Effects of Quebracho Tannins on Growth Performance and Blood Routine of Simmental Fattening Cattle

Yang YU Ningan MEI Zixin LIU Xuefeng MA Haohe WANG Ruigang WANG Wu JIANG Yuchen MEI Xiaojun LIANG

Abstract    [Objectives]  The effects of condensed quebracho tannins on the production performance and blood routine indices of Simmental fattening cattle were investigated experimentally.

[Methods] Twenty four Simmental fattening cattle were selected and randomly divided into two treatment groups according to their body weight， with 12 animals in each group. The diet of the control group consisted of beef cattle concentrate supplement+silage+hay， and the diet of the experimental group consisted of beef cattle concentrate supplement+silage+hay+tannins， and the experimental period was 30 d.

[Results]  Compared with the control group， the addition of tannins [30 g/（cattle·d）] to the diet of beef cattle increased the daily weight gain of Simmental beef cattle by 24.68% （ P <0.01）， while the feed conversion ratio decreased by 2.57% （ P >0.05）. The gross profit per cattle increased by 973.63 yuan， and the economic benefit increased by 114.78%. Platelets were higher in the experimental group than in the control group （ P <0.01）; hemoglobin was lower in the experimental group than in the control group （ P <0.01）; leukocytes， neutrophils， monocytes and lymphocytes were lower in the experimental group than in the control group （ P <0.01）; and erythrocytes were lower in the experimental group than in the control group （ P <0.05）.

[Conclusions] This study provides a theoretical basis for the rational utilization of quebracho tannins.

Key words   Condensed quebracho tannins; Simmental; Fattening cattle; Growth performance; Blood routine

Condensed tannins （CTs） are natural polyphenols derived from plants. Their common structural monomers include catechin， epicatechin， gallocatechin and epigallocatechin. Condensed tannins are a class of oligomers or polymers formed by the condensation of flavan-3-ols or flavan-3，4-diols through 4→8 （or 4→6） CC bonds （or C-O-C bonds）， also known as proanthocyanidins （95% of proanthocyanidins appear in quebracho）  [1-2] . The indiscriminate use of antibiotics in the current animal husbandry production process has led to serious food safety problems and the  emergence  of drug-resistant strains. Ministry of Agriculture and Rural Affairs issued No. 194， marking that China has fully entered the antibiotic-free era. Finding alternatives to antibiotics is a hot and difficult issue in current industry research， and there is an urgent need for the promotion and application of new， green， pollution-free and antibiotic-free functional feed additives. Condensed quebracho tannins have antioxidant， anti-inflammatory and antimicrobial effects， and they can promote animal growth and improve nutrient utilization， and have anti-stress and immunity-enhancing effects. Tannins， as antibiotics produced by plants， have toxic effects on bacteria， fungi and yeast， and can be used as feed  additives  to replace antibiotics in animal feeds  [3-4] .

In this study， the feeding effect of condensed quebracho tannins added to the diet on Simmental fattening cattle and its antibiotic substitution effect were investigated， aiming to provide a reference for the rational utilization of condensed quebracho tannins.

Materials and Methods 

Experimental products

Condensed tannins （extracted from quebracho）， active substance R （% Min） 90， and natural quebracho polyphenol d （% Min）≥64， provided by Ningxia Haohe Biotechnology Co.， Ltd.

Experimental design 

Experimental design method

The experiment adopted a completely randomized design， and was a one-factor experiment. The experimental period was 30 d.

Experimental animals and grouping

Twenty four Simmental beef cattle were selected and randomly divided into 2 groups with 12 individuals in each group. The control group used the conventional diet， and the experimental group was supplemented with condensed tannins on the basis of the conventional diet， which was added with condensed tannins at an amount of 30 g/（cattle·d）. The initial body weight was 515.42 kg in the experimental group and 513.33 kg in the control group， and the difference was not significant.

Diet composition and nutritional levels

The diet of the control group consisted of beef cattle concentrate supplement+silage+hay， while the diet of the experimental group consisted of beef  cattle  concentrate supplement+silage+hay+tannins. The diet compositions and nutrient levels are shown in Table 1.

Daily management of feeding experiment

During the pre-test period， deworming and stomach strengthening work were carried out， and the cattle farm was thoroughly disinfected. A special person was responsible for ration and feeding every day. The cattle were fed twice a day， first coarse and then refined， and they can drank water and exercise freely. Food intake and feces were observed in detail.

Observation indices

（1） The cattle were weighed on an empty stomach at the beginning and end of the experiment， and the daily weight gain， feed intake， and feed conversion ratio were calculated.

（2） At the beginning and end of the experiment， blood was drawn for the blood routine， and the indices mainly included red blood cell count （RBC）， hemoglobin （HGB）， white blood cell count （WBC）， neutrophil （GR）， monocyte （MO）， lymphocyte （LY）， blood platelet count （PLT）.

Data analysis

The experimental data were subjected to biostatistics and multiple comparison analysis.

Experimental Results 

Experimental observation

There were no significant changes between the experimental group and the control group. The cattle were good in stool， coat color and mental state， and no clinical symptoms were observed.

Weight gain

The initial weight and final weight of the experimental beef cattle were measured， and the results are shown in Table 2.

It can be seen from the results in Table 2 that the average daily weight gain of beef cattle fed with condensed tannins was  24.68%  higher than that of the control group （ P <0.01）， but the feed conversion ratio in the experimental group was 2.57% lower than that in the control group （ P >0.05）.

Blood routine

Blood routine analysis is shown in Table 3.

It can be seen from the results in Table 3 that at the beginning of the experiment， platelets were higher in the experimental  group than  in the control group （ P <0.01）， and hemoglobin was higher in the experimental group than in the control group as well  （ P <0.05） ， while other indices had no significant differences  （ P >0.05）.

As can be seen from the results in Table 4， at the end of the experiment， platelets were higher in the experimental group than in the control group （ P <0.01）; hemoglobin was lower in the experimental group than in the control group （ P <0.01）; leukocytes， neutrophils， monocytes and lymphocytes were lower in the experimental group than in the control group （ P <0.01）; and  erythrocytes  were lower in the experimental group than in the control group （ P <0.05）.

Economic benefits

The economic benefit analysis is shown in Table 5.

The economic benefit analysis showed that the gross profit of the experimental group was 973.63 yuan， which was 430.31 yuan higher than that of the control group （453.32 yuan）， showing an increase of 114.78%.

Conclusions and Discussion 

Feeding condensed quebracho tannins had no adverse effect on growth of Simmental fattening cattle

The experimental observation showed that the experimental group and the control group were good in feces， coat color and mental state， and no clinical symptoms were observed.

Production performance analysis

Feeding condensed quebracho tannins to beef cattle could significantly improve the growth rate of the experimental fattening cattle， and the per cattle average daily weight gain of the experimental group was 24.68% higher than that of the control group  （ P <0.01） ; and it could improve the feed reward of beef cattle ration and reduce feed cost， and the per cattle feed conversion ratio was reduced by 2.57% （ P >0.05）. The analysis showed that condensed quebracho tannins could significantly improve the production performance of Simmental fattening cattle  [5] .

Blood routine analysis

Platelets were higher in the experimental group than in the control group （ P <0.01）; hemoglobin was lower in the experimental group than in the control group （ P <0.01）; leukocytes，  neutrophils， monocytes and lymphocytes were lower in the experimental group than in the control group （ P <0.01）; and erythrocytes  were lower in the experimental group than in the control group  （ P <0.05）.  The analysis showed that condensed quebracho tannins could significantly improve the resistance of Simmental fattening cattle and enhance the immunity of the body  [5] .

Economic benefit analysis

The gross profit of weight gain in the experimental group was 973.63 yuan， which was 430.31 yuan higher than that in the control group （453.32 yuan）， that is， an increase of 114.78%. The analysis showed that the addition of condensed quebracho tannins to beef cattle diets could greatly improve the culture benefit of Simmental fattening cattle.

Yang YU  et al.  Effects of Quebracho Tannins on Growth Performance and Blood Routine of Simmental Fattening Cattle

References

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[2] TANG QS， XU E， JIANG ZY，  et al.  Advance in biological function of tannin and its application in livestock and poultry[J]. Chinese Journal of Animal Science， 2021， 57（5）： 33-39. （in Chinese）.

[3] ZHANG GN， LI JM， XU HY，  et al.  Application of tannic acid in animal husbandry production[J]. Guangdong Feed， 2017， 26（6）： 39-40. （in Chinese）.

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[5] NIU XY， LI DB. Nutritional and physiological role of plant tannin and its application in animal production[J]. Feed Research， 2020， 43（11）： 146-150. （in Chinese）.

 Editor： Yingzhi GUANG   Proofreader： Xinxiu ZHU