According to the projected growth in global human population, by 2050 the world human population will reach 9.1 billion, 34 percent higher than current estimated 6.3 billion (FAO, 2015). Populations in the developing countries are growing so quickly that the arable lands and the available fresh water are unable to sustain their needs. In Egypt, about 95% of the land is desert, where the soil is sandy and most of the available ground-water is too saline to raise and sustain conventional crops. On the other side, shortage of feed resources is a common characteristic in arid and semi-arid regions and is considered the main constraint to improve livestock productivity. Therefore, intensive efforts have been directed to find alternative feed resources from agricultural by-products of salt-tolerant grasses (El-Shaer, 2006). Agricultural wastes such as barley straw are carbohydrate-rich materials with a large potential as a source of dietary energy for ruminants. However, such feeds have poor nutritional value with low nitrogen and high fiber content (Tang et al., 2013; Ghorbani et al., 2014 and Kholif et al., 2014), thus high fiber content also prevents the access of ruminal hydrolytic enzymes to cellulose and hemicellulose (Chesson, 1984). Browse species such as Acacia saligna is a leguminous shrub which provides large amounts of fodder for ruminants in arid and semi-arid regions (Ben Salem et al., 1999 and Safinaz et al., 2010), particularly during the dry season when poor quality roughage and crop residues prevail (Krebs et al., 2007). Their foliage may be used as a protein and energy supplement when animals are given low quality roughage (Moujahed et al., 2000). The major limiting factor in the use of A. saligna is the presence of high concentration of tannins (Moujahed et al., 2005; Shumuye and Yayneshet, 2011). Many investigators treated range plants and agricultural by-products by sprouting technique to improve their nutritive values (Fayed, 2011, Helal, 2012, 2015a and 2015b and Helal and Hassan, 2013a and 2013b). Today, sprouting technology is an alternative to traditional method of fodder crops cultivation especially in arid and semi-arid areas due to shortage of fresh water or saline water, saline soil unsuitable for cultivation of fodder crops, more growth period and costs of various agricultural processes, etc. Several studies on the effect of sprouting on seeds found that germination can increase protein, fiber and mineral bioavailability with reduced tannin and phytic acid contents (Ghavidel and Prakash, 2007). Also, sprouting improved the protein digestibility and their nutritive value by decreasing the anti-nutritional factors (Amal et al., 2007 and Mahmoud and El-Anany, 2014). Green forage is an important component of the dairy nutrition, otherwise, the productive and reproductive performances of the dairy animals are adversely affected. The nutritive value and fermentative characteristics of hydroponically grown forages positively influenced the performance of late gestation and lactating ewes (Herrera et al., 2010 and Gebremedhin, 2015). High fiber content of fodder increases the production of milk fat due to acetic and butyric acid donations from microbial fermentation (Nugrohoa et al., 2015). Therefore, for a sustainable dairy farming, quality green fodder should be fed regularly to the dairy animals (Naik et al., 2012). The sprouting green fodder production is an option that helps to solve the problem by producing food during drought and scarcity periods with acceptable yields and great value. The aim of this study was to investigate the impact of using dried Acacia saligna pruning and barley straw as media for growing barely seeds to produce green fodder in dried seasons, increase the nutritive value, palatability, and reproductive and productive performance of Barki ewes under arid conditions in South Sinai, Egypt.
Materials and methods
This experiment was carried out at South Sinai research Station (Ras Sudr), South Sinai governorate that belongs to the Desert Research Center, Ministry of Agriculture and Land Reclamation, Egypt.
Preparation of seeds and media before Planting:
Local barley seeds (Hordeum vulgare L.) were cleaned from debris and other foreign materials. It was sterilized by soaking for 30 minutes in a 2% sodium hypochlorite solution to control the formation of mould and Planting trays were also cleaned and disinfected. The seeds were then washed well from residues of bleach and resoaked in tap water overnight (about 12 hours) before planting, while dried A. saligna and barley straw were collected from the Farm of South Sinai Research Station and chopped mechanically into 2-3 cm and used as bedding media.
Production of sprouted green barley:
Production method for seed sprouts was tray method as described by (Fayed, 2011 and Helal, 2015a), using about 5-7 cm thick layer of barley straw, A. saligna and mixture of them as sprouting media. Seeding rate used in this experiment was about 10% density of the roughage media, soaked seeds were spread on the top of the tested media. Germination period on the media surface lasted about 15 days to get shoot sprouts, shoot length was 20-25 cm. Planting trays were irrigated with tap water once a day early in the morning to provide enough water to keep the seeds/ seedlings moist.
Animals and experimental design:
Forty-four Barki ewes (average body weight 32.71±1.68 kg) and aged 1.5-2.5 years were randomly divided into four equal groups (11 ewes each). Ewes of the first group were fed a control diet of berseem hay (Trifolium alexandrinum) and CFM. The second group (D1) was fed ad libitum sprouted barley grains on barley straw (SBS) with CFM. The third group (D2) was fed ad libitum sprouted barley grains on acacia pruning (SAS) with CFM and the fourth group was fed ad libitum sprouted barley grains on similar mixture of SBS and SAS with CFM. The chemical analysis of local barley grains, 92.23 DM, 96.11 OM, 9.38 CP, 6.28 CF, 2.43 EE, 3.89 ash, 77.60 NFE, 18.94 NDF and 9.21 ADF (as % DM basis), while the concentrate feed mixture (CFM) which contains of 25% cotton seed cake, 35% yellow corn, 30% wheat bran, 3% rice bran, 3% molasses, 1% urea, 2% limestone and 1% common salt). The whole ration was given to cover energy maintenance and production requirements of ewes during the different physiological stages according to the nutritional requirements of Kearl (1982). Table (1) shows the chemical composition of experimental diets offered to ewes of control, D1, D2 and D3 which was determined according to AOAC (2007).
Table 1: Formulation of experimental rations on dry matter basis.
The ewes of each group were fed and kept in a semi-closed pen, well ventilated, clean cement floored shed. The berseem hay and CFM were weighed and offered twice a day at 8 a.m. and 4 p.m. Sprouted fodder also was offered ad libitum at 9 a.m.; refusals were daily collected and weighed for each group of ewes to estimate the actual feed intake. Fresh and clean drinking water was made available twice daily. Feed allowances were adjusted every month according to body weight and milk yield (Kearl (1982). All ewes were weighed monthly and those were weighed in the morning before supplementary feeding and after fasting period about 12 hours. The offspring were individually weighed at birth and then weekly until weaned and weaning weight was recorded and adjusted for 90 days. Milk yield was estimated from all ewes in both groups immediately after birth and every week from lambing up to 12 weeks of lactation period using complete hand. Milk samples were randomly taken from 6 animals within each respective group during lactation period, in plastic bags and kept under -20 0C for further analysis.
Four lactating ewes of each group with an average live weight (30.39±0.33 kg) were used for the digestibility trial in metabolic cages as fifteen days adaptation period followed by 5 days collection periods. During the collection periods, fecal and urine samples were collected daily (10% by weight of daily samples). At the end of collection periods of digestibility trial, rumen liquid was sampled by stomach tube at 0 and 4 hours and blood samples were taken from jugular vein before feeding. Analytical procedures: The proximate constituents of feeds, feed refusals, feces and total nitrogen in urine were determined by AOAC (2007). Neutral detergent fiber (NDF) and acid detergent fiber (ADF) were determined according to Van Soest (1991). Rumen pH samples were determined using pH meter. Total volatile fatty acids (TVFA´s) (Warner (1964) and ammonia nitrogen (NH3-N) AOAC (2007) were determined too. Serum samples were taken to determine total protein (Armstrong and Carr 1964), albumin (Doumas and Biggs, 1971) and globulin were obtained by subtracting the albumin values from the total proteins, while A/G ratio was calculated according to results of albumin and globulin. Creatinine (Henry, 1965), urea (Patton and Cruouch, 1977) were also determined. Samples used for milk composition were determined by using milk scan (Bently-Belguim). The ash content of milk was determined after heating in muffle furnace at 550C for 16 hour and solid not fat content was calculated by differences. Solids-Not-Fat (SNF) was calculated (TS-fat). Actual milk yield was corrected to 4% FCM according to the formula of Gaines (1923).
General linear model procedure was used for statistical analysis (SAS, 2004). However, Duncan's multiple ranges test (Duncan, 1955) was applied for comparison of means.
Results and discussion
Chemical compositions of feed ingredients and tested diets are presented in Table 2. The results revealed that there are wide variations in chemical compositions of the investigated feeds, A. saligna and barley straw had a lower content of CP (8.07 and 4.05%) with higher CF content (34.96 and 35.58%) compared with berseem hay or CFM. It was clear that sprouting barley grains on barley straw (D1) had improved CP content being 9.36% compared with un-sprouted straw (4.05%) also improved CP content of sprouted A. saligna being 9.91% (D2) compared with un-sprouted (8.07%). The increase in CP content may be attributed to the loss in DM, particularly carbohydrates during the germination (Naik et al., 2015). Moreover, Morsy et al. (2013) reported that sprouting has been alter the amino acid profile of maize grains and increases the crude protein content of sprouted fodder. At the same trend, ether extract showed higher improvements for sprouting barley grains on roughages. The increase in EE content may be due to the increase in the structural lipids and production of chlorophyll associated with the plant growth (Naik et al., 2015). However, CF content was decreased from 35.58 to 29.32% and 34.96 to 30.81% for barley straw and A. saligna, respectively. Similar trends were observed with fiber fractions content (NDF and ADF). Generally, authors in many ways demonstrated that sprouted barley grains on roughage media had improved the chemical compositions compared with un-sprouted roughages (Fayed, 2011and Helal, 2012 and 2015a). The improvement in chemical composition may be attributed to increase in enzymatic activity of sprouted barley grains on roughage media. Similar results were obtained by Chavan and Kadam (1989).
Voluntary feed intake:
Ewes fed the three experimental fodders recorded higher (P<0.01) fresh fodder intake (g/h/d) as compared to the control diet but there were insignificant difference between the three treated groups in early and late pregnant (Table 3). This may be due to high water content of the sprouted green fodder (Naik et al., 2017). The highest (P<0.05) dry fodder (g/h/d) was recorded by ewes fed D2 diet compared with other diets during stages of pregnancy, which may be attributed to increase in the palatability of D2 diet. The results of present investigation are in agreement with those of Eshtayeh (2004), Singh and Chaudary (2007), Dung et al. (2010), Fayed (2011) and Raeisi et al. (2018). Also, Naik et al. (2017) reported that hydroponics fodder is palatable and consumes completely without any wastage. Moreover, Pond et al. (1984) revealed that the release of soluble carbohydrates and nitrogen from sprouts barley seeds stimulated microbial growth and colonization, and improved degradation of the low protein forage used in their experiments. However, it didn’t has significant effects in other studies (early pregnant). Also, ewes fed D2 diet showed the highest (P<0.05) values of TDMI (1.545 g/h/d) and DMI/kg BW (46.95 g/kg BW) with no significant effects in roughage: concentrate ratio at late pregnant period. Likewise, DM intake/ 100 kg BW was significantly (P<0.05) higher in D2 diet (4.69) than others and higher than many reports (Muhammad et al., 2013; Naik et al., 2014 and 2017 and Verma et al., 2015). On the contrary, there are reports found that DM intake was decreased in animals fed hydroponics fodder (Fazaeli et al., 2011 and Naik et al., 2014).
Table 2: Chemical composition of feeds and roughages (on % DM basis).
Table 3: Dry matter intake of pregnant ewes fed the experimental roughages.
Digestibility coefficients and nutritive values:
Total dry matter intake (DMI), digestion coefficients, nutritive values and nitrogen utilization are shown in Table 4. Results revealed that total DMI was insignificantly affected by the experimental treatments for lactating Barki ewes. These results are in agreement with those reported by Fayed (2011). Crude protein digestibility was not affected by the type of roughage while DM, OM, CF, NDF and ADF digestibility were (P<0.05) higher with sprouted barley seeds on A. saligna and barely straw (D2, D1 and D3) than ewes fed the control diet. Also, values of EE and NFE digestibility were (P<0.01) higher for animals fed D2 diet than those fed the control diet. The present findings are in agreement with those of Ibrahim et al. (2001) who noted that all nutrients digestibility improved by sheep fed sprouted barley grains on rice straw. Raeisi et al. (2018) also reported that digestibility of OM, CP, and NDF were (P<0.05) higher in experimental diet containing 21% hydroponics barley fodder compared to control diet. Moreover, Helal (2015a) recorded higher digestibility coefficients by goats fed sprouted barley grains on roughages compared to the un-sprouted group. The improvement in the nutrients digestibility by ewes fed sprouted fodder might be attributed to increasing in the enzymes of germination of barley seeds (Shipard, 2005) and the tenderness of the fodder due to its lower age (Naik et al., 2014 and 2017). In a review, Pandey and Pathak (1991) noted that nutrients digestibility of sprouted barley fodder was comparable with highly digestible legumes like berseem and other clovers and were optimum to meet the production requirement of the lactating cows.
Nutritive values expressed as TDN and DCP% are shown in Table 4. Total digestible nutrients (TDN%) showed higher (P<0.05) improvements for ewes fed D2 followed by control diet, D3 and the lowest was D1. However, There were insignificant differences among treatment groups in digestible crude protein (DCP%) values. It is clearly indicated that total ration of TDN and DCP% was close to the reports of the earlier works (Fayed, 2011and Naik et al., 2014). The gradual increase in nutritive values of sprouts green fodders may be attributed to grass juice factor and enzymes that improve the performance of livestock (Finney, 1982).
From the data of Table 4, it seems that nitrogen intake, nitrogen in feces and digested nitrogen did not affect significantly by dietary treatments. On the other hand, the lowest (P<0.05) values of nitrogen in urine and total nitrogen excretion for ewes fed D1 and D2 without insignificant differences between the two groups. Nitrogen balance value was (P<0.05) increased in D2 diet compared to other diets. This finding may be related to higher improvement in CP intake and digestibility of ewes fed D2 diets than those fed the control diet. Agreed results were reported by Fayed (2011) and Helal (2015b). However, Dung et al. (2010) found that supplementing sprouted barley fodder with poor quality roughage (oat hay) did not affect microbial outflow and nitrogen retention in sheep. The absence of negative effects of tannin in A. saligna on intake, digestibility, nutritive values and nitrogen balance could be attributed to effect of sprouted barley grains on acacia pruning and drying acacia before treated. Amal et al. (2007) reported that sprouting improved the protein digestibility and their nutritive value by decreasing the anti-nutritional factors.
Some rumen liquor parameters are shown in Table 5. There were no significant differences among tested groups in pH and ammonia-nitrogen (NH3-N) but lactating ewes fed sprouted barley grains on roughages showed higher (P<0.05) total volatile fatty acid (TVFA´s) than ewes fed the control diet. Similar results concluded that sheep fed on sprouted technique recorded higher (P<0.05) values of TVFA´s than those fed un-sprouted diets (Ibrahim et al., 2001; Dung et al., 2010; Fayed, 2011 and Helal, 2012). The improvement in yield of TVFA´s may be due to sprouts supply a good source of vitamins, enzymes which serve as bioactive catalysts to support in metabolism of feed and the release of energy (Shipard, 2005). Concentrations of TVFA´s showed (P<0.05) increase after feeding and reach its peak after 4 hours post feeding. Similar results were obtained by Fayed (2011). Ewes fed D2 diet recorded numerically insignificantly higher NH3-N than other diets. This is may be due to such treatment contained high level of protein and its degradability (Fayed, 2011). The highest values of NH3-N were 37.48 mg post feeding after 4 hours. The rate of NH3-N release from herbage NPN was faster than that of water soluble sugars in sprouted barley resulting in NH3-N accumulation (Hafla et al., 2014).
Milk yield and its composition:
Milk production and milk analysis data are shown in Table 6. There was insignificant increase in the milk yield and 4.0% FCM between all diets. Similar trend was observed by Ewes fed D2 diets that recorded the highest milk yield (617.22 g/h/d) and 4.0% FCM (607.96 g/h/d) compared to other diets. Increase (8.07%) in milk yield of D2 diet than the control diet (617.22 vs 571.11 g/h/d) due to feeding of sprouted barley fodder had been reported by earlier authors, which was attributed to higher TDN and DCP content of the diets (Reddy et al., 1988 and Naik et al., 2014). Moreover, Fazaeli et al. (2012) showed that replacing 50% of the maize silage with 18 kg of hydroponic barley grass increased cow's milk yields by 8.7% although milk fat was depressed. Milk composition contents as total protein, lactose, solid and not fat% were insignificantly affected by our treatments; previous results were in agreement with Shtaya (2004), Saidi and Abo Omar (2015) and Badran et al. (2017). However, ewes fed D2 diet recorded the highest (P<0.05) values of fat (3.90%), total solids (14.89%), ash (0.93%) and energy (843.54 kcal/kg milk). Some studies reported that increasing of protein content in the diets showed no increase in DMI, milk yield, milk protein and total solid (Pereira et al., 2009 and Voltolini et al., 2010).
The reproductive performance data of Barki ewes fed sprouted barley grins are shown in Table 7. It is clear that feeding Barki ewes on sprouted fodder from the time of mating up to parturition did not compromise reproductive efficiency. Conception rate showed similar trends for ewes fed D2 and those fed control diet (being 80%) while it was 90% for ewes fed D1 diet and the lowest was D3 (70%). At the same trend was observed for weaned offspring/100 joined ewes. On the other hand, lambing rate, weaned offspring% and weaned offspring/100 pregnancy ewes were similar between all diets (100%) with no mortality cases were found in the current study till weaning. Ewes fed sprouted fodder did not show negative effects on reproductive performance. These results are agreed with those reported by Cervantes et al. (2016) who reported that the reproductive performance of ewes did not affected by feeding sprouted green fodder. In addition, Saidi and Abo Omar (2015) observed that sprouted barley fodder had positive effects on ewes' health conditions, mortalities, conception rates and abortion.
Table 4: Digestibility coefficients, nutritive values and nitrogen utilization on lactating ewes.
Table 5: Ruminal parameters of lactating ewes fed the experimental roughages.
Table 6: Milk yield and milk composition of lactating ewes fed the experimental roughages.
Table 7: Reproductive performance of ewes fed the experimental roughages.
Body weight change of Ewes:
Body weight changes data are shown in Table 8. The changes in body weight (kg) by ewes were not affected by sprouted barley fodder feeding. Similar results were obtained by Badran et al. (2017). Data indicated insignificant difference in body weight changes of all physiological stages for ewes fed sprouted barley grains on roughages compared to the control diet. Similar results on ewes fed levels of acacia leaves and twigs were obtained by Mehrez et al. (2011). Also, Saidi and Abo Omar (2015) found that sprouted barley fodder had no effects on feed intake and body weight change for lactating ewes. However, Intissar and Estayeh (2004) showed (P<0.05) increased in body weight change by ewes fed sprouted barley fodder compared to other diets. The slight increase in changes in body weight might be due to the increase in extracellular fluid as reported by (Shawkat et al., 1988 and Abou El-Nasr 1998).
Table 8: Live body weight (kg) of ewes during the experimental period.
Growth performance of lambs:
Data of birth weight, weaning weight and average daily gain are presented in Table 9. The findings of the present study showed highest (P<0.05) average male birth weight being 3.58, 3.56, 3.37 and 2.92 kg for D2, control, D1 and D3 diets, respectively. Average female birth weight also was highest (P<0.05) for lambs in control diet, followed by D2, D1 and the lowest value was recorded by D3 diet. In our study, there were insignificant differences in body weight during the first, second and third (weaning) month. Similar results were obtained by Mehrez et al. (2011). Average daily gain values were 154.67, 152.89, 150.56 and 145.33 g for lambs fed D2, control, D3 and D1 diets, respectively. Previous findings showed higher (P<0.05) average daily gain for animals fed sprouted fodder compared to those of the control diet (Intissar and Estayeh, 2004; Fayed, 2011; Helal, 2012; Gebremedhin, 2015; Muthuramalingam et al., 2015 and Verma et al., 2015). The improvement in performance of livestock may be attributed to sprouts fodder is rich sources of bioactive enzymes and contain grass juice ingredients (Naik et al., 2013b).
Furthermore, Verma et al. (2015) reported higher average daily gain for male calves fed sprouted fodder than those fed the control diet, which may due to better intake, digestibility and high nutritive value of sprouted fodder as based diet. In contrast to that, little study has declared that there is no significant effect on animal performance with feeding hydroponic sprouts (Farlin et al., 1971).
Table 9: Growth rates of lambs as affected by feeding the experimental period.
Data of total proteins, albumin, globulin, urea and creatinine are given in Table 10. Blood parameters were not affected by treatments. This agrees with the reports of Raeisi et al. (2018). Mehrez et al. (2011) also found that the differences were not significant between the concentration of total proteins, albumin, globulin, urea and creatinine in blood serum of lactating ewes fed containing levels of acacia leaves and twigs. Ewes fed D2 diet had insignificantly higher in total proteins and albumin than other her diets. This is in accordance with those reported by Kumar et al. (1981) who found a positive correlation between dietary protein and plasma protein concentration. However, Fayed (2011) reported that ewes fed sprouted barley on roughages had significantly higher values of serum total proteins. This may be due to high CP content in treated roughages. Also, globulin concentration showed increased in ewes fed alfalfa (control diet) and D2 diet compared to other diets. The high level of globulin of sprouted barely treatments may indicate good developed immunity status as given by Ibrahim et al. (2001). Serum urea and creatinine were similar among ewes fed sprouted barely gains on roughage and animals receiving the control diet. Raeisi et al. (2018) conclude that the process of converting ammonia to urea in the liver of sheep fed on the experimental diets was similar. In contrast, AL-Saadi (2016) found that both urea and creatinine concentrations were higher (P<0.05) for Awassi male lambs fed on sprouted barley fodder than lambs fed control diet. This might reflect the higher metabolic rates due to activation of amylase and lipase enzymes via germination of seeds which increases sugar and essential fatty acids content of grains.
Table 10: Some blood parameters of lactating ewes fed the experimental roughages.
Feed intake and economic efficiency:
Daily dry matter intake and feed efficiency by ewes are shown in Table 11. Data revealed that total dry matter intake (g/h/d) were very similar, being 1355, 1340, 1370 and 1300 kg for ewes fed control, D1, D2 and D3 diets, respectively. The consistent daily TDN and DCP intakes (gm) also similar, being 813, 765, 904 and 767 gm TDN and 119, 113, 123 and 113 gm DCP. These intakes were sufficient to meet the requirements of the animals according to Kearl (1982) recommendations. The lowest total feed cost along the feeding period was observed for animals fed D3 (3.90 L.E) vs. those fed control group (5.70 L.E). This result is similar to the findings of Fayed (2011) and Helal (2012) who found the lowest feed cost and highest profit in lambs fed dietary mixture of sprouted barley grains and Tamarix mannifera. Economical efficiency (price of kg milk/cost kg total of consumed feed) showed that the highest value was for ewes fed control (2.90) followed by D1 (2.05), D2 (2.41) and D3 (1.80), respectively. The highest relative feed cost/ g FCM recorded by ewes fed D2 being 83% followed by those fed D1 (70%) and D3 (62%) compared with control group (100%). Similar results are in agreement with those of Saidi and Omar (2015) who reported that sprouted barley fodder can be reduced cost of fed 42% for lactating ewes. Previous studies showed that hydroponic sprouts may have profitable application in intensive and small-scale livestock situations with high value outputs, where land and alternative feed costs are high (Naik et al., 2014; Verma et al., 2015; Gebremedhin, 2015; Swati et al., 2015 and Muthuramalingam et al,. 2015). In contrast, Fazaeli et al. (2011) reported that the cost of feeding was 24% higher (P<0.05) for the calves received sprouted green forage diet than those fed the control diet due to the extra expenses needed for production.
Table 11: Feed intake, feed efficiency and economic efficiency of ewes fed the experimental roughages.
It could be concluded that the sprouting technology is an option that helps to solve the problems feed shortage in arid and semi-arid regions by utilizing dried Acacia saligna pruning and barley straw as media to produce green forage high palatable and nutritive value to improve livestock productivity.
This article was originally published in Research Journal of Animal and Veterinary Sciences, 10 (1):35-46. DOI: 10.22587/rjavs.2018.10.1.5. This is an Open Access article distributed under the terms of the Creative Commons Attribution License.