Research On Grazing Nutrition Monitoring And Energy And Protein Nutrition Requirements Of Alpine Merino Rams

Alpine Merino sheep are a new national wool sheep breed adapted to high altitude ecological environment.At present,its nutritional management mainly refers to the nutritional needs of other sheep,and there is almost no research on its nutritional requirement,which not only hinders the promotion of new varieties,but also delays the pace of large-scale mating.At present,the core herd of the new breed is mainly grazing,and the nutrition of the mating ram needs to play a decisive role in the mating process of the new breed.In order to reveal the law of nutrition requirement and provide theoretical and technical support for scientific feeding,the nutrition supply and demand characteristics of alpine Merino rams under grazing and feeding conditions were studied in this study.The main research work is as follows:1.Alpine Merino ram grazing nutrition monitoringNutrition monitoring studies were conducted on cold season and warm season pastures of Alpine Merino rams.The results showed that:?1?the dominant herbage in the cold season pasture was Kobresia,Elymus dahuricus grass and Stipa.In the warm season,the pastures are Kobresia,Elymus dahuricus,Stipa,Potentilla,Medicago archiducis-nicolai,Radix Bupleuri and Alpine bistort.Forage dominance index in cold season was significantly lower than that in warm season?P<0.05?,diversity index difference was not significant?P>0.05?,evenness index in cold season was significantly lower than that in warm season?P<0.05?,richness index difference was not significant?P>0.05?,aboveground biomass in cold season was significantly lower than that in warm season?P<0.05?.?2?the content of organic matter in edible herbage in cold season pasture was significantly higher than that in warm season pasture?P<0.05?,while the content of crude ash and crude protein was the same in cold season pasture.The difference between neutral washing fiber and acid washing fiber was not significant?P>0.05?.The content of organic matter in grazing herbage of sheep in cold season was significantly higher than that in warm season?P<0.05?,the content of crude ash in cold season was significantly lower than that in warm season?P<0.05?,the content of crude protein in cold season was significantly higher than that in warm season?P<0.05?,and there was no significant difference between neutral washing fiber and acid washing fiber?P>0.05?.?3?to gather the food grazing sheep rumen fermentation,according to the results of in vitro gas production feed cold season grass at 6 h is significantly higher than warm pasture?P<0.05?,other time between two seasons pastures comparative difference was not significant?P>0.05?,but at the time of 3 h feed cold season between the two seasons pasture grass on a trend,comparison between dry matter disappear rate difference was not significant?P>0.05?,the fermentation parameters comparison results for two seasons pastures feed forage in vitro fermentation parameters between comparative difference was not significant?P>0.05?,There was no significant difference in vitro fermentation pH between herbage grazing in cold season and herbage grazing in warm season for 48h?P>0.05?,no significant difference in nh3-n concentration between pastures in two seasons?P>0.05?,and no significant difference in volatile acid parameters between pastures in two seasons?P>0.05?.?4?dry matter intake of male sheep in cold season pasture is higher than that in warm season pasture;There was no significant difference in hair follicle density,S/P,primary hair follicle diameter and secondary hair follicle diameter between two seasons?P>0.05?.?5?there was no significant difference in organic matter intake,digestibility and digestibility of ram between the two seasons.Protein intake,digestibility and digestibility of ram in cold season were significantly higher than those in warm season?P<0.05?.Digestibility of NDF and ADF in cold season was higher than that in warm season?P<0.05?.The rumen pH in cold season pasture was significantly higher than that in warm season pasture?P<0.05?,the butyric acid content in cold season pasture was higher than that in warm season pasture?P<0.01?,and there was no significant difference in acetic acid,propionic acid,pentanoic acid content and total acid concentration between the two pastures rams?P>0.05?.2.Effects of feeding levels on the performance of alpine Merino rams32 alpine merino rams with good reproductive traits,good health and similar body weight?87.29±2.12kg?were randomly divided into two groups,16 in each group,namely,the mating group and the non-mating group.Four nutrient supply gradients were set in the two groups,namely,free forage group?AL?,80%AL,60%AL,and 40%AL,respectively.During the experiment,sheep were fed in a single stall and drank freely.The results showed that:?1?the mating task had an extremely significant effect on the dry matter digestibility and dry matter digestibility of RAMS?P<0.01?,the gradient feeding had no significant effect on the dry matter digestibility of RAMS?P>0.05?,and the interaction between the mating task and the gradient feeding had no significant effect on the dry matter digestibility of RAMS?P>0.05?.The mating task had no significant effect on average daily weight gain of RAMS?P>0.05?,the gradient feeding had extremely significant effect on average daily weight gain of RAMS?P<0.01?,and the interaction between the mating task and gradient feeding had no significant effect on average daily weight gain of RAMS?P>0.05?.?2?breeding task of primary follicle bulb diameter has significant effect?P<0.05?,breeding task interactions with gradient breeding has significant effect on primary hair follicle bulb diameter?P<0.05?,breeding task and the interaction of the feeding time of secondary follicle bulb diameter have significant effect?P<0.05?,breeding task,feeding time and gradient density of the interaction of the breeding of hair follicles,S/P,the primary hair follicle bulb diameter and secondary follicle bulb diameter had no significant effect?P>0.05?;The comprehensive score of the free feeding behavior increased by 0.1,decreased by 0.1 in the 80%AL group,decreased by 1.7 in the 60%AL group,and decreased by 3.2 in the 40%AL group.Nutrient utilization of alpine Merino breed rams and their energy and protein needs.32 alpine merino rams with good reproductive traits,good health and similar body weight?87.29±2.12kg?were randomly divided into two groups,16 in each group,namely,the mating group and the non-mating group.Four nutrient supply gradients were set in the two groups,namely,free forage group?AL?,80%AL,60%AL,and 40%AL,respectively.During the experiment,sheep were fed in a single stall and drank freely,to feed into the nitrogen?NI?and nitrogen deposition?RN?linear regression analysis,linear relationship is:the RN=a+b×NI,when NI=0,RN corresponding to intercept a requirement for the nitrogen,to produce heat?HP?against the number and the metabolizable energy intake?MEI?linear regression analysis,linear relationship is:LgHP=a+b MEI,when MEI=0,HP is required for maintaining metabolic energy?NEm?;When MEI=HP,the iterative method was used to calculate MEI as the maintenance net energy demand?MEm?.?1?the mating task had an extremely significant effect on the apparent digestibility of organic matter?P<0.01?,the gradient feeding had no significant effect on the apparent digestibility of organic matter?P>0.05?,and the interaction between the mating task and the gradient feeding had no significant effect on the apparent digestibility of organic matter?P>0.05?.Brought to feed sheep breeding task apparent digestibility of neutral detergent fiber and acid washing fiber had no significant influence?P>0.05?,the gradient toward raising sheep and neutral detergent fiber and acid washing fiber apparent digestion rate had no significant effect?P>0.05?,breeding toward task interactions with gradient breeding sheep neutral detergent fiber and acid washing fiber apparent digestion rate had no significant effect?P>0.05?.?2?there was no significant difference in fecal nitrogen output,urine nitrogen output,nitrogen deposition,apparent digestibility of nitrogen and nitrogen retention rate between the mating tasks?P>0.05?.Gradient feeding showed significant difference in fecal nitrogen output,urine nitrogen output and deposition nitrogen?P<0.01?,but no significant difference in apparent digestibility and retention of nitrogen?P>0.05?.There was no significant difference in fecal nitrogen output,urine nitrogen output,nitrogen deposition,apparent digestibility of nitrogen and nitrogen retention rate between the interaction between mating task and gradient feeding?P>0.05?.?3?the rumen total volatile acid content,isobutyric acid,isopentanoic acid and pentanoic acid ratio of RAMS were significantly affected by gradient feeding?P<0.01?,and the interaction between mating task and gradient feeding had a significant difference on the effect of pentanoic acid?P<0.05?.?4?the mating task had no significant effect on fecal energy,urine energy,methane energy,total energy digestibility and total energy metabolism rate?P>0.05?.There were significant differences in the effects of gradient feeding on fecal energy,urine energy and methane energy?P>0.01?,but no significant differences in the effects on total energy digestibility and total energy metabolism rate?P>0.05?.The interaction between the mating task and gradient feeding had no significant effects on fecal energy,urine energy,methane energy,total energy digestibility and total energy metabolism rate?P>0.05?.?5?Feeding level had no significant effect on the apparent digestibility of OM,NDF and ADF of Alpine Merino rams.NPm of non-mating and mating groups were 381.875 mg/(kg·W^0.75·d)and 416.25 mg/(kg·W^0.75·d),MPm were 7.90 g/(kg·W^0.75·d)and 8.85 g/(kg·W^0.75·d),NEm were 312.90 KJ/(kg·W^0.75.d)and 318.42 KJ/(kg·W^0.75·d),MEm were 0.65MJ/(kg·W^0.75·d)and 0.72 MJ/(kg·W^0.75·d)respectively;DCP requirements were 10.68g/(kg·W^0.75·d)and 11.75 g/(kg·W^0.75·d),CP requirements were 12.72 g/(kg·W^0.75·d)and 13.99 g/(kg·W^0.75·d),ME requirements were 0.67 MJ/(kg·W^0.75·d)and 0.75MJ/(kg·W^0.75·d),DE requirements were 0.83 MJ/(kg·W^0.75·d)and 0.90 MJ/(kg·W^0.75·d),respectively.In summary,the vegetation of the grazing land of the Alpine Merino ram are mainly grasses and sedge grasses,which is the main food source of grazing sheep.The quality of pasture in the cold season is higher than that in the warm season,and the rumen environment of the ram is not affected.The effect of forage grass on the amount of feed intake was significantly different.The seasonal factors and feeding level of forage grass had no significant effect on the hair production performance of the ram,and the grazing nutrition monitoring and nutritional needs of the rams were adopted.The results of the research,clarifying the nutrient requirements and the grazing nutritional status during the no-feed season,provide theoretical support for the scientific breeding of the alpine Merino ram.