Study On The Characteristics Of Sweat Glands And Thermoregulation In Different Breeds Of Cattle

Under high temperature conditions,evaporative heat loss is the main way of livestock heat loss,including skin evaporative heat loss and respiratory tract evaporation heat loss,while skin evaporative heat loss includes vasomotor heat loss and sweat glands sweat heat loss.Sweat glands are skin accessory organs,and their perspiration function is the main way of skin evaporative heat loss.Increasing skin blood flow to transfer heat to the body surface is also an important way for livestock to loss heat in summer.In this experiment,the experiment was conducted in summer and winter.The skin tissues of Wandong cattle and Holstein cattle were collected in summer,and the skin tissues of Jinjiang cattle,Cattle-yak and Buffalo were collected in winter to study the skin thickness,sweat gland morphology and the characteristics of skin heat dissipation regulation in different parts of the cattle,and to analyze the differences in evaporative heat loss of different breeds of cattle.This test is divided into three parts,as follows:1 The difference in skin and sweat gland morphology of Wandong cattle and Holstein cattle in summerIn order to explore the differences of regulation in skin tissue morphology and heat dissipation between Wandong cattle and Holstein cattle during the high temperature season of summer,4 female Wandong Cattle from Anhui Daming Animal Husbandry were culled in 4 parities,weighing(384.17±13.77)kg,and 4 Holstein(Hol)was culled in 3 parities,and weighing(531.25±21.75)kg were selected,slaughtered and sampled after feeding for one week in summer(average temperature above 30℃),and then collecting skin samples from neck,shoulders,back,abdomen,buttocks and legs.The distribution and morphology of the sweat glands(SWG)and sebaceous glands(SEG)of the skin analyzed by HE staining,Periodic acid-Schiff(PAS)and Alcian bluePeriodic acid-Schiff(AB-PAS).Result:(1)Wandong cattle and Holstein cattle were in a healthy physiological state during the test.Glycogen is present in the sweat glands and sebaceous gland secretions of the two breeds;AB-sweat glands and sebaceous gland mucus were blue purple,it is an acidic neutral mixture.(2)There is an interaction between skin thickness and epidermal thickness between breeds and parts(P<0.05).Compared with Holstein cattle,the average skin thickness of Wandong cattle was higher and the average epidermal thickness was thinner(P<0.05).In comparison between the body parts,the back epidermis of Wandong cattle and Holstein cattle was the thickest,and the neck epidermis was the thinnest(P<0.05).(3)There was no significant difference between the density of SSW and SEG(P>0.05).Compared with Holstein cattle,the average length,diameter,depth,volume of SSW and SEG of Wandong cattle have obvious superiority(P<0.05).(4)In comparison between body parts,the density of sweat glands in the neck and legs of Wandong cattle was significantly higher than that of shoulders,abdomen,back and buttocks(P<0.05).Holstein cattle had the largest sweat gland density in the neck and the smallest in the back(P<0.05).The back sweat gland volume of Wandong cattle is the largest,and the volume of sweat glands of Holstein cattle in leg is the smallest(P<0.05).It can be concluded that compared with Holstein cattle,Wandong cattle have thicker skin and thinner epidermis,the skin sweat glands and sebaceous glands of Wandong cattle and Holstein cattle are active and have normal secretory functions,and SSW and SEG of Wandong cattle have structural advantages in volume.2 The difference in heat loss regulation of skin tissues of Wandong cattle and Holstein cattle in summerIn this chapter,neurotransmitters,enzymes,genes and proteins of the skin tissues of the shoulder,back and buttocks of Wandong cattle and Holstein cattle are measured to explore the differences in heat dissipation regulation of the skin tissues of Wandong cattle and Holstein cattle.The acetylcholine(ACh)concentration,acetylcholinesterase(ACh E)activity,acetylcholine transferase(ACh T)activity,and the expression of related genes and proteins in the skin tissues of the shoulder,back and buttock of Wandong cattle and Holstein cattle were measured.Results:(1)Comparison of shoulder,back and buttocks skin in Wandong cattle and Holstein: there was no significant difference in ACh concentration in skin tissue between Wandong cattle and Holstein cattle in summer(P>0.05),the highest was found in the buttock,followed by the shoulder and the lowest was in the back(P<0.05).Breeds and parts have an interactive effect on the skin acetylcholinesterase activity and transferase activity(P<0.05).In Wandong cattle,the the back is the lowest(P<0.05).In Holstein cattle,the acetylcholinesterase activity of the buttock skin tissue is the higher.There was no significant difference in the individual effects of acetylcholine transferase activity in breeds and parts(P>0.05).(2)Breeds and parts have no interaction effect on the m RNA expression of M3 R,e NOs and AQP5 in skin tissues(P>0.05).The m RNA expression of acetylcholine M3 receptor in Wandong cattle was higher than that in Holstein(P<0.05).The m RNA level of nitric oxide synthase in Wandong cattle was lower than that in Holstein cattle(P<0.05).The m RNA level of AQP5 in Wandong cattle was higher than that in Holstein cattle(P<0.05).(3)Western blot analysis showed that the protein level of acetylcholine M3 receptor in shoulder skin of Wandong cattle was higher than that of Holstein cattle,while the expression level of e NOs was significantly lower than that of Holstein cattle(P<0.05).In conclusion,the synthesis of acetylcholine M3 receptor protein and AQP5 of Wandong cattle is higher,and sweat-regulated heat dissipation is dominant.The m RNA and protein levels of e NOs in Holstein cattle are higher than those in Wandong cattle,and the regulation of heat dissipation via vasomotor is superior.3 The difference in skin and sweat gland morphology of Jinjiang cattle,Cattle-yak and Buffalo in winterThe purpose of this experiment is to study the differences in skin and sweat gland morphology of Jinjiang cattle,Cattle-yak and Buffalo in winter.On winter days when the average temperature is lower than 10℃,select healthy 18-month-old male Jinjiang cattle(380±10)kg,male cattle(179±24)kg and male buffalo(209±29)kg each with 4heads and then collecting skin samples from neck,shoulders,back,abdomen,buttocks and legs.The distribution and morphology of the sweat glands and sebaceous glands of the skin analyzed by HE,PAS and AB-PAS staining.Result:(1)In comparison between breeds,the average skin thickness of buffalo is the thickest,followed by Jinjiang cattle,and Cattle-yak is the thinnest(P<0.05).The average epidermis thickness of Jinjiang cattle was the thickest,followed by buffalo,and Cattle-yak thinnest(P<0.05).(2)In comparison between breeds,the average sweat gland density of Cattle-yak was significantly higher than that of Jinjiang cattle,and the density of buffalo was the smallest(P<0.05).There was no significant difference in average sebaceous gland density of Jinjiang cattle,Cattle-yak,and water buffalo(P>0.05).The average volume of sweat glands and sebaceous glands of Jinjiang cattle were both larger than Cattleyak and water buffalo(P<0.05),there is no significant difference in volume between Cattle-yak and water buffalo(P>0.05).In comparison between the body parts,the sweat gland density of Jinjiang cattle,Cattle-yak and Buffalo was both the largest in the back and the smallest in the abdomen(P<0.05).Jinjiang cattle had the largest volume of sweat glands in the back and buttocks,and the smallest in the neck and abdomen;Cattle-yak had the largest volume of sweat glands in the back and abdomen,and the smallest in the neck;buffalo had the largest volume of sweat glands in the neck,and the smallest in the abdomen(P<0.05).Jinjiang cattle had the largest density of sebaceous glands in the buttocks,the legs were the smallest;Cattle-yak had the largest density of sebaceous glands in the back,the smallest in the legs;Buffalo had the largest density of abdomen skin,and the neck and back were the smallest(P<0.05).Jinjiang cattle had the largest volume of sebaceous glands in the back,the smallest in the legs;Cattle-yak had the largest volume of sebaceous glands in the back skin,the smallest in the abdomen and legs(P<0.05);Buffalo had the largest volume of sebaceous glands in the shoulders,and the difference in other parts is not significant(P>0.05).It can be concluded that the skin of Buffalo in winter is thicker than that of Jinjiang cattle and Jinjiang cattle,but the density and volume of Buffalo sweat glands are smaller,and sweat gland secretion activity is not obvious.Jinjiang cattle have a large diameter and their volume is significantly higher than that of Jinjiang cattle and Buffalo.4 The difference in in heat loss regulation of skin tissues of Jinjiang cattle,Cattleyak and Buffalo in winterThrough the determination of neurotransmitters,enzymes and genes in the skin tissues of the shoulder,back and buttocks of Jinjiang cattle,Cattle-yak and Buffalo,to explore the differences in skin cold resistance and environmental adaptability of Jinjiang cattle,Cattle-yak and Buffalo.RT-q PCR and Western Blot were respectively performed to detect the m RNA and protein levels of muscarinic acetylcholine receptor,endothelial nitric oxide synthase and aquaporin 5.Result:(1)The acetylcholine concentration,acetylcholinesterase activity and acetylcholine transferase activity of Jinjiang cattle,Cattle-yak and Buffalo all had interactions between breeds and parts(P<0.05).In Jinjiang cattle,the back had the highest concentration of acetylcholine(P<0.05);In Cattle-yak,there was no significant difference in acetylcholine concentration on the shoulder,back and buttocks(P>0.05);In Buffalo,the buttocks had the highest concentration of acetylcholine,and the shoulder was the lowest(P<0.05).Jinjiang cattle,Cattle-yak and Buffalo both had the lowest acetylcholinesterase activity in the shoulder(P<0.05).The acetylcholine transferase activity of Jinjiang Cattle and Cattle-yak were the highest on the back and the lowest on the shoulders(P<0.05),while Buffalo had the highest activity on the buttocks,and the shoulders and back were lower(P<0.05).(2)The relative expression levels of acetylcholine M3 receptor gene,nitric oxide synthase gene and aquaporin 5 gene of Jinjiang cattle,Cattle-yak and Buffalo had interactions between breeds and parts(P<0.05).The relative expression of acetylcholine M3 receptor gene and nitric oxide synthase gene of buffalo was higher in the back(P<0.05),while the expression in the buttocks was lower.The expression of acetylcholine M3 receptor gene and nitric oxide synthase gene of Jinjiang cattle were higher in the back(P<0.05).In Jinjiang cattle,the relative expression of aquaporin 5gene was the highest in the bottocks,and the lowest in the back(P<0.05);In Cattle-yak,the expression of acetylcholine M3 receptor and aquaporin 5 genes were the highest in the shoulder and the lowest in the buttocks(P<0.05).It can be concluded that Jinjiang cattle and Buffalo have higher M3 R m RNA expression level,Buffalo e NOs m RNA expression level is higher than that of Cattleyak and Jinjiang cattle,Buffalo has strong vasomotor and body temperature regulation ability.