Agricultural Studies, Vol. 6, Issue 1, Apr  2022, Pages 49-55; DOI:

Growth Performance and Digestibility of California White Rabbits as Affected by Protein Levels

, Vol. 6, Issue 1, Apr  2022, Pages 49-55.


Unung Hillary Ubanaye 1* , Mwansat, G.S. 1 , Adediran Opeyemi 2 , Joel Elizbeth 2 , Asiruwa Peter 2 , Dawet, A. 1 , Oyedapo Folashade 3 , Johnson Mfon 3 , Oshibanjo Debola Olusegun 3

1 Department of Zoology, Faculty of Natural Science, University of Jos, Jos, Nigeria

2 Department of Animal Science, University of Ibadan, Ibadan, Nigeria

3 Department of Animal Production, Faculty of Agriculture, University of Jos, Jos, Nigeria

Received: 25 December 2021; Accepted: 15 February 2022; Published: 10 May 2022


The aim of this study is to seek the effects of Protein Levels on Growth Performance and Digestibility in California white Rabbits. A, one hundred and twenty (120) day feeding trial was conducted to determine the effect of different dietary protein levels (13%, 14% and 18%). Thirty California white weaner rabbits of known genetic purity (88%) within the ages of 6 weeks old with an average initial weight of 1,004g were randomly assigned to three dietary treatments of 10 rabbits per treatment in a completely randomized design experiment. The results obtained showed that the final weight, average daily weight, relative growth rate, performance index and feed intake differed significantly (p


California White, Dietary Proteins, Growth Characteristics, Digestibility

1. Introduction

Nigeria and many other developing countries in the world are currently facing problems of inadequate animal protein availability. This negative trend is seen to affect mostly the low income earners who constitute over 70% of our population. estimated the average animal protein consumption in Nigeria to be 7.4g/caput /day as compared to 38g/caput/day of animal protein consumed in South Africa. The increasing demand for animal protein in Nigeria and the economic hardship faced by the populace have stimulated greater interest in fast growing animals with short generation intervals such as rabbits[1]. Rabbits play an important role in supply of animal protein to the Nigeria populace [2]. Among the attributes posed by rabbits are; (i) They are efficient converters of food to meat and can utilize up to 30% crude fibre as against 10% by most poultry species [3], (ii) Rabbits belongs to the class of white meat, low in cholesterol level and are good for consumption by both diabetic and hypertensive patients.

Feeding is one of the most critical factors in any livestock production enterprise as it accounts for over 70% of the total cost of production [1]. Protein and Energy remains the basic nutrient, whose requirements must be met in animal nutrition for optimum production to be attained. Various crude protein percentages have been used to compound diets for rabbits to ascertain their growth potentials; [1] recommended a crude protein percentage of 13% and 18% for rabbits at maintenance and production rations, respectively. However, [4] established that crude protein levels above 17% in rabbit’s diets yielded no significant result. According to [5] a crude protein percentage of 12 and 17 were required for maintenance and production respectively Well over forty breeds of rabbits have been reported in the United States [6]. The popular breeds of rabbits in Nigeria are the Newzealand white, California white, Dutch belted, America Chinchilla, Flemish Giant, Florida white, and Champagne [7]. These breeds according to [7] differ in coloration, body size, conformation growth rate & fecundity which are governed by both genetic and environmental factors. The study is designed to determine the effect of different dietary protein levels on growth indices and nutrient digestibility in California white rabbis at (88%) purity.

2. Materials and Methods

The experiment was conducted in Bukuru, Jos, Plateau State. Thirty hybrid weaner rabbits of California white origin of 6-8 weeks old were purchased from Dagwom farm, Jos, Plateau State. Rabbits were of equal sex ratio, with an average initial weight of 1,000g. Prior to commencement of the experiment, rabbits were pre-conditioned for two weeks, during which they were exposed to their environment (feed) for acclimatization. Rabbits were treated within this period with 0.02 ml doses each of Ivomectin to guide against endo and ecto parasites. Rabbits were randomized into individual hutches measuring 50 x 30 x 40cm and raised 50cm above the ground level in an enclosed but well ventilated structure for protection against predators. Each experimental cage was fitted with drinkers, feeders and aluminum trays for collection of faeces and urine. Rabbits were also assigned randomly into three dietary treatmentsof ten rabbits per treatment in a completely randomized design. Data collection for feed served, feed refusal, initial body weight and final body weight for each rabbit on treatment basis were carried out weekly. The control diet used in the study was the conventional commercial rabbit’s grower mash of vital feed. Other diets used for the experiment were formulated at 13% and 18% crude protein levels. Ingredients were sourced from the local market in Bukuru. Composition of experimental diets are shown in Table 1.

Table 1. Ingredient Composition of Experiment Diets.


13% cp

18% cp

Control Diet




Crude Protein 14%




Crude fat 8.00%

Brewer dried Grain



Crude fibre 15.00%

Bone Meal



Calcium 1.00%

W/heat offal



Phosphorus 0.35%

Vitamin Premier



Amino Acid








Anti-Oxidant Probiotic

Common salt







M.E/kcal 2600 kcal/kg

Calculated Values

Crude Protein



Crude fibre



Ether extract









Analysed Values

Dry matter




Crude Protein




Crude fibre




Ether extract
















NFE Nitrogen Free Extract = 100-(% CP + % CF +% E.E + % ASH)

2.1. Data collection

Data were collected for feed served, feed refusal, initial body weight and final body weight and the following parameters were calculated Average feed intake, Average daily weight gain, Relative growth rate, performance index, feed conversion ratio and feed efficiency.

* Relative Growth Rate (%) =

* Performance Index (%) =

* Feed conversion Ratio =

2.2. Digestibility Trial

On the last week of the experiment, faecal samples were collected from each of the rabbits for 3 days. Collected samples were bulked together, oven dried for 48 hours and analyzed for proximate composition.

Apparent nutrient digestibility was determined using the formula:


Chemical Analysis: Proximate analyses of faecal sample were carried out using the procedures of [8].

Statistical Analysis: Data collected were subjects to one-way analysis of variance (ANOVA) According to [9] and least significant difference procedure was used to separate means at 5% level of significance.

3. Results and Discussion

3.1. Results

Rabbits fed 18% dietary protein level, differ significantly (P< 0.05) in final weight, average daily weight gain, relative growth rate, performance index and feed intake, when compared to those served diet containing 13% crude protein level. Similarly, significant (P< 0.05) difference existed between rabbits fed diet containing 13% crude protein level and (14%) in final weight, relative growth rate and performance index. There was no significant (p> 0.05) difference between rabbits fed 18% dietary protein level and the control in almost all the parameters measured except average daily weight gain and feed intake which differ significantly (P< 0.05) between treatments. (Table 2, Table 3)

Table 2. Performance characteristics of California white rabbits fed different levels of dietary proteins.


Control Diet

13% cp

18% cp

Initial Weight (g)

1,000 ± 79.23

998 ± 116.69

995 ± 95.82

Final Weight (g)

2,105 ± 96.91a

2,037 ± 131.53b

2,115.5 ± 51.54a

Av. Daily weight

95.59 ± 2.23b

91.68 ± 1.75b

102.66 ± 1.78a

Gain (g)

Relative Growth

71.18 ± 0.61a

68.47 ± 0.52b

72.06 ± 0.19a

Rate (%)


83.20 ± 1.21a

81.49 ± 1.28b

82.32 ±1.31a

Index          (%)

Av. Feed intake (g)

242.27 ± 5.50b

230.45 ± 4.38b

263.38 ± 6.84a

Feed Conversion

2.53 ± 0.05

2.51 ± 0.07

2.57 ± 0.06


Feed Efficiency

0.39 ± 0.11

0.40 ± 0.12

0.39 ± 0.13





Mean difference is significant at (0.05) level. Means in a row with common letter(s) superscript do not differ (p> 0.05).

Table 3. Apparent nutrient digestibility of California white rabbits at 88%.

Parameter (%)

Control Diet

13% CP

18 % CP

Dry Matter

90.44 ± 0.08

89.65 ± 0.25

89.81 ± 0.09

Crude Protein

26.14 ± 0.71a

20.40 ± 4.19 b

26.03 ± 6.14a

Crude Fibre

82.20 ± 2.65a

48.00 ± 6.03 b

90.40 ± 2.32a

Ether Extract

81.60 ± 0.93a

30.40 ± 5.85b

72.20 ± 1.53a

Nitrogen free Extract

42.28 ± 1.37

44.39 ± 3.19

45.27 ± 0.99

Mean difference is significant at (0.05) level. Means in a row with common letter(s) superscript do not differ (p> 0.05).

3.2. Discussions

Values obtained for final weight was highest for rabbits fed 18% crude protein diet, than values obtained for rabbits fed 13 and 14%, crude protein since you are including results from other authors, then try . Results obtained from the study were higher than those reported by [10].

Significant (p< 0.05) differences in weight gain and feed intake between rabbits that received 13%, 18% and the control (14%) observed in the study is in consonance with the report of [11] that low levels of dietary proteins fed to rabbits reduces their weight gain and impairs reproductive performance. It also agrees with the report of [12] that rabbits consume more of feed with low caloric density. It equally corroborates the report of [13] who observed weight gain in rabbits as protein levels in their diets increased. The result however, disagrees with the findings of [14] that rabbits on low crude protein diet consume more feed to compensate for low level of dietary protein in their diets. The increase in relative growth rate and performance index observed in the study for rabbits fed 18% crude protein diet and the control, did not agree with the findings of [15] who reported rather an increase in relative growth rate and performance index with rabbits fed diets containing lower dietary protein level. The result however, agrees with the report of [16] who recorded an increase in growth traits of rabbit as the Protein level in their diet increased.

Values obtained from study for feed conversion ratio were better than 5.11-7.66, 5.82-7.12, 4.50 4.73 and 3.48-4.78 reported by [17,18,19,20] respectively. Variation in feed conversion ratio observed in the study could be a reflection of the differences in their efficiency of feed utilization by the breed of rabbits used [21]. Rabbits fed diet containing 18% crude proteins level had the best in terms of feed utilization. This is in consonance with the report of [22] balanced nutrition enhances growth rate and feed utilization of rabbits.

Apparent nutrient digestibility of dry matter (DM) and nitrogen free extract (NFE) did not differ significantly (P> 0.05) between treatment groups of 13 and 18% and the control group. Crude fibre (CF) crude protein (CP) and ether extract (E.E) digestibility differ significantly (P> 0.05) with rabbit groups fed 18% and control (14%) diet compared to those fed diet containing 13% crude protein level. The apparent nutrient digestibility for California white rabbits at 88% purity shows that, rabbits fed diet containing 18% crude protein and the control (14%), utilized their feedmore compared to those fed diet containing 13% crude protein. The low nutrient digestibilityrecorded in this study rabbit group fed 13% dietary Protein level, could be attributed to increase in fibre content in the feed. Hence, rabbits are less efficient in the digestion of fibre than sheep, goat and cattle [24].

4. Conclusions

In conclusion, dietary protein levels of 14 -18% enhance better California white rabbits performance characteristics and nutrient digestibility due to its higher daily weight gain and performance index when compared with other treatment groups.

Conflicts of Interest

The authors declare that there is no conflict of interest regarding the publication of this article.


This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.


© 2017 by the authors. Licensee International Technology and Science Press Limited. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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