Seven tests were carried out from June to November 1993 to make urea-blocks (UB) using a variety of agricultural by-products and binders. In a factorial arrangement of the treatments, two binders (slaked lime and cement) at three levels (0, 5 and 10%), were studied in test 1. In test 2, the effect of level of screened poultry litter (25, 35, 45, 55%) on the quality of UB was examined. In test 3, the influence of ground barley grain and of chopped barley straw (0.5-2 cm) on UB characteristics was studied. In a fourth test the effect of level of water (4 vs. 6 litres per 10 kg mix) on the characteristics of UB formulae with or without ground barley grain or chopped straw was examined. In another test (test 5), the effect of level of brewers grain (0, 50 and 65%) and of binder on UB characteristics was studied. Finally, in another two tests the characteristics of UB made of different levels (0, 50 and 65%) of tomato pulp (test 6) and crude olive cake (COLC) (10, 20, 30, 40, 50 and 78%) (test 7) were studied.

Slaked lime was effective in replacing cement for UB making (trial 1). Combination of the two binders gave harder blocks (UB3 vs. UB5). Lime gave harder UB than cement (UB3 vs. UB7). Ten percent cement or lime alone gave soft blocks whereas 5% of each gave blocks of good hardness (H) and compactness (C). Test 2 showed that combination of PL with wheat bran along with binders, salt and urea gave UB of poor H and C. Contrary, in test 3 incorporation and of ground barley grain gave better quality UB. Increasing the level of water from 40 to 60 l per 100 kg mixture did not affect the H but improved the C of blocks. Incorporation of brewers grain improved UB block quality. Tomato pulp incorporation gave UB that could be easily transported but were of low density and spongy. On the other hand, COLC gave UB of good H and C. It is concluded that UB can be made of a variety of by-products without any molasses and that lime can replace most of the cement.

Poor quality roughage comprises the only part of the diet for ruminant animals in many parts of the world for a considerable part of the year (Preston and Leng 1987). Animals on such diet are in negative energy balance and supplementary feeding with energy and nitrogen has been used for improving their nutritional status (Capper et al 1989). Molasses-urea blocks (MUB) have been used as supplements for animals kept under extensive systems of production (Sansoucy 1986). Despite promising results from MUB feeding their wider application is restricted due to lack of molasses in certain countriesand/or areas within countries. As a result, urea block manufacturing without any molasses was promoted by the Food and Agricultural Organization of the United Nations in different parts of the world (Hassoun 1989; Hadjipanayiotou et al 1993a,b). The present work reports studies carried out in Cyprus aiming at UB manufacturing using a variety of agricultural by-products and of binders.

Six tests were carried out over the period June to August 1993. Another test using crude olive oil cake (COLC) was carried out in November 1993. Thirty nine UB formulae were tested. The chemical composition of the ingredients used is in Table 1. The percentage composition of each formula is in Tables 2 to 8. Taking into consideration the experience gained in Syria (FAO/UNDP Project aiming at the greater and improved use of agricultural by-products in ruminant animal diets-SYR/89/003) where a number of by-products were used for UB manufacturing, a number of tests were undertaken to verify previous findings, to reconfirm the possible use of slaked lime as partial replacement for cement and study the possibilities of using other by-products (chopped straw, fresh tomato pulp, fresh COLC and brewers grains) for UB manufacturing.

Table 1: Chemical composition (g/kg DM) of ingredients used in different block formulae
	DM	CP	CF	Ash	ADF	NDF	ADL	"D"
Brewers grain	175	298	106	20	202	520	43	597
Wheat bran	921	168	89	52	133	441	23	679
Ground barley	911	118	50	21	63	258	8	863
COLC	489	48	443	13	694	512	ND	122
Tomato pulp	147	181	322	67	412	673	168	579
Poultry litter	870	275	172	122	220	395	75	518

ND not determined; COLC Crude Olive Cake

In a factorial arrangement of treatments (test 1, Table 2), two binders (slaked lime and cement) at three levels (0, 5 and 10%),were tested.The objective of test 2 was to study the effect of graded levels of screened poultry litter (PL) (Table 3) on UB qualities and how an increasing level of lime may affect UB characteristics. In test 3, the possibilities of using ground barley grain and/or chopped straw for UB manufacturing were examined (Table 4). In another test (test 4) the effect of water level on UB qualities was studied (Table 5). In a fifth test the effect of graded levels of brewers grains and of binders on UB qualities was studied (Table 6). Finally, in tests 6 and 7 the effect of graded levels of tomato pulp and COLC on UB characteristics were examined.

Table 2: Formulation (%) and characteristics of urea blocks using different types and levels of binders (Test 1, made 18/6/93).
Formulae #	2	3	4	5	6	7	8	9
Brewers grain	50	50	50	50	50	50	50	50
Poultry litter	19	16	19	16	14	16	14	11
Wheat bran	18	16	18	16	13	16	13	11
Urea	5	5	5	5	5	5	5	5
NaCl	3	3	3	3	3	3	3	3
Slaked lime	5	10	-	5	10	-	5	10
Cement	-	-	5	5	5	10	10	10
Water (litre/10kg)	1.5	1.5	1.5	1.5	1.5	1.5	1.5	1.5
Hardness (H)@	S	M	S	M/G	M/G	S	M/G	M
H*(kg/cm2)
22/6/93	.4	1.1	.4	1.8	1.8	.6	2.1	1.3
24/6/93	.92	1.7	.98	2.2	2.6	.95	2.3	1.6
26/6/93	.95	1.8	1.0	2.5	2.7	1.1	3.0	2.1
29/6/93	1.3	2.2		3.0	3.3	1.7	3.0	2.7
1/7/92	1.5	2.8		3.4	3.5	1.8	3.5	3.0
5/8/92	3.0	3.3	3.1	>4.5	>4.5	3.8	>4.5	>4.5
Compactness@	N	M/G	N	G	G	M/G	G	G
Density (kg/m3)	660	698	661	749	809	726	764	718

# The treatment without any binder is not taken into consideration
@ Measurement taken by Hassoun's method four days after manufacturing
* Hardness measured on specific dates using a penetrometer
M/G In this and other tables means H and C between medium and good

Tomato pulp, COLC, brewers grains and wheat bran were used without any processing. Barley grain was ground in a hammer mill. PL collected from a commercial broiler house bedded with wood shavings was screened using a 20 mm metal grid to remove wood and caked material. Screened PL with a moisture content of 22% was stacked (1.5 m heap) under a shed for at least 6 weeks to eliminate pathogens (Riffin 1977).

Mixing was made in batches of 10 kg in a "Hobart" mixer, model D-300, with a bowl of 20 litres capacity and a flat beater of 25 cm width. The mixing procedure was as follows: water was added in the bowl followed by simultaneous addition of urea, salt, binder(s), and after about 2 minutes mixing the wet material (tomato pulp/COLC/brewers grains) was added. Following a further mixing of 1 to 2 minutes. to attain a homogenous mix., the other ingredients were added as follows: PL, chopped straw, ground barley grain, wheat bran. Each new ingredient was added only after a homogenous mixing of the other ingredients was attained.

The well mixed material was placed in steel (1.25 mm thickness) moulds (20 x 20 x 20 cm) (Allen 1992). The material was pressed manually using a simple hand operated presser consisting of a square plate (19.5 x 19.5 cm) of 0.6 cm thickness, mounted on a T-type handle (63 x 30 cm). Wooden moulding-boards (100 x 20 x 2 cm) were fitted in the base of the plate-mould.

Blocks were unmoulded as soon as pressing of all blocks per mould was completed. The moulding board was used as a "mini-pallet" for transporting the blocks to storage shelves for curing and drying. Blocks were dried in the open air under shelter.

Hardness (H) and compactness (C) of blocks were measured by three persons independently four days after manufacturing following the method of Hassoun (1989). Hardness was assessed by pressing with the thumb in the middle of the block. A block was characterized soft (S), medium (M) or good (G) when the thumb penetrated easily, very little or only with greater pressure, respectively. The C was assessed by trying to break the block by hand. A block was characterized either null (N), medium (M) or good (G) when it was broken easily, with difficulty and/or with great effort, respectively. Furthermore, H was determined using a penetrometer on the 22/6, 24/6/, 26/6, 29/6, 1/7 and 5/8/93. The date of manufacturing of UB within a test is shown in the respective Tables. Since UB in test 7 were made in late November (high humidity), they were kept for one week after unmoulding on a shelf and were then dried in an air-forced oven (80 ?C); hardness and compactness, by both methods, was made 4 hr after removal from the oven.

The chemical composition of the ingredients is given in Table 1. Analyses made at random on some formulae showed that the composition of finished blocks was related to that of individual ingredients. Formulation (%) and characteristics of UB using different levels of Ca(OH)₂ (slaked lime) and cement are in Table 2. Slaked lime was an effective binder. This is in line with Syrian studies (Hadjipanayiotou et al 1993a) but at variance with tests in other FAO projects (Rene Sansoucy and Michael Allen, personal communication) where lime was not a very effective binder.

The combination of two binders (Table 2, test 1) improved H and C of UB (formula 3 vs. 5); five percent cement and 5% lime gave better UB than when 10% lime or 10% cement were used. Lime gave harder UB than cement (formula 3 vs. 7). There is no need for more than 10% binder; UB 5 was equally as good as UB 6, 8 and 9. Hardening of UB increased with advancing storage period. Sansoucy (1986) reported that resistance of 5-6 kg/cm² to penetration would seem appropriate to ensure the desirable level of production. In test 1, only UB formulae 5, 6, 8 and 9 reached the desired H in 47 days after manufacturing; this long period was certainly due to the high moisture content of brewers grains. Other UB formulae of lower moisture content at manufacturing (Tables 3 and 5) that were assessed as S four days after manufacturing attained good hardness in a shorter period of time. UB made of wheat bran and graded levels of PL were soft when tested at 4 days after manufacturing (Table 3, test 2). Increasing lime from 7 to 10% and decreasing cement from 7 to 5% improved UB qualities (UB 14 vs. UB 11, Table 3). UB formulae composed mostly of wheat bran and PL might attain good hardness though they are of medium compactness; the latter was improved by increasing the level of lime and decreasing that of cement. It has been reported (Sansoucy et al 1988; Hadjipanayiotou et al 1993a) that long storage of at least some formulae results in an extremely hard blocks that could reduce block intake seriously.

Table 3 : Formulation (%) and characteristics of urea blocks using different levels of poultry litter (Test 2, made 26/6/93).
Formulae	10	11	12	13	14
Urea	7	6.6	6.2	5.8	6
Salt	5	5	5	5	5
Cement	7	7	7	7	5
Lime	7	7	7	7	10
Poultry litter	25	35	45	55	35
Wheat bran	49	39.4	29.8	20.2	39
Water (litres/10 kg mix.)	4	4	4	4	4
Hardness#	S	S	S	S	M/G
H* (5/8/93)	>4.5	>4.5	>4.5	3.8	>4.5
Compactness*	M	M	G	M	G
Density (kg/m3)	664	591	607	575	720

# Measurement taken by Hassoun's method four days after manufacturing
* Hardness measured on specific dates using a penetrometer measuring resistance up to 4.5 kg/m³

UB formulae 5, 6, 9, 15, 19, 24, 27 and 29 had resistance greater than 4.5 kg/ cm² on the 5th of August, whereas their resistance was 3.6, 3.8, 3.7, 2.5, 3.2, 3.4, 3.0, 3.5 and 3.4, respectively when they were wrapped with polyethylene sheet 15 to 20 days after manufacturing. It is preferred that UB are made at a time prior to their use that they would reach the desired degree of hardness at the time required. However, when long storage period is inevitable, wrapping and/or storing the blocks in polyethylene sheets/bags will maintain the desired hardness.

Incorporating ground barley grain (Table 4, test 3) in blocks improved UB qualities (comparison of UB 10, 11 and 12 with UB 15, 16,17). UB 10, 11 and 13 were of medium compactness, whereas UB 15, 16 and 17 were good. Chopped barley straw used with PL and wheat bran gave null and of medium to hard UB; contrary, the same formulae but with 60 litres of water had better compactness (UB 18 vs. UB 24). Similarly, in test 4 the use of 60 instead of 40 litres of water/ 100 kg mix improved the compactness of UB formulae (UB 21, 23 vs. UB 22, 24). This can be ascribed to the fact that a better mixing of the binder(s) with the ingredients is attained with more water.

Table 4 : Formulation (%) and characteristics of urea blocks with or without ground barley and/or chopped straw (Test 3, made 30/6/93).
Formulae	14*	15	16	17	18
Urea	6	7	7	7	6
Salt	5	5	5	5	5
Cement	5	7	4	2	5
Slaked lime	10	7	7	8	10
Barley grain	-	25	26	26	-
Poultry litter	35	25	26	26	32
Wheat bran	39	24	25	26	32
Choppedstraw	-	-	-	-	10
Water(litres/10kg mix.)	4	4	4	4	4
Hardness#	M/G	M/G	M/G	M/G	M/G
H@5/8/93	>4.5	>4.5	>4.5	>4.5	3.6
Compactness#	G	G	G	G	M/N
Density(kg/m3)	690	810	726	708	435

* Repeated from previous test
# Measurement taken by Hassoun's method four days after manufacturing
@ Hardness measured on specific dates using a penetrometer
M/N compactness between medium and null

Table 5: Composition (%) and characteristics of urea blocks at different level of water (Test 4, made 8/7/93)
Formula	19	20	21	22	23	24
Urea	7	7	7	7	6	7
Salt	5	5	5	5	5	5
Cement	5	5	2	2	5	5
Slaked lime	10	10	8	8	10	10
Poultry litter	26	26	26	26	32	26
Ground barley	-	-	26	26	-	-
Wheat bran	49	49	26	26	32	39
Barley straw	-	-	-	-	10	10
Water	4	6	4	6	4	6
Hardness*	G	G	M/G	G	M/G	G
H#5/8/93	>4.5	>4.5	>4.2	>4.5	3.6	>4.5
Compactness*	M	G	M/N	G	M	M/G

* Measurement taken on 5/8/93 by Hassoun's method
# Hardness measurement taken using a penetrometer

Incorporating brewers grain to UB improved UB quality (UB 25 vs. UB 26, 27, 28,and 29) (Table 6, test 5). It must be underlined, however, that this was always the case in a "Hobart" mixer , but not with a concrete mixer. The concrete mixer is just turning and mixing the material, whereas the Hobart mixer beats and compresses the material against the walls of the container. This smearing action produces UB of higher density resulting in better contact between the binder(s) and the bulky brewers grains. It is my opinion that mixers that beat and compress the material against the walls of the container might have to be used for making good quality UB without molasses.

Table 6: Composition (%) and characteristics of urea blocks at different levels of brewers grain and binders (Test 5, made 8/7/93)
Formula	25	26	27	28	29
Urea	6	5	5	5	3.3
Salt	5	3	3	3	2.2
Cement	5	-	3	3	2.2
Slaked lime	10	7	5	7	4.3
Poultry litter	35	18	17	16	12
Brewers grain	-	50	50	50	65
Ground Barley	-	-	-	-	-
Wheat bran	39	17	17	16	11
Water(litres/10 kg mix)	4	1.5	1.5	1.5	1
Hardness*	M	G	G	G	G
H# 5/8/93	4.1	>4.5	>4.5	>4.5	>4.5
Compactness*	M/N	G	G	G	G
Density (kg/m3)	623	843	840	751	674

* Measurement taken on 5/8/93 by Hassoun's method
# Hardness measurement taken using a penetrometer

Tomato pulp used at two levels (50 and 64.5%) in test 6 gave soft and null UB and of low density (Table 7); these, like other UB of high moisture content required longer period to dry and obtain the desirable hardness. UB of high moisture content would require around 10 to 15 days after manufacturing before being transported. Fresh COLC (test 7) on the other hand, gave UB of good H and C (Table 8). Indeed, COLC seems to have binding qualities, and at high levels of inclusion (15%) may facilitate the use of less quantities of binders. The fact that COLC is available during the rainy season, make its use for UB manufacturing problematic, since dehydration of UB is longer. Surpluses of COLC, however, can be easily preserved by ensiling in heaps next to oil mills (Hadjipanayiotou 1994), and utilized in UB after february.

Table 7: Composition (%) and characteristics of urea blocks using different levels of tomato pulp and water (Test 6 made 23/7/93).
Formulae	14*	30	31	32	33
Urea	6	5	5	5	3.4
Salt	5	3	3	3	2.15
Cement	5	-	2.5	2.5	2.15
Lime	10	7.5	5	7.5	4.3
Poultry litter	35	17.5	17.5	16	11.9
Tomato pulp	-	50	50	50	64.5
Wheat bran	39	17	17	16	11.6
Water (litres/10 kg mix)	4	1.5	1.5	1.5	1
Hardness#	M/G	S	S	S	S
H@ 5/8/93	>4.5	3.3	2.7	3.5	2.4
Compactness#	G	N	N	N	N
Density (kg/m3)	1710	626	622	654	560

* Repeated from previous test
# Measurement taken on 5/8/93 by Hassoun's method
@ Hardness measurement taken using a penetrometer

Table 8: Composition (%) and characteristics of urea blocks using different level of crude olive cake (Test 7, made 25/11/93)
Formulae	36	37	38	39	40	41
Urea	7	7	7	7	7	7
Salt	5	5	5	5	5	5
Cement	2	2	2	2	2	2
Slaked lime	8	8	8	8	8	8
Poultry litter	34	29	24	19	18	-
Olive cake	10	20	30	40	50	78
Wheat bran	34	29	24	19	10	-
Water (litres/kg mix)	4	3.8	3.5	3.0	2.5	2.0
Hardness#	G	G	G	G	G	G
H@	>4.5	>4.5	>4.5	>4.5	>4.5	>4.5
Compactness#	G	G	G	G	G	G
Density (kg/m3)	570	576	589	624	688	797

# Measurements taken (see material and methods) following Hassoun's proposal
@ Hardness measurement taken (see material and methods) using a penetrometer

It is concluded that it is possible to make UB of good hardness and compactness without any molasses. Brewers grain and COLC when available, not only can be used for UB but they can also improve UB qualities. Furthermore, tomato pulp can be used in UB, and incorporation of high moisture by-products in UB will reduce the amount of water, but will increase storage/curing area required. Slaked lime can replace a great part of cement; the selection of the binder therefore, should depend upon price and availability.

The author is grateful to his colleagues at the Institute: Drs A P Mavrogenis and Ch. Papachristoforou, and Dr R Sansoucy, Feed Resources Group, FAO for reviewing the manuscript, Mr A Photiou and Mesdames M Theodoridou and M Karavia and the staff of the Central Chemistry Laboratory for skilled technical

Hadjipanayiotou M, Verhaeghe L, Kronfoleh A R, Labban L M, Shurbaji A, Al-Wadi M, Dassouki M, Shaker B and Amin M 1993a Urea blocks. I. Methodology of block making and different formulae tested in Syria. Livestock Research for Rural Development 5(3):6-15

Hadjipanayiotou M, Verhaeghe L, Kronfoleh A R, Labban L M, Amin M, Al-Wadi M, Badran A, Dawa K, Shurbaji A, Houssein M, Malki G, Naigm T, Merawi A R and Harres A K 1993b Urea blocks. II. Performance of cattle and sheep offered urea blocks in Syria. Livestock Research for Rural Development 5(3):16-23

Received 1 November 1996