Study On Main Minerals Distribution And Requirement Parameters Of Dorper And Thin-tailed Han Sheep Crossbred Lambs (F1) During Their20to35kg Body Weight

Based on Dorper×thin-tailed Han crossbred lamb （F1） between20and35kg body weight andcomparative slaughter experiments, the content and distribution status of calcium （Ca）, phosphorus （P）,sodium（Na）, potassium（K）, magnesium（Mg）, copper（Cu）, manganese（Mn）, zinc（Zn） and iron（Fe） indifferent tissues were studied systematically.Factorial models were used to estimate growth requirementand maintenance requirement and the recommended minerals requirement for lambs in this variety wasgiven in this study. The report was mainly divided into three parts as following.Part1: Study on distribution of mineral elements under different physiological conditions inDorper×thin-tailed Han crossbred lamb （F1） from20to35kg body weight.This experiment was conducted to investigate the contents and distributions of Ca, P, Na, K, Mg,Cu, Mn, Zn and Fe under different physiological conditions in Dorper×thin-tail Han sheep crossbredlambs from20to35kg of body weight.35male lambs and35female lambs were randomly assigned tofive groups respectively: group BL, group M, group AL, group IR70and group IR40. Each group wasgiven the same feed but subjected to different processing methods. The former three groups were fed adlibitum and slaughtered at20kg,28kg or35kg and the later two groups were given70%and40%ofthe feed intake of group AL respectively and were slaughtered at the same time with group AL. Thenthe data of contents and distributions of mineral elements in different part of body were collected. Theresult showed that, as the body weight increasing, the contents of mineral elements in muscle showedthe opposite trend（P<0.05）,whereas that in bone, leather and viscera showed a rising trend at differentlevel; feed level showed no significant effect to the contents of mineral elements in bone,muscle,leather, fleece and fat as a whole（P>0.05）. Ca, P, Na and Mg were mainly distributed in thebone while Cu, Mn and Fe were mainly existed in viscera. Zn can be seen mostly in bone and muscle.Muscle contained the most of K, also softtissue and wool were rich in K. Few mineral elements can beseen in fat.Part2: Study on the prediction model for growth requirement in Dorper×thin-tailed Hancrossbred lambs （F1） from20to35kg body weight.This experiment was conducted to investigate growth requirement prediction model of Ca, P, Na, K,Mg, Cu, Mn, Zn and Fe for Dorper×thin-tail Han sheep crossbred lambs.21male lambs and21femalelambs were randomly assigned to three groups respectively: group BL, group M and group AL. Eachgroup was given the same feed and slaughtered at20kg,28kg or35kg respectively. Data of mineralcontents and body weight were collected to estimate the prediction model. The result shows that duringthe body weight from20to35kg period, the net requirement for growth of Ca (NRG_Ca)=15.2138×EBW^-0.1674; NRG_P=9.2033×EBW^-0.1951; requirement of male lambs isNRG_Na=1.5336×EBW-0.085and female is NRG_Na=2.3006×EBW^-0.1033; requirement for K of male and female lambs is NRG_K=1.9426×EBW0.023and NRG_K=2.4580×EBW0.1518, respectively;NRG_Mg=0.2675×EBW0.0982; requirement for Cu of male and female lambs is NRGCu=1.0400×EBW^0.7977and NRGCu=5.5133×EBW^-0.0261; and requirement for Mn of male lambs is NRG.4774Mn=0.5658×EBW0;requirement for Zn of male and female lambs is NRG_Zn=19.3709×EBW0.0883andNRG_Zn=36.9916×EBW-0.0863, respectively; and requirement for Fe of male and female lambs isNRG_Fe=55.1093×EBW^0.2129and NRG_Fe=105.1819×EBW^-0.2879. This study also showed that genderplayed an important role inthe net requirement for growth of lambs.Part3: Mineral maintenance requirement of Dorper×thin-tailed Han crossbred lambs （F1） from20to35kg body weight.This experiment was conducted to investigate the requirement parameters for maintenance ofDorper and thin-tailed Han Sheep Crossbred Lambs （F1） during their20to35kg body weight,35malelambs and35female lambs were randomly assigned to five groups respectively: group BL, group M,group AL, group IR70and group IR40. Each group was given the same feed but subjected to differentprocessing methods. The former three groups were fed ad libitum and slaughtered at20kg,28kg or35kg and the later two groups were given70%and40%of the feed intake of group AL respectively andwere slaughtered at the same time with group AL. Then the relationship between retained body mineraland DMI was established to predict the maintenance requirement formain mineral in lamb body. Theresult showed that the maintenance requirement of Ca, P, Na, K, Mg and Zn was0.40g/d、0.41g/d、0.13g/d、0.21g/d、0.026g/d and2.34mg/d, with no difference between male lambs and female lambs; themaintenance requirement of Cu for male lambs was0.41mg/d, and for female lambs was1.12mg/d; themaintenance requirement of Mn for male lambs was0.29mg/d, and the requirement for female lambswas slightly lower as0.22mg/d; the maintenance requirement of Fe for male lambs and female lambswere11.49mg/d and5.98mg/d, respectively. It revealed that the maintenance requirement of lambswas influenced by the breed and gender.