahim et al., 2001, El- Tahan et al., 2003, Mohammadi et al., 2007 and Fayed 2011). Many studies treated range plants by several physical, chemical and biological treatments to improve palatability and nutritive values (Fayed et al., 2008, and Fayed 2009). Innovative method for production green fodder throughout the year to provide consistent high amount of food 100% organic and the systems of environment friendly technologies as well as reduce the cost of feeding ruminants. The use of barley sprouts provide a source of rapidly available nutrients made available due to the action of hydrolytic enzymes releasing readily available amino acids and soluble carbohydrates (Plaza et al., 2003). There is also a synthesis of vitamins such as B complex, K and C causing an increase in their concentrations; minerals like calcium and sodium. Moreover, 3-5% of water is needed to produce the same amount of fodder in comparison to that produced under field conditions Al-Karaki (2010). The objective of the present work is to study the effect of planting barely seeds on dried Acacia saligna and rice straw as media to produce green fodder in dried seasons to increase the nutritive value and palatability of Acacia and rice straw. Green fodder was fed to growing sheep to study their effects on growth, digestibility, some rumen and blood parameters of sheep.
The study was carried out at south Sinai Research station, Desert Research Center, Southern Sinai Governorate and lasted for six months.
Dried Acacia saligna was collected and chopped into 2-3 cm and rice straw also was chopped into 2-3 cm, and used as bedding media.
Production method for seed sprouts was tray method as described by Mohammadi et al., (2007) using about 10 cm thick layer of chopped rice straw (Rs) or Acacia saligna (As) as a sprouting media. Seeds of local barley were cleaned from debris and other foreign materials. Then the cleaned seeds were surface sterilized by soaking for 30 minutes in a 20% sodium hypochlorite solution to prevent the formation of mould. Planting trays and the growing cabinet also were cleaned and disinfected. The seeds were washed well from residues of bleach and re-soaked in tap water overnight (about 12 hours) before sowing. At the end of soaking period soaked seeds were spread evenly on the top of Acacia saligna (As) or Rs media. Germination period on the media surface lasted about 15 days to get shoot sprouts, shoot length was 20-26 cm, seeding rate used in this experiment was about 20% density of roughage (rice straw and Acacia), Planting trays were irrigated tap water once a day early in the morning to provide enough water to keep the seeds/seedlings moist.
Chemical composition of feeds residues, faeces and urine were determined according to the A.O.A.C. (1997). Fiber fraction (NDF and ADF) were determined according to Goering and Van Soest (1970). Rumen total volatile fatty acids (TVFA's) were tested (Warner, 1964) and ammonia nitrogen values were also evaluated (A.O.A.C. 1997). Sodium (Na) and potassium (K) were determined in feed, refusal, feces, urine and drinking water by using the standard flame photometry (Jackson, 1958). Blood serum samples were assayed for total protein (Armstrong and Carr 1964), albumin (Doumas etal 1971). Globulin was obtained by substracting the total proteins values from the albumin values. Serum creatinine (Henry1965) and urea (Patton and Crouch1977). All blood serum analysis was measured using Jenway spectrophotometer (UK) and using kits purchased from Human Company (Germany).
The data were subjected to the statistical analysis system according to SAS (1998). Differences in mean values between groups were compared by Duncan's multiple Range tests (1955).
As shown in Table (1) cleared that DM, OM, CF, NDF, ADF, ADL and Cellulose content was lower in treated than untreated rice straw (Rs) and Acacia saligna (As). This finding may be attributed to increase of the activity of sprouted barley hydrolytic enzymes which catabolized starch to soluble sugars for use in respiration and cell-wall synthesis during the germination and early stage of plant growing and lead to improvements in chemical composition of rice straw and acacia (Chavan and Kadam 1989). While Acacia saligna had higher OM, CP, CF, NDF, ADF, ADL and Cellulose than rice straw. The crude protein (CP) content in Rs or SRs as lower by 60.00, 24.87 than that in Acacia, respectively. Also, SRs, SAs and 50% SRs + 50% SAs were higher in CP %, ether extract (EE), nitrogen-free extract (NFE) and ash% and lower in crude fiber (CF) contents. The increase in EE could be due to the production of chlorophyll associated with plant growth (Mayer and Poljakoff-Mayber 1975). Generally, changes affected the proportion of the other nutrients such as protein that could be shown a higher percentage Morgan et al., (1992).
Data in Table (2) shows that average green fodder yield were significantly (P≤0.05) increased in all tested media. The amount of green fodder yield ranged from 1.95 to 2.30 kg per 100g of barley grain plus 500g of media (50% Rs + 50% As and SRs) at 15 days. This increase in fresh weight of fodder was due to the large uptake of water during germination of the seeds, resulted in a sharply reducing of DM percentage in green fodder of SRs, (50% Rs + 50% As) and SAs being 24.86, 25.90 and 43.13%, respectively. These results were in accordance with those of Morgan et al., (1992) and Bautista (2002) who reported a significant difference in wet weight and dry weight of the sprouted green fodder. SAs recorded the highest yield (861.9 g) of DM weight with percent (56%) with a negative relation between DM content and fresh weight yield; such low DM content would have a limitation effect on intake of green fodder when fed to animals (Peer and Leeson 1985). Highest percent of conversion ratio (amount of fresh fodder produced per unit of seed used) was recorded by SRs (3.84 times). While, sprouted barley seeds on acacia (SAs) had best significantly (P≤0.05) values of CR in CP, EE, NFE, ASH, NDF and ADF compared with SRs and 50% Rs + 50% As. The results are also in conformity with Fazaeli et al. (2011).Who reported that Fresh weight of green fodder increased about 4.5 times of the original seed weight, after sprouting barley grain. This ratio depended on several factors such as management, type and quality of grain, amount and frequency of irrigation, nutritious solution, temperature, humidity, density and position of lights, bulk of seeds on each tray and number of days allowed to grow (Trubey et al., 1969; Molla and Birhan 2010).
As shown in Table (3) DM, OM, CP, EE and NFE digestibility were significantly (P≤0.05) higher with sprouted barley on Acacia and rice straw (G4 and G3) than untreated Rs and As. Agreement results were reported by Shipard (2005) who found that feeding sprouted grains provided animals with living feed which has a rich supply of enzymes which results in all nutritional components being highly digestible and extremely nutritious. Generally, digestibility coefficients of all nutrients were significantly (P≤0.05) higher in sprouted Acacia (G4) compared with other groups. NDF, ADF and Hemicellulose digestibility were significantly higher in G4 (SAs) and G3 (SRs) than the other treatments. This may be attributed to increasing in the bioactive catalysts which assist in the digestion and metabolism of feeds and the release of energy. Similar findings were noticed by Shipard (2005). In general, most of nutrients digestibility was increased with sprouted barley grains on Acacia or rice straw. Similar trends were observed by (Fayed 2011) who found that the digestibility coefficients of all nutrients for sprouted barley on rice straw and Tamarix were higher than that of untreated. Mean effects of dietary treatments on nutritive values of the experimental rations (Table 3) showed that Acacia significantly (P≤0.05) increased total digestible nutrients (TDN g/kg B.W), digestible crude protein (DCP %) than that of untreated and treated rice straw, respectively. These results may be attributed to low digestibility of most nutrients of rice straw than that of Acacia. TDN g/kg BW or TDN % and DCP g/kg B.W. or DCP% for sprouted barley on Acacia or rice straw were higher than those for untreated roughages. Similar results were obtained by (Fayed 2011).
As shown in Table (4) nitrogen intake (NI g/kgB.W) was significantly (P≤0.05) higher in G4 (0.674) followed by G3 (0.591) while the lowest was recorded for G1. The higher nitrogen intake may due to high content of crude protein in sprouted acacia (SAs). Lambs fed G1 and G3 had more (P≤0.05) nitrogen in feces, while lambs fed G3 and G4 had significant (P≤0.05) higher amounts of urinary nitrogen compared with other groups. Lambs fed SAs retained higher (P≤0.05) nitrogen than the other treatments. Nitrogen retention (NR) was higher for both G4, G5 and G2 than G1 or G3 while lambs fed As (G2) retained nitrogen more than those fed G1 and G3. Nitrogen retention as a percent of total nitrogen intake (NR% of NI) for G4 was significantly (P≤0.05) higher than the other lambs fed the experimental roughages. This finding may be related to higher improvement in CP intake and its digestibility in sprouted Acacia compared with other experimental roughages. Agreement results were reported by Fayed (2011).
Data of rumen total volatile fatty acids (TVFA, s) (Fig. 1) revealed that sprouted barley grains on Acacia or rice straw and mixture of them (G4, G3 and G5) respectively, increased (P≤0.05) TVFA, s concentrations in the rumen than untreated G1 and G2. While G4 (SAs) had an increase (P≤0.05) in TVFA, s concentration (8.76 meq/ 100 ml) compare to G5 and G3 (7.50 and 5.40 meq/ 100 ml). The lowest (P≤0.05) values of TVFA,s were showed in G1 and G2 (untreated ) being 4.05 and 5.05 meq/ 100 ml, these results are in similar with those reported by Fayed (2011) who reported that TVFA,s concentration were higher (P≤0.05) for sprouted barely on rice straw and Tamrix Mannifera than untreated. The increase in TVFA, s concentration with sprouted barley may be due to that sprouts provide a good supply of vitamins, enzymes which serve as bioactive catalysts to assist in metabolism of feed and the release of energy (Shipard 2005). Concentration of VFA, s increased after feeding and reaches its peak after 3 hr post feeding. Similar results were obtained by Fayed (2011). Nitrogen ammonia (NH3 –N) concentrations were reported in Fig.2. The greatest value of NH3 –N was recorded for lambs fed G4. This is may be due to such treatment contained high level of protein and its degradability; where G1 showed the lowest values of NH3 –N. Similarly, other researchers reported an increase in rumen ammonia N with increase in CP supplementation (Bohnert et al., 2002; Salisbury et al., 2004).
Data of Table (5) showed that total proteins concentration, Albumin, Globulin, A/G ratio Urea and Creatinine were significantly elevated (P≤0.05) by treatments. G4 (SAs) and G5 (SAs + SRs) were increased (P≤0.05) in serum total proteins, albumin and Globulin. The high level of globulin of sprouted barely treatments may indicate good developed immunity status (Ibrahim et al., 2001). A/G ratio significantly (P≤0.05) increased in G3 (SRs) compared with other groups. This is in accordance with those reported by Kumar et al., (1980) who found a positive correlation between dietary protein and plasma protein concentration. Also, means of serum urea and creatinine increased significantly (P≤0.05) with G4 and G5. This was probably due to the high level of CP content in G4 and G5. The lowest value of serum urea and creatinine were recorded by G1 and G2. These results are in harmony with those reported by Fayed (2011).
Data of Table (7) showed that animals fed G3 (SRs) consumed total DM and roughages intake more than other treatments (1073.10, 356.00 g/head/day respectively) followed by G5 and G4 which have comparable values of total DM and roughages. However, the lowest was G1 (Rs) followed by G2 (As). Sprouted barley grains increased roughage intake by 44.25% on rice straw and by 18.94% on Acacia which may be attributed to increasing the palatability of SRs or SAs. Similar results were reported by (Fayed 2011). All treatments were fed approximately similar amounts of CFM. The results of animal performance (Table 6) showed that the greatest value of daily gain was achieved with female lambs fed G4 (SAs). This may be due to its nitrogen retention was the highest (0.283g/kg.B.W). On the other hand, the significant (P≤0.05) lowest daily gain was recorded for lambs fed the untreated roughages G1 and G2 in descending order. However, differences of daily gain between the treated groups (G3, G4, G5) were not significant. The increase in weight gain of lambs received barley sprouts may be attributed to enhancing of microbial activity in the rumen (Tudor et al., 2003). Also, this observation may be due to lowest nitrogen retention and lowest digestibility of DM, OM, CP, EE and NFE of untreated rice straw and Acacia. Feed conversion expressed as g feed/ g gain indicated that the lambs fed G4 (SAs) were more feed conversion as DMI (10.58), TDN (6.38) followed by G3 (SRs) and G5 (50% SRs+ 50% SAs) (13.62, 13.54, 6.77and7.15 respectively), while the worst were the control treatments (G1, G2). These results agree with data showed by (Eshtayeh 2004 and Fayed 2011). On the other hand feed conversion was more with lambs fed SAs than lambs fed SRs. Also, lambs fed As were more efficient than that of Rs. Feeding animals green forage from sprouting which have simpler forms of vitamin, starch, protein, and lipids might affect the animals performance (Mayer and Poljakoff-Mayber, 1975; Kruglyakov, 1989).
Economical efficiency was affected by type of roughages Table (8). Lambs fed sprouted barley grains on Acacia (G4) had better values of economical efficiency (1.65) than other experimental roughages G5, G3, G2 and G1 in descending order the values were 1.38, 1.25, 1.10 and 0.92 respectively. These results indicate that sprouted barley grains on Acacia had minimum price for production one kilogram gain by about 44.2, 24.2, 16.4 and 33.3% than G1, G3, G5 and G2 respectively. This may be attributed to the highest values of feed conversion as DMI, TDN/ kg gain, to that the price of rice straw was expensive than the price of collection Acacia. The results are also in agreement with Fayed (2011).
It could be concluded that sprouted barley on roughages, especially in arid season to produce green fodder high nutritive value for the animals and environment-friendly as well as reduce the cost of feeding by utilizing dried salt plants and rice straw by simple methodology using crop sprouts. Rice straw by-product could employ to produce forage feed instead of being burned and causing pollution.
This article was originally published in Proceedings of the 5th Animal Wealth Research Conference in the Middle East & North Africa and it was submitted by the author for its reproduction.