Variation in milk performance of Holstein dairy cows under the effects of season, parity and lactation stage in South China
-
摘要:目的
分析华南地区季节变化、繁育胎次、泌乳时期对泌乳性状的影响。
方法采集广州某规模化牛场2015年全年10 450头次的荷斯坦牛的奶牛群改良计划(DHI)测定数据,提取产奶量、乳脂率、蛋白率和脂蛋比等泌乳性状数据,运用统计模型评估季节、胎次、泌乳时期等因素对泌乳性状的影响,分析各性状之间的相关性。
结果季节、泌乳时期和胎次分别对产奶量和乳成分含量产生极显著的影响(P<0.001)。夏季产奶量极显著低于其他季节(P<0.01);在乳成分上,夏季的各项指标均为最低值,且极显著低于春冬季节(P<0.01),春季各项指标值极显著高于冬季(P<0.01);产奶量和乳蛋白率在12月(非气温最低的1月)达到最高值;不同胎次牛的产奶量上,1胎牛在第3个泌乳月份达到泌乳高峰,其他胎次牛则出现在第2个泌乳月且峰值高于1胎牛,但1胎牛产奶量下降速率明显低于其他胎次牛。1胎至2胎牛产奶总量逐渐升高,之后随着胎次的增加而下降;从乳成分的变化来看,各项指标在第1胎次时最高,随着胎次的增加逐步降低,到4和5胎时出现增加。在泌乳时期内,脂蛋比出现前期高后期低的变化规律,且乳脂率和乳蛋白率之间存在极显著的正相关性(r=0.63,P<0.01)。
结论华南地区泌乳牛不仅遭受长期的热应激影响,在冬季同样受到低温冷应激作用而制约其泌乳性能。高胎次(3胎以上)奶牛所占的群体比例较低导致全年泌乳胎次较低,同时当前的日粮营养和饲养水平已严重阻碍高胎次牛在泌乳后期的生产表现。
Abstract:ObjectiveTo identify the effects of season change, parity and lactation stage on milk performance traits of Holstein dairy cows in South China.
MethodDairy herd improvement (DHI) records of 10 450 Holstein cows were collected from a large dairy farm in Guangzhou throughout 2015. Information of milk performance traits including milk yield, milk fat percentage, milk protein percentage and fat-to-protein rate were extracted. The effects of season, parity and lactation stage on milk performance traits were evaluated. The correlations among factors and traits were analyzed.
ResultSeason, parity and lactation stage all had highly significant effects on both milk yield and milk nutrient contents (P<0.001). Summer milk yield was highly significant lower compared with the other seasons (P<0.01). All indexes of milk constituents reached the lowest in summer and were highly significantly lower than those in spring or winter (P<0.01), and the spring values were significantly higher than winter values(P<0.01). Milk yield and milk protein percentage were the highest in December, but not in January which was the coldest month of the year. Peak milk yields of first-parity cows reached during the third month of lactation, but those of the other parity cows reached during the second month of lactation with higher peak values compared to first-parity cows. However, the decreasing rate of milk yield was slower in first-parity cows than in the other parity cows. Milk yield increased gradually from first to second parity, and then decreased with rising parity. For milk constituents, all indexes reached the maximum at first-parity, decreased gradually with rising parity and then increased from fourth to fifth parity. During lactation, fat-to-protein rate was higher at an early stage and lower at a later stage, and there was highly significant positive correlation between milk fat and protein percentages(r=0.63, P<0.01).
ConclusionLactation cows of South China are subjected not only to heat stress in summer, but also to cold stress in winter, which restricts the milk performance traits. High parity (above third-parity) cows account for a low percentage of the studied population, resulting in a low value of annual milk parity. Low dietary nutrition and feeding level are strongly restricting the production performance at a later lactation stage for high parity cows.
-
Keywords:
- Holstein dairy cow /
- milk performance trait /
- season /
- parity /
- milk yield /
- milk composition
-
-
表 1 各因素与泌乳性状之间的方差分析(P值)
Table 1 Variance analysis between various factors and lactation performances (P values)
性状或因素 季节 胎次 泌乳时期 季节×胎次 季节×泌乳时期 胎次×泌乳时期 产奶量 <2×10–16 <2×10–16 <2×10–16 2×10–9 9×10–15 <2×10–16 乳脂率 <2×10–16 <2×10–16 <2×10–16 <2×10–16 7×10–3 <2×10–16 乳蛋白率 <2×10–16 <2×10-16 <2×10–16 6×10–13 <2×10–16 <2×10–16 脂蛋比 <2×10–16 3×10–11 <2×10–16 2×10–15 5×10–5 2×10–7 表 2 季节对产奶量和乳成分含量的影响1)
Table 2 Effects of season on milk yield and milk nutrient contents
季节 样本量/头 产奶量/kg 乳脂率/% 乳蛋白率/% 脂蛋比 春 2 867 23.23±7.23Bb 4.42±0.75Aa 3.39±0.45Bb 1.31±0.17Aa 夏 2 294 19.55±6.45Cc 4.17±0.80Cc 3.35±0.50Bc 1.25±0.18Cc 秋 2 463 23.51±8.15Bb 4.19±0.83Cc 3.36±0.53Bbc 1.25±0.22BCbc 冬 2 801 25.36±7.60Aa 4.34±0.75Bb 3.44±0.46Aa 1.27±0.18Bb 1) 同列数据后凡是具有一个相同小写或大写字母者,表示在 0.05 或 0.01 水平差异不显著 (Bonferroni 法) 表 3 胎次对产奶量和乳成分含量的影响1)
Table 3 Effects of parity on milk yield and milk nutrient contents
胎次 样本量(占比/%) 产奶量/kg 乳脂率/% 乳蛋白率/% 脂蛋比 1胎 5 467(52.55) 21.91±6.07Cc 4.41±0.80Aa 3.45±0.49Aa 1.28±0.17Aa 2胎 3 140(30.18) 24.88±8.58Aa 4.20±0.76Bb 3.37±0.49Bb 1.25±0.20Bb 3胎 811(7.80) 23.71±9.71Bb 4.10±0.72BCc 3.29±0.47Cc 1.26±0.20Bb 4胎 439(4.22) 23.81±9.43ABab 3.99±0.70Cc 3.25±0.42CDcd 1.24±0.21Bb 5胎 307(2.95) 22.05±9.71BCc 4.13±0.77BCbc 3.17±0.41Dd 1.31±0.23Aa 6胎及以上 239(2.30) 23.25±8.82BCbc 4.04±0.67BCc 3.18±0.38CDd 1.28±0.21ABab 1) 同列数据后凡是具有一个相同小写或大写字母者,表示在 0.05 或 0.01 水平差异不显著 (Bonferroni 法) 表 4 泌乳时期对产奶量和乳成分含量的影响1)
Table 4 Effects of lactation stage on milk yield and milk nutrient contents
泌乳时期 样本量(占比/%) 产奶量/kg 乳脂率/% 乳蛋白率/% 脂蛋比 早期 3 024(29.01) 27.69±7.37A 3.97±0.77C 3.09±0.44C 1.29±0.23A 中期 2 908(27.89) 25.15±6.50B 4.20±0.71B 3.32±0.40B 1.27±0.18B 晚期 4 493(43.10) 18.58±5.96C 4.57±0.74A 3.64±0.43A 1.26±0.16B 1) 同列数据后凡是具有一个相同大写字母者,表示在 0.01 水平差异不显著 (Bonferroni 法) 表 5 各泌乳性状之间的Pearson相关系数1)
Table 5 Pearson correlation coefficients among different milk performance traits
性状 产奶量 乳脂率 乳蛋白率 脂蛋比 产奶量 1.00 乳脂率 –0.34** 1.00 乳蛋白率 –0.53** 0.63** 1.00 脂蛋比 0.09** 0.64** –0.18** 1.00 1) “**”表示相关性达到 0.01 的显著水平 -
[1] PRENDIVILLE R, PIERCE K, BUCKLEY F. An evaluation of production efficiencies among lactating Holstein-Friesian, Jersey, and Jersey×Holstein-Friesian cows at pasture[J]. J Dairy Sci, 2009, 92(12): 6176-6185.
[2] KELSEY J A, CORL B A, COLLIER R J, et al. The effect of breed, parity, and stage of lactation on conjugated linoleic acid (CLA) in milk fat from dairy cows[J]. J Dairy Sci, 2003, 86(8): 2588-2597.
[3] VUJANAC I, KIROVSKI D, ŠAMANC H, et al. Milk production in high-yielding dairy cows under different environment temperatures[J]. Large Anim Rev, 2012, 18(1): 31-36.
[4] HOPKINS D, STEER C D, NORTHSTONE K, et al. Effects on childhood body habitus of feeding large volumes of cow or formula milk compared with breastfeeding in the latter part of infancy[J]. Am J Clin Nutr, 2015, 102(5): 1096-1103.
[5] QUIST M A, LEBLANC S J, HAND K J, et al. Milking-to-milking variability for milk yield, fat and protein percentage, and somatic cell count[J]. J Dairy Sci, 2008, 91(9): 3412-3423.
[6] HECK J M, VAN VALENBERG H J, DIJKSTRA J, et al. Seasonal variation in the Dutch bovine raw milk composition[J]. J Dairy Sci, 2009, 92(10): 4745-4755.
[7] 熊本海, 易渺, 杨琴, 等. 中国北方荷斯坦奶牛乳成分及相关指标的季节性与胎次变化规律研究[J]. 畜牧兽医学报, 2013(1): 31-37. [8] 魏琳琳, 杨继业, 秦雪, 等. 季节、胎次、泌乳时期与奶牛产奶量及乳成分的相关分析[J]. 中国奶牛, 2015(Z3): 10-14. [9] JOHNSTON J, HAMBLIN F, SCHRADER G. Factors concerned in the comparative heat tolerance of Jersey, Holstein and Red Sindhi-Holstein (F) cattle[J]. J Anim Sci, 1958, 17(2): 473-479.
[10] 汪翔. 娟姗牛的杂交应用研究进展[J]. 中国奶牛, 2016, 317(9): 12-19. [11] NGUYEN T T, BOWMAN P J, HAILE-MARIAM M, et al. Genomic selection for tolerance to heat stress in Australian dairy cattle[J]. J Dairy Sci, 2016, 99(4): 2849-2862.
[12] 常玲玲, 杨章平, 陈仁金, 等. 南方集约化饲养条件下荷斯坦奶牛乳脂率和乳蛋白率变化规律的初步研究[J]. 中国畜牧杂志, 2010(1): 43-47. [13] CURTIS A, SCHARF B, EICHEN P, et al. Relationships between ambient conditions, thermal status, and feed intake of cattle during summer heat stress with access to shade[J]. J Therm Biol, 2017, 63: 104-111.
[14] COX B, GASPARRINI A, CATRY B, et al. Mortality related to cold and heat. What do we learn from dairy cattle?[J]. Environ Res, 2016, 149: 231-238.
[15] 廉红霞, 周亚丽, 高腾云. 胎次对荷斯坦牛产奶量及乳脂率的影响[J]. 畜牧兽医杂志, 2013, 32(6): 26-28. [16] 王根林, 养牛学[M]. 2版. 北京: 中国农业出版社, 2006. [17] 肖西山, 付静涛, 雷莉辉, 等. 奶牛胎次与日产奶量和体细胞数量的关系分析[J]. 当代畜牧, 2014(6): 42-43. [18] 张瑞华, 张峥臻, 张克春. 上海地区规模奶牛场牛只淘汰原因与胎次、月份关系的研究[C]//第五届中国奶业大会论文集. 北京: 中国奶业协会, 2014. [19] PULINA G, NUDDA A, BATTACONE G, et al. Effects of nutrition on the contents of fat, protein, somatic cells, aromatic compounds, and undesirable substances in sheep milk[J]. Anim Feed Sci Tech, 2006, 131(3): 255-291.
[20] MACHADO S C, MCMANUS C M, STUMPF M T, et al. Concentrate∶forage ratio in the diet of dairy cows does not alter milk physical attributes[J]. Trop Anim Health Prod, 2014, 46(5): 855-859.
[21] GAO S, GUO J, QUAN S, et al. The effects of heat stress on protein metabolism in lactating Holstein cows[J]. J Dairy Sci, 2017, 100(6): 5040-5049.