Ludwiczak Agnieszka, Składanowska-Baryza Joanna, Kuczyńska Beata, Sell-Kubiak Ewa, Stanisz Marek
Department of Animal Breeding and Product Quality Assessment, Poznań University of Life Sciences, Słoneczna 1, 62-002 Suchy Las, Poland.
Animal Breeding Department, Faculty of Animal Breeding, Bioengineering and Conservation, Warsaw University of Life Sciences, Ciszewskiego 8, 02-786 Warsaw, Poland.
Animals (Basel). 2021 Sep 5;11(9):2608. doi: 10.3390/ani11092608.
The goal of this study was to analyze the reproductive performance of does, growth of their kits, and chemical composition of their milk over nine consecutive parities in order to indicate the boundary of female reproductive profitability. The novelty of this study results from the combinations of three factors: extensive reproductive rhythm, commercial farming conditions, and a period of nine consecutive parities, showing the actual lifespan of a rabbit doe on commercial farms. The data was collected on 60 Hycole females kept at a commercial rabbit farm. Throughout the study, 32 does were excluded due to different reasons (e.g., excluded by means of selection-43.8% and mortalities-25.0%). The does were first inseminated at 28 weeks of age. Following artificial inseminations were conducted 14-15 days after each parturition. All kits were weaned at the age of 35 days. The following characteristics were analysed: body weight of rabbit does at artificial insemination, milk production per lactation, litter size, litter weight, average kit weight, and milk chemical composition. Rabbit does had a significant decrease in kindling rate between the eighth and the ninth parity (by 10.0 percentage points; = 0.039). The litter size at weaning in the ninth parity was significantly lower to litters weaned at other analysed parities. The amount of milk produced per lactation was affected by the parity order (6.31-6.76 kg; = 0.042). The litter weights on day 21 and 35 were the lowest at ninth parity. The content of total solids (TS), solids-not-fat, and fat was affected by the parity order on both analysed lactation days. The content of TS and fat in rabbit milk was characterized with a decreasing trend over the analysed period, on both lactation days. The results clearly indicate that rabbit does under extensive reproductive cycles characterize with a very good reproductive performance and can be successfully used for reproduction even up to the eighth parity. However, further research is needed if keeping them longer will not be profitable.
本研究的目的是分析母兔连续九个繁殖周期的繁殖性能、其所产仔兔的生长情况及其乳汁的化学成分，以确定母兔繁殖盈利能力的界限。本研究的新颖之处在于将三个因素结合起来：广泛的繁殖节律、商业化养殖条件以及连续九个繁殖周期，展示了商业兔场中母兔的实际寿命。数据收集自一家商业兔场饲养的60只海科尔母兔。在整个研究过程中，32只母兔因不同原因被排除（例如，通过选种排除的占43.8%，死亡的占25.0%）。母兔在28周龄时首次进行人工授精。每次分娩后14 - 15天进行后续人工授精。所有仔兔在35日龄时断奶。分析了以下特征：人工授精时母兔的体重、每泌乳期的产奶量、窝产仔数、窝重、平均仔兔体重以及乳汁化学成分。母兔在第八和第九个繁殖周期之间的产仔率显著下降（下降10.0个百分点；P = 0.039）。第九个繁殖周期断奶时的窝产仔数显著低于其他分析的繁殖周期断奶时的窝产仔数。每泌乳期的产奶量受繁殖周期顺序影响（6.31 - 6.76千克；P = 0.042）。第九个繁殖周期第21天和35天的窝重最低。在两个分析的泌乳日，总固体（TS）、非脂固体和脂肪含量均受繁殖周期顺序影响。在两个泌乳日，分析期间兔奶中TS和脂肪含量均呈下降趋势。结果清楚地表明，处于广泛繁殖周期的母兔具有非常良好的繁殖性能，甚至在第八个繁殖周期之前都可成功用于繁殖。然而，如果饲养母兔超过这个周期是否盈利，还需要进一步研究。
