Chinese Journal of Animal Nutrition >

2023 , Vol. 35 >Issue 12: 7892 - 7902

DOI: https://doi.org/10.12418/CJAN2023.716

RESEARCH PAPER

Effects of Dietary Phosphorus Levels on Lactation Performance, Phosphorus Digestion and Metabolism and Blood Indices of Lactating Buffaloes

  • SHAO Pengcheng , 1 ,
  • CUI Zheng’an 1, 2, * ,
  • WEI Guicong 1 ,
  • ZOU Caixia , 1, ** ,
  • $\boxed{\hbox{XIA Zhongsheng}}$ 1
Expand
  • 1 College of Animal Science and Technology, Guangxi University, Nanning 530005, China
  • 2 Chimelong Wild Animal World, Panyu District, Guangzhou City, Guangzhou 513430, China
** professor, E-mail:

* Contributed equally

Received date: 2023-06-22

  Online published: 2023-12-11

Fold

Abstract

This experiment was conducted to investigate the effects of dietary phosphorus levels on lactation performance, phosphorus digestion and metabolism and blood indices of lactating buffaloes. Thirty-two healthy buffaloes with good body condition, similar parity, about 3 months of lactation and roughly equal milk output were randomly divided into 4 groups according to body weight with 8 buffaloes in each group and 1 buffalo in each replicate. The buffaloes in the four groups were fed diets with phosphorus levels of 0.30%, 0.39%, 0.48% and 0.57%, respectively, and the other nutrient levels were consistent. The experiment lasted for 35 days, including 14 days of pre-trial period and 21 days of trial period. In the last 5 days of the trial period, 3 buffaloes in each group were randomly selected to perform digestion and metabolism tests by total feces and urine collection method. The results showed as follows: 1) dietary phosphorus levels had no significant effects on the average daily milk yield, 4% fat correction milk yield, milk protein rate, milk fat rate, milk non-fat milk solid rate, milk calcium content and milk phosphorus content of lactating buffaloes (P>0.05), and the 4% fat correction milk yield in 0.39% phosphorus level group was the highest. 2) Dietary phosphorus levels significantly affected the contents of intake phosphorus, fecal phosphorus, total phosphorus excretion and available phosphorus of lactating buffaloes (P<0.05), and the above indices were increased with the increase of dietary phosphorus level; dietary phosphorus levels significantly affected the neutral detergent fiber (NDF) apparent digestibility, phosphorus apparent digestibility, fecal phosphorus to phosphorus intake ratio and milk phosphorus to phosphorus intake ratio of lactating buffaloes (P<0.05), the NDF apparent digestibility in 0.48% phosphorus level group was significantly higher than that in the other 3 groups (P<0.05), the phosphorus apparent digestibility in 0.30% phosphorus level group was significantly lower than that in the other 3 groups (P<0.05), the fecal phosphorus to phosphorus intake ratio in 0.39% phosphorus level group was significantly higher than that in the other 3 groups (P<0.05), and the milk phosphorus to phosphorus intake ratio in 0.48% phosphorus level group was significantly lower than that in the other 3 groups (P<0.05). 3) Dietary phosphorus levels significantly affected the blood phosphorus content and serum alkaline phosphatase (ALP) activity of lactating buffaloes (P<0.05), in which the blood phosphorus content was increased with the increase of dietary phosphorus level, and the serum ALP activity was decreased with the increase of dietary phosphorus level. In conclusion, combining lactation performance, phosphorus digestion and metabolism, and blood indices, and considering phosphorus excretion and environmental pollution, the feeding effects on lactating buffaloes in 0.39% phosphorus level group is better, and it is recommended that the dietary phosphorus level for lactating buffaloes should be 0.39%.

Key words： dietary phosphorus levels; lactating buffaloes; lactation performance; phosphorus digestion and metabolism; blood indices

Cite this article

SHAO Pengcheng , CUI Zheng’an , WEI Guicong , ZOU Caixia , $\boxed{\hbox{XIA Zhongsheng}}$ . Effects of Dietary Phosphorus Levels on Lactation Performance, Phosphorus Digestion and Metabolism and Blood Indices of Lactating Buffaloes[J]. Chinese Journal of Animal Nutrition, 2023 , 35(12) : 7892 -7902 . DOI: 10.12418/CJAN2023.716

水牛是产奶和产肉的重要家畜品种之一。水牛奶营养丰富,富含蛋白质和脂肪,是我国广西等南方地区鲜奶的主要来源之一[1]。磷是动物营养重要的矿物质元素之一,在动物的骨骼生长、能量代谢及遗传信息传递等生命活动中具有重要作用[2]。饲粮中磷添加量不足会造成动物机体磷代谢障碍而引发疾病,而饲粮磷添加量过高则会引起尿磷和粪磷排泄量增加而造成环境污染[3]。研究泌乳水牛饲粮磷的添加量对发挥其生产潜力及减少磷的排泄量具有重要意义。刘振等[4]通过对我国华东地区4个规模牛场进行调查,结果表明奶牛饲粮总磷含量为0.44%~0.56%,均高于NRC(2001)推荐值。Souza等[5]研究表明,水牛饲喂磷含量为8、12、15和18 g/(头·d)的饲粮,随着饲粮磷水平的提高粪便磷排泄量增加,磷利用率降低。Feng等[6]研究发现,当饲粮中磷需求量为总需要量的50%时,增加无机磷瘤胃灌注量,不会对奶牛的产奶量和乳磷含量产生显著影响,但增加了粪磷排泄量。同样,Wächter等[7]研究表明,在奶牛妊娠后期饲喂低磷饲粮对奶牛的产奶量和干物质采食量没有显著影响。但Knowlton等[8]研究发现,给泌乳早期的奶牛饲喂磷水平为0.34%的饲粮时,磷的供给不能满足其产奶的需要,必须调动体内骨磷才能满足需求;当饲喂磷水平为0.51%和0.67%的饲粮时,能减少体内骨磷的调动。由此可见,国内外关于奶牛磷需要的研究结果不一。饲粮磷水平过高不仅会影响泌乳水牛的健康、生产水平和经济效益,而且还会造成磷排泄量增加而污染环境,但泌乳水牛饲粮添加量研究较少,还没有明确的添加量,因此亟需确定泌乳水牛饲粮磷的添加量以解决实际运用的难题。因此,本试验旨在研究饲粮磷水平对泌乳水牛泌乳性能、磷消化代谢和血液指标的影响,确定泌乳水牛饲粮磷的适宜添加量,以期为提高饲粮磷的利用率、减少磷排泄和制定水牛饲养标准提供基础数据。

1 材料与方法

1.1 试验设计

试验选择体况良好、胎次相似、泌乳3个月左右以及泌乳量大致相等的32头健康水牛,其中摩拉水牛11头、尼里水牛11头和三品杂水牛10头,根据体重随机分成4组,每组8头牛,每头牛为1个重复。4组水牛分别饲喂磷水平为0.30%、0.39%、0.48%和0.57%的饲粮,饲粮其他营养水平保持一致。试验饲粮参考本课题组邹彩霞等[9]之前的研究数据配制,饲粮组成及营养水平见表1,精料补充料组成及营养水平见表2。试验期35 d,包括14 d的预试期和21 d的正试期。
表1 饲粮组成及营养水平(风干基础)

Table 1 Composition and nutrient levels of diets (air-dry basis)

项目
Items		 饲粮磷水平Dietary P levels/%
0.30 0.39 0.48 0.57
原料Ingredients/%
精料补充料Concentrate supplement 32.60 32.60 32.60 32.60
木薯渣Cassava residue 32.40 32.40 32.40 32.40
麦芽渣Malt residue 16.50 16.50 16.50 16.50
象草Elephant grass 18.50 18.50 18.50 18.50
合计Total 100.00 100.00 100.00 100.00
营养水平Nutrient levels
泌乳净能NEL/(MJ/kg) 12.32 12.32 12.32 12.32
粗蛋白质CP/% 14.90 14.90 14.90 14.90
中性洗涤纤维NDF/% 28.70 28.70 28.70 28.70
酸性洗涤纤维ADF/% 16.20 16.20 16.20 16.20
磷P/(g/kg) 0.30 0.39 0.48 0.57
钙Ca/(g/kg) 0.78 0.78 0.78 0.78
钙磷比Ca to P ratio 2.60 2.00 1.63 1.37

泌乳净能依据中国饲料数据库计算得出,计算公式为泌乳净能(MJ/kg)=0.102 5×总可消化养分(%)-0.502;其余营养水平均为实测值。表2同。

NEL was calculated according to China Feed Database and the calculation formula was NEL(MJ/kg)=0.102 5×TDN(%)-0.502, while the other nutrient levels were measured values. The same as Table 2.

表2 精料补充料组成及营养水平(风干基础)

Table 2 Composition and nutrient levels of the concentrate supplement (air-dry basis) %

项目
Items		 饲粮磷水平Dietary P levels/%
0.30 0.39 0.48 0.57
原料Ingredients
玉米Corn 60.00 60.00 60.00 60.00
豆粕Soybean meal 16.50 16.50 16.50 16.50
棉籽粕Cottonseed meal 15.00 15.00 15.00 15.00
磷酸氢二钠Na2HPO4 0.80 1.60 2.50
预混料Premix 1.00 1.00 1.00 1.00
氯化钠NaCl 1.00 1.00 1.00 1.00
麦饭石Medical stone 2.50 1.70 0.90 0.00
石粉Limestone 4.00 4.00 4.00 4.00
合计Total 100.00 100.00 100.00 100.00
营养水平Nutrient levels
泌乳净能NEL/(MJ/kg) 27.33 27.33 27.33 27.33
粗蛋白质CP/(g/kg) 17.20 17.20 17.20 17.20
中性洗涤纤维NDF 15.60 15.60 15.60 15.60
酸性洗涤纤维ADF 6.80 6.80 6.80 6.80
钙Ca/(g/kg) 1.51 1.51 1.51 1.51
磷P/(g/kg) 0.49 0.72 0.96 1.21

每千克预混料含有 One kilogram of the premix contained the following:VA 500 000 IU,VD 150 000 IU,VE 3 000 IU,Fe 4 g,Cu 13 g,Mn 3 g,Zn 6 g,I 80 mg,Se 50 mg,Co 80 mg。

1.2 饲养管理

饲养试验在广西水牛研究所附属牛场进行,采用全混合日粮模式饲喂,水牛自由采食和饮水。试验前对栏舍进行打扫和严格消毒,并进行药物驱虫处理。试验水牛采用单栏饲养,每天07:00和14:00各饲喂1次,并在喂食后人工挤奶,每天共挤奶2次,记录产奶量。随后进入14 d预试期。在预试期间,熟悉试验水牛饲养管理流程,观察水牛的健康状况,记录各组试验水牛的采食量,根据前1天的采食量调整第2天的饲喂量,确保饲槽内有10%左右的剩料。预试期结束后进入正试期,正试期饲养管理流程同预试期。

1.3 样品采集及处理

1.3.1 奶样采集

于正试期的第10天和消化代谢期间每天08:00和14:00,分2次一共采集600 mL乳样,分装成2份马上送回实验室,一份立刻进行乳成分分析,另一份放在-20 ℃冰箱中保存待测。

1.3.2 血样采集

于正试期的第20天10:00用灭菌6号针头从泌乳水牛颈静脉抽取10 mL新鲜血液,分装成2瓶,一瓶装入肝素钠抗凝管中,1 122.5×g离心10 min,取血清于-20 ℃冰箱中冷冻保存待测;另一瓶马上送到广西壮族自治区民族医院检验科进行血液生化检验。

1.3.3 消化代谢试验

在正试期的最后5 d,每组随机选取3头水牛,采用全粪尿收集法进行消化代谢试验,每天记录每头牛的排粪量和排尿量。将每天收集的鲜粪样混匀称重后按总质量的10%取样,加入10%稀盐酸固氮;将每天收集的尿样经8层纱布过滤称重后按体积的10%取样,加入10%稀盐酸使pH低于3.0固氮。每天采集各组200 g混合精料、200 g粗饲料和剩料样本。全部样品均于-20 ℃冰箱中保存备用。

1.4 测定指标及方法

1.4.1 饲粮、粪和尿中常规养分含量

饲粮、粪样测定初水分后经65 ℃烘干48 h,回潮2 h,利用粉碎机粉碎过40目筛后用于养分含量测定,尿样经湿法消解后用于养分含量测定。饲粮及粪样中干物质(DM)、粗蛋白质(CP)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、钙和磷含量分别参照GB/T 6435—2014、GB/T 6432—2018、GB/T 6434—2006、NY/T 1459—2007、GB/T 6436—2018和GB/T 6437—2018方法测定。

1.4.2 产奶量和乳成分测定

正试期内每天记录早、晚产奶量,计算日均产奶量。乳脂率、乳蛋白率和乳非脂固形物率采用乳成分分析仪(HZDY-UL80BC)测定,乳钙含量按照GB/T 5009.92—2003方法测定,乳磷含量按照GB/T 5009.87—2003方法测定。

1.4.3 血液矿物质元素含量、血清生化指标和相关酶活性测定

血液钙、铜、铁、锌和镁含量采用原子吸收光谱仪(北京博晖创新光电技术股份有限公司)测定,血清碱性磷酸酶(ALP)活性和血液磷含量采用日立全自动生化分析仪测定,血清骨钙素(OC)、降钙素(CT)、醛固酮(ALD)、甲状旁腺激素(PTH)、1,25-二羟基维生素D3[1,25-(OH)2D3]含量采用放射免疫法测定,试剂盒购买于天津协和生科技发展有限公司。

1.5 数据统计分析

试验数据采用Excel 2013软件进行初步整理后,采用SPSS 22.0软件进行单因素方差分析,效应显著者采用Duncan氏法进行多重比较,P<0.05表示差异显著,结果以“平均值±标准误”表示。

2 结果与分析

2.1 饲粮磷水平对泌乳水牛产奶量和乳成分的影响

由表3可知,饲粮磷水平对泌乳水牛日均产奶量、4%标准乳产量、乳蛋白率、乳脂率、乳非脂固形物率、乳钙含量和乳磷含量均无显著影响(P>0.05);其中0.39%磷水平组的4%标准乳产量最高,且随着饲粮磷水平的升高4%标准乳产量呈先升高后下降的趋势。
表3 饲粮磷水平对泌乳水牛产奶量和乳成分的影响

Table 3 Effects of dietary P levels on milk yield and milk composition of lactating buffaloes

项目
Items		 饲粮磷水平Dietary P levels/% P值
P-value
0.30 0.39 0.48 0.57
日均产奶量
Average daily milk yield/(kg/d)		 7.77±2.34 7.74±2.21 8.59±2.21 8.13±1.73 0.063
4%标准乳产量4% FCM yield/(kg/d) 12.29±3.01 13.53±1.21 13.16±2.30 12.63±2.18 0.073
乳蛋白率Milk protein rate/% 4.41±0.50 4.72±0.43 4.09±0.24 4.16±0.13 0.052
乳脂率Milk fat rate/% 7.98±1.45 9.01±2.16 7.66±1.86 7.68±2.01 0.065
乳非脂固形物率Milk not-fat solid rate/% 10.12±0.67 10.64±0.24 10.07±0.34 10.19±1.34 0.054
乳钙Milk Ca/(g/kg) 2.16±0.20 2.25±0.18 2.22±0.10 2.03±0.21 0.051
乳磷Milk P/(g/kg) 1.15±0.68 1.21±0.25 1.22±0.30 1.26±0.21 0.052

同行数据肩标相同字母或无字母表示差异不显著(P>0.05),不同字母表示差异显著(P<0.05)。下表同。

In the same row, values with the same letter or no letter superscripts mean no significant difference (P>0.05), while with different letter superscripts mean significant difference (P<0.05). The same as below.

根据公式4%标准乳产量(kg/d)=产奶量(kg/d)×{[乳脂含量(g/d)-40]+[乳蛋白质含量(g/d)-31]}×0.011 55+1.0[10]计算出4%标准乳产量,以试验期间食入磷含量为横坐标(x),4%标准乳产量为纵坐标(y),获得最佳拟合方程为一元二次方程,即y=-0.004 6x2+0.445x+2.702 7,由图1可知,当食入磷含量为48.315 g/d时,得到4%标准乳产量最大值为13.540 kg/d。
图1 泌乳水牛食入磷含量与4%标准乳产量的关系

Fig.1 Relationship between P intake content and 4% FCM yield of lactating buffaloes

2.2 饲粮磷水平对泌乳水牛磷消化代谢的影响

由表4可知,饲粮磷水平显著影响泌乳水牛食入磷和粪磷含量(P<0.05),其中各组间食入磷含量差异极显著(P<0.05),0.57%磷水平组粪磷含量显著高于其他组(P<0.05),且其他各组间粪磷含量差异不显著(P>0.05);饲粮磷水平显著影响泌乳水牛总排泄磷含量(P<0.05),其中0.57%磷水平组总排泄磷含量显著高于其他3组(P<0.05),且其他3组间总排泄磷含量差异不显著(P>0.05);可利用磷是指食入磷减去总排泄磷,饲粮磷水平显著影响泌乳水牛可利用磷含量(P<0.05),其中0.48%和0.57%磷水平组可利用磷含量显著高于0.30%和0.39%磷水平组(P<0.05);乳磷含量随饲粮磷水平的提高呈现先上升后下降的趋势,但差异不显著(P>0.05)。
表4 饲粮磷水平对泌乳水牛磷消化代谢的影响

Table 4 Effects of dietary P levels on P digestion and metabolism of lactating buffaloes g/d

项目
Items		 饲粮磷水平Dietary P levels/% P值
P-value
0.30 0.39 0.48 0.57
食入磷P intake 32.57±0.19d 42.34±0.07c 52.11±0.12b 61.88±0.13a 0.006
粪磷Fecal P 30.03±0.81b 32.73±2.54b 32.21±2.75b 42.87±0.22a 0.009
尿磷Urine P 1.16±0.44 1.19±0.12 1.55±0.24 1.62±0.07 0.051
乳磷Milk P 9.33±1.60 11.18±2.52 11.95±1.80 11.32±0.07 0.054
总排泄磷Total P excretion 31.20±0.40b 33.93±2.51b 33.77±2.93b 44.50±0.14a 0.008
可利用磷Available P 1.37±0.40c 8.41±2.51b 18.34±2.93a 17.37±0.14a 0.009

2.3 饲粮磷水平对泌乳水牛营养物质表观消化率的影响

由表5可知,随着饲粮磷水平的提高,泌乳水牛对CP的表观消化率呈先升高后降低的趋势,但差异不显著(P>0.05);饲粮磷水平显著影响泌乳水牛NDF表观消化率(P<0.05),其中0.48%磷水平组NDF表观消化率显著高于其他3组(P<0.05),且其他3组间NDF表观消化率差异不显著(P>0.05);随着饲粮磷水平的提高,泌乳水牛对ADF和钙的表观消化率呈先升高后降低的趋势,但差异不显著(P>0.05);饲粮磷水平对泌乳水牛磷表观消化率有显著影响(P<0.05),其中0.48%和0.57%磷水平组磷表观消化率显著低于其他2组(P<0.05),0.39%磷水平组磷表观消化率显著高于0.30%磷水平组(P<0.05),而0.48%和0.57%磷水平组间差异不显著(P>0.05)。
表5 饲粮磷水平对泌乳水牛营养物质表观消化率的影响

Table 5 Effects of dietary P levels on nutrient apparent digestibility of lactating buffaloes %

项目
Items		 饲粮磷水平Dietary P levels/% P值
P-value
0.30 0.39 0.48 0.57
粗蛋白质CP 68.98±2.94 71.24±2.67 73.40±1.02 70.23±0.84 0.072
中性洗涤纤维NDF 52.69±0.82b 53.18±0.90b 55.31±0.75a 53.28±1.17b 0.046
酸性洗涤纤维ADF 33.53±2.22 33.48±2.07 34.18±1.94 33.15±2.75 0.068
钙Ca 37.41±3.37 43.81±8.26 45.69±6.15 40.63±3.70 0.071
磷P 7.77±2.50c 22.68±5.99b 38.18±5.27a 30.78±0.35a 0.008

2.4 饲粮磷水平对泌乳水牛磷利用的影响

由表6可知,饲粮磷水平显著影响泌乳水牛粪磷占食入磷比例(P<0.05),其中0.39%组粪磷占食入磷比例显著高于其他各组(P<0.05),0.48%和0.57%磷水平组粪磷占食入磷比例显著高于0.30%磷水平组(P<0.05),但0.48%和0.57%磷水平组间差异不显著(P>0.05);饲粮磷水平显著影响泌乳水牛乳磷占食入磷比例(P<0.05),其中0.30%、0.39%和0.48%磷水平组乳磷占食入磷比例显著高于0.57%磷水平组(P<0.05),且0.30%、0.39%和0.48%磷水平组间差异不显著(P>0.05);饲粮磷水平对泌乳水牛粪磷占总排泄磷比例、尿磷占食入磷比例、尿磷占总排泄磷比例以及乳磷占总排泄磷比例均无显著影响(P>0.05)。
表6 饲粮磷水平对泌乳水牛磷利用的影响

Table 6 Effects of dietary P levels on P utilization of lactating buffaloes %

项目
Items		 饲粮磷水平Dietary P levels/% P值
P-value
0.30 0.39 0.48 0.57
粪磷占食入磷比例
Fecal P to P intake ratio		 92.23±2.50c 77.32±6.00a 61.82±5.27b 69.29±0.04b 0.008
粪磷占总排泄磷比例
Fecal P to total P excretion ratio		 96.28±1.45 96.48±0.50 95.42±0.50 96.34±0.82 0.058
尿磷占食入磷比例
Urine P to P intake ratio		 3.56±0.13 2.80±0.29 2.98±0.47 2.63±0.12 0.058
尿磷占总排泄磷比例
Urine P to total P excretion ratio		 3.72±1.45 3.52±0.50 4.58±0.50 3.66±0.18 0.059
乳磷占食入磷比例
Milk P to P intake ratio		 28.63±4.92a 26.40±5.96a 22.94±3.45a 18.31±1.12b 0.034
乳磷占总排泄磷比例
Milk P to total P excretion ratio		 22.23±3.30 24.78±5.57 26.22±4.50 20.29±4.08 0.062

2.5 饲粮磷水平对泌乳水牛血液矿物质元素含量、血清生化指标和相关酶活性的影响

由表7可知,饲粮磷水平显著影响泌乳水牛血液磷含量(P<0.05),血液磷含量随饲粮磷水平的升高呈上升趋势,其中0.48%和0.57%磷水平组血液磷含量显著高于0.30%和0.39%磷水平组(P<0.05);饲粮磷水平对泌乳水牛血液钙、镁、铜、铁和锌含量均无显著影响(P>0.05);饲粮磷水平对水牛血清ALP活性影响显著(P<0.05),其中0.30%和0.39%磷水平组血清ALP活性显著高于0.48%和0.57%磷水平组(P<0.05),且0.48%磷水平组显著高于0.57%磷水平组(P<0.05);饲粮磷水平对泌乳水牛血清OC、CT、PTH、ALD和1,25-(OH)2D3含量均无显著影响(P>0.05)。
表7 饲粮磷水平对泌乳水牛血液矿物质元素含量、血清生化指标和相关酶活性的影响

Table 7 Effects of dietary P levels on blood mineral element contents, serum biochemical indices and related enzyme activities of lactating buffaloes

项目
Items		 饲粮磷水平Dietary P levels/% P值
P-value
0.30 0.39 0.48 0.57
血清Serum
碱性磷酸酶ALP/(U/L) 115.25±5.49a 112.00±23.87a 104.88±13.95b 91.86±6.26c 0.038
骨钙素OC/(ng/mL) 0.78±0.62 0.79±0.71 0.84±0.60 1.00±0.56 0.052
降钙素CT/(pg/mL) 320.84±70.48 345.79±20.63 363.10±58.45 405.58±93.24 0.073
甲状旁腺激素PTH/(ng/dL) 64.72±8.00 65.31±5.48 70.74±3.60 60.53±11.59 0.063
醛固酮ALD/(pg/mL) 12.15±1.71 12.95±1.10 15.04±1.84 14.23±1.28 0.056
1,25-二羟基维生素D3
1,25-(OH)2D3/(nmol/L)		 18.51±3.73 24.61±5.97 25.25±3.99 21.58±3.73 0.053
血液Blood
磷P/(mmol/L) 2.08±0.15b 2.15±0.15b 2.26±0.15a 2.37±0.23a 0.009
钙Ca/(mmol/L) 1.71±0.45 1.69±0.18 1.83±0.18 1.95±0.49 0.058
镁Mg/(mmol/L) 1.08±0.16 1.10±0.19 1.11±0.17 1.06±0.15 0.056
铜Cu/(nmol/L) 14.75±1.82 14.87±2.51 15.11±3.52 14.63±2.58 0.052
铁Fe/(nmol/L) 8.36±1.13 8.80±1.04 8.58±0.58 8.43±0.84 0.051
锌Zn/(nmol/L) 61.04±20.59 51.67±5.51 50.95±10.65 58.57±15.29 0.059

3 讨论

3.1 饲粮磷水平对泌乳水牛产奶量和乳成分的影响

乳成分是衡量水牛奶质量的重要指标,影响水牛乳成分的因素有很多,如品种、胎次、饲养管理水平、营养水平、地域和季节等[11]。本试验饲喂磷水平为0.30%、0.39%、0.48%和0.57%的试验饲粮对泌乳水牛日均产奶量、4%标准乳产量、乳蛋白率、乳脂率、乳非脂乳固形物率、乳钙含量和乳磷含量均无显著影响,其中0.39%磷水平组4%标准乳产量最高,饲喂效果最好。Ferris等[12]通过4年试验发现,在奶牛的4个泌乳期饲喂磷水平为0.49%和0.36%(干物质基础)的饲粮,不同组之间的产奶量和乳成分无显著差异。Guo等[13]报道了饲喂磷水平为0.44%、0.39%和0.34%的试验饲粮,随着饲粮磷水平的降低,奶牛产奶量和乳成分没有显著变化。Begum等[14]研究发现,饲喂NRC推荐饲粮磷水平80%、100%和120%的试验饲粮对尼利拉维水牛的乳成分没有显著影响。以上研究结果与本试验结果一致,但本试验饲粮磷水平范围更广。多数研究表明,牛奶的乳蛋白率和乳脂率不受饲粮磷水平影响[15⇓-17]。Wang等[18]研究发现,饲喂磷水平为0.37%饲粮组的奶牛乳脂含量略高于饲喂磷水平为0.47%饲粮组的奶牛。本试验结果显示,0.30%和0.39%磷水平组泌乳水牛乳脂率要比0.48%和0.57%磷水平组要高但差异不显著,这与Wang等[18]的研究结果相似。本试验中,0.39%磷水平组乳蛋白率为4.72%,高于其他3个组,但差异不显著。Lopez等[19]研究发现,饲粮磷水平为0.37%的奶牛乳蛋白率平均值为2.90%,而饲粮磷水平为0.57%的奶牛乳蛋白率平均值为2.91%,2组奶牛乳蛋白率差异不显著,这与本试验结果一致。目前,饲粮磷水平对牛奶乳成分的影响没有统一的结论,本试验结果表明,饲粮磷水平为0.39%时,4%标准乳产量最高,泌乳性能较好。

3.2 饲粮磷水平对泌乳水牛磷消化代谢的影响

尽管磷摄入量是决定磷消化、吸收、唾液循环和粪便排泄的主要因素[20],但其他饮食因素也会影响磷的利用和排泄。例如,植酸盐和植酸酶已被证明会影响奶牛的总磷消化率和磷排泄[21-22]。其中,粪磷排泄主要由饲粮磷摄入量决定,并与饲粮磷摄入量呈线性关系[21,23]。Senaratne等[24]通过多元回归分析法研究了饲粮磷水平与奶牛粪磷排泄量的关系,结果表明饲粮磷水平与奶牛粪磷排泄量呈正相关。本试验中,饲粮磷水平显著影响泌乳水牛粪磷和总排泄磷含量,且随着饲粮磷水平的升高粪磷和总排泄磷含量也随之升高,本试验结果与上述结果一致。合适的钙磷比能提高奶牛的泌乳性能、养分表观消化率和钙磷代谢平衡。王浩等[25]研究表明,陕北白绒山羊断奶羔羊适宜钙磷比为1.78。赵巧丽等[26]研究发现,14月龄的奶牛适宜钙磷比为2.10。本试验4组饲粮钙磷比分别为2.60、2.00、1.63和1.37,结合泌乳性能结果本试验的适宜钙磷比为2.00。在奶牛中,磷以磷酸钙的形式分泌到牛奶中,主要通过与酪蛋白(20%)或脂肪部分(10%)结合,其中较大部分以胶体无机磷酸钙(40%)和可溶性无机正磷酸盐(30%)的形式分泌[27]。磷利用效率与牛奶磷含量呈正相关,随着产奶量的增加,更多的磷被输送到牛奶中,这反过来可能导致消化道对磷的吸收增加,从而按比例减少粪便中磷的排泄[28]。本试验结果显示,0.39%磷水平组乳磷占食入磷比例最高,0.30%组磷水平组乳磷含量最低。瘤胃磷是微生物生长的一个限制因素,因为低磷与纤维素消化率降低有关[20]。Durand等[29]研究发现,当瘤胃中磷含量减少时,纤维素菌分解活性迅速下降,从而降低饲粮纤维消化率。陈月丽[30]研究发现,随着饲粮磷水平的升高对水牛NDF表观消化率显著影响。本试验结果显示,饲粮NDF表观消化率随饲粮磷水平的升高呈先上升后下降的趋势,其中0.30%磷水平组最低,这与陈月丽[30]的结果一致。目前,关于饲粮磷水平对牛磷表观消化率影响的报道多是降低饲粮磷水平会提高磷表观消化率。例如,Ekelund等[31]研究发现,在泌乳期前4个月,饲喂2种磷水平饲粮的多胎奶牛中0.32%磷水平组磷表观消化率高于0.43%磷水平组。Shore等[32]研究发现,饲粮磷水平为0.36%组奶牛磷表观消化率低于饲粮磷水平为0.24%组。本试验中,饲粮磷水平对泌乳水牛磷表观消化率有显著影响,其中0.48%磷水平组磷表观消化率显著高于0.30%磷水平组。本试验与上述研究结果不同,本试验中随着饲粮磷水平的升高,泌乳水牛磷表观消化率呈先上升后下降的趋势,当饲粮磷水平为0.48%时泌乳水牛磷表观消化率最高,0.30%磷水平组磷表观消化率和可利用磷最低。可能原因是0.30%~0.48%磷水平组饲粮磷水平还不能满足泌乳水牛的需要量,而0.57%磷水平组磷水平则处于过量状态,抑制了纤维分解菌的活性,导致消化率降低。

3.3 饲粮磷水平对泌乳水牛血液矿物质元素含量、血清生化指标和相关酶活性的影响

血液指标能反映机体代谢水平,而血液磷和钙含量是衡量机体钙磷代谢的重要指标。水牛泌乳期磷需求量大,饲粮中的磷不足会导致低磷血症等疾病。有研究显示,短期的低磷饲粮不影响奶牛机体磷平衡,而长期饲喂低磷饲粮会使奶牛血液中磷含量低于正常值,引起机体磷代谢失调[18]。饲粮磷水平低会影响血液中钙离子浓度导致钙离子浓度升高,钙离子浓度升高会刺激甲状旁腺导致PTH分泌量减少,进而降低肾脏中磷的排泄;此外,还会导致血液中1,25-(OH)2D3含量升高,促进肾脏对于磷的重吸收和肠道对食糜中磷的吸收[33]。反刍动物体内钙磷代谢调节和控制主要由PTH、CT和1,25-(OH)2D3等激素协调完成[34]。一般认为,血液磷含量反映奶牛磷的摄入量,奶牛血液正常磷含量为1.3~2.6 mmol/L。本试验中,饲粮磷水平对泌乳水牛血液磷含量有显著影响,但4个组血液磷含量都在正常范围内。Ferris等[35]通过4年的奶牛试验发现,饲喂低磷水平饲粮的奶牛在前4个哺乳期相对于饲喂高磷水平饲粮的奶牛血液磷含量显著降低,这与本试验结果一致。ALP是动物体内与矿物质代谢有重要关系的一种化学物质,当血液磷含量下降时,ALP加快骨骼磷动员使骨磷脱离骨骼进入血液,从而增加血液磷含量并伴随着破骨细胞数量上升,以迅速分解部分骨质,进而也促使成骨细胞活性增强以重新建立骨质。欧阳依娜等[36]研究发现,高磷水平组云南半细毛羊血清ALP活性显著高于低磷水平组。胡凤明等[37]则研究发现,随着饲粮钙和磷水平的提高,察哈尔羔羊血清ALP活性有降低的趋势。在本试验中,饲粮磷水平显著影响泌乳水牛血清ALP活性,且血清ALP活性随泌乳水牛食入磷的增加呈现下降趋势,这是由于水牛在食入磷不足的情况下为了维持正常的血液磷含量提高了血液ALP活性。本试验中,饲粮磷水平对泌乳水牛血液常量矿物质元素钙、镁和微量矿物质元素铜、铁、锌的含量影响均不显著,孙伟丽[38]研究结果与本研究结果相似。本试验中,饲粮磷水平对泌乳水牛血清OC、CT、PTH、ALD和1,25-(OH)2D3含量影响均不显著,陈月丽[30]和Guo等[13]研究结果与本试验结果一致。

4 结论

在本试验条件下,综合泌乳性能、磷消化代谢和血液指标并考虑磷排泄和环境污染的情况下,以0.39%磷水平组泌乳水牛饲喂效果较好,建议泌乳水牛饲粮磷水平以0.39%为宜。

References

Publishing order | Descend order by publishing year | Descend order by cited within
[1]
邹彩霞, 杨炳壮, 韦升菊, 等. 水牛乳能值与乳成分的相关性研究[J]. 动物营养学报, 2010, 22(4):964-968.

ZOU C X, YANG B Z, WEI S J, et al. A study on correlation of milk energy and composition of water buffalo[J]. Chinese Journal of Animal Nutrition, 2010, 22(4):964-968. (in Chinese)

[2]
郭勇庆, 屠焰, 张乃锋, 等. 中国饲料磷推荐水平及磷酸盐应用现状和优化分析[J]. 中国农业科学, 2018, 51(3):581-592.

DOI

GUO Y Q, TU Y, ZHANG N F, et al. Current situation and optimization strategy of phosphorus recommendation level and phosphate application of feed in China[J]. Scientia Agricultura Sinica, 2018, 51(3):581-592. (in Chinese)

DOI

[3]
王慧敏. 育成及泌乳期崂山奶山羊饲粮中适宜磷水平的研究[D]. 硕士学位论文. 青岛: 青岛农业大学, 2018:23-34.

WANG H M. Study of dietary phosphorus level on performance of growing and lactation period Laoshan dairy goat[D]. Master’s Thesis. Qingdao: Qingdao Agricultural University, 2018:23-34. (in Chinese)

[4]
刘振. 日粮磷水平对奶牛生产性能及磷排放的影响[D]. 硕士学位论文. 杭州: 浙江大学, 2011:25-35.

LIU Z. Effect of dietary phosphorus amount on milk production and phosphorus excretion of dairy cows in china[D]. Master’s Thesis. Hangzhou: Zhejiang University, 2011:25-35. (in Chinese)

[5]
DE SOUZA N H, FRANZOLIN R, SOARES W V B. Metabolismo mineral em bubalinos com ingestões de diferentes níveis de fósforo[J]. Revista Brasileira de Zootecnia, 2009, 38(6):1149-1154.

DOI

[6]
FENG X, RAY P P, JARRETT J P, et al. Short communication:effect of abomasal inorganic phosphorus infusion on phosphorus absorption in large intestine,milk production,and phosphorus excretion of dairy cattle[J]. Journal of Dairy Science, 2018, 101(8):7208-7211.

DOI

[7]
WÄCHTER S, COHRS I, GOLBECK L, et al. Effects of restricted dietary phosphorus supply during the dry period on productivity and metabolism in dairy cows[J]. Journal of Dairy Science, 2022, 105(5):4370-4392.

DOI PMID

[8]
KNOWLTON K F, HERBEIN J H. Phosphorus partitioning during early lactation in dairy cows fed diets varying in phosphorus content[J]. Journal of Dairy Science, 2002, 85(5):1227-1236.

PMID

[9]
邹彩霞, 杨炳壮, 韦升菊, 等. 泌乳前期水牛能量代谢及其需要量初探[J]. 动物营养学报, 2011, 23(6):950-955.

ZOU C X, YANG B Z, WEI S J, et al. A preliminary study on energy metabolism and requirement of water buffalo in early lactation[J]. Chinese Journal of Animal Nutrition, 2011, 23(6):950-955.

[10]
BORGHESE A. Buffalo production and research[M]. Rome: Food and Agriculture Organization of the United Nations, 2005.

[11]
李玲, 杨攀, 唐艳, 等. 不同品种奶水牛全泌乳期产奶量及乳成分的分析[J]. 饲料研究, 2019, 42(10):8-11.

LI L, YANG P, TANG Y, et al. Study on milk yield and milk composition of different buffalo breeds during the whole lactation period[J]. Feed Research, 2019, 42(10):8-11. (in Chinese)

[12]
FERRIS C P, MCCOY M A, PATTERSON D C, et al. Effect of offering dairy cows diets differing in phosphorus concentration over four successive lactations:2.Health,fertility,bone phosphorus reserves and nutrient utilisation[J]. Animal, 2010, 4(4):560-571.

DOI

[13]
GUO Y Q, TONG B X, WU Z G, et al. Dietary manipulation to reduce nitrogen and phosphorus excretion by dairy cows[J]. Livestock Science, 2019, 228:61-66.

DOI

[14]
BEGUM I, AZIM A, AKHTER S, et al. Mineral dynamics of blood and milk in dairy buffaloes fed on calcium and phosphorus supplementation[J]. Pakistan Veterinary Journal, 2010, 30(2):105-109.

[15]
WU Z, TALLAM S K, ISHLER V A, et al. Utilization of phosphorus in lactating cows fed varying amounts of phosphorus and forage[J]. Journal of Dairy Science, 2003, 86(10):3300-3308.

PMID

[16]
红敏, 高民, 赵瑞霞, 等. 不同磷水平日粮对奶牛生产性能和磷排放量的影响[J]. 中国奶牛, 2020(11):17-21.

HONG M, GAO M, ZHAO R X, et al. Effect of different phosphorus levels on milk production and phosphorus excretion of cows[J]. China Dairy Cattle, 2020(11):17-21. (in Chinese)

[17]
KEANTHAO P, GOSELINK R M A, DIJKSTRA J, et al. Effects of dietary phosphorus concentration during the transition period on plasma calcium concentrations,feed intake,and milk production in dairy cows[J]. Journal of Dairy Science, 2021, 104(11):11646-11659.

DOI

[18]
WANG C, LIU Z, WANG D M, et al. Effect of dietary phosphorus content on milk production and phosphorus excretion in dairy cows[J]. Journal of Animal Science and Biotechnology, 2014, 5(1):23.

DOI PMID

[19]
LOPEZ H, KANITZ F D, MOREIRA V R, et al. Effect of dietary phosphorus on performance of lactating dairy cows:milk production and cow health[J]. Journal of Dairy Science, 2004, 87(1):139-145.

DOI

[20]
KLOP G, ELLIS J L, BANNINK A, et al. Meta-analysis of factors that affect the utilization efficiency of phosphorus in lactating dairy cows[J]. Journal of Dairy Science, 2013, 96(6):3936-3949.

DOI PMID

[21]
HAESE E, MÖHRING J, STEINGASS H, et al. Effect of dietary mineral phosphorus and phytate on in situ ruminal phytate disappearance from different concentrates in dairy cows[J]. Journal of Dairy Science, 2017, 100(5):3672-3684.

DOI PMID

[22]
HUMER E, ZEBELI Q. Phytate in feed ingredients and potentials for improving the utilization of phosphorus in ruminant nutrition[J]. Animal Feed Science and Technology, 2015, 209:1-15.

DOI

[23]
QU Q B, YANG P, ZHAO R, et al. Prediction of fecal nitrogen and phosphorus excretion for Chinese Holstein lactating dairy cows[J]. Journal of Animal Science, 2017, 95(8):3487-3496.

DOI PMID

[24]
SENARATNE V, PLAIZIER J C. Relationships between dietary and cow factors with the fecal phosphorus contents of dairy cows in Manitoba[J]. Canadian Journal of Animal Science, 2020, 100(1):210-213.

DOI

[25]
王浩, 林昌龙, 周广琛, 等. 陕北白绒山羊断奶羔羊钙磷需要量的研究[J]. 畜牧兽医学报, 2018, 49(1):121-130.

WANG H, LIN C L, ZHOU G C, et al. Study on calcium and phosphorus requirement of weaned lamb in Shaanbei white cashmere goat[J]. Acta Veterinaria et Zootechnica Sinica, 2018, 49(1):121-130. (in Chinese)

[26]
赵巧丽, 郭变. 日粮中钙磷水平对奶牛生长性能、血液生化指标及钙磷代谢的影响[J]. 中国饲料, 2023(12):64-67.

ZHAO Q L, GUO B. Effects of calcium and phosphorus levels on growth performance,blood biochemical indexes and mineral metabolism of dairy cows[J]. China Feed, 2023(12):64-67. (in Chinese)

[27]
National Research Council. Nutrient requirements of dairy cattle[S]. Washington,D.C.:The National Academies Press, 2001:456-458.

[28]
KLOP G, ELLIS J L, BLOK M C, et al. Variation in phosphorus content of milk from dairy cattle as affected by differences in milk composition[J]. The Journal of Agricultural Science, 2014, 152(5):860-869.

DOI

[29]
DURAND M, KOMISARCZUK S. Influence of major minerals on rumen microbiota[J]. The Journal of Nutrition, 1988, 118(2):249-260.

DOI

[30]
陈月丽. 不同钙、磷水平日粮对11-14月龄奶水牛生长性能、养分消化率和血液指标的影响[D]. 硕士学位论文. 南宁: 广西大学, 2016:16-22.

CHEN Y L. Effect of different calcium and phosphorus levels on growth performance, digestive rate,blood indicators of 11-14 months growing buffalo[D]. Master’s Thesis. Nanning: Guangxi University, 2016:16-22. (in Chinese)

[31]
EKELUND A, SPÖRNDLY R, HOLTENIUS K. Influence of low phosphorus intake during early lactation on apparent digestibility of phosphorus and bone metabolism in dairy cows[J]. Livestock Science, 2006, 99(2/3):227-236.

DOI

[32]
SHORE K V, ODONGO N E, MUTSVANGWA T, et al. Phosphorus status of lactating dairy cows fed total mixed rations containing 0.24% vs. 0.36% phosphorus[J]. Canadian Journal of Animal Science, 2005, 85(3):409-412.

DOI

[33]
孙国强, 王书芝, 吕永艳, 等. 饲粮磷含量对11-15月龄青年奶牛生长性能、血液指标和磷排泄的影响[J]. 动物营养学报, 2015, 27(12):3912-3919.

DOI

SUN G Q, WANG S Z, LYU Y Y, et al. Effects of dietary phosphorus content on growth performance,blood indicators and phosphorus excretion of heifers aged 11 to 15 months[J]. Chinese Journal of Animal Nutrition, 2015, 27(12):3912-3919. (in Chinese)

[34]
BERNDT T J, SCHIAVI S, KUMAR R. “Phosphatonins” and the regulation of phosphorus homeostasis[J]. American Journal of Physiology:Renal Physiology, 2005, 289(6):F1170-F1182.

DOI

[35]
FERRIS C P, PATTERSON D C, MCCOY M A, et al. Effect of offering dairy cows diets differing in phosphorus concentration over four successive lactations:1.Food intake,milk production,tissue changes and blood metabolites[J]. Animal, 2010, 4(4):545-559.

DOI

[36]
欧阳依娜, 王思宇, 梁家充, 等. 空怀期云南半细毛羊磷需要量[J]. 动物营养学报, 2021, 33(11):6213-6222.

DOI

OU YANG Y N, WANG S Y, LIANG J C, et al. Phosphorus requirement for Yunnan semi-fine wool sheep during non-pregnancy[J]. Chinese Journal of Animal Nutrition, 2021, 33(11):6213-6222. (in Chinese)

[37]
胡凤明, 司丙文, 张博, 等. 内蒙古牧区察哈尔羔羊饲粮钙磷适宜水平研究[J]. 草业学报, 2017, 26(3):100-110.

DOI

HU F M, SI B W, ZHANG B, et al. Effect of dietary calcium and phosphorus on growth,blood metabolites,and digestion in Chahaer lambs in Inner Mongolia[J]. Acta Prataculturae Sinica, 2017, 26(3):100-110. (in Chinese)

[38]
孙伟丽. 梅花鹿钙磷代谢规律及鹿茸功效的物质基础研究[D]. 博士学位论文. 北京: 中国农业科学院, 2019:17-19.

SUN W L. Calcium and phosphorus metabolism of sika deer and effective ingredients of velvet antler[D]. Ph.D. Thesis. Beijing: Chinese Academy of Agricultural Sciences, 2019:17-19. (in Chinese)

Options
Outlines

/

〈 〉

京ICP备17050989号-2
Copyright © Chinese Journal of Animal Nutrition, All Rights Reserved.
Tel: 010－62817823　E-mail: cjan@vip.163.com
Powered by Beijing Magtech Co., Ltd.