|
|
|
Figure 1: Effect of dietary treatments on egg production, egg mass and egg weight |
| Back to contents |
The effect of crude rice bran oil (CRBO) on performance of Hisex Brown laying hens was evaluated. Five different levels of 1, 1.5, 2, 2.5 and 3% CRBO and 1.5% of animal fat (lard) were supplemented in a basal diet, which included no fat supplementation.
Hens fed dietary oil or fat improved egg production (P=0.05) egg mass and feed efficiency as compared to those fed basal diet (P<0.01). Egg weight, yolk index, yolk color were not affected by dietary treatments, but Haugh unit, albumin index and shell thickness ratio was better in the hens fed 3% of CRBO (P<0.05). Plasma cholesterol, HDL-chloesterol and triglycerides were also not influenced by CRBO supplementation, but at levels of 2.5 and 3% of CRBO had beneficial effect on lowering yolk cholesterol (P=0.07).
In Vietnam, rice is a staple food for Vietnamese people, the nation average yield is 5.23 tones per hectare in 2009 and the Mekong delta is the biggest rice production zone in whole country. Rice bran is by-product of the milling rice contains the bran layer and germ of rice and has high fat content (13-15%).
Crude rice bran oil can be extracted from rice bran by solvent extraction or using ohmic heating, it is rich in unsatturated fat, which consists of 41% monounsaturates (39% oleic acid), 36% polyunsaturates (34% linoleic acid) and 19% saturates (Kahlon et al, 1992). Rice bran oil contains over 4% of unsaponifiable matter (Sharma, 1986). Oryzanol, a mixture of ferulic acid esters of triterpenoid alcohols, composes 20% to 30% of unsaponifiable matter and 1.1% to 2.6% of bran oil. Oryzanol is antioxidant compound and is also associated with depressing plasma cholesterol (Yoshino et al, 1989). Xu et al. (2001) reported that gamma ozyzanol has antioxidant activities in the inhibition of cholesterol oxidation.
There are several studies on human and animals showing that orizanol have cholesterol lowering property (Sharma et al., 1986; Kahlon et al., 1992). The composition of rice bran oil is well documented (Patel and Naik, 2004), in consideration of its potential, crude rice bran oil is a source of energy, contains essential fatty acids and may be benefits through supplementing the diet of laying hens, achieved in reducing plasma cholesterol and yolk. In addition, the cost of crude rice bran is less as compared to the other vegetable oil, it is producible and available in the Mekong delta, hence crude rice bran oil can be used as feed in laying hen.
The aim of the study was to determine the effect of the crude oil bran on egg production and quality, plasma and yolk cholesterol and return over feed cost of laying hens,
The experiment was conducted from April 2012 to July 2012 in a private farm in Tien Giang province.
Four hundred and twenty 30-wk-old hens of Isa Brown were housed in an environmentally controlled house. 4 birds at live weight of approximately 1.9 kg±0.1 were placed in a cage and used for a period of 120 days, a daily photoperiod consisted of 15 h of light and 9 h of darkness (15L: 9D). Birds will be vaccinated against diseases of IB, ND and H5N1.
A basal diet was formulated as a control (ME=11.9MJ/kg and CP=16.56%). Feed and water was provided ad libitum. The basal diet was supplemented with 0 (control), 1, 1.5, 2, 2.5, 3% of crude rice bran oil and 1.5% of animal fat (lard).
Crude oil bran and was purchased from Wilmar Agro Vietnam Company limited, Cantho city. The components and fatty acid profile of crude rice bran are presented in Table 2.
A basal diet formulated to feed laying hens with 7 treatments
Control: basal diet (BS diet)
Treatment 1: Basal diet + 1.5% animal fat (lard) (AF)
Treatment 2: basal diet + 1% crude rice bran oil (CRBO1)
Treatment 3: basal diet + 1.5% crude rice bran oil (CRBO1.5)
Treatment 3: basal diet + 2 % crude rice bran oil (CRBO2)
Treatment 2: basal diet + 2.5% crude rice bran oil (CRBO2.5)
Treatment 4: basal diet + 3 % crude rice bran oil (CRBO3)
The formulation and composition of basal diet is shown in Table 1.
The experimental diets were allocated according to a randomized completely design with 7 treatments, 15 replicates and 4 hens per treatment to give a total of 420 birds.
All birds were fed the basal diet in 2 weeks prior to start of the experiment. Feed consumption was daily recorded and feed efficiency (kg feed/kg egg) was calculated during the 10 weeks experimental period. Egg production and egg weights were daily recorded and egg mass was calculated by multiplying egg production by egg weight to determine actual egg yield. After one month feeding experimental feed, eggs were taken from each treatment for two consecutive days, they were weighed and their shape index and shell weight were measured, yolk and albumin height, width and length were recorded. The Haugh unit, yolk index, egg shape index, albumin and yolk index were calculated.
Prior the end of the experimental period two weeks, four hens per replicate were randomly selected for serum lipid analysis. Blood samples were taken from the wing vein in the morning before feeding by using sterilized syringe and needles into sterile tubes without anticoagulation and the serum samples were directly send to the laboratory for analysis.
Return over feed cost of eggs reared under different inclusion levels of crude rice bran oil was calculated by using the prevailing market rates.
|
Table 1: Formulation and composition of the basal diet for laying hens |
|
|
Ingredients |
% (air dried basis) |
|
Maize |
27 |
|
Defatted rice bran |
20 |
|
Broken rice |
20 |
|
Soybean meal |
18 |
|
Fish meal |
4 |
|
Gravel |
6 |
|
Oyster shell |
2.4 |
|
Dicalciphosphate |
1.6 |
|
Premix |
0.75 |
|
Salt |
0.25 |
|
Composition |
% |
|
Dry matter |
89.9 |
|
Crude protein |
16.5 |
|
Ash |
12.9 |
|
Ether extract |
4.81 |
|
NDF |
14.9 |
|
Crude fibre |
2.89 |
|
Calcium |
3.78 |
|
Phosphorus |
1.65 |
|
ME, MJ/kg |
12.0 |
Laboratory analysis
Egg yolk was extracted according to the method of Pasin et al (1998), yolk cholesterol analysed using Kits of Human Diagnotistics Worlwide (Human GmbH-65205 Wiesbaden- German).
The concentrations of total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) in serum were measured according to the colorimetric method using a biochemistry analyser Siemens Advia 1200.
Diet was analysed for dry matter, crude protein, crude fibre, and crude fat according to the Association of Official Analytical Chemists (1995).
Data were analysed by analysis of variance using the General Linear Models procedure in Minitab (2001).When differences among treatment were significant, Tukey’s test was used
|
Table 2: Contents of vitamin E, sterols and fatty acid profiles of crude rice bran oil |
|
|
Water content |
0.09 |
|
Wax content (MEK -%) |
3.2 |
|
Unsaponifiable matter (%) |
5.8 |
|
Oryzanol (%)* |
1.86 |
|
α-tocopherol (ppm) β/γ-tocopherol (ppm) d-tocopherol (ppm) Total tocopherols (ppm) α-tocotrienol (ppm) γ-tocotrienol (ppm) Total tocotrienols (ppm) Total |
192 182 44 418 106 885 991 1409 |
|
Total Sterols (%) |
2.19 |
|
Fatty Acid composition (%) C14:0 C16:0 C18:0 C18:1 C18:2 C18:2 trans C18:3 C18:3 trans C 20:0 C 20:1 Total trans |
0.3 20.5 1.9 43.2 32.1 N.D 1.1 N.D 0.5 0.2 N.D |
|
Source: Wilmar Agro Vietnam Company limited |
|
Egg weight was not affected by dietary treatment (P=0.16), but dietary inclusion of different levels of CRBO increased egg production (P=0.05) as compared to the those fed basal diet (86.46%), which was particularly in the hens fed AF diet (95.37%, Table 3 and Figure 1). The diets included fat increase energy intake, may indirectly improve egg production.
Therefore, egg mass (g/hen/day) was increased in hens fed diets included CRBO or AF (P<0.01) comparing to the basal diet. Feed intake of hens (g/day) fed either CRBO or FA were significant lower those fed basal diet (P<0.01), which was low in energy content as compared to the experimental diets supplemented with oil or fat. As a result of lower in feed intake and higher in egg production, feed intake (kg feed/kg egg) and feed efficiency (feed intake: egg mass, g/g) of hens receiving CRBO or AF was lower than in the basal diet (P=0.05).
The basal diet was formulated with ingredients containing low fat content, twenty percent of defatted rice bran was used to leave out the effect of oil containing in rice bran and simultaneously observed the influence of different levels of CRBO in the experimental diets and a diet included 1.5% of lard was also use as a reference. Except the basal diet, the all treatments showed the supplementation effect of different levels of CRBO or fat on improving egg production and feed efficiency, these results were similar to a number of the experiments have been conducted to study the effect of inclusion dietary oils or fat on utilization of energy in laying hens (Sell et al., 1979; 1989; Scragg et al., 1987; Grobas et al., 2001; Bhonzack et al., 2002). This positive effect was likely due to increased energy intake and linoleic acid. Crude rice bran oil is rich in linoleic acid (Nguyen Nhut Xuan Dung and Le Thanh Quang, 2012) and tocopherols (Table 2). The beneficial effects of essential fatty acid on egg weight and egg production have been well documented (Jensen, 1963; March 1989; Balnave et al., 1975; March et al., 1990).
|
Table 3: Effect of dietary treatments on egg production, egg mass and feed intake |
|||||||||
|
|
BS diet |
CRBO1 |
CRBO1.5 |
CRBO2 |
CRBO2.5 |
CRBO3 |
AF |
SEM |
P |
|
Egg weight, g |
62.9 |
63.6 |
63.83 |
63.93 |
64.65 |
63.29 |
63.64 |
0.45 |
0.16 |
|
Egg production, % |
86.5b |
90.7ab |
92.8ab |
93.67ab |
94.58ab |
92.58ab |
95.37a |
2.01 |
0.05 |
|
Egg mass, g/hen/day |
54.5 |
56.1 |
58.1 |
58.60 |
59.13 |
58.20 |
59.49 |
1.23 |
<0.01 |
|
Feed intake, g/d |
123a |
117b |
119b |
120b |
120ab |
118b |
120b |
0.82 |
<0.01 |
|
Feed intake, g/egg |
154a |
131b |
130b |
129b |
128b |
130b |
127b |
3.94 |
<0.01 |
|
Feed intake, kg feed/kg egg |
2430a |
2115b |
2087b |
2072b |
2057b |
2074b |
2037b |
58.00 |
0.05 |
|
Feed efficiency, feed intake: egg mass (g/g) |
2.29a |
2.11ab |
2.07b |
2.05b |
2.04b |
2.04b |
2.02b |
0.05 |
0.02 |
|
ab means in the same row for each parameter with different superscripts are different at P<0.05 |
|||||||||
Table 4 shows the effects of CRBO or FA on egg quality of laying hens. Shape index, yolk index, yolk color and shell thickness were not significantly affected by dietary treatments. However, diets included 3% of CRBO and 1.5% of AF increased Haugh unit and albumin index (P<0.01). In addition, shell ratio was also greater (P<0.01) in CRBO3 (P<0.01). Some authors (March 1989, March and Mc Millan, 1990, Grobas and Mateos, 1999) found that fat supplementation to diets as well as supplemented with linoleic acid increased yolk weight. CRBO contained 33% linoleic acid (Nguyen Nhut Xuan Dung et al., 2012), thus diets of CRBO2.5 and CRBO3 had 0.8 and 1% of linoleic acid, respectively, and these figures met NRC requirement (1994), this indicated that these diets were good enough to have good eggs in term of quality and quantity.
|
|
|
Figure 1: Effect of dietary treatments on egg production, egg mass and egg weight |
|
Table 4: Effect of dietary treatments on egg quality |
|||||||||
|
|
BS diet |
CRBO1 |
CRBO1.5 |
CRBO2 |
CRBO2.5 |
CRBO3 |
AF |
SEM |
P |
|
Shape index |
76.8 |
77.3 |
77.71 |
76.32 |
76.97 |
76.93 |
77.43 |
0.33 |
0.08 |
|
Haugh unit |
91.3ab |
91.9ab |
90.1bc |
91.1ab |
87.2c |
93.9a |
92.0ab |
0.82 |
<0.01 |
|
Albumin index |
0.12a |
0.11ab |
0.10ab |
0.11ab |
0.10b |
0.12a |
0.12a |
<0.01 |
<0.01 |
|
Yolk index |
0.44 |
0.43 |
0.43 |
0.43 |
0.43 |
0.43 |
0.52 |
0.04 |
0.50 |
|
Albumin ratio, % |
60.2 |
59.9 |
60.5 |
60.5 |
60.6 |
59.9 |
60.70 |
0.26 |
0.11 |
|
Yolk ratio, % |
27.1 |
26.7 |
26.6 |
26.4 |
26.4 |
26.5 |
26.3 |
0.22 |
0.19 |
|
Shell ratio, % |
12.7c |
13.5ab |
12.9bc |
13.1abc |
12.9bc |
13.6a |
13.0bc |
0.13 |
<0.01 |
|
Yolk color |
8.90 |
8.64 |
8.67 |
8.80 |
8.56 |
8.91 |
8.74 |
0.07 |
0.10 |
|
Shell thickness, mm |
0.41 |
0.42 |
0.42 |
0.42 |
0.42 |
0.42 |
0.43 |
0.00 |
0.70 |
|
ab means in the same row for each parameter with different superscripts are different at P<0.05 |
|||||||||
As presented in Table 5, the supplementation of CRBO or AF in laying hen diets did not affect on plasma levels of cholesterol, triglyceride, HDL and LDL (P>0.05). However, the use of CRBO at different levels tended to reduce the level of total cholesterol in 1 g of yolk (P=0.07). In the same trend, total cholesterol in egg of hens fed 2.5 and 3% of CRBO had lower total cholesterol (P=0.04) than in the AF treatment.
Crude rice bran oil is a rich source of important phytoceuticals such as, oryzanol, tocopherols, tocotrinols and linoleic acid (Table 2). Gamma oryzanol is one of a component having antioxidant property. The role of gamma oryzanol in decreasing plasma or serum cholesterol was showed by Kahlo (1992a and 1992b), lowering cholesterol absorption, decreasing platelet aggregation and lowering LDL-cholesterol were well documented (Patel and Naik, 2004). However, plasma cholesterol, HDL-cholesterol and triglycerides of hens fed CRBO was not different from those fed basal diet or FA, this could explain that hens get rid of cholesterol via egg. The egg mass of hens fed diets supplemented with CRBO was significantly increased; there was very high mobilisation of blood lipid components in laying hens, this could be seen when observed the concentration of Triglycerides content in blood of laying hens, it was particularly very high as compared to that in Hi-sex brown pullets (Van Dac Thang, 2012). Formula of Friedwald (1992) in calculating LDL-cholesterol could not be applied in the case of laying hens due to too high triglycerides content in plasma.
|
Table 5: Effect of dietary treatments on egg quality |
|||||||||
|
|
BS diet |
CRBO1 |
CRBO1.5 |
CRBO2 |
CRBO2.5 |
CRBO3 |
AF |
SEM |
P |
|
Plasma, mmol/dl |
|
|
|
|
|
|
|
|
|
|
Cholesterol |
3.23 |
4.38 |
3.29 |
3.30 |
3.32 |
3.29 |
3.35 |
0.54 |
0.73 |
|
HDL-Chol |
0.90 |
0.86 |
0.78 |
0.84 |
0.90 |
0.78 |
0.82 |
0.07 |
0.81 |
|
Triglycerid |
14.9 |
18.9 |
17.2 |
18.1 |
19.0 |
17.8 |
17.1 |
1.53 |
0.56 |
|
Cholesterol |
|
|
|
|
|
|
|
|
|
|
mg/g yolk |
9.81 |
11.3 |
13.0 |
11.2 |
9.33 |
9.26 |
13.2 |
1.04 |
0.07 |
|
mg/egg |
166 |
200 |
227 |
189 |
153 |
154 |
211 |
16.5 |
0.04 |
|
|
|
Figure 2: Effect of crude rice bran oil on lowering cholesterol in egg yolk |
The feed costs of hens fed diets supplemented with CRBO or AF were increased because total eggs of these treatments were higher than the control diet. This advantage gave a different in total egg cost among treatments, higher benefit found on hens fed supplemented CRBO and AF (table 7).
| Table 7: Economic analysis | |||||||
|
|
BS diet |
CRBO1 |
CRBO1.5 |
CRBO2 |
CRBO2.5 |
CRBO3 |
AF |
|
Cost, kg/VND |
7,700 |
7,883 |
7,975 |
8,066 |
8,158 |
8,249 |
7,823 |
|
Total feed intake, kg |
517 |
490 |
500 |
502 |
504 |
497 |
502 |
|
Feed cost, VND |
3,981,701 |
3,865,098 |
3,985,990 |
4,046,632 |
4,107,611 |
4,098,598 |
3,927,678 |
|
Number of eggs |
3632 |
3809 |
3896 |
3934 |
3972 |
3888 |
4006 |
|
Egg cost, VND |
4,866,532 |
5,103,470 |
5,220,533 |
5,271,748 |
5,322,962 |
5,210,402 |
5,367,424 |
|
Different cost, VND |
884,831 |
1,238,372 |
1,234,543 |
1,225,116 |
1,215,351 |
1,111,804 |
1,439,746 |
Conclusions
The authors express their gratitude to the MEKARN program financed by the Sida-SAREC project for providing the opportunity and the budget to do the research. We would like to say thank you Prof. Thomas Preston and Prof. Brian Ogle for your kindness that helped us very much in carrying out our research.
AOAC 1990 Official Method of Analysis. Association of Official Analytical Chemists. 15th edition (K Helrick editor). Arlington pp 1230
Balnave D and Weatherup S T C 1974. The necessity of supplementing laying hen diets with linoleic acid. Br. Poultry Sci. 15:325-331.
Bhonzack C R, Harms R H, Merkel V D and Russell G B 2002. Performance of commercial layers when fed diets with four levels of corn oil or poultry fat. J. Appl. Poult. Res., 11: 68-76.
Friedewald W T, Levy R I and Fredrickson D S 1972. Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge. Clin Chem,18:499-502.
Grobas S, Mateos G G and Mendez J 2001. Influence of dietary linoleic acid on production and weight ofeggs and egg components in young brown hens. J.Appl. Poult. Res., 8: 177-184.
Jensen L S and Shutze J V 1963 Essentia1 fatty acid deficiency in the laying hen. Poultry Sci. 42:1014- 1019.
Kahlon T S, Chow F I, Sayre N R, and Betschart A A 1992. Cholesterol lowering in hamsters fed rice bran at various levels, defatted rice bran and rice bran oil. J .Nutr. 122:513-519.
Kahlon T S, Chow F I, Sayre R N and Betschart A A. 1992 Cholesterol-lowering in hamsters fed rice bran at various levels, defatted rice bran and rice bran oil. J . Nutr. 122:513-519.
Kahlon T S, Saunders R M, Sayre R N, Chow F I, Chiu M M, and Betschart A A 1992. Cholesterol-lowering effects of rice bran and rice bran oil fractions in hypercholesterolemic hamsters. Cereal Cheni. 69:485-489.
March B E 1989 Linoleic acid as a limiting factor in hepatic synthesis of egg lipoproteins. Poultry Sci. 68:89 (Abs.)
March B E and McMillan C 1990. Linoleic acid as a mediator of egg size. Poultry Sci. 69634-639.
National Research Council 1994. Nutrient Requirements of Domestic Animals. Nutrient Requirements of Poultry. 9th Rev. Edition. Natl. Acad. Sci., Washington, DC.
Patel M, Naik S N 2004 Gamma-oryzanol from rice bran oil: A review. J Scien. and Ind. Res, 63 (7), str. 569-578
Scragg R H, Logan N B and Geddes N 1987. Response of egg weight to the inclusion of various fats in layer diets. Br. Poult. Sci., 28: 15-21.
Sell J L, Angel R and Escribano F 1987. Influence of supplemental fat on weights off eggs and yolks during early egg production. energy utilization by laying hens. Poult. Sci., 66: 1807-1812.
Sell J L, Tenesaca G and Bales G L 1979. Influence Requirementsof Poultry. Ninth Revised Edition. National Academy Press. Washington D.C.
Sharma R D and Rukmini C 1986 Rice bran oil and hypocholesterolemia in rats. Lipids 21:715-717
Van Dac Thang 2011 Effect of supplementating garlic and tra fish oil on performance, resistant and plasma lipids of Hi-sex Brown pullets. Ms. Thesis, Can tho Univeristy.
Xu Z M, Hua N and Godber J S 2001 Antioxidant activity of tocopherols, tocotrienols, and gamma- oryzanol components from rice bran against cholesterol oxidation accelerated by 2,2 '-azobis (2-methylpropionamidine) dihydrochloride. J. Agri. and Food Chem., 49(4): 2077-2081.
Yoshino G, Kazumi T, Amano M, Takeiwa M, Yamasak T, Takashima S, Iwai M, Hatanaka H and Baba S 1989. Effects of gamma-oryzanol and probucol on hyperlipidemia. Current Therapy Research 45,975-982.
