Livestock Research for Rural Development 35 (4) 2023 LRRD Search LRRD Misssion Guide for preparation of papers LRRD Newsletter

Citation of this paper

Effects of maize and molasses supplementation with different levels in diets on growth performance of New Zealand White crossbred rabbits

Pham Thi Cam Nhung, Nguyen Thiet1 and Truong Thanh Trung

College of Agricuture, Can Tho University, Can Tho City, Vietnam
tttrung@ctu.edu.vn
1 College of Rural Development, Can Tho University, Can Tho City, Vietnam

Abstract

The aims of this study was to evaluate the effects of maize and molasses supplementation with different levels in diets on growth performance of New Zealand White crossbred rabbits. The experiment was a completely randomized design with 5 treatments and 4 replications, and 4 rabbits with balanced sexually per trial unit. The treatments were the different dietary digestible energy levels and sources including 10 MJ/kgDM (control, DE10); either supplementation with maize: 11 MJ/kgDM (DE11M) and 12 MJ/kgDM (DE12M) or molasses: 11 MJ/kgDM (DE11Mo) and 12 MJ/kgDM (DE12Mo). The experiment was carried out 12 weeks. The results of experiment showed that DE12M group was higher daily weight gain and final live weight than other treatments (p<0,05). However, DE11Mo group was lowest FCR and best economic efficiency as compared to other groups. It concluded that supplementation of molasses in diet with 11 MJ/kg DM have improved growth performance in crossbred rabbit.

Key words: crossbred rabbit, maize, molasses, performance


Introduction

Mekong Delta has known as an area with diversity vegetation, cheap and available agro-industrial by-products. Rabbits are one of herbivorous, which not only utilizes agro-industrial by-products, but also converts 20% of their protein intake into meat compared to 16-18% in pigs and 8-12% in cattle (Thu and Dong 2011). O'Meara et al (1992) reported rabbit meat has great nutritional value, due to its high protein content (20 - 21%), low fat (4 - 5%) and low cholesterol (45 mg/kg), it is recommended for people patients with cardiovascular disease can use (Hu and Willett 2002). Therefore, it is possible to meet requirements for high quality protein in human food. Molasses is a by-product of the sugar processing industry. The main component of molasses is sugar, mainly sucrose with a little glucose and fructose (Trach 2003). Kpodékon et al (2008) showed that molasses supplementation in the diet of fattening rabbits did not affect the daily weight gain and weight of rabbits during rearing. Besides, maize is also known as a source of energy in the diet, rich in carotene that can be supplemented for cattle. Some studies have suggested that the optimal DE in the diet of growing rabbits is 2500 kcal/kg feed (NRC 1977; Lebas 1980) de Blas and Mateos 2020 recommended DE for breeding doe rabbits to be 10.7 MJ and fattening rabbits to be between 9.7 - 11.5 MJ without any adverse effects. Linga and Lukefahr (2000) showed that supplementation of Molasses in alfalfa diets improved the growth performance of New Zealand rabbits and Altex rabbits compared with alfalfa-based diets. Amici and Finzi (1995) recommended the use of molasses block as a feed source to increase the growth performance of rabbit meat in developing countries.

The use of maize and molasses in the diet as energy sources for growth rabbits both utilizes the agricultural by-products and lowers production costs, however, currently studies on these feeds are still very limited in terms of livestock production in Vietnam. The study of effects of digestible energy sources and levels in diets on growth performance of New Zealand White crossbred rabbits was carried out with the following objectives: to determine the optimal level of digestible energy in the diet for growth performances of crossbred rabbits. Besides that, identification of an appropriate energy source for growth rabbits. From there, the results are recommended to farmers to contribute to the development of rabbit farming and increase income, contributing to improving the lives of farmers.


Materials and methods

Location and time

The experiment was carried out at the farm in Thoi Hoa ward, O Mon district, Can Tho city, Vietnam. The chemical composition of experimental diets was analyzed at the laboratory E205 of the Faculty of Animal Sciences, College of Agriculture, Can Tho University. The implementation of this study was from Feb to October 2022.

Experimental design

The experiment consisted of 80 New Zealand White weaned crossbred rabbits (New Zealand White x local rabbits) at period 30 – 40 days old (560±11,64 g/head) were produced at the farm. Rabbits are vaccinated against parasitic diseases, polio and respiratory diseases. The experiment was a completely randomized design with 5 treatments and 4 replications with 2 males and 2 female rabbits per trial unit. The treatments were the different dietary digestible energy levels and sources including 10 MJ/kgDM (control, DE10); either supplementation with maize: 11 MJ/kgDM (DE11M) and 12 MJ/kgDM (DE12M) or molasses: 11 MJ/kgDM (DE11Mo) and 12 MJ/kgDM (DE12Mo). The experiment was carried out 12 weeks consisting a week for adaptation and 11 weeks for data collection. The rabbits were housed in individual cages and had free access to clean drinking water. The ingredients and chemical composition of experimental diets were shown in Table 1 and 2.

Table 1. Ingredients and chemical composition of experimental diets

Feed (%DM)

Treatments

DE10

DE11M

DE12M

DE11Mo

DE12Mo

Ingredients

Operculina turpethum

65

43

26

52

37

Soybean extraction meal

11

17

23

18

25

Soya waste

24

19

10

16

9

Maize

0

21

41

0

0

Molasses

0

0

0

14

29

Total

100

100

100

100

100

Chemical composition

DM, %

15.9

21.1

31.2

19.7

26.1

OM, %

90.5

92.6

94.3

90.2

89.9

CP, %

19.0

19.0

18.9

19.0

18.9

EE, %

6.86

5.89

4.84

5.55

4.20

NDF, %

40.0

33.1

27.0

33.2

25.7

ADF, %

28.1

21.6

15.5

22.8

17.2

CF, %

20.0

14.7

10.0

16.1

11.9

Ash, %

9.51

7.40

5.71

9.84

10.10

DE, MJ/kgDM

10.0

11.0

12.0

11.0

12.0

DE 10: digestible energy containing in diet was 10 MJ/kgDM without using maize and mollases , DE 11.0M: digestible energy containing in diet was 11 MJ/kgDM with using maize, DE 12.0M: digestible energy containing in diet was 12 MJ/kgDM with using maize, DE 11.0Mo: digestible energy containing in diet was 11 MJ/kgDM with using mollases, DE 12.0M: digestible energy containing in diet was 12 MJ/kgDM with using mollases

Data collection and management

The rabbits were fed twice daily at 7:00h and 17:00h. All rabbits were weighed once a week throughout the experiment and before feeding in the morning.

Feed offered and refusals were recorded daily in the morning during the experiment. The samples were collected every 2 weeks. Samples were dried at 550C for 48 hours until the weight unchanged, then finely ground for chemical composition analysis.

The experimental of nutrient digestible period was conducted at the 6 th week of the experiment and carried out during 6 days continuously. The feeds offered, refusals, feces and urine were collected for nutrient digestibility and nitrogen retention measurement. Samples of feed offered, refusals and feces were dried and finely ground. Then mix the samples of 3 days according to each experimental unit to analyze the nutrient components such as DM, OM, CP, EE, NDF and Ash.

Statistical analysis

All data were analyzed with the General Linear Model of Minitab 13.21 program (Minitab, 2016). The significance of pairwise comparisons was determined by Tukey posttest. Significance was declared at p <0.05.


Results and discussion


Table 2. Effects of maize and molasses supplementation on nutrient intake in crossbred rabbits

Feed

Treatments

SE

p

DE10

DE11M

DE12M

DE11Mo

DE12Mo

Dry matter, g/per/day

Operculina turpethum

48.1a

32.7c

18.3e

38.3b

26.6d

0.600

0.001

Soybean extraction meal

7.09c

13.0b

19.0a

12.6b

18.6a

0.663

0.001

Soya waste

14.2a

13.8a

7.82c

11.2b

6.62c

0.590

0.001

Maize

-

17.1b

34.0a

-

-

0.692

0.001

Molasses

-

-

-

10.8b

19.7a

0.481

0.001

Nutrient intake daily, g/per/day

DM

69.3c

76.6ab

79.1a

73.0bc

71.5bc

1.932

0.018

OM

62.5c

71.0ab

74.8a

65.8bc

64.3bc

1.821

0.001

CP

13.0b

14.5ab

15.1a

13.7ab

13.9ab

0.405

0.025

EE

4.71a

4.46a

3.75b

4.01b

3.06c

0.094

0.001

NDF

28.2a

25.2b

20.8c

24.1b

18.7d

0.464

0.001

ADF

19.7a

16.3b

11.7c

16.6b

12.5c

0.293

0.001

CF

14.2a

11.1b

7.42d

11.8b

8.62c

0.183

0.001

Ash

6.82a

5.63b

4.32c

7.26a

7.15a

0.122

0.001

DE, MJ

0.69c

0.85b

0.96a

0.80b

0.85ab

0.024

0.001

a, b, c, d, e Mean values ​​with different superscripts within the same row are different at p<0.05 DE 10: digestible energy containing in diet was 10 MJ/kgDM without using maize and mollases , DE 11.0M: digestible energy containing in diet was 11 MJ/kgDM with using maize, DE 12.0M: digestible energy containing in diet was 12 MJ/kgDM with using maize, DE 11.0Mo: digestible energy containing in diet was 11 MJ/kgDM with using mollases, DE 12.0M: digestible energy containing in diet was 12 MJ/kgDM with using mollases

Table 3 showed the amount of feed and nutrients daily intake of experimental rabbits in the growth period. In general, all the indicators in the table have statistically significant differences among treatments ( p<0.05). The DM intake of Operculina turpethum was the highest at DE10 (48.1 g/per/day) and the lowest at DE12M (18.3 g/per/day). In contrast, the DM intake of soybean extraction meal reached the highest value at DE12Mo (18.6 g/per/day) and the lowest at DE10 (7.09 g/per/day). The highest and lowest DM intake of soya waste was in DE10 and DE12Mo groups (14.2 g/per/day and 6.62 g/per/day respectively).

Total DM intake was statistically significant (p<0.05) among treatments, reaching the highest value at DE12M (79.1 g/per/day) and the lowest at DE10 (69.3 g/per/day). These results were higher than the study result of  Dong and Thu (2021) when adding molasses to the diet of growing rabbits, the amount of DM increased gradually with the level of molasses addition in the diet from 0 to 24% molasses. The value of DM intake ranged from 69.3 to 79.1 g/per/day and was similar to the results of Trung et al (2016) when gradually increasing the level of ME10.0 to ME12.0, the DE intake gradually increased from ME10.0 – ME11.0 then decreased from ME11.5 and ME12.0 with DM intake ranging from 69.4 - 74.5 g/per/day.

The amount of OM and CP intakes had statistically significant differences (p<0.05) among treatments and reached the highest value at DE12M and the lowest at DE10 with values of 74.8 and 15.1 g/per/day compared with 62.5 and 13.0 g/per/day.

The amount of EE and NDF intakes was significantly different (p <0.05) among treatments and reached the highest value at DE10 (4.71 and 28.2 g/per/day) and lowest at DE12Mo (3.06 and 18.7 g/per/day). From these results, it showed that the NDF intake is lower than the optimal NDF intake for rabbits as recommended by De Blas and Mateos (2010).

The differences in ADF, CF and Ash intakes was statistically significant ( p<0.05) and reached the highest value at DE10 of 19.7; 14.2 and 6.82 g/per/day and the lowest at DE12M was 11.7; 7.42 and 4.32 g/per/day. The amount of ADF intake was lower than the optimal level which recommended by De Blas and Mateos (2010) from 18-20% of ADF. The amount of DE intake was significantly different (p<0.05) and reached the highest value at DE12M (0.96 MJ) and the lowest at DE10 (0.69 MJ). In summary, the DE12M and DE12Mo had the same energy levels, but nutrient intakes from DE12M were higher than in DE12Mo.

Table 3. Daily weight gain of the growth rabbit

Items

Treatments

SE

p

DE10

DE11M

DE12M

DE11Mo

DE12Mo

Initial live weight, g

560

562

563

568

565

11.64

0.986

Final live weight, g

2290c

2482ab

2535a

2472ab

2355bc

30.87

0.001

Daily weight gain, g/day

20.6c

22.9a

23.5a

22.7ab

21.3bc

0.312

0.001

FCR

3.37

3.35

3.37

3.22

3.36

0.090

0.743

a, b, c Mean values ​​with different superscripts within the same row are different at p<0.05 DE 10: digestible energy containing in diet was 10 MJ/kgDM without using maize and mollases , DE 11.0M: digestible energy containing in diet was 11 MJ/kgDM with using maize, DE 12.0M: digestible energy containing in diet was 12 MJ/kgDM with using maize, DE 11.0Mo: digestible energy containing in diet was 11 MJ/kgDM with using mollases, DE 12.0M: digestible energy containing in diet was 12 MJ/kgDM with using mollases

Table 4 showed the growth performance of experimental rabbits. Initial weight ranged from 560 – 568 g/per, and this difference was not statistically significant (p>0.05). Final weight gradually increased as maize supplementation increased, whereas final weight decreased as molasses supplementation (Table 4, p<0.05). DE12M had the best weight gain of 23.5 g/per/day, the final weight results were higher than that of the other treatments. This result is higher than the research result of Linh and Thu (2017) with the final weight ranging from 1908 to 2205 g.

The results of daily weight gain had a statistically significant difference (p< 0.05), the highest at DE12M and the lowest at DE10 was 23.5 and 20.6 g/per/day, respectively. Thus, the supplementation of maize and molasses in diet improved daily weight gain. Daily weight gain tended to increase gradually from DE10 to DE11M and DE12M, and gradually decreased at DE11Mo and DE12Mo. The weight gain of rabbits was from 20.6 to 23.5 g/per/day, this result was higher than the research results of Chau (2015) from 17.5 to 19.7 g/per/day with adding different levels of crude protein and essential amino acids and higher than the results of Dong and Thu (2021) with adding molasses to the diet of growing rabbits, the weight gain was from 15.2 – 20.0 g/per/day. This was suitable with the results of Trung et al (2016) with daily weight gain from 20.5 to 24.5 g/per/day.

FCR was not statistically significant differences among treatments (p>0.05). This result was lower than the results of Linh and Thu (2017), whose FCR of crossbred rabbits was 3.48 to 3.73 and lower than the results of Kpodékon et al (2008) had a FCR of rabbits in the fattening stage with molasses supplying in diets was 3.59. Economic returns of treatment DE12M had a profit of 57.531 VND/head, lower than 80.244 VND/head of DE11Mo.

Table 4. Digestibility nutrients of rabbits during the nutrient digestible period

Items

Treatments

SE

p

DE10

DE11M

DE12M

DE11Mo

DE12Mo

Digestibility nutrients

DMD

75.0c

79.7ab

80.9a

77.7bc

78.2ab

0.709

0.001

OMD

74.8c

79.9ab

81.4a

77.6bc

78.3ab

0.713

0.001

CPD

79.0b

82.9ab

83.4a

81.4ab

81.7ab

0.912

0.031

EED

88.1a

87.8ab

85.5b

86.4ab

83.0c

0.539

0.001

NDFD

57.4b

63.2a

61.1ab

60.9ab

58.8b

0.918

0.004

ADFD

49.2

56.2

49.9

55.0

51.6

1.701

0.060

Nitrogen balance

N intake, g

2.37b

2.56ab

2.59a

2.45ab

2.48ab

0.045

0.024

N feces, g

0.50

0.44

0.43

0.44

0.45

0.025

0.376

N urine, g

0.60

0.55

0.48

0.45

0.56

0.040

0.111

N retention, g

1.26b

1.58a

1.68a

1.54a

1.47ab

0.057

0.002

%NR/NI

53.7b

61.6a

65.0a

62.8a

59.0ab

1.654

0.003

NI/W0.75

1.83

1.88

1.87

1.80

1.88

0.066

0.874

NR/W0.75

0.98b

1.16ab

1.22a

1.13ab

1.10ab

0.045

0.025

a, b, c Mean values ​​with different superscripts within the same row are different at p<0.05 DE 10: digestible energy containing in diet was 10 MJ/kgDM without using maize and mollases, DE 11.0M: digestible energy containing in diet was 11 MJ/kgDM with using maize, DE 12.0M: digestible energy containing in diet was 12 MJ/kgDM with using maize, DE 11.0Mo: digestible energy containing in diet was 11 MJ/kgDM with using mollases, DE 12.0M: digestible energy containing in diet was 12 MJ/kgDM with using mollases

The nutrient digestibility of DM, OM, CP, EE and NDF were all statistically significant (Table 4, p<0.05) among treatments, excepting for ADF (p>0.05). The digestibility of nutrients was highest at DE12M with DM, OM, and CP at 80.9; 81.4 and 83.4%. This result was almost same to the research result of Dong and Thu (2016) with the highest nutrient digestibility of DM, OM, CP at 75.9; 76.6 and 84 % and higher than results of Giang (2010) were 66.6; 68.3; 75.2%.

Nitrogen intake, N retention, NR/W0.75 and %NR/NI were significantly different (p<0.05) between treatments and reached the highest value at DE12M and lowest at DE10, the values were 2.59 g, 1.68 g, 1.22 and 65.0%, respectively, compared with 2.37 g, 1.26 g, 0.98 and 53.7%. This result was higher than that of Dong et al (2008) when water spinach leaves were added to the diet of Para grass on hybrid rabbits growing in the Mekong Delta, the nitrogen intake and nitrogen retention ranged from 1.21 to 1.6 and 0.76 to 1.07. This result was lower than that of Trung et al (2016) has the highest %NR/NI of 68.7% at ME12.0.


Conclusion

The results from current study indicated that crossbred rabbits supplemented molasses as energy sources with 11 MJ/kg DM is the best choice to improve economic return.


References

Amici A Finzi 1995 Molasses blocks as supplementary feed for growing rabbits. Word Rabbit Sci. 1995, 3 (2), 69-73.

Carlos de Blas and G G Mateos 2020 Chapter 12: Feed Formulation. Blas, C. de (Carlos), editor. Wiseman, J. (Julian), editor. Nutrition of the Rabbit, 3rd Edition (pp. 243-253).

Chau N T V 2015 Study on optimal levels of dietary nutrients for crossbred rabbits (New Zealand x local) in the Mekong Delta of Vietnam. PhD Thesis. Can Tho University, Vietnam.

De Blas J C and Mateos G G 2010 Feed Formulation. In: De Blas C., Wiseman J. (Eds). The Nutrition of the Rabbit. CABI Publishing. CAB International, Wallingford Oxon, UK, 222-232.

Dong N T K and Thu N V 2016 Effect of sweet potato by-products combined with coconut oil meal on daily weight gain, carcass quality and nutrient digestibility of hybrid rabbits. Scientific Journal of Can Tho University. Topic number: Agriculture (2016)(2): 113-119. DOI:10.22144/ctu.jsi.2016.053.

Dong N T K and Thu N V 2021 Growth performance of rabbits fed fibrous diets supplemented with molasses. Livestock Research for Rural Development 33 (7) 2021.

Dong N T K, Thu N V, Brian Ogle and Preston T R 2008 Effect of supplementation level of water spinach (Ipomoea Aquatica) leaves in diets based on para grass (Brachiaria Mutica) on intake, nutrient utilization, growth rate and economic returns of crossbred rabbits in the Mekong Delta of Vietnam. Livestock Research for Rural Development 20 (9) 2008.

Giang N T 2010 Effects of dietary levels of sweet potato and molasses on daily weight gain and nutrient digestibility of hybrid rabbits in the Mekong Delta. Master thesis. Can Tho university.

Kpodékon T M, Youssao A K I, Tossou C M, Djago A Y, Coudert P 2008 Effects of molasses incorporation in rabbit fattening diet on growth performances, 9th World Rabbit Congress – June 10-13, 2008 – Verona – Italy, http://world-rabbit-science.com/WRSA-Proceedings/Congress-2008-Verona/Papers/N-Kpodekon.pdf .

Kpodékon T M, Youssao A K I, Tossou C M, Djago A Y, Coudert P 2008 Effects of molasses incorporation in rabbit fattening diet on growth performances, 9th World Rabbit Congress – June 10-13, 2008 – Verona – Italy.

Lebas F 1980 Proc. 2nd World rabbit congress, vol. 2, 1-17.

Linga S S and S D Lukefahr 2000 Feeding of alfalfa hay with molasses blocks or crumbles to growing rabbit fryers, Livestock Research for Rural Development 12 (4), http://www.cipav.org.co/lrrd/lrrd12/4/ling124.htm

Linh D T K and Thu N V 2017 Effect of different levels of Mulato II substitution for sweet potato vine in the diet on nutrient utilization, growth rate and carcass quality of local rabbits in Tien Giang province. Journal of Animal Science and Technology 80: 59-68.

O'Meara N M, Devery R A, Owens D, Collins P B, Johnson A H and Tomkin G H 1992 Alterations in cellular cholesterol metabolism following administration of 6-hydroxydopamine to rabbits. Br J Pharmacol. 1992 Feb; 105(2): 495–499.Hu & Willett, 2002

Thu N V and Dong N T K 2011 Rabbit monograph - Technology for nurturing and processing products, Agriculture Publishing House, Ho Chi Minh City.

Trach N X 2003 Use molasses as animal feed. Faculty of Livestock and Aquaculture, Hanoi University of Agriculture.

Trung T T, Dong N T K and Thu N V 2016 A response of feed utilization, nutrient digestibility, growth and carcass value of californian rabbits to dietary metabolizable energy. Can Tho University Journal of Science Vol 3 (2016) 25-31. DOI: 10.22144/ctu.jen.2016.101.