GROWTH PERFORMANCE, NUTRIENT DIGESTIBILITY, NITROGEN BALANCE, AND CARCASS CHARACTERISTICS IN RABBITS FED DIETS SUPPLEMENTED WITH PANICUM MAXIMUM CV. MOMBAÇA HAY

GROWTH PERFORMANCE, NUTRIENT
DIGESTIBILITY, NITROGEN BALANCE, AND
CARCASS CHARACTERISTICS IN RABBITS FED
DIETS SUPPLEMENTED WITH PANICUM MAXIMUM
CV. MOMBAÇA HAY
Mohamed O. Ettaib and Mousa S. Bahar
Department of Animal Production, Faculty of Agriculture, Bani Waleed University,
Libya.Email:mohamedettaib6164@gmail.com
Keywords: Panicum maximum, growing rabbit, nutrient digestibility,
carcass and economic efficiency.
ABSTRACT
The present study aimed to investigate the effects of partial replacement
of berseem hay (BH) with different levels of Panicum maximum cv. mombaça
hay (PmH) in rabbit diets on growth performance, digestibility, carcass traits
and economic efficiency. Sixty weaned male New Zealand White (NZW)
rabbits about 6 weeks old (average body weight 701.15 g) were randomly
allotted into four dietary groups in a completely randomized design experiment.
The control group was fed a basal diet including 300 Kg/Ton of BH (D1);
whereas, PmH was incorporated into the other three experimental diets at levels
30, 60, and 90% in place of the dietary BH to represent the treatments D2, D3
and D4, respectively. The experimental period lasted for 8 weeks.
Results showed that D4 had the best (P≤0.05) final body weight, body
weight gain and feed conversion ratio. Dietary PmH improved digestibility
coefficients of DM, OM, CP, EE and nutritive values as TDN and DCP.
Including PmH in the tested diets slightly improved the digestible coefficients
of CF as compared with the control diet. The D4 significantly (P≤0.05)
increased N-intake, digestible N, retained N, the utilization efficiency of N and
TVFA's production in caecum, while it significantly (P≤0.05) decreased
urinary-N (g/day) and NH3-N (mg\100 dL) production in caecum compared
with D1 (control). Also, D2 significantly (P≤0.05) increased carcass weight
and total edible parts. D4 achieved the best profit per feed unit (2.01 £E/ Kg
diet) and REE (136%).Conclusively, PmH may become a promising
unconventional feed ingredient in growing rabbits feeding.
1. INTRODUCTION
No doubt, the prices of the imported feed components were elevated in
Egypt, which led to a substantial drop in rooster production and high price of
meat and fish. The crucial action is therefore vital for solving the problems, plus
increasing rabbit's production. Rabbit meat is high quality and safe. Rabbit is
appropriate to be raised for meat production due to its high feed conversion
competence, high fecundity, and short generation interval (1). Moreover, rabbits
use the protein more efficiently than broilers and up to 20% roughage can be
Egypt. J. of Appl. Sci., 36 (3) 2021 21-36
included in their diet (2). In these circumstances, it is imperative to search nontraditional
feeds in animal feeding having low cost and to raise the product and
decreasing the marketing price of rabbit products. On the other side, with a lack
of arable land, water and feed ingredients in many countries, rabbits can help in
food production by converting many agricultural by-products into meat.
Generally, there is no need to use major forages for rabbit feeding, and there is
no need to use grains that are fit for human consumption. The gradient of what
ingredients can be combined into rabbit feed is huge and growing continuously
(3). Rabbit diets are formulated basically with plants and soybean meals as the
main source of protein. The addition of roughage, including grasses and
legumes, represents approximately 350 g/kg to 400 g/kg of feed composition.
Use of grasses and shrub leaves by herbivores may be limited by the adverse
effects of secondary complexes on digestion (4 -7). Rabbits have an acute sense
of smell that enables them to find accepted plants. When they find a spot with
available feeds, they will come back time and again until the supply is gone.
The Egyptian Pm is a tall grass growing in Egypt in the early times. It is
generally found in arid land, such as Nobaria. This grass was traditionally used
in the west and central Africa and others in the tropical regions of South
America and Asia as a fiber source in the diet of growing rabbits (8). It is also
an auspicious feed supply because of its numerous compensations such as its
high nutritive value, where it contains 10.5% CP, 2.5% EE, 30.4% CF, and
7.5% ash as reported by (27). Most research has discussed this material at low
doses or supplemented as fresh. Rabbits fed Pm recorded the highest feed intake
compared to other forages as Centrosema pubescens and Sida acuta was
observed by (9). Moreover, Rabbits fed concentrate mixture plus Pm (1:2) had
developed weight gain values compared with those received the same dietary
ratio (1:2) of concentrate mixture with Myrianthus arboreus or concentrate
mixture with Gmelina arborea (10).
The impartiality of the current work was to study the consequence of
feeding of growing rabbits on graded levels of Pm hay partial replacer of
berseem hay on growth performance, digestibility coefficient of nutrients,
nitrogen metabolism, carcass traits and economic efficiency.
2. MATERIALS AND METHODS
2.1. Experimental rabbits and management
The experimental work of this study was carried out at Nobaria Animal
production Research Station, Beheira Governorate, Animal Production
Research Institute, Egypt from October 2020 to March 2021. Sixty male New
Zealand White (NZW) rabbits aged 42 days with an average body weight of
701.15 g, were divided into four equal groups (fifteen animals per each) in a
completely randomized design experiment. Rabbits were individually housed in
galvanized wire cages (30 × 35 × 40 cm). Stainless steel feeders and nipples for
22 Egypt. J. of Appl. Sci., 36 (3) 2021
drinkers were supplied for each cage. Feed and water were offered ad libitum.
The feeding period was extended for 56 days. During the experimental period,
both the weight and the consumed feed intake were recorded weekly per rabbit.
Rabbits of all groups were kept under the same management conditions.
2.1.1. Experimental diets
Pm cultivated in the newly reclaimed land at Nobaria, Beheira
Governorate, Egypt were collected, sun-dried, chemically analyzed according
to (11) and kept in clean bags until diet formulation. PmH was incorporated into
four the experimental diets at graded levels 0,30, 60, and 90% as a partial
replacer the dietary berseem hay (BH) to represent the treatments D1, D2 ,D3
and D4, respectively. The basal diet was formulated and pelleted to cover the
nutrient requirements of rabbits, according to (12) as shown in Table 1.
Table 1. Formulation of the experimental diets (Kg/Ton)
Ingredients Experimental diets
D1 D2 D3 D4
Berseem hay 300 210 120 30
Panicum maximum cv. Mombaça hay __ 90 180 270
Barley grains 220 220 220 220
Plant Concentrate 20 20 20 20
Yellow corn 80 80 80 80
Wheat bran 148.4 148.4 148.4 148.4
Soybean meal 44% CP 180 180 180 180
Molasses 30 30 30 30
Limestone 10 10 10 10
Di-calcium phosphate 5 5 5 5
Sodium chloride 3 3 3 3
Premix 1 3 3 3 3
DL-Methionine 0.6 0.6 0.6 0.6
Price in (£E 2/ Ton) 5900 5700 5500 5300
1 Premix ,Vitamins and Minerals Mixture which Each kilogram of it contains:
2000.000 IU Vit. A, 150.000 IU Vita. D, 8.33 g Vit. E, 0.33 g Vit. K, 0.33 g Vit. B1,
1.0 g Vit. B2, 0.33g Vit. B6, 8.33 g Vit. B 5, 1.7 mg Vit. B 1,2 3.33 g Pantothenic acid,
33 mg Biotin, 0.83g Folic acid, 200 g Choline chloride, 11.7 g Zn, 12.5 g Fe, 16.6 mg
Se, 16.6 mg Co, 66.7 g Mg and 5 g Mn.
2 Price =£E, Egyptian pounds.
Rabbits were individually housed in galvanized wire cages (30 x 35 x 40
cm). Stainless steel nipples for drinkers and feeders allowing recording
individual feed intake for each rabbit were supplied for each cage. Feed and
water were offered ad libitum. Rabbits of all groups were kept under the same
management conditions and were individually weighed and feed consumption
was individually recorded weekly during the experimental period.
Egypt. J. of Appl. Sci., 36 (3) 2021 2233
2.2. Digestibility and nitrogen balance trials:
At the end of the experimental period, all rabbits were used in
digestibility trials over a period of 7 days to determine the nutrient digestibility
and nutritive values of the tested diets. Amounts of daily feed intake were
recorded. Feces were daily collected quantitatively. Representative samples of
feces were dried at 60 °C for 48 hours, ground, and stored for proximate
chemical analysis. Samples of feed and feces were analyzed for dry matter
(DM), crude protein (CP), ether extract (EE), crude fiber (CF), and ash
according to the (12) classical methods. The nitrogen-free extract (NFE) was
calculated by difference. The nutritive value of the experimental diets as DCP
and TDN value were calculated according to (13). Neutral detergent fiber
(NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) were also
determined in the experimental rations according to (14).
Hemicellulose was calculated as the difference between NDF and ADF,
while cellulose was calculated as the difference between ADF and ADL. Gross
energy [GE , kilo calories (kcal) per kg DM] was calculated according to (15),
where: CP=5.65 kcal/g, each g of EE=9.40 kcal/g and both of CF and NFE
=4.15 kcal/g. Digestible energy (DE) was calculated according to (16) using the
following equation:
DE (kcal/ kg DM) = 4253 - [32.6 (CF %)] –[144.4 (total ash)].
Non-fibrous carbohydrates (NFC) were calculated according to (17) using the
following equation:
NFC = 100 - (CP + EE + Ash + NDF).
The condensed tannins (CT) of PmH were determined according to (18),
phenolic compounds were determined using the high-performance liquid
chromatography using the procedure (19).
The urine of each animal was collected in a glass recipient, containing 10
ml of a HCl: H2O solution (1:1), to avoid bacterial production and possible
losses by volatilization.
The values of nitrogen consumption, nitrogen excreted in feces, and
nitrogen excreted in urine were determined. The nitrogen balance (Retained
nitrogen) was calculated as a percentage of nitrogen intake.
2.3. Slaughtering and carcass traits:
At the end of the experimental period, six male rabbits were randomly
taken from each treatment, fasted for 12 hours, weighed individually and
slaughtered immediately. Slaughter procedure and carcass analysis were carried
out as described by (21). After complete bleeding, pelt, viscera and tail were
removed then the carcass and its components were weighed as edible parts. The
non-edible parts including lung, spleen, stomach, large intestine, small intestine,
and kidney fat were also weighed as a percentage of pre-slaughter weight. The
dressing percentage was calculated by dividing the hot-dressed carcass weight
of pre-slaughter weight and expressed as a percentage according to (22).
24 Egypt. J. of Appl. Sci., 36 (3) 2021
Gastrointestinal tracts were individually removed from three slaughtered
rabbits from each group, weighted cecum and measured the pH of the caecal
content by a digital pH meter (Model 20, Digital pH meter for Orion Research).
Then, to determine total volatile fatty acids ((TVFA's ,mmol/100 ml) and
ammonia nitrogen NH3-N (mg\100 dL) by steam distillation (UDK 139- Semi -
Automatic Distillation Unit), (20).
2.4. Relative economic efficiency:
The relative economic efficiencies of the experimental diets for the cost
of feed required for producing one kg of body weight gain were calculated. The
cost of the experimental diets was calculated according to the prevailing prices
of all feed ingredients in the local market at the time of experimentation.
Economic efficiency was calculated as a ratio between the profit and the cost of
the consumed feed.
2.5. Statistical Analysis:
The experimental design was completely randomized using the General
Linear Means of (23). Measured parameters were analyzed using the following
statistical model:
Yij = μ + di + εij .
Where yij is the value measured, μ is the overall mean effect, di is the ith
diet (i = 1,…., 4 ) effect and εij is the random error associated with the jth rabbits
assigned to the ith diet. Significant differences of P≤0.05 among means were
determined using (24).
3. RESULTS
3.1. Chemical analysis of berseem hay, PmH and the tested diets
The proximate chemical composition and cell wall constituents
(CWC) of PmH ,BH and the experimental diets are presented in Table 2.
Contents of DM, OM, CP, CF, EE, NFE, ash, GE, DE, NFC and CWC
(hemicelluloses, cellulose, and ADL) with PmH seemed to be around those
with BH. The experimental diets were isocaloric and isonitrogenous. Protein
contents for the four tested diets (17.11 to 17.19%), also the values of the DE
(2553.7 to 2584.3 kcal/ kg DM) were similar.
The PmH contained considerable concentrations of secondary
metabolites including condensed tannins (CT) and other phenolic compounds
(Table 2). There is no CT in BH, while PmH had a relatively moderate content.
3.2. Nutrients digestibility and nutritive values of the experimental diets
Digestibility coefficients and nutritive values (%) of the experimental
diets are shown in Table 3. Dietary treatments had no significant effects on
CF digestibility. Significant (P≤0.05) rises in DM,OM,CP,NFE
digestibilities and nutritive values as TDN and DCP were observed with D3
and D4 in comparison with D1 (the basal diet). Rabbits fed on D3 diet
recorded the highest digestibility coefficients of EE followed by D4.
Egypt. J. of Appl. Sci., 36 (3) 2021 25
Table 2. Chemical analysis and cell wall constituents (%) of the berseem
hay, Pm hay and the experimental diets
Item
Tested materials Experimental diets
BH PmH D1 D2 D3 D4
Chemical analysis
Dry matter 91.25 93.47 91.5 91.22 91.27 91.23
Chemical analysis on DM basis
Organic matter (OM) 85.03 86.21 91.29 91.58 91.37 91.41
Crude protein (CP) 12.18 12.25 17.19 17.17 17.11 17.12
Crude fiber (CF) 29.91 22.87 13.43 13.89 13.90 13.83
Ether extract (EE) 2.67 3.26 3.04 3.07 2.99 2.98
Nitrogen-free extract (NFE) 40.27 47.83 58.63 57.45 57.37 57.48
Ash 14.97 13.79 8.71 8.42 8.63 8.59
Gross energy 1 Kcal/kg DM 3851.6 1824.7 4247.5 4219.3 4206.8 4205.5
Digestible energy 2 Kcal/kg DM 1116.3 1516.2 2557.5 2584.3 2553.7 2561.8
Non fibrous carbohydrates 3 NFC 24.24 26.75 33.62 33.95 33.68 33.7
Cell wall constituents
Neutral detergent fiber (NDF) 45.94 43.95 37.74 37.39 37.59 37.61
Acid detergent fiber (ADF) 40.9 38.7 22.5 22.2 22.4 22.4
Acid detergent lignin (ADL) 27.3 22.7 10.3 8.8 9.4 9.9
Hemicellulose 5.04 5.25 15.24 15.19 15.19 15.21
Cellulose 13.6 16.0 12.2 13.4 13.0 12.5
Phenolic compounds Nil 8.32 ND ND ND ND
Condensed tannins Nil 3.7 ND ND ND ND
D1, D2, D3, and D4 are the experimental diets that included Panicum maximum cv.
Mombaça hay (PmH) at levels 0,30, 60, and 90%, respectively, as a partial
substitute of the dietary berseem hay (BH).
1Gross energy, calculated according to (15), where: CP=5.65 kcal/g, each g of EE=9.40
kcal/g and both of CF and NFE =4.15 kcal/g.
2Digestible energy, calculated according to (16) using the following equation:
DE (kcal/ kg DM) = 4253 - [32.6 (CF %)] – [144.4 (total ash)].
3Non fibrous carbohydrates (NFC), calculated according to (17) using the following
equation:
NFC = 100 - [CP + EE + Ash + NDF].
Hemicellulose = NDF - ADF.
Cellulose = ADF - ADL.
ND, not determined.
Table 3. Digestibility coefficients and nutritive values (%) of the
experimental diets
Item
Experimental diets
SEM P-value
D1 D2 D3 D4
Digestibility:
Dry matter 60.28b 65.56ab 68.12a 70.83a 1.48 0.0400
Organic matter 72.33b 75.07ab 76.62a 77.56a 0.90 0.0400
Crude protein 75.10b 76.20b 79.01a 79.00a 0.28 0.0003
Crude fiber 54.34 55.98 56.33 56.33 3.41 0.9858
Ether extract 65.20b 66.03b 70.86a 67.95ab 1.05 0.0500
Nitrogen-free extract 78.24b 80.45ab 81.61a 82.37a 0.70 0.0090
Nutritive values:
Total digestible nutrient 67.78b 69.97ab 72.09a 72.75a 0.85 0.0300
Digestible crude protein 12.91b 13.08b 13.52a 13.52a 0.05 0.0001
D1, D2, D3, and D4 are the experimental diets that included Panicum maximum cv.
Mombaça hay (PmH) at levels 0,30, 60, and 90%, respectively, as a partial
substitute of the dietary berseem hay (BH).
a and b ,means in the same row having different superscripts are significantly different
(P≤0.05).
SEM, standard error of the mean.
26 Egypt. J. of Appl. Sci., 36 (3) 2021
3.3. Growth performance
The productive performance Data are presented in Table 4. The
dietary level of PmH in D4 (90%) led to significant (P=0.0001, 0.001 and
0.001) increases in the final body weight, total body weight gain and
average daily gain, respectively. In comparison with the control diet (D1),
all inclusion levels of PmH in the tested diets marginally (P>0.05) lowered
the average intake of DM, CP and DE values. On the other side, the
digestible crude protein (g/h/d) and total digestible nutrient (g/h/d) with
rabbits fed on D3 and D4 were better than those with D1.
Among all of the tested diets, the level of PmH in D4 significantly
(P≤0.05) improved the feed conversion ratio (g intake /g gain) of DM, while
the best feed conversion values (g intake /g gain) of CP, DCP, TDN and
(kcal intake /g gain) of DE were achieved with D2.
Table 4. Growth performance of the experimental groups
Item
Experimental diets
SEM
PD1
D2 D3 D4 value
Initial weight g 705.8 703.8 697.5 697.5 15.84 0.9850
Final weight g 1997.1c 1983.2c 2052.1b 2119.3a 17.69 0.0001
Body weight gain g 1291.3b 1279.4c 1354.6b 1421.8a 25.34 0.0010
Feeding period days 56
Average daily gain g 23.1b 22.9b 24.2b 25.4a 0.45 0.0010
Feed intake:
Average dry matter g/h/d 97.3 96.3 96.3 94.9 0.94 0.3850
Crude protein g/h/d 16.73 16.53 16.48 16.25 0.16 0.4990
Digestible crude protein g/h/d 12.3b 12.5b 13.0a 12.8ab 0.13 0.0020
Total digestible nutrient g/h/d 65.9b 67.4ab 69.4a 69.0a 0.76 0.0110
Digestible energy kcal/h/d 248.8 252.1 248.1 244.9 2.44 0.2600
Feed conversion g intake/ g gain
Dry matter 4.23a 4.25a 4.02a 3.75b 0.08 0.0008
Crude protein 0.588 0.564 0.596 0.576 0.018 0.6264
Digestible crude protein 0.442 0.430 0.471 0.455 0.014 0.2130
Total digestible nutrient 2.362 2.323 2.511 2.461 0.07 0.3020
Digestible energy Kcal intake /g
gain
8.896 8.702 8.979 8.733 0.27 0.8820
D1, D2, D3, and D4 are the experimental diets that included PmH at levels 0,30, 60, and
90%, respectively, as a partial substitute of the dietary berseem hay (BH).
a ,b and c ,means in the same row having different superscripts are significantly
different (P≤0.05).
SEM, standard error of the mean.
3.4. Nitrogen balance and caecum activity
Effects of replacement BH by PmH at different levels on nitrogen
metabolism and caecum activity are illustrated in Table 5. Incorporating the
PmH in the experimental diets had no significant effect (P=0.1795) on the
fecal nitrogen (FN) values. While, nitrogen intake (IN), digestible nitrogen
(DN), retained nitrogen (RN), the DN/IN efficiency (%),the RN/IN
efficiency (%) and the RN/DN efficiency (%) significantly increased with
Egypt. J. of Appl. Sci., 36 (3) 2021 27
increasing the PmH levels (P= 0.01, 0.001, 0.01, 0.05, 0.05 and 0.04,
respectively).
During the term of cecum activity, the NH3-N concentrations (mg\100
dL) were significantly decreased (P=0.04) with including and increasing the
PmH in the tested diets compared with the control diet. On the Other hand,
values of TVFA's were significantly (P=0.01) raised D4 (6.87 mmol/100ml)
compared with the other tested diets.
In comparison with D1, the highest tested level of dietary PmH with
the growing rabbits in D4 resulted in improving the biochemical traits of
caecum content, whereas the lower NH3 (24.30 versus 34.52 mg\100 dL;
P=0.04), pH values (6.07 versus 6.37; P=0.05) and the TVFA's
concentration (6.87 versus 5.83 mmol/100 ml; P=0.01) indicated to a higher
fermentation of gut microflora.
Table 5. Nitrogen metabolism and caecum activity of the experimental
treatments
Item
Treatments
SEM P-value
D1 D2 D3 D4
Nitrogen intake g/day (NI) 1 3.08b 3.17b 3.26b 3.65a 0.19 0.0100
Fecal nitrogen g/day (FN) 2 1.08 1.09 1.17 1.15 0.21 0.1795
Urinary nitrogen g/day (UN) 3 0.97a 0.98a 0.81b 0.73b 0.11 0.0500
Digestible nitrogen g/day (DN) 4 2.00b 2.08b 2.09b 2.50a 0.73 0.0010
Retained nitrogen g/day (RN) 5 1.03b 1.10b 1.28b 1.77a 0.09 0.0100
DN/NI (%) 6 64.94b 65.62b 64.11b 68.49a 1.70 0.0500
RN/NI (%) 7 33.44b 34.70b 39.26b 48.49a 1.16 0.0500
RN/DN (%) 8 51.50c 52.89c 61.24b 70.80a 2.99 0.0400
Caecum activity
pH value 6.37 6.29 6.11 6.07 1.31 0.1500
NH3-N mg\100 dL 34.52a 29.72b 28.41b 24.30c 0.59 0.0400
TVFA's mmol/100 ml 5.83b 5.97b 5.93b 6.87a 0.17 0.0100
D1, D2, D3, and D4 are the experimental diets that included PmH at levels 0,30, 60,
and 90%, respectively, as a partial substitute of the dietary berseem hay (BH).
a ,b and c ,means in the same row having different superscripts are significantly
different (P ≤ 0.05).
SEM, standard error of the mean.
4DN = (1) – (2).
5RN = (1) – (2) – (3).
6DN/IN (%), the conversion efficiency of nitrogen intake into digestible nitrogen.
7RN/IN (%), the conversion efficiency of nitrogen intake nitrogen into retained
nitrogen.
8RN/DN (%), the conversion efficiency of digestible nitrogen into retained nitrogen.
3.5. Carcass traits
The effect of PmH inclusion on the carcass characteristics of NZW
rabbits are displayed in Table 6 .Among all treatments, rabbits fed on D2
showed a significant (P≤0.05) improvement in hot carcass weight. Besides a
significant (P≤0.05) increase in total edible parts (%) with D2 and D4
28 Egypt. J. of Appl. Sci., 36 (3) 2021
compared with D1. While, the partial substitution of dietary BH with PmH
had no significant (P>0.05) effects on dressing percentage, edible giblets
and total non-edible parts (%).
Table 6. Carcass characteristics of NZW rabbits as affected by dietary
treatments
Item
Experimental diets
SEM
PD1
D2 D3 D4 value
Pre-slaughter weight g 1977.2 1975.0 1996.0 1949.0 21.35 0.5380
Hot Carcass weight1 g 1152.5b 1202.5a 1205.5b 1207.7b 14.90 0.0352
Dressing % 58.3 61.5 60.4 62.0 1.12 0.1755
Edible Giblets 2 % 3.82 4.12 4.10 4.20 0.09 0.0686
Total edible parts 3 % 63.04b 66.32a 63.16b 65.42a 1.05 0.0111
Total Non-edible parts % 36.96 33.68 36.84 34.70 1.15 0.0812
D1, D2, D3, and D4 are the experimental diets that included PmH at levels 0,30, 60, and
90%, respectively, as a partial substitute of the dietary berseem hay (BH).
a and b ,means in the same row having different superscripts are significantly different
(P≤0.05).
SEM, standard error of the mean.
1 Weight of hot carcass, including head as a percentage of pre-slaughter weight.
2 Edible giblets (%) = [(liver g + kidney g + heart g) /pre-slaughter weight g] × 100.
3 Total edible parts (%)=[(carcass weight g + weight of edible giblets g) /pre-slaughter
weight g ×100.
3.6. Economic evaluation:
Final body weight, length of the growing period and feeding cost are
major factors concerning the achievement of maximum efficiency values of
meat production. The relative economic efficiency (REE) of the
experimental diets is exposed in Table 7.
Table 7. Economical efficiency as affected by dietary treatments
Items
Treatment groups
D1 D2 D3 D4
Total average weight gain g 1997 1983 2052 2119
The price of 1 kg body weight £E 40 40 40 40
Selling price/rabbit 1 £E 79.88 79.32 82.08 84.76
Total feed intake Kg 5.45 5.39 5.39 5.31
Price/kg feed £E 5.90 5.70 5.50 5.30
Total feed cost/ rabbit 2 £E 32.16 30.72 29.65 28.14
Profit 3 £E 47.73 48.60 52.44 56.62
Profit/feed unit 4 £E/ Kg diet 1.48 1.58 1.77 2.01
Relative economic efficiency 5 % 100 106 120 136
D1, D2, D3, and D4 are the experimental diets that included Panicum maximum cv.
Mombaça hay (PmH) at levels 0,30, 60, and 90%, respectively, as a partial
substitute of the dietary berseem hay (BH).
3 profit = (1) – (2) in Egyptian pound (£E)
4 Profit/feed unit = (3) / (2).
5 Relative economic efficiency= [economic efficiency (Ec.Eff) of D2, D3 or D4 / Ec.Eff.
of D1]×100.
Calculations were carried out according to the prevailing market prices of both
rabbits selling and feeds.
Egypt. J. of Appl. Sci., 36 (3) 2021 29
Results indicated that using PmH as a partial replacer of BH in diets
of growing NZW rabbits enhanced the profit and reduced the total feed cost.
The lowest total feed cost/rabbit (28.14 £E) accompanied with the best profit
was observed in rabbits fed on diet D4. In general, all the inclusion level of
PmH in the tested diets led to ameliorate profit per feed unit and REE. The
substitution level of 90% of the dietary BH with PmH (D4) achieved the
best profit per feed unit (2.01 £E/ Kg diet) and REE (136%). No available
feasibility study about the cost of diets when PmH was partially replaced
with BH. The PmH may become a promising unconventional feed
ingredient in growing rabbits feeding.
4. DISCUSSION:
4.1. Chemical analysis of PmH and the tested diets
All chemical analysis parameters were similar for the different
experimental diets. The PmH contained an adequate amount of DM, organic
matter, crude protein, NDF, ADF and DE, which support moderate growth
of livestock (25). The cellulose content in the leaf and stem of Panicum
shrubs was 33.98%, hemicelluloses was 29.56%, lignin was 18.6% and ash
was 2.21% of Panicum maximum (26). Our results on chemical analysis of
PmH agreed with (27) who recorded that the proximate analysis of Panicum
hay was 11.65% crude protein, 2.67% crude fat, and 30.66% crude fiber.
4.2. Nutrients digestibility and nutritive values of the experimental diets
Increased digestibility and N-utilization may be due to the positive
impacts of PmH on the absorption and utilization of nutrients. Low to
medium concentrations of CT (20–40 g/kg DM) occurred in panicum
forages, increased the efficiency of protein digestion by increasing flow of N
to the intestine relative to N intake, increased flow of essential amino acids
of the monogastric by 50 % and increased net absorption of essential amino
acids from the small intestine by 59–63 %, with no effect on digestibility
(28).Also, rabbits have the ability to adjust its voluntary feed intake in
response to changes in dietary energy concentration (29). These results may
be due to the limited dose of polyphenol from which has the ability to inhibit
alpha-amylase that may influence different steps in starch digestion in a
synergistic manner (30).
4.3. Growth performance
Rabbits fed D4 had significantly higher final weight ( by about 6.12%)
than those fed the control diet. This enhancement in growth with D4 may be
due to increasing the feed utilization in this group (Table 3) as elucidated by
(31) who indicated that the high growth rate could be due to increasing
digestibility and N-utilization. These results were consistent with (27) who
found that final live body weight, average daily gain, feed intake and feed
efficiency of rabbits fed PmH in place of 45% of BH were higher (P<0.05)
than those fed and 30% and the control diet. Besides, this improvement may
be due to better quality of mixing panicum hay (grass hay) with legume hay
30 Egypt. J. of Appl. Sci., 36 (3) 2021
(berseem hay) than only the berseem hay (basal diet) as documented by
(32). In this contest, daily weight gain, daily feed intake and feed conversion
ratio were significantly (p≤0.05) affected by the feeding of combinations of
concentrate and/or Pannicum maximum or Leucaena leucocephala when
compared to sole concentrate diet feeding (33).
The D4 diet increased the average daily gain by 10.10%. So, results
indicate that the responses to dietary tannin are variable and depend on the
type, source and concentration of tannin used, animal species and basal diet
fed, which were in parallel with (34) who showed that rabbits fed the tannin
enriched diet for 57 days reached a live weight higher by 6% (P<0.01) than
that with the control group.
Regarding feed intake, fiber is one of dietary components which
usually contain 35 to 40% neutral detergent fiber (35). It helps to maintain a
high rate of passage, avoiding the accumulation of digesta in the caecum that
reduce feed intake and impairs growth (36).
4.4. Nitrogen metabolism and Caecum activity
Results of nitrogen balance could be used to calculate the expected
daily gain. The pH values did not (p>0.05) effected among all treatments.
The high replacing level (90%) of the dietary BH by PmH in D4 presented
an improvement in nitrogen intake, digestible N, retained N, the efficiencies
of nitrogen utilization. The higher nitrogen retained from the Panicum
maximum showed that more N could be available for microbial growth and
multiplication that could improve digestion of feeds, thereby improving feed
intake, and consequently, animal productivity. Volatile fatty acids (VFA's)
produced as a result of caecal fermentation of digestible fiber or undigested
nutrients provide a vital source of energy for the rabbits (37). Also,
decreasing acid detergent lignin linearly increased the caecal VFA's
concentration of growing rabbits ( بالجدول ADL راجع قيم Table 2). These
values are in general agreement with those obtained by (38). Moreover,
phenolic glycosides and salicin could be an important source of glucose
which may increase the fermentation activity and synthesis of microbial
protein. However, the significant decline of NH3-N with raising the dietary
level of PmH may attribute to its content of CT. These results consented
with those who reported that CT binding strongly to proteins to form a pHdependent
complex, which is not degradable at a high pH value (>7) in the
intestine (39).
4.5. Carcass traits
Concerning dressing percentage and edible giblets, our results are in
accordance with (27) who found that partial replacing of BH with PmH at
graded levels up to 45% in rabbits diets had no (P>0.05) effect on carcass
traits compared to rabbits fed the control diet.
Egypt. J. of Appl. Sci., 36 (3) 2021 31
4.6. Economic evaluation:
No available feasibility study about the cost of diets when PmH was
partially replaced with BH. The PmH may become a promising
unconventional feed ingredient as a substitute for BH in growing rabbit's
diets.
5. CONCLUSION
Results of this study revealed that all tested levels of PmH were
useful as a substitute forage of BH with maintaining the performance,
digestibility, carcass traits and could enhance the REE of diets for the
grower rabbits.
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النمو والهضم ومي ا زن الأزوت وخصائص الذبيحة في الأ ا رن المغداة عمى
علائق تحتوى عمى دريس حشيشة البانيکم.
محمد عمر التائ ، موسى سالم بحر.
قسم الإنتاج الحيواني / کمية الزا رعة / جامعة بني وليد / ليبيا
استهدفت الد ا رسةة الحاليةة معرفةة تةثيي ا رت الاسةتبدا الجزيةي لةدريس البرسةيم بمسةتويات ملتم ةة
مةةةر دريةةةس حبيبةةةة البةةةانيکم فةةةي عمي ةةةة او ا رنةةةل عمةةة النمةةةو واله ةةةم و ةةة ات ال بيحةةةة والک ةةةا
الاقت ةةادية لمع.يةةتق تةةم ت سةةيم کةةور او ا رنةةل النيوزيمنديةةة البي ةةا الم ومةةة )عةةدد ا 06 وعمر ةةا
حةوالي 0 أسةابي، و ومتوسة وزر الجسةم 07 ق 560 جةمب ببةک عبةوايي إلة أربة، مجموعةات اييةة
فةي تجربةة ت ةميم کامة التعبةيةق تةم تي يةة مجموعةة الم ارنةة عمة عمي ةة تحتةو عمة 266 کجةم /
ر مر )اوول ب ؛ بينما تم إدلا حبيبة البةانيکم فةي الع.يةت التجريبيةة الي.يةة اولةر بمسةتويات
Egypt. J. of Appl. Sci., 36 (3) 2021 35
26 و 06 و 06 ٪ کةةة ح. جزيةةةي لةةةدريس البرسةةةيم لتميةةة المعةةةام.ت اليانيةةةة والياليةةةة وال ا ربعةةةة عمةةة
الترتيلق وقد استمرت ال تر التجريبية لمد 8 أسابي،ق
أظهرت النتايج أر ال وزر النهايي لمجسم والزياد ف وزر الجسةم ونسةبة تحوية الية ايي کةار
أف وب ور معنوية م، العمي ة ال ا ربعة ق حسّر دريس حبيبةة البةانيکم مةر معةام.ت ةم المةاد
الجافةةةة والمةةةاد الع ةةةوية والبةةةروتير اللةةةام والةةةد ر اللةةةام وال ةةةيم الي اييةةةة کمجمةةةو مرکبةةةات اييةةةة
مه ةةومة وبةةروتير مه ةةوم ق حسّةةر دريةةس حبيبةةة البةةانيکم مةةر معةةام.ت ةةم المةةاد الجافةةةة
والمةةاد الع ةةوية والبةةروتير اللةةام والةةد ر اللةةام وال ةةيم الي اييةةة کمجمةةو مرکبةةات اييةةة مه ةةومة
وبةروتير مه ةومق إر إدلةا دريةس حبيبةة البةانيکم فة الع.يةت الملتبةر قةد أد إلة تحسةر ية
فةةي معةةام.ت ةةم اوليةةا اللةةام م ارنةةة بعمي ةةة الم ارنةةةق ا زدت العمي ةةة ال ا ربعةةة وببةةک معنةةو مةةر
النيتةةروجير المةةثکو و والنيتةةروجير المه ةةومو والنيتةةروجير المحتجةةز بالجسةةمو وک ةةا الاسةةت اد مةةر
النيتةةروجير و إنتةةاج اوحمةةا الد نيةةة ال يةةار بةةاوعور و بينمةةا انل ةة وببةةک معنةةو النيتةةروجير
الم ةود فة البةو )جةم / يةومب ن وانتةاج اومونيةا فةي اوعةور م ارنةة بالمعاممةة اوولة )الم ارنةةبق وقةد
ارت ة، أي ة ا وزر ال بيحةة ن واجمةالي اوجة ا ز المثکولةة معنويةا مة، العمي ةة اليانيةة ق وقةد ح ةت العمي ةة
ال ا ربعةة أف ة ربة لکة وحةد عمة ) 60 ق 1 جنية/ / کجةم عمي ةة ب وک ةا اقت ةادية نسةبية ) 020 ٪بق
ولتامةة ا و ف ةةد ي ةةب دريةةس حبيبةةة البةةانيکم مکو نةةا واعةة دا کعمةة يةةر ت ميةةد فةةي تي يةةة او ا رنةةل
الناميةق
الکممات المفتاحية : حبيبة البانيکم – او ا رنل النامية – ةم العنا ةر الي اييةة – ال بيحةة –الک ةا
الاقت اديةق
36 Egypt. J. of Appl. Sci., 36 (3) 2021