Citation of this paper

The performance of layers fed diets containing varying levels of sortex rejected rice from the processing of whole rice grains

A N A Tagoe^1,2, J A Hamidu¹, A Donkoh¹ and H Gariba¹

¹ Department of Animal Science, Faculty of Agriculture, College of Agriculture and Natural Resources, KNUST, Kumasi, Ghana
alberttagoe.at@gmail.com
² Ejura Agricultural College, P O Box 29, Ejura Ashanti Region-Ghana

Abstract

This study was conducted to determine the performance of layers (Bovan Goldline) fed diet containing varying levels of Sortex Rejected Rice (SRR). A total of three hundred and sixty (n=360) 20 weeks old pullets were allocated to 4 SRR inclusion levels replacing maize at 0% (T0), 25% (T1), 50% (T2), and 75% (T3). Each dietary treatment had six (6) replicates with 15 birds per replicate making a total of 90 birds per treatment. The treatment diets were used to feed the layers for 28 weeks. The birds had unrestricted access to feed and water. Weekly feed intake, weekly body weight, hen day egg production, egg quality, and reproductive indicators: age at first egg and age at 50% egg production were measured. The feed intake and egg mass were used to calculate the feed conversion ratio (FCR). Data recorded were analyzed as one-way ANOVA using SAS Proc. GLM at p < 0.05. The results showed no significant differences in the weekly weight gained, feed intake, FCR. The age at onset of egg production and 50% of egg production, average egg weight, and egg quality parameters (yolk, shell, and albumen) were not different between treatments. Birds fed SRR performed better (63.64%, 64.66%, and 64.88%) than the control (58.78%) in terms of egg production and egg quality. The SRR inclusion resulted in feed cost saving between GH¢ 0.15 and GH¢ 0.46 per kg feed as a replacement for maize in layer diet at various levels. It can be concluded that the SRR as a replacement for maize increases egg production and reduce feed cost.

Keywords: egg production, egg quality, feed cost savings, feed intake

Introduction

The rising cost of poultry feeds has continued to be a major problem in developing countries as feed cost is about 65-70% and 70-75% of the total production cost compared to about 50-60% in developed countries (Ashour et al 2015; Scott 2017). Cereal grains, such as maize are a dominant component of the poultry diet which serves as the main carbohydrate component and serves as the principal energy source in the poultry diet (Sittiya and Yamauchi 2014). About 70-80% of maize production is used as a feed ingredient in the world for both humans and animals. Maize and its milling by-products have conventionally been used as the main sources of energy in animal feeds (Rama et al 2000). It makes up to 30% protein, 60% energy, and 90% starch in an animal’s diet (Dado 1999).

However, recent challenges in the utilization of maize in a poultry diet have emerged especially in the tropical region. It often becomes scarce due to the seasonality in production, competition between man and animals as food, and its affinity to lead to aflatoxin infection. Its use for biodiesel and demand from breweries and domestic industries is also large (Akbar et al 2018). Maize serves as the main energy source in the poultry diet especially for egg production because the number of eggs is influenced greatly by energy (Pérez-Bonilla et al 2012; Die 2017).

Rice and rice by-products appear to be closer alternatives when considering a cheaper source of energy for poultry production part from maize (Ashour et al 2015). Rice waste has a crude protein level ranging from 7% to 9.4% and low fibre level of 3.14% and metabolizable energy above 3200Kcal/kg (Bodie et al 2019; Njuguna 2007). Sortex rejected rice (SRR) is by-product during the processing of rice. The sortex is a machine used to make sure that in the dehusking and polishing process the final rice grains that comes out is of even size and colour, and devoid of any contaiminant. The sortex machine isolates and successfully eliminates imperfections on the grain and removes all unfamiliar material like pieces of stones, bad rice, dark rice, half-husked rice and undesirable foreign seeds. This leaves completely sorted, clean, and polished rice. All the materials that are isolated and eliminated are called Sortex rejected rice. The price of the SRR is only 35% of the price of normal polished rice and 37.5% the price of maize in the open market.

In a recent study, using rice by-product (Sortex rejected rice (SRR) as a partial replacement for maize up to 75% showed no difference in 8 to 20 weeks old pullets target body weight, feed intake, and FCR. However, a diet with a higher inclusion level of SRR resulted in higher financial savings indicating an excellent replacement for maize where necessary (Tagoe et al 2019). The objective of the current study was to assess the potential impact on egg laying performance and economics of production of the same inclusion level of the Sortex rejected rice (SRR) for maize (0-SRR, 25-SRR, 50-SRR and 75-SRR) during the egg-laying phase of chickens.

Materials and methods

Experimental site

The study was conducted at the Department of Animal Science, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi. The study area is located within the semi-deciduous humid forest zone of Ghana characterized by a bimodal rainfall pattern with an annual rainfall of 1300mm. Daily temperatures range from 20^oC to 35^oC with an average of 26^oC. The relative humidity varies from 97% during the morning of the wet season to as low as 20% during the late afternoon in the dry season (2019 Meteorological data, Department of Animal Science, Unpublished). All experimental procedures followed the appropriate ethical Procedure for Animal Research Ethics Committee (AREC) of the Kwame Nkrumah University of Science and Technology, Kumasi-Ghana, Quality Assurance, and Planning Unit (KNUST POLICY 0016) (AREC 2018).

Experimental design

A total of 360 twenty-week old birds, which had been used for pullet studies using SRR, were used (Tagoe et al 2019). The treatment group used for the pullet studies were maintained in this study in a Complete Randomized Design. The SRR was used to replace maize at different levels of 0-SRR, 25-SRR, 50-SRR and 75-SRR (Table 1) representing 0, 25%, 50% and 75% of maize. Each treatment had six (6) replicates with 15 birds per replicate making 90 birds per treatment. The treatment diets were used to feed the birds for 28 weeks. The birds had unrestricted access to feed and water. The birds were housed in 24 deep litter pens measuring 1.22m X 2.44m. Each bird had an average space of 0.198m². Wood shavings were spread on the floor to serve as litter for the birds. To ensure a clean environment at all times, the wood shavings were changed at monthly intervals. The vaccination and medication program was planned and followed carefully following the recommendations of the Veterinary Service Directorate of the Ministry of Food and Agriculture.

Data collection

Feed consumption

The feed consumed per bird per replicate was calculated by weighing the feed left in the feeding trough at the end of the week and subtracting the weight of the total feed provided per week. The figure recorded was further divided by the number of birds in a replicate and the number of days per week to obtain feed intake per bird per day.

Live body weight and live body weight gain

The initial live body weights for each replicate were recorded at the beginning of the trial and taken at weekly intervals thereafter. Birds in a replicate were weighed together and the weight obtained was divided by the number of birds in each replicate to obtain the mean live weight per bird. The initial average live weight per bird was subtracted from the weekly average live weight to obtain the live weight gain per week.

Feed conversion ratio (FCR)

The feed conversion was calculated by dividing the feed consumed by the total mass of eggs produced.

Mortality

Mortality was recorded as it occurred throughout the experimental periods. Dead birds were sent for post-mortem examination at the Veterinary Service Directorate of the Ministry of Food and Agriculture, Kumasi to ascertain the cause of death.

Egg collection

Eggs were collected three times daily between the hours of 09:0–10:00 hours, 12:00–13:00, and 1600–1700 hours GMT. The daily records were used to calculate the hen-day egg production and the hen- housed egg production by using formulas recommended by North and McDonald (1990) as follows;

Egg quality characteristics

Eggs were assessed for internal and external quality characteristics. The external egg qualities recorded included egg weight, egg measurements (diameter, length, and width in millimetres), shell weight, and shell thickness, while the inner egg parameters included albumen weight, albumen height, yolk height, yolk weight, and Haugh unit. The egg diameter and shell thickness were estimated utilizing Digital Vernier callipers (Al-shami et al 2011). For internal egg quality, individual eggs were broken on a level white surface and egg content carefully poured with a consideration regarding keep the vitelline film of the yolk unblemished. The yolk and albumen were then carefully isolated and placed in pre-weighed Petri dishes. The distinction between the yolk or albumen and the petri dish was determined. The albumen and yolk heights were determined utilizing the egg quality slide rule (Mohammed and Dei 2013). The breadth of the thick albumen was assessed utilizing a micrometre screw gauge with sensitivity to the closest 0.01 mm. Shell thickness was estimated from 3 unique pieces of the egg (equator, sharp end, and wide end) utilizing a micrometre screw gauge (Ikeme et al 1983). Haugh unit was determined from utilizing albumen height and egg weight as described previously utilizing the equation: Haugh unit = 100 log (H+7.57W0.37), where H = observed albumen height (mm) and W = observed egg weight (g) (Fasuyi and Ojo 2012). The yolk colour was determined using a Roche Yolk Color Fan Edition 1965 was utilized to subjectively 5 measure yolk colours (Roberson et al 2005) on a glass plate with heavy white paper set underneath the glass as an impartial foundation. Three eggs were utilized per each replicate totalling 18 for every treatment group and 72 eggs in all.

Statistical analysis

Means and associated standard errors for measured parameters were computed. Data analysis was done using SAS Proc. GLM (SAS 2014) and significance separated at P>0.05 using Student Newman-Kuels (SNK) test.

Results and discussion

Growth performance and mortality

There were no differences in the feed intake, weights gain, feed convertion ratio (FCR) and mortality of the birds. The final weight showed differences among treatments, however, this did not cause differences in the weight gained at the end of the experimental period (Table 1). This could be an indication that SRR would not negatively influence the feed intake, weight gain and FCR of layers. The appreciable performance of birds on 75-SRR could de due to lower fibre and higher starch content in rice. The FCR is reputable signal of how effective the SRR or a feeding strategy was. This results of this study confirm an earlier study with pullets (Tagoe et al 2019). This reults also confirm the reports of Asyifah et al (2012), Filgueira et al (2014) and Vu et al (2016) when corn was replaced with broken rice.

Table 1. Growth performance and mortality of layer birds fed sortex rejected rice as a replacement for maize
Item	0-SRR	25-SRR	50-SRR	75-SRR	SEM	p-Value

Daily feed intake (kg)	0.11	0.11	0.12	0.12	0.00	0.141
Initial weight (kg)	1.55	1.55	1.53	1.54	0.03	0.955
Final weight (kg)	1.81^ab	1.86^ab	1.75^b	1.92^a	0.04	0.048
Weight gained (kg)	0.26	0.32	0.22	0.38	0.05	0.155
FCR	3.89	3.37	3.52	3.58	0.14	0.086
Mortality (%)	1.33	1.33	0.50	0.83	0.50	0.569

Age at onset and 50% of laying

The common data used for calculating early egg production are ages at first egg, 5 %, and 50 % egg production (North and McDonald 1990). The results of this study have shown that the experimental diets did not exert any effects on the age at first egg laid and 50% laying (Table 2). Although there were no differences, the age at 1^st lay decreased with SRR inclusion level in the diet. Birds fed with SRR diet during their growing period reached the point of lay earlier than those on the control diet did. The early laying by bird fed with SRR could be attributed to the SRR as the same birds were used during the pullet phase (Tagoe et al 2019). Earlier study by Abubakar et al (2011), however, reported that birds fed rice bran during the growing period laid their first egg earlier than the control birds.

Table 2. Egg production indices of layer birds fed sortex rejected rice as a replacement for maize
Parameter	0-SRR	25-SRR	50-SRR	75-SRR	SEM	p-value

Age at 1^st egg-laying (day)	136	134	133	134	2.08	0.723
Age at 1^st 50% egg-laying (day)	148	147	150	151	1.91	0.549
Weight at 1^st laying (kg)	1.65	1.63	1.63	1.65	0.02	0.798
Hen day egg production (%)	58.78	64.88	64.66	63.64	1.84	0.097
Henhouse egg production (%)	56.10	62.29	62.79	61.42	2.19	0.150

Hen day and hen house egg production

Hen day egg and hen house egg production are parameters, which are used as pointers for egg production in chicken (North and McDonald 1990). Overall, the dietary treatments did not exert any differences on the hen day and hen house production (Table 4). However, the weekly egg production showed differences during certain weeks (Table 3 and 4). No differences were observed in the weekly henday egg production until the 31^st week. In the 31^st and 35^th week, SRR-50 was higher (64.47) than SRR-0 (48.62). In the 32^nd week, differences existed within all the treatments. In the 33^rd and 34 ^th week, SRR-50 had higher (56.85 and 76.05) production than the rest of the treatments. In the 36^th week, the SRR-0 produced lower (53.37) eggs than birds fed SRR. In the 39^th week, SRR-25 produced higher (86.02) than the SRR-0. It is only the 45^th week that the SRR-75 had higher hen day production thanthe rest of the treatment (Table 3).

Table 3. Effect of sortex rejected rice as a replacement for maize on weekly hen day egg production
Week	0-SRR	25-SRR	50-SRR	75-SRR	SEM	p-value

21	24.8	29.1	24.0	21.4	5.43	0.792
22	48.1	54.1	48.1	45.9	5.42	0.735
23	60.0	64.1	63.4	60.6	5.18	0.927
24	67.5	71.1	69.9	67.8	4.26	0.916
25	56.5	64.5	61.1	57.5	4.09	0.514
26	53.5	52.5	52.8	58.6	4.13	0.701
27	57.6	59.4	57.5	58.3	4.21	0.989
28	55.6	56.5	62.2	60.2	3.15	0.430
29	46.8	52.2	55.9	55.0	4.95	0.574
30	45.8	54.9	53.3	48.7	4.78	0.525
31	48.6^b	56.5^ab	65.5^a	57.0^ab	3.32	0.017
32	35.6^c	51.3^b	63.8^a	49.1^b	3.05	<.0001
33	35.1^a	39.1^a	56.9^b	40.8^a	3.50	0.002
34	56.2^a	65.8^a	76.1^b	64.0^a	4.34	0.033
35	6628^b	74.6^ab	81.6^a	78.0^ab	4.46	0.120
36	53.4^b	65.9^a	74.6^a	70.6^a	3.94	0.007
37	58.9	69.1	68.7	68.2	3.82	0.207
38	55.3	65.9	61.8	62.5	4.94	0.508
39	73.3^b	86.0^a	82.6^ab	78.4^ab	3.44	0.083
40	76.7	84.7	80.2	79.4	3.36	0.428
41	65.2	66.4	69.2	69.0	3.39	0.798
42	77.2	81.4	78.8	79.0	3.81	0.885
43	74.9	81.5	74.4	79.7	3.47	0.399
44	74.7	77.2	71.3	77.2	4.42	0.757
45	74.2^ab	75.9^ab	63.1^b	78.8^a	4.41	0.094
46	75.8	82.4	74.4	82.1	4.03	0.378
47	74.7	73.0	69.1	74.9	4.26	0.751
48	68.7	75.7	71.2	75.4	3.75	0.500

Table 4. Effect of sortex rejected rice as a replacement for maize on weekly hen house egg production
Week	0-SRR	25-SRR	50-SRR	75-SRR	SEM	P-value

21	24.8	28.3	23.6	21.4	5.61	0.848
22	48.1	54.1	47.6	45.9	5.36	0.721
23	60.0	64.1	62.5	60.8	5.07	0.939
24	67.5	71.1	69.1	67.8	4.18	0.924
25	56.5	64.5	60.5	57.6	4.13	0.541
26	53.5	52.5	52.2	58.5	4.16	0.691
27	57.1	59.4	56.5	58.5	4.26	0.963
28	54.3	56.4	61.9	59.4	3.66	0.490
29	45.7	52.2	54.9	54.3	5.01	0.560
30	44.8	54.9	51.9	47.9	4.71	0.461
31	47.5^b	56.5^ab	63.8^a	55.6^ab	2.98	0.009
32	37.8^c	51.3^b	62.5^a	47.1^b	2.62	<.0001
33	33.8^b	41.4^ab	56.5^a	42.1^ab	3.38	0.001
34	48.3^b	58.9^ab	70.2^a	57.8^ab	4.39	0.019
35	67.1	75.4	79.5	77.0	4.38	0.246
36	49.2^b	64.1^a	70.3^a	64.8^a	4.14	0.012
37	59.2^b	71.3^a	72.7^a	70.0^a	3.25	0.032
38	47.3	58.4	57.6	57.3	4.62	0.302
39	63.7	77.8	73.3	70.6	4.47	0.188
40	73.8	82.9	81.0	78.9	3.18	0.244
41	59.5	63.8	66.7	64.9	4.25	0.678
42	69.4	69.5	74.6	73.5	4.12	0.733
43	71.0	76.7	75.1	76.2	4.69	0.820
44	67.0	70.8	66.5	72.5	4.83	0.776
45	69.1	68.6	62.9	73.5	4.49	0.439
46	69.2	74.0	69.5	79.4	4.92	0.442
47	68.6	68.3	66.5	72.2	4.94	0.870
48	65.9	66.2	68.6	70.2	4.39	0.885

Results obtained for weekly hen house egg production was not much different from the weekly hen day egg production. From Table 6, it can be seen that SRR-50 had higher henhouse egg production than SRR-0 during the 31^st, 33^rd, and 34^thweek. In the 32 ^nd week, differences existed among all the treatment but the birds fed the SRR had higher hen house egg production than SRR-0. In the 36 ^thand 37^th week, the control production was lower (59.21) than birds fed SRR. Although they had similar ME energy and crude protein, rice, in general, has higher protein digestibility among staples crops and lower dietary fibre among the cereals including maize (Juliano 1993). The SRR had higher (3542 Kcal/kg) ME than maize (3420 Kcal/kg) and this could have resulted in higher egg production of birds fed with it as a replacement for maize. A report by Maina et al (2013) indicates that birds fed diets containing rice-milling by-products performed better in terms of egg-laying than those under control. Sittiya and Yamauchi (2014) also reported that laying performance and egg qualities, except for yolk colour, were not influenced by dietary treatment in which corn was replaced with rice at different levels. On the other hand, an investigation by Zaefarian et al (2019) proof that egg production of hens can be decreased due to excessive fats and lipogenic nature from the broken rice-based diet.

The effect of SRR on egg quality

Dietary treatment did not exert any effect no effect of SRR treatments on the egg quality parameters including eggshell thickness, albumen height, yolk width, yolk colour, and Haugh unit (Table 5). This could be an indication that SRR will not exert any negative influence if incorporated in the layer diet. The results in this study confirm that of Sittiya and Yamauchi (2014) when they carried out a study to find the effects of replacing corn with whole-grain paddy rice in laying hen diets on egg production performance.

Table 5. Egg quality characteristics of birds fed SRR
Parameter	0-SRR	25-SRR	50-SRR	75-SRR	SEM	p-value

Shell thickness(mm)	0.59	0.59	0.63	0.60	0.01	0.123
Albumen height (mm)	6.67	6.75	6.81	7.47	0.28	0.199
Yolk width (cm)	4.40	3.96	4.31	4.37	0.18	0.303
Yolk color	1.39	1.22	1.44	1.22	0.11	0.380
Haugh unit	80.7	82.4	82.0	86.2	1.67	0.143

References

Akbar M R, Purwoko B S, Dewi I S and Suwarno W B2018. Agronomic and drought tolerance evaluation of doubled haploid rice breeding lines derived from another culture. SABRAO Journal of Breeding & Genetics, 50(2).

Al-Shami M A, Salih M E and Abbas T E 2011 Effects of dietary inclusion of alfalfa leaf meal and Xylan enzyme on laying hens’ performance and egg quality. Res. Opin. Anim. Vet. Sci. 2:14–18.

AREC 2018 Animal Research Ethics Committee (AREC) Standard Operating Procedures. https://keep.knust.edu.gh/node/75.

Ashour E A, Reda F M and Alagawany M 2015 Effect of graded replacement of corn by broken rice in growing Japanese quail diets on growth performance, carcass traits and economics. Asian Journal of Animal Sciences, 9(6), pp.404-411.

Asyifah M N, Phang L Y and Azlian M N 2012 Brown rice as a potential feedstuff for poultry. The Journal of Applied Poultry Research 21(1):103-110. DOI: 10.3382/japr.2011-00379

Bodie A R, Micciche C, Atungulu G, Rothrock M J and Ricke S C 2019 Current trends of rice milling byproducts for agricultural applications and alternative food production systems. Front. Sustain. Food Syst, 3.

Dado R G 1999 Nutritional benefits of speciality corn grain hybrids in dairy diets. Journal of animal science, 77(2), 197-207.

Dei H K 2017 Assessment of maize (Zea mays) as a feed resource for poultry. Manafi, M. (Comp.). Poultry science. IntechOpen, 1-32

Fasuyi A O and Ojo O G 2012 Quantitative feed restriction threshold in Bovan Nera laying pullets in the warm wet tropics. J. Anim. Sci. Adv. 2:158–165.

Filgueira T M B, Freitas E R, Quevedo F I B, Fernandes D R, Watanabe P H and de Oliveira A N 2014 Corn replacement by broken rice in meat-type quail diets. Brazilian Journal of Poultry Science, 16(4), pp.345-350.

Ikeme A I, Roberts C, Adams R L, Hester P Y and Stadelman W J 1983 Effects of supplementary water-administered vitamin D3 on eggshell thickness. Poult. Sci. 62:1120–1122.

Juliano B O 1993 Rice in human nutrition (No. 26). Int. Rice Res. Inst. http://www.fao.org/3/t0567e/T0567E00.htm#Contents

Maina J G, Kamau W N and Kabuage L W 2013 Evaluation of high levels of rice milling byproducts in chicken layer diets: effects on layer performance, egg quality and economic returns. Livestock Research for Rural Development, 25(7), 119.

Mohammed A and Dei H K 2013 Effect of false yam on laying performance. Ghanaian J. Anim. Sci. 7:106–116.

Njuguna K W 2007 Evaluation of rice milling by-products from Mwea Irrigation Scheme in layer chicken diets (Doctoral dissertation, University of Nairobi).

North M O and McDonald D B 1990 Commercial chicken production manual. Van Nostrand Reinhold, New York. Pp. 45 – 60.

Pérez-Bonilla A, Novoa S, García J, Mohiti-Asli M, Frikha M and Mateos G 2012.Effects of energy concentration of the diet on productive performance and egg quality of brown egg-laying hens differing in initial body weight. Poultry Science, 91(12), 3156–3166. https://doi.org/10.3382/ps.2012-02526

Rama R S V, Reddy M R, Prarharaj N K and Shyam S G 2000 Laying performance of broiler breeder chickens fed various millets or broken rice as a source of energy at a constant nutrient intake. Tropical Animal Health and Production; 329-338.

Roberson K D, Kalbfleisch J L, Pan W and Charbeneau R A 2005 Effect of corn distiller’s dried grains with solubles at various levels on performance of laying hens and egg yolk colour. Int. J. Poult. Sci, 4(2), 44-51.

SAS Institute Inc, 2014 . SAS/STAT ® 9.3 Procedures Guide. Cary, NC: SAS Institute Inc.

Scott R. 2017 Ghana 2017 Ghana Poultry Report Annual.

Sittiya J and Yamauchi K E 2014 Effects of replacing corn with whole-grain paddy rice in laying hen diets on egg production performance. Journal of Advanced Agricultural Technologies Vol, 1(1).

Swain B K, Sundaram R N S, Chakurkar E B and Barbuddhe S B 2006 Feeding value of broken rice for Japanese quail layers. Indian Journal of Animal Nutrition, 23(3), 193-195.

Tagoe A N A, Hamidu J A, Donkoh A, Kofitse M M and Amankwa R 2019 Manipulating layer feed for energy during the pullet phase: effect on growth performance (9-20 weeks). Ghanaian Journal of Animal Science, 10 (1): 43-50.

Vu M T, Tran V T, Nguyen M T T and Cao V 2016 Effect of Replacement of Corn by Brown Rice on the Performance of Chicken Production in Vietnam. Research in Agriculture, Livestock and Fisheries. Vol. 3, No. 1, April 2016, pp. 139-144.

Zaefarian F, Abdollahi M R, Cowieson A and Ravindran V 2019 Avian Liver: The Forgotten Organ. Animals: an open-access journal from MDPI, 9(2), 63.