Livestock Research for Rural Development 29 (6) 2017 Guide for preparation of papers LRRD Newsletter

Citation of this paper

New development of feed blocks technology in the Sultanate of Oman

Alaa D Salman, Khalfan M El Shargi, Rashid S Al-Habsi and Talal Al-Sadairi

Directorate General of Agriculture and Livestock Research Ministry of Agriculture and Fisheries
PO Box 50 Seeb, Postal code 121,Muscat, Sultanate of Oman.
alaasalman2006@yahoo.com

Abstract

This study was conducted to develop new methodology in feed blocks making from locally raw materials in Oman. Feed Blocks manufacturing equipment were manufactured locally at local artisan. This included pan mixer with capacity of 100 kg per batch and heavy duty Hydraulic press with four moulds. Different formulae of feed blocks were produced. These formulae were depending mainly on local dates palm trees byproducts (Inferior quality dates fruit, sun dried sardines fish, Dibis (Date syrup), ground date frond leaves and local wheat bran. Urea was used as source of nitrogen. The main binders used were bentonite clay, quick lime and Calcium sulfate (CaSO4). Whole barley grain was included (5 %) in these formulae to improve the palatability of feed blocks. The produced feed blocks were characterized with excellent compactness and medium to soft hardness. The excellent compactness of feed blocks was result of high pressure applied through heavy duty hydraulic press, whereas the soft hardness is result of low level inclusion of binders (gelling agents). This type of feed blocks can be considered as major breakthrough in feed blocks making in the region.

The results of performance trial showed that the palatability of feed blocks by Omani goat is very high. The average daily intake was about 293g/d/ animal. Goats were easily turned on feed blocks due to the presence of whole barley grains and also due to sweet nice aroma of dibis and the whole dates fruit in the formula. Using feed blocks as supplementary feed resulted a highly significant (P<0.01) improvement in goat weight gain (73%) as compared with un-supplemented group (NFB). The present results also showed that the goats reproductive performance improved considerably due feed blocks supplementation. The Jabbali goats fed feed blocks as supplementary feed during mating season had higher conception rate (23%) and kidding rate (24%) than non-supplemented group (NFB).

This new development in feed blocks technology can be promoted as small agribusiness and medium scale enterprise (SME) for producing feed blocks as alternative feed supplement for small ruminants in Oman.

Keywords: cull dates, feed blocks manufacturing equipment, goat performance, sundried sardinesf fish


Introduction

One of the main factors limiting ruminant productivity in Oman is the shortage of feed resources, which can meet their nutrient requirements. This is mainly due to the declining of natural pasture contribution to the total feed resources for ruminants (Al-Mashakhi and Koll 2007). The high cost of concentrate feeds prohibits their wide scale use by animals’ owners especially by small farmers. Whereas considerable amount of agro-industrial by-products are available in Oman (inferior quality dates, date frond leaves, dates pulp, date stone, low quality dibis (dates syrup) and sun dried sardines fish are available in commercial quantities (El Hag et al 1999). Recently it has been estimated that more than 80 thousand tons of inferior dates fruits (Cull dates),2 thousand tons of inferior quality dates syrup (Dibis) and dates pulp are produced annually in Oman. These are the byproducts of dates processed into dates syrup for human consumption. Also more than 25 thousand tons of sun dried sardines fish are produced annually in Oman (MAF 2016). However, these by-products have not been efficiently utilized in animal feeding (Salman and El Shargi 2016). Opportunity in Oman exists to fill part of the gap between the supply of and the demand for the feed resources through efficient utilization of these by-products.

Comprehensive studies were conducted to evaluate the use of dates palm byproducts and sundried sardines fish as low cost locally available feed resources for ruminants in Oman (El Hag and El Khanjari 1992; El Hag et al 1999). Despite the positive results obtain of utilization of these byproducts as alternative for animals the adoption was low. This is mainly because the feed mills available in Oman are designed to produce commercial concentrate feed for poultry and high density concentrate feed for ruminants. More than 97% of raw materials that utilize by these feed mills are imported from the international market imported from the international market. Therefore, in order to utilize these byproducts commercially, special design high investment feed mill need to be established. Whereas the most appropriate technical option in enabling the optimization of conventional feed resources and efficient utilization of agro-industrial by-products as alternative feeds is the feed blocks technology (Salman et al 1999; and Salman 2008a). The ICARDA’s Mashreq/Maghreb experience in the development of feed blocks technology was widely adapted by many countries in the region (Salman and Mamdouh 2002). Building on these experience new methodology for feed blocks manufacturing equipment formulation and manufacturing procedure has been promoted in Oman. One of the important lessons learned from Iraqi experience that feed blocks can be produced in small-scale, medium-scale and large-scale industry. The private sector plants played a leading role in the development of feed blocks production in Iraq. Twenty-one manufacture plants were established in Iraq. These plants produced until the end of 2002 more than 39850 tons of feed blocks distributed among 9060 sheep owners. It estimated that more than million heads of sheep fed feed blocks during this period (Salman 2008a). The investment in establishment the feed blocks plant is considerably lower than other feed industries because the technology employed in a feed blocks plant is simple (not sophisticated), whereas technology employed in feed mill is complex and highly specialized.

Initiative was made in Oman on utilization of agro-industrial byproducts in feed blocks making (El Hag et al 2002). This feed blocks were manufactured according to classical method developed by Sansoucy (1986). But the feed blocks intake was very low (36/head/day for sheep and only 6/head/day for goats). Previous study indicated that the uptake of low consumption feed blocks by animals’ owners was very slow (Salman 2008a). One of the important aspects for the feed blocks technology in Iraq was the development high energy feed blocks which depend on high moisture dates pulp as main energy source ingredient to be used as replacement of whole barley grain (Salman 1996; Salman 2008a). This type of feed blocks accelerated the adoption of the technology in Iraq, because animal’s owners had a great interest in replacing barley grain with other cheaper feed resources.

The main objectives of this study were to develop new methodology in feed blocks making (equipment, formulation, and manufacturing procedure) to be disseminated to end-user as small agribusiness and medium scale enterprise (SME) and evaluation of feed blocks as alternative feed supplement for small ruminants in Oman.


Materials and methods

In order to promote feed blocks technology in Oman, new methodology in feed blocks making (equipment, formulation and manufacturing procedure) and evaluation of the produced feed blocks as alternative feed supplement were implemented.

Manufacturing equipment

Feed blocks manufacturing unit was established at Rumis Research station, Animal Production Research Center, Directorate General of Agriculture and Livestock Research, Ministry of Agriculture and Fisheries, Al Batinah South Governorate, Sultanate of Oman. Feed Blocks manufacturing equipment were manufactured locally at local artisan under the supervision of Omani team. This included pan mixer with capacity of 100 kg per batch and heavy duty hydraulic press with four moulds. The production capacity of this feed blocks unit is about 1-2 tons/day.

The pan mixer

The Pan Mixer machine was initially developed in Iraq in 1992 (Salman 1996; Salman 2008a). Originally pan mixer is designed specifically for paver tiles manufacturers. The Iraqi team was able through Reverser Engineering approach and with help of local artisan to fabricate pan mixer suitable for feed blocks making (Salman 2008b). The private sector played a major role in modifying and improving the efficiency and scale of the manufacturing equipment and scaling up this development in Iraq. This mixer spilled over to other countries in the region (Salman 2008a; Salman 2008b). In Oman heavy-duty pan mixer was manufactured locally at local artisan (Photo 1). The capacity of mixer was 100 kg per batch and this according the density of ingredients. The pan (drum) size was 110 mm diameter X 600 mm height from inside and 1250 mm the total height. The pan mixer was equipped with electric motor with 15 HP power and heavy duty reduction gearbox for transferring of power to mixing arms. The loading of raw ingredients was from the top and discharge of mixed feed from the bottom. The revolution of the mixer was 32 RPM.

Photo 1. Pan mixer
The mechanical hydraulic press

Previous experiences of simple manufacturing pressing equipment were used in small scale of production of feed blocks. These were included moulding, pressing and demoulding equipment. The PVC cylindrical moulds, simple hand press and a demoulding tube were the main components of pressing equipment (Salman 2008a). However, in Iraq and due to increasing demand for feed blocks by animals’ owners the private sector manufacture plants in Iraq developed new methodology of manufacturing feed blocks. This included mechanization of moulding, pressing and demoulding procedures instead of manual procedure. This was done through modification the cement blocks mechanical press to mobile mechanical feed blocks press. Using this type of pressing machine resulted a saving of manpower by 50%. Most private sector plants in Iraq adapted this methodology and spilled over to other countries in the region (Salman and Mamdoub 2002; Salman 2008a). In Oman heavy-duty stationed hydraulic press was developed (Photo 2). This press was fabricated by local artisan under the supervision of Omani team. The maximum pressure for the hydraulically operated feed block press was about 100 kg/cm square. Four heavy-duty stain steel cylindrical moulds were used in feed blocks making. The size of steel mould is 240 mm diameter and 260 mm height. Four heavy-duty pistons were used in the pressing operation. The hydraulic press was equipped with electric motor with 7.5 HP power and heavy duty hydraulic pump. The size of produced feed blocks 236 mm diameter and 200 mm height.

Photo 2. Mechanical hydraulic press
Feed blocks formulation

Based on the inventory of local agro-industrial by-products in Oman different ingredients were available, which could be used in feed blocks formulation. The nutritive value of these ingredients was obtained from previous studies conducted in Oman (El Hag and El Khanjari 1992; El Hag et al 1999). Different formulae of feed blocks were produced (Table 1). These formulae were dependent mainly on local dates palm trees byproducts (whole dates not suitable for human consumption, Dibis (Date syrup), ground date frond leaves), dry sardines fish and local wheat bran. Inferior whole dates fruits were used as main energy and sundried sardines fish as source of undegradable protein (UDP) in feed blocks formulae. Molasses was used also when there was shortage of Dibis due to its seasonality production. Salt (NaCl) was used (5%) as a source of sodium and as preserver. Salt can be used also to regulate animal’s consumption of feed blocks. Urea was used as source of nitrogen and preserver. The main binders used were bentonite clay and quick lime because they are produced locally in Oman. Inclusion of high percentage of bentonite clay (6%) will accelerate the drying procedures of feed blocks during winter time. Calcium sulfate (CaSO4) was included in these formulae as source of sulfur which is usually needed for ruminants fed urea as source of nitrogen. Whole barley grain was included (5 %) in these formulae to improve the palatability (palatability enhancer) of feed blocks and encourage animals turn on to feed blocks when they were exposed to feed blocks for the first time.

Table 1. Feed blocks formulae produced
Ingredients 1 2 3 4 5 6 7
Inferior dates 27

27

25 25 25 25 25
Sun dried sardine fish 5 5 5 7 8 8 7
Wheat bran 40 35 32 37 34 34 37
Ground dates frond leaves 5 5 5 0 0 0 0
Whole barley grains 5 5 5 5 5 5 5
Inferior dates syrup (Dibis) 0 0 5 5 5 0 0
Molasses 0 0 0 0 0 5 5
Urea 3 4 4 4 4 4 4
Plaster of Paris (CaSO4.2H20) 2 2 2 5 2 2 2
Bentonite clay 8 12 12 7 6 4 4
Quick lime 0 0 0 0 6 8 6
Salt 4.8 4.8 4.8 4.8 4.8 4.8 4.8
Minerals+ Vitamins* 0.2 0.2 0.2 0.2 0.2 0.2 0.2

* Composition per 1 kg contained (vitamin A, 450,000 IU; vitamin D3, 11,000,000 IU; vitamin E, 3.18 g, Mn, 10.9 g; I, 1.09 g; Zn, 22.73 g; Fe, 22.73 g; Cu, 2.73 g; Co, 0.635; Mg, 100 g; Se, 0.1 g). ** G= Good, M= Medium, S= Soft

Feed blocks manufacture procedure

Based on previous experience in feed blocks technology and on the trial operation of the new machines conducted after the delivery of equipment, the main steps of manufacture procedure of feed blocks are indicated below.

Preparation of the ingredients

All the ingredients should be weighed out before introducing them into the mixer. In order to accelerate this job a standard volume can be used for each ingredient. But when wet by-products are used in the formula, the quantity should be adjusted according to their dry matter content. Inferior whole dates fruits and sundried sardines fish were grinded (4-6 mm screen) before introduced to the mixer. Wheat bran was used directly without any preparation. Fiber source (date frond leaves) was grounded (6-8mm screen). Urea of fertilizer grade was used as a source of nitrogen. Since urea is hygroscopic, it is possible that during stocking lumps form in the sacks, therefore, urea was dissolved in water before mixing it with other ingredients. Quick lime, bentonite clay and plaster of Paris (CaSO4.2H20) were used as gelling agent without any preparation because they are produced locally in Oman. Salt was fine or coarse grounded before inclusion in feed blocks making.

Mixing

For efficient mixing the ground inferior whole dates, dried sardines fish and Dibis or molasses were first introduced to the mixer and then successively the dissolved urea plus binder salt and at last the wheat bran and the ground date frond leaves. Urea was dissolved in water and mixed with binder, salt and trace element vitamins in the same bucket. The solution was then poured in the mixer with wet by-products, and after they were well mixed, the other ingredients were introduced to the mixer. The amount of water to be added to the mixture depends on the moisture content of the wet by-products. Simple subjective tests based on the Iraqi experience (Salman, 1996; Salman 1999; Bensalem and Nefzaoui 2003) were developed to determine first the amount of water need to be added to the mixture and second to test the mixture is ready for pressing. The first test is a sample of the mixture must be squeezed by hand; if very small amount of liquid leaks between fingers, no water needs to be added. The second test a small mixture was taken from time to time during mixing procedure and pressed by hand, if the compressed mixture maintains its compacted form, the mixture was ready for pressing procedure. The mixture then was emptied into wheelbarrows and transport to the pressing machine.

Pressing

Working with new methodology of manufacturing feed blocks, the manual procedures moulding, pressing and demoulding has been replaced with mechanical hydraulic press (Photo 2). The four moulds were filled with mixtures evenly and then pressed by mechanical hydraulic press at each time. The mixtures inside the mould were pressed by the pistons once in order to get feed blocks with good compactness. A manual T shape metal scraper (pusher) was used in filing the four moulds. Hand filing of mixture in the moulds should be avoided. After pressing the pressed feed blocks were then removed and transport to the drying areas.

Drying

The produced feed blocks in this new methodology high pressure mechanical hydraulic press resulted low moisture feed blocks. This may have a significant impact on handling and shorting the drying period. The feed blocks were dried in open walls shade areas. Also, the feed blocks were turned on their side after 6-8 hrs to accelerate the drying operation. The dried feed blocks were stored in well-ventilated place.

Assessment of feed blocks

After drying the feed blocks were assessed for their hardness and compactness. The degree of hardness and compactness were determined according to the method suggested by Hassoun (1989) and Hadjipanayiotou et al (1993a).

Evaluation of feed blocks manufactured from dates palm trees byproducts and sun dried sardines fish as feed supplement for local Omani goats

This study was carried out at the Rumis livestock research station, Ministry of Agriculture and Fisheries to evaluate feed blocks palatability and their effect as supplementary feed on the performance of local Omani goats. Twenty-six mature local Jabbali Does (mean initial live weight 32.0 0.81 kg) aged 3-5 years were allocated according to their weight into two groups (13 animals/ group). Group (NFB) was Jabbali Does fed conventional concentrate feed plus Rhodes grass hay ad libitum. Group (FB) Jabbali Does fed conventional concentrate feed plus feed blocks and Rhodes grass hay ad libitum.

The two groups were fed on group basis. The conventional concentrate (CP 12%) fed at the rate of 350 g /doe/ day. All the ewes received ad libitum Rhodes grass hay. Feed intake was measured daily and animals’ weights were measured at start and at the end of the trial. The feed blocks formula was 25% ground inferior dates, 8% sundried sardine fish, 34% wheat bran, 5% whole barley grain, 5% dibis (dates syrup), 4% urea, 2% CaSO4, 6% bentonite clay, 6% Quick lime, 4.8% salt and 0.2% minerals and vitamins premix. The chemical analysis of feed blocks, commercial concentrate feed and Rhodes grass hay are presented in Table 2. The chemical analysis was conducted for feed according to (AOAC 1990). Data were analyzed using SAS Software (2004) version 6.0 with GLM procedure to test significance between each group.

Table 2. The chemical Analysis of feed blocks, commercial concentrate feed and Rhodes grass hay

Nutrient, %

Feed
Blocks

Concentrate
feed

Rhodes
grass hay

Dry Matter

87

90

89.70

Crude Protein

23.4

12.0

7.22

Crude Fiber

9.04

10.5

34.3

Ether Extract

1.85

2.0

1.00

Ash

12

8.0

9.80

NFE

53.71

67.5

47.70

ME, MJ/kg DM*

9.7

10.5

8.0

Calcium

1.32

1.0

0.20

Phosphor

0.62

0.5

0.18

* ME metabolizable energy calculated from literature values


Results and discussion

The main objective of this study was to develop new methodology in feed blocks making (equipment, formulation, and manufacturing procedure) and evaluation of feed blocks as alternative feed supplement for small ruminants in Oman.

Feed blocks equipment

The pan mixer developed in Oman gave excellent homogeneous mixture and was more efficient than any other mixer, particularly when working on formulae without any molasses. The pan mixer does not only mix the ingredients, but also beats and compresses the ingredients against the wall of the mixer. This smearing action results in better mixing of the ingredients, blocks of higher density, compactness and hardness resulted. The mixer can be operated continuously during the production operation because it contains two inlets for input raw ingredients and the output for the mixed ingredients. Whereas previous experience on feed blocks making by the food and Agricultural Organization of the United Nations (FAO) projects around the world, suggested using concrete mixer in mixing the ingredients (Sansoucy 1995; Hadjipanayiotou et al 1993a;Preston T R 1995; Hadjipanayiotou 1996). But experiences in Iraq and other countries in the region indicated that this concrete mixer was not efficient for continuous operational production (Salman 1999; Salman 2008a). Also it does not necessarily give homogeneous mixture due to different densities of ingredients. Heavy ingredients stick to the wall of mixer without falling off. This type of mixer is a main constraint for making good quality feed block, because it is just turning and mixing the ingredients. Similar observation was reported by Indian experience on using concrete mixer in feed blocks making (Garg et al 2007). They observed that the mixing of various ingredients was not homogenous, and, as a result, some of the blocks were hard while others remained soft. Also they noticed that about 25 percent of the mixture remained stuck in the container and had to be removed manually. This increased batch processing time and reduced turnover; hence the idea of using a concrete mixer was discarded. Heavy duty hydraulic press was introduced to improve compactness and lowering the hardness of feed blocks by reducing inclusion level of binders in the feed blocks formulae. This could result that ash content could be reduced and then the organic dry matter content increased in the produced feed blocks by this methodology.

Inclusion of high moisture date pulp, which is available in Iraq in commercial quantity, gave excellent blocks regarding hardness and compactness. The date pulp can be incorporated up to 46% of the feed blocks formula. The main binders used in feed blocks making were the quick lime and bentonite clay, which are available in Iraq in commercial quantity. These both binders gave feed blocks with very good compactness and medium to good hardness even when the feed blocks store for a long period (Table 3).

Table 3. Feed blocks formulae tested for Hardness and Compactness
Formulae* 1 2 3 4
 
5 6 7

Compactness

G G G G
 
G G G

Hardness

S S S S
 
M M M

* See Table 1 for the details of different formulae

Initially the amount of water used in feed blocks making was adjusted to simple subjective test developed by Salman (1996) and confirmed by Bensalem and Nefzaoui (2003) which was equivalent to 50 L/100 kg mixture. According to this procedure the produced feed blocks started to be cracked due to high ambient temperature (over 40C ) at summer time. When water content reduced to 35 L/100 kg mixture no cracking in feed blocks was observed during drying period. The main outcome was low moisture feed blocks were produced and this will overcome the main constraint in feed blocks making which was long drying period. The produced feed blocks in this new methodology were top quality feed blocks especially regarding the compactness and hardness. The produced feed blocks were characterized with excellent compactness and soft hardness. The excellent compactness of feed blocks was result of high pressure applied through heavy duty hydraulic press, whereas the soft hardness is result of low level inclusion of binders (gelling agents).

Goats Performance

This study was conducted as part of several applied and adaptive on-station and on-farm experiments which are implemented to evaluate the potential of feed blocks manufactured with this new methodology (equipment, formulation, and manufacturing procedure) as supplementary feed for small ruminants at different stages of production (growth, fattening, mating, pregnancy and lactation).

The nutritive value of the feed blocks supplements together with the other feed stuffs used in feeding trials is presented in Table 2. The feed block is very rich in CP (23.4 %) and energy content (calculated as ME and expressed as MJ/Kg DM) was also good (9.7 MJ), also it was good source if mineral. Dates fruit and dates byproducts are excellent sources of energy (rich source of sugars) and also contain a good supply of macro and micro minerals (Mg, Ca, P, Na, Zn, Cu, Fe, and Mn) (Chaira et al 2007). The nutritive value of feed blocks used in current study is almost similar to the nutritive value of feed block manufactured from Dibis and dates byproducts produced before by El Hag et al (2002) in Oman. But the enrichment of sun dried sardines fish which was also available in Oman in commercial quantity in feed blocks formulae could upgrade the nutritive value considerably.

The feed blocks were introduced to animals directly without adaptation period. But no sign of urea poisoning was occurred. This mainly due to the manufactured procedure applied in feed blocks making when urea dissolved completely in water and then sprayed on raw materials. Similar observation was indicated by Asaolu (2012). It was found that more complete dissolution of urea before incorporation into the feed blocks offered a greater prospect of controlling urea intake by animals, and thus reducing the risks of urea toxicity. Also using bentonite clay as binder might slow release of urea to the rumen. Inclusion of bentonite clay in feed blocks making could reduce the risk of urea toxicity, because it improves nitrogen utilization and decreases the rate of breakdown of urea into ammonia in the rumen (Al-Ani et al 1998; Bensalem and Nefzaoui 2003). Calcium sulfate which was used as source of sulfur might slow release of urea in the rumen. Cherdthong et al (2011) reported that slow urea release properties have been obtained by mixing urea with calcium sulfate in feed blocks making.

The results of the effect of feeding feed blocks manufactured from dates palm trees byproducts and sun-dried sardines fish as supplementary feed on animals feed blocks intake, goats weight gain and reproductive performance are presented in Table 4.

Table 4. Effect of Using Feed Blocks as Supplementary Feed on the Performance of Local Omani Does

Groups

NFB

FB

SEM

p

Experiment Period (day)

60

60

No. of Does

13

13

Average Initial wt. (kg/doe)

32.06

31.85

1.44

0.37

Average Mating BCS

2.33

2.32

0.19

0.05

Average Final wt. (kg/doe)

34.51

36.09

1.70

0.81

Average Weight Gain (kg/doe)

2.45

4.24

0.37

4.60*

Feed Blocks Consumption (g / doe /d)

-

293

Concentrate Consumption (g/ doe /d)

315

315

Rhodes Grass Hay intake (g DM/ doe /d)

508

236

Total Intake (g DM/ doe /d) **

823

844

ME Intake (MJ/ doe /d)

7.36

8.02

CP Intake (g/ doe /d)

75

122

CP/ME ratio

10.2

15.2

Fertility rate a (%)

69

92

0.14

0.1

Kidding rate b (%)

85

108

0.23

0.3

* Statistically significant; ** Group Feeding
a no of Does kidded / no of Does exposed to Buck
b no of Kids born/ no of Does exposed to Buck

These results showed that the palatability of feed blocks by Omani goat was very high. The average daily intake was about 293g/d/ animal. Goats were easily turned on feed blocks due to the presence of whole barley grains and also due to sweet and a very pleasant aroma in Dibis and the dates in the formulae. Whereas Habib (2007) reported that animal adaptability to feed block varied enormously among different animal species and among individual within the same species. Some animals did not consume blocks for the first 10 days, and then slowly started licking. The higher feed blocks intake in the current study was mainly due to soft and medium hardness. Previous studies observed that feed blocks intake was closely related to feed blocks hardness (Mwendia and Khasataili 1990; Herrera et al 2007). Similar intake of feed blocks manufactured from high moisture dates pulp as main energy source was reported by Salman (2008a). Promotion of high intake feed blocks accelerate the adoption of feed technology by sheep owners in Iraq (Salman 1997; Salman 2008a). Similar observation was obtained in Indonesia, where soft hardness feed blocks was more popular and effective in increasing milk production (Makkar 2007).

Using feed blocks as supplementary feed during mating season resulted a highly significant (P< 0.01) improvement in goat weight gain (73%) as compared with un-supplemented group (NFB). The present result confirmed previous studies conducted before when feed blocks were used as substation supplement for sheep during mating season (Ibrahim 2005; Salman et al 2009). These results indicated that feed block improved the weight gain of ewes’ dependent on cereal stubble or whole barley grains and cereal straw as their main diets. The present study is in agreement with other studies that used feed blocks as supplementary feed for goats fed poor quality forages or roughages as their basal diets (El Hag et al 2002; Hinojosa et al 2000; Morales et al 2000).

This improvement in goats’ weight gain is mainly because using feed blocks as supplementary feed would improve the efficiency of utilization of the crop residues by supplying the deficient nutrients (protein and minerals) and then improve the rumen ecosystem for fermentative digestion (Hendratno et al 1991). However, using feed blocks manufactured from dates palm byproducts as supplementary for goats resulted a reduction in goats' Rhodes grass hay intakes and this confirm other study which showed that barley straw intake reduced when yearling Awassi ewes fed feed blocks as catalyst supplement (Ibrahim 2005). The important aspects in the present study, that using feed blocks as supplement improved the nutritional status for Jabbali goats during mating period. The ME intake, crude protein intake and CP/ME ratios improve considerably (Table 4) due feed blocks supplementation.

The present results also showed that goats reproductive performance improved considerably due feed blocks supplementation (Table 4). The Jabbali goats fed feed blocks as supplementary feed during mating season had higher conception rate (23%) and kidding rate (24%) than un-supplemented group (NFB) but the differences was not significant (P>0.05) due to limited number of replicates used in current study. The current results confirmed previous on-station and on-farm trials conducted in dry areas of Iraq (Salman 2000; Salman 2008a). The improvement of reproductive performance of supplemented group is reflection of significant improvement in goat weights gain due to feed blocks supplementation. It was found that the improvement of conception rates and lambing rates of ewes were closely related to improvement of ewes’ weight gain and body condition during mating period (Treacher 1997; Salman et al 2009). The improvement of conception rate and kidding rate for supplemented group might also due inclusion of sun dried sardines fish as source of undegradable protein (UDP) in feed blocks formula. It was found that when feed blocks enriched with cotton seed meal and brewer grains (source of UDP) resulted in considerable improvement in conception rate and lambing rate for Awassi ewe depend on whole barley grains and cereal crop residues as their basal diet (Al-Haboby et al 1999; Salman 2000; Salman et al 2005). Other studies showed that a small amount of protein that is directly available to the animal (i.e. undegradable protein) stimulates both productivity and efficiency of feed utilization (Preston and Leng 1987; Leng et al 1991). Previous experience indicated that for high production animals, blocks containing ‘rumen undegradable protein’ sources (“by-pass” protein sources), such as fishmeal, cottonseed meal, have been developed and used in India and Venezuela (Garg et al 2007; Herrera et al 2007.


Conclusion

It can be concluded that there is a great potential and good prospect in Oman for manufacturing and using feed blocks as alternative feed supplement for small ruminants. The feed blocks produced by this methodology are characterized by excellent compactness and medium to soft hardness. Inclusion of inferior whole dates fruits as energy source and sun dried sardines fish as source of bypass protein in blocks making will upgrade the nutritive value of feed blocks. This type of feed blocks can be used as replacement for costly imported concentrate feed. Adopting the new methodology in feed blocks manufacturing will stimulate the promotion of large production of feed blocks through small and medium scales agribusiness enterprise (SME) in feed industries in Oman.

The implantation of this technology will have great economic and impact on the animals farming in Oman and other Arab peninsula countries due to availability of huge amount of whole dates not suitable for human consumption which is not utilized in animals feeding.


Acknowledgements

The authors thanks all the staff at the sheep and goats research division for their help and support during this work. Thanks also is extended to Dr. Hamoud Al-hasni, Director General for Agriculture and Livestock Research for his always encourages and support.


References

Al-Ani A N, Al-Sultan A A and Raoof S O 1998 Evaluation of feed blocks containing bentonite or date pulp in Awassi sheep nutrition. DIRASAT. 25: 474-481.

Al-Haboby A H, Salman A D and Abdul Kareem T A 1999 Influence of protein supplementation on reproductive traits of Awassi sheep grazing cereal stubble. Small Ruminant Research, 34:33-40.

Al-Mashakhi M S A and Koll E H B A 2007 Country Pasture/Forage Resource Profiles. FAO. 23 p. www.fao.org/ag/agp/agpc/doc/counprof/PDF%20files/ Oman.pdf

AOAC 1990 Official methods of analysis. Association of official Analysis (15th edition). Washington, D.C, USA.

Asaolu V O 2012 Development of moringa multi-nutrient block as a dry season feed supplement for ruminants http://www.lrrd.org/lrrd24/3/asao24046.htm

Bensalem H and Nefzaoui A 2003 Feed blocks as alternative supplements for sheep and goats. Small Ruminant Research. Volume 49, Issue 3, September. pp. 275-288.

Chaira N, Ferchichi A, Marbet A and Sghairoun M 2007 Chemical composition of the flesh and the pit of date palm fruit and radical scavenging activity of their extracts. Pakistan Journal of Biological Sciences, 13, 2202- 2207. http://scialert.net/qredirect.php?doi=pjbs.2007.2202.2207&linkid=pdf

Cherdthong A, Wanapat M and Wachirapakorn C 2011 Effects of urea–calcium mixture in concentrate containing high cassava chip on feed intake, rumen fermentation and performance of lactating dairy cows fed on rice straw. Livestock Science. 136: 76-84.

El Hag M G and Elkhanjari H H 1992 Dates and sardines as potential animal feed resources. World Animal Review. No. 73, 16-23. http://www.fao.org/3/a-u8750t/u8750T0a.htm

El Hag M G, El Shargi K M and El Khangeri H H 1999 Utilization of Date By-Products and Fish Sardines as Feed for Ruminant and Poultry. Arab Agricultural Research Journal. 3 (1):151-175.

El Hag M G, Al-Merza M A and Al Salti B 2002 Growth in the Sultanate of Oman of Small Ruminants Given Date Byproducts-Urea Multinutrient Blocks. Asian-Aust. J. Anim. Sci. 2002. 15 (5) : 671-674). http://ajas.info/upload/pdf/15_104.pdf

Garg M R, Sanyal P K and Bhanderi B M 2007 Urea-molasses mineral block supplementation in the ration of dairy animals – Indian experiences (Editors: Makkar, H. P. S., Sanchez, M. and Speedy, A. W.) Feed Supplementation Blocks. Urea-molasses multinutrient blocks: simple and effective feed supplement technology for ruminant agriculture. FAO Animal Production and Health Paper 164, pp 1 – 12. ftp:ftp://ftp.fao.org/docrep/fao/010/a0242e/a0242e01.pdf

Habib G 2007 Experience with development and feeding of multinutrient feed supplementation blocks in Pakistan In (Editors: Makkar, H. P. S., Sanchez, M. and Speedy, A. W.) Feed Supplementation Blocks. Urea-molasses multinutrient blocks: simple and effective feed supplement technology for ruminant agriculture. FAO Animal Production and Health Paper 164, pp 1 – 12. ftp:ftp://ftp.fao.org/docrep/fao/010/a0242e/a0242e00.pdf

Hadjipanyaiotou M, Verhaeghe L, Allen M, Kronfoleh A R, Labban L M, Shurbaji A, Al-Wadi M, Dassouki M, Shaker B, Labban L M, Shurbaji A, Al-Wadi M, Dassouki M, Shaker B and Amin M 1993a Urea blocks. Methodology of block making and different formulae tested in Syria. Livestock research for Rural Development 5(3): 1-7 httphttp://www.lrrd.org/lrrd5/3/syria1.htm

Hadjipanayiotou M 1996 Urea blocks without molasses made of a variety of by-products and binders. Livestock Research for Rural Development 8(4):6-15. httphttp://www.lrrd.org/lrrd8/4/miltos84.htm

Hassoun P 1989 Manufacture of urea block without molasses. Mimeograph. FAO. Rome, Italy.

Hendratno C, Nolan J V and Leng R A 1991 The importance of urea-molasses multinutrient blocks for ruminant production in Indonesia. In: Proceedings of an international symposium on nuclear related techniques for animal production and health. International Atomic Energy Agency, Vienna, Austria, 15–19 April 1991.

Herrera P, Birbe B, Dominguez C and Martinez N 2007 Experiences with multinutrient blocks in Venezuelan tropics. In (Editors: Makkar, H. P. S., Sanchez, M. and Speedy, A. W.) Feed Supplementation Blocks. Urea-molasses multinutrient blocks: simple and effective feed supplement technology for ruminant agriculture. FAO Animal Production and Health Paper 164, pp 1 – 12. ftp://ftp.fao.org/docrep/fao/010/a0242e/a0242e00.pdf

Hinojosa O, Stemmer A and Valle Zarate A 2000 Effect of Multinutrient blocks on growing of kids at the end of the dry season in Bolivia .Proceedings of the 7th InteInternational Conference on Goats , France ,15-21 May 2000.P:173

Ibrahim Hadeel K 2005 Effect of time of using feed blocks as supplementary feed on the weight changes and reproductive performance of Awassi yearling ewes depend on crop residues as basal diet. Iraqi J. Vet. Med. 29 (1):129- 139.

Leng R A, Preston T R, Sansoucy R and George Kunju P J 1991 Multinutrient block as a strategic supplement for ruminants. World Animal Review, 67:11-19. http://www.fao.org/docrep/U1200T/u1200T07.htm

MAF 2016 Agriculture and Livestock Research Annual Report, Directorate General of Agriculture and Livestock Research, Ministry of Agriculture and Fisheries, Sultanate of Oman.

Makkar H P S 2007 Feed supplementation block technology – past, present and future. In (Editors: Makkar H P S, Sanchez M and Speedy A W.) Feed Supplementation Blocks. Urea- molasses multinutrient blocks: simple and effective feed supplement technology for ruminant agriculture. FAO Animal Production and Health Paper 164, pp 1 – 12. ftp://ftp.fao.org/docrep/fao/010/a0242e/a0242e00.pdf

Morales A R, Galina M A and Haenlein G F W 2000 Nutritional and economic effects of using non protein feed supplementation to dairy goats on low quality forage . Proceedings of the 7th International Conference on Goats , France , 15-21 May 2000.P:145-149

Mwendia C and Khasatsili M 1990 Molasses blocks for beef cattle. pp. 389–403, in: B.H. Dzowela A.N. Said, A. Windem-Agenehu and J.A. Kategile (eds). Utilization of Research Results on Forage and Agricultural By-Product Materials as Animal Feed Resources in Africa. Proceedings of the first joint workshop held in Lilongwe Malawi, 5–9 December 1988.

Preston, T R and Leng R A 1987 Matching ruminant production systems with available resources in the tropics and sub-tropics. Penambul Books: Armidale, Australia pp. 245 http://cipav.org.co/PandL/index.htm

Preston T R 1995 Tropical animal feeding: a manual for research workers, FAO, Rome, Italy. pp 83 – 135. Available at http://www.fao.org/docrep/003/v9327e/v9327e00.htm

Salman A D 1996 The potential of by-product feed blocks in Tunisia. Consultancy Report. ICARDA. Mashreq/Maghreb Project (The Development of Integrated Crop-Livestock Production Systems in West Asia and North Africa). TuniTunis, Tunisia 10-24 January 1996.

Salman A D 1997 The role of multinutrient blocks for sheep production in integrated cereal-livestock farming system in Iraq. pp. 209–219, in: Second FAO electronic conference on tropical feeds. 9 September 1996–28 February 1997. See http://www.fao.org/ag/aga/agap/frg/conf96.htm/salman.htm

Salman A D 1999 Formulation and manufacturing of feed blocks. Regional Workshop on " Feed blocks Technology and its Impact on Animal Resources Improvement. " IPA, ICARDA, M/M Project and FARSC. 22-24 March 1999. Baghdad, Iraq.

Salman A D 2000 Effect of feed blocks supplementation on the reproductive performance of Awassi ewes grazing cereal stubble. International Symposium "Livestock Production in Climatic Uncertainty in the Mediterranean. ANPA, EAAP, ClHEAM and FAO. 22-24 October 1998. Agadir-Morocco.

Salman A D and Qassem Mamdouh 2002 Feed Blocks Supplementation under Drought Conditions: Mashreq–Maghreb Experience. Proceedings of Sixth International Conference on Development of Dry Lands “ Desert and Dryland Development: Challenges and Potential in the New Millennium” Editor John Ryan. UNEP, ICARDA, 22-27 August 1999, Cairo, Egypt.

Salman A D, Ibrahim H K, Ali D A and Ibrahim R A 2005 Influence of feeding different types feed blocks as supplementary feed on reproductive performance of Aawssi ewes grazing cereal stubble. Iraqi J. Vet. Med. 29 (1): 143-150.

Salman A D 2008a New New approach in development of feed blocks technology in the WANA Region. Regional Experts Consultation Meeting on the Utilization of Crop Agricultural Residues. FAO, AARINEA and ARC, Cairo, Egypt. 6-8 June 2004.

Salman A D 2008b Development of new methodology in feed blocks making for the promotion of large scale production in Tunisia. Consultancy Report/ Mashreq/Maghreb Project Phase III (Developing Sustainable Livelihoods of Agropastoral Communities of West Asia & North Africa) SponSponsored by: IFAD and AFESD and Coordinated by ICARDA. Sfax, Tunisia. 5-20 May 2008.

Salman A D, Ibrahim H K, Al-Khalisy A F and Ibrahim R A 2009 Effect of body condition and supplementary feeding on the reproductive performance of Awassi ewes. Iraqi J. Vet. Med. 33 (2): 138-145.

Salman A D and El Shargi K M 2016. New approach for utilization of agro-industrial by-products in ruminants feeding in Oman. Regional Conference for Animal Genetic Resources Conversion Toward Sustainable Utilization. February 23-24 2016, Muscat-Sultanate of Oman.

Sansoucy R 1986 The Sahel: Manufacture of molasses – urea blocks. World Animal Review 57: 40-48.

Sansoucy R 1995 New development in the manufacture and utilization of multinutrient blocks. World Animal Review, 82: 78–83 http://www.fao.org/docrep/V4440T/v4440T0s.htm

SAS 2004 SAS/STAT 9.1 User’s Guide. SAS Institute, Inc. Cary, NC.

Treacher T T 1997 Guidelines for the management of the nutrition of flocks in West Asia during the dry and mating period: what information do we have and what do we need. In: Haddad, N., Tutwiler, R., Thomson, E. (Eds.), Improvement of Crop-Livestock Integration Systems in West Asia and North Africa. Proceedings of the Regional Symposium on Integrated Crop-Livestock Systems in Dry Areas of West Asia and North Africa, Amman, Jordan. ICARDA, Aleppo, Syria, November 6-8, 1995.


Received 8 February 2017; Accepted 17 March 2017; Published 1 June 2017

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