Rabbits are one of the most popular livestock breeds raised for their meat, fur, and companionship. Rabbit meat is fast gaining prominence as a healthier meat compared with beef, mutton, pork and chevon, which are mostly consumed in Nigeria. This study investigated breed differences in mortality, survival rates and post-weaning growth rate of rabbits reared under inimical environmental conditions. The animals were fed commercially compounded feed with 18% crude protein and 2300Kcal metabolizable energy with intermittent feeding of Panicum sp and Tridax sp. The study area, located at latitude 6.5867° N and longitude 3.9700° E, had an average daily temperature of 35°C and relative humidity of 64%, which negatively impacted the adaptation, survival rates and growth performance of the rabbits. A total of 48 weaner rabbits 8 wk of age, comprising 12 each (9 does and 3 bucks) of Checkered, Chestnut, Dutch and Hyla breeds were reared for 10 wk post-weaning. Mortality was recorded across the breeds and the body weights (BW) of the rabbits were also recorded on a weekly basis for the entire 10-wk period. The study evaluated survival rates across breeds and sex and BW gain. Statistical analyses were conducted using the Minitab software for Chi Squared test of independence for counts and descriptive statistics and general linear model analysis of variance for bodyweight gain. The statistical model describing the analysis was Yijk = µ + αi + (α:β)ij + eijk where αi is the ith fixed effect of breed and βj is the jth fixed effect of sex. The model accounted for 67.03% variation in total weight gain. Further mean separation was done using the Tukey’s multiple comparison procedure. Mortality rates across breeds on the average was 56.25%, with Checkered, Chestnut, Dutch and Hyla respectively recording 66.67%, 41.67%, 50.00% and 66.67% mortality, respectively. Mortality rate across sexes was 63.89% for does and 33.33% for bucks; however, mortality rates were independent (P > 0.05) of both breed and sex with a Chi-Squared value of 2.285 and 3.41, respectively, despite the numerical differences in mortality rates across breeds and sexes. Average total BW gain during the study period across the breeds and within breeds is as presented in Table 1. The nesting of sex within breed revealed that the only significant (P > 0.05) difference was noticed between the Hyla buck and Chestnut doe, while other means were not statistically different (P > 0.05). The Chestnut breed with the least BW gain adapted well in the environment with greatest survival rate, while the Hyla breed had the greatest BW gain and least survival rate throughout the study. This study indicated a negative relationship between survival rates and BW gain, that lighter breeds of rabbit tend to have greater survival rates than the heavier breeds.

中文翻译：

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423 尼日利亚炎热潮湿气候下 4 个品种兔子断奶后性能特征比较


兔子是最受欢迎的牲畜品种之一，因其肉、皮毛和陪伴而饲养。与尼日利亚主要消费的牛肉、羊肉、猪肉和雪佛龙相比，兔肉作为一种更健康的肉类迅速受到重视。本研究调查了在恶劣环境条件下饲养的兔子在死亡率、存活率和断奶后生长率方面的品种差异。动物饲喂粗蛋白含量为 18% 且代谢能量为 2300Kcal 的商业复合饲料，间歇性饲喂 Panicum sp 和 Tridax sp。研究区位于北纬 6.5867°，东经 3.9700°，日平均气温 35°C，相对湿度 64%，对兔子的适应、成活率和生长性能产生了负面影响。共有 48 只 8 周龄断奶兔，包括方格兔、栗子兔、荷兰兔和海拉兔品种各 12 只（9 只和 3 只雄兔），断奶后 10 周饲养。记录了各个品种的死亡率，并且在整个 10 周期间每周记录兔子的体重 （BW）。该研究评估了不同品种的存活率和性别以及 BW 增加。使用 Minitab 软件进行统计分析，用于计数和描述性统计的卡方独立性检验以及体重增加方差的一般线性模型分析。描述分析的统计模型是 Yijk = μ + αi + （α：β）ij + eijk，其中 αi 是品种的第 i 个固定效应，βj 是性别的第 j 个固定效应。该模型占总增重的 67.03% 变化。使用 Tukey 多重比较程序进行进一步的均值分离。不同品种的平均死亡率为 56。25%，其中 Checkered、Chestnut、Dutch 和 Hyla 的死亡率分别为 66.67%、41.67%、50.00% 和 66.67%。雄鹿的性别死亡率为 63.89%，雄鹿为 33.33%;然而，尽管不同品种和性别的死亡率存在数值差异，但品种和性别的死亡率是独立的 （P > 0.05），卡方值为 2.285 和 3.41。研究期间各品种和品种内的平均总体重增加如表 1 所示。品种内性别的筑巢表明，Hyla buck 和 Chestnut 母鹿之间唯一显着的差异 （P > 0.05），而其他平均值在统计学上没有差异 （P > 0.05）。BW 增益最少的 Chestnut 品种在环境中适应良好，存活率最高，而 Hyla 品种在整个研究过程中 BW 增加最大，存活率最低。这项研究表明，存活率与 BW 增加之间存在负相关关系，较轻的兔子品种往往比较重的品种具有更高的存活率。