| Selenium(Se)and cobalt (Co) are two kinds of important essential trace elements to forage and animal production. In Henan Province, the fine grass and green milk production zones are mainly distributed along the Yellow river beach where soils are sandy and sterile with lower Se and Co contents. Deficiency of Se and Co in soils affects local forage and animal production level as well as the qualities and securities of fodder and animal products. This paper put forward a concept of nutrient flow in Soil-Pasture-Feed -Animal Chain(SPFAC), and conducted a seris of field trials and animal experiments from 2006 to 2009 in order to study the multiple effects of Se and Co on soil fertility, growth and nutrition of forage plant(alfalfa[Medicago sativa L.]), animal feed conversion efficiency, and feasible concrete measurements to enhance production levels of grass and animal products rich in Se,Co and other nutrients, furtherly, established a set of effective technical ways to solve trace element gaps of soil, forage plant and animal diets, i.e. by basal fertilization of Se and Co fertilizers in soil, inorganic Se and Co could be accumulated in alfalfa plants by root absorption and transformed into organic Se and Co mostly, the pasture rich in Se and Co could also be uesed as fodder to produce animal products with higher extra values.The results showed as following:1. The effects of Se and Co on soil fertility Se fertilization could promote the growth of root nodule of alfalfa in a depth of 0-20cm soil, and improve top soil structure and increase available N and organic matter significantly. Co fertilization had less effects on soil fertility mentioned above. Combined application Se and Co not only raised the contents of available N and organic matter significantly, but also enhanced content of available K. When applying rates of Se and Cobalt being 570 g/hm~2 and 1548 g/hm~2, contents of available N, available K and organic matter could raise by 8.9 %, 7.2 % and 7.1 %, respectively.2. The effects of Se and Co on the growth, yield and fodder quality of alfalfa Single or rational combined application Se and Co fertilization could promote the growth of alfalfa, raise forage yields,improve nutrition levels of fodders and add contents and accumulation volumes of trace elements (such as Se, Co, Mo, Cu, B, Fe, Mn and Zn) in alfalfa plant.(1)The effects of Se and Co on the growth, yield of alfalfa plant Rational basal single and combined application of Se and Co all could not only enforce nitrate reductase activities and nitrogen metabolitic levels, but also promote net photosythetic efficiency,decrease plant respiration loss, enhance production rate of dry matter as well as seed growth from ramification to florescence, and raise alfalfa hay production before florescence. When application rates of Se being 570 g/hm~2, 762 g/hm~2, Se-Co combined fertilizers had best application effects on forage production and grain development, alfalfa hay was increased by 8.06 %(P<0.05)and 1000-grain weight was increased by 12.85 %(P<0.05).(2)The effects of Se and Co on disease-resistance of alfalfa plant Se and Cobalt combined basal fertilizer had great disease prevention effects on rust,brown spot,summer black stem and appeared more obvious effects in flowering-ripening stage. Under combined basal fertilization when application rate of Se was 765 g/hm~2, that of Cobalt was 762 g/hm~2 1548 g/hm~2, respectively, rust, brown spot, summer black stem could be prevented effectively, and alfalfa rust could be decreased by 24.7 % and 31.6 %, respectively, brown spot could be decreased by 25.2 % and 22.7 %, respectively, summer black stem could be decreased by 25.2 % and 19.0 %, respectively. Furthermore, Se and Co combined basal fertilizer also had obvious preventing effects on root rot which could be decreased by 19.8 % and showed more obvious effects in pods formation-ripening stage when Se application rate being 57 g/hm~2 and Cobalt application rate being 1548 g/hm~2.(3)The effects of Se and Co on major nutrients of alfalfa hay Se and Co single and combined fertilization had significant effects on major nutrients of alfalfa hay. When application rates of Se being 765g/hm~2, 762 g/hm~2, Se and Co single and combined fertilization had optimal applied effects which enhanced the contents of crude protein (CP)and ether extract(EE), kept stabilities of crude fiber(CF) and nitrogen-free extract(NFE) and enhanced feed values of alfalfa hay. Other single and combined fertilizers could enhance the content of CF more significantly,decrease the content of EE, and had no significant effluence on the of CP and NFE.(4)The effects of Se and Co fertilization on the contents of Se and Co in alfalfa hay Alfalfa had stronger capacities to absorb,transfer and utilize Se and Co from soil to plant root. Single basal application of Se and Co could increase the contents of Se and Co of alfalfa hays (and more Se in soil,more Se in hays).Within all Se and Co single and combined fertilization,there were more significant correlation(P﹤0.01)between Se applied amount and Se accumulation amount of alfalfa hay. Co accumulation amount of alfalfa hay kept stable. When Co applied rate increased the certain level, if more Co was applied in soil, some surplus Co might be wasted. Rational combined application of Se and Co could raise utilization rate of Se and ratio of transfor from inorganic Se from fertilizers to organic Se in forage. Effectiveness and securement of Se were all enhanced obviously. When applied rates of Se being 765 g/hm~2 and 762 g/hm~2, Se and Co combined use can raise Se accumulation amount effectively by 1097.52 % and 69.39 % in comparation with the control and Se single use. When applied rates of Se being 765 g/hm~2 and 1548 g/hm~2, Se and Co combined application can raise Co accumulation amount effectively by 144.44 % and 27.02 % in comparation with the control and Co single fertilization.(5)The effects of Se and Co fertilization on the contents of Mo, Cu, B, Fe, Mn and Zn in alfalfa hay Se and Cobalt applied fertilizers could enhance the contents of Mo, Cu, B, Fe, Mn and Zn more significanly(P﹤0.05). Of all 6 kinds of trace elements, the contents of Mo had most significant increasing levels (142.3% -476.2 %), next to Fe, Mn and Zn ( 48.1%-59.4 %, 32.9%-41.7% and 37.1 %-96.4%, respectively), Cu and B had lower increasing levels (13.4 %-37.3 % and 14.6 %-39.7%, respectively). When application rates of Se and Co being 765g/hm~2and 762 g/hm~2, respectively. The contents and accumulation of 6 trace elements mentioned above can reach optimal levels.3. The effects of Se and Co on feed nutrition levels while transmitted through SPFAC Supplement of alfalfa dust (rich in Se and Co)can raise the contents of Se, Co, Zn, Mo, B, Cu, Fe and Mn of animal(Holstein cows, Dorper sheep, New-Zealand rabbits and San Huang chicken)diets.Alfafa dust rich in Se and Co(produced when combined application rates of Se and Co being 765 g/hm~2,1548g/hm~2 respectively)had optimal effects on animal production. When alfalfa dust (rich in Se and Co)were supplemented with 5 %-15 %,.animal production were more efficient and safe. Based on studies and analysis of feedlize techniques about alfalfa produced by Se and Co basal fertilization,feed rationing techniques of high trace elements were formulated in animals(milk cattle,dorper sheep,rabbit and chicken).4. The effects of Se and Co on growth , feed utilization level and product quality of animal production while transmitted through SPFAC Adopting separate feeding, the effects of diets supplemented with alfalfa hay or dust (rich in high trace elements) on growing performances, feed conversion level and animal product quality were studied in some animal production coorporation and bases, such as Henan Sino-Dutch Dairy Technology and Development Co., Ltd, Xinmi New-star Rabbit Raising Base and Zhongmou Dorper Sheep Extension Base, etc. According to the animal growing and producing performances, more effective feed techniques along with multiple benefits were formulated simultaneously, some key techniques and index parameter were definited clearly concerning with grass planting and animal raising in SPFAC.(1)The effects of Se and Co fertilization on animal growth and feed utilization while transmitted through SPFAC When supplemented with three kinds of alfalfa dusts(rich in Se,Co and Se+Co) in diets of animals(including 3.5-year-old Holstein Lactating cows, 50-day-old Dorper sheep, 40-day-old weaned New-Zealand rabbits, 35-day-old San Huang chicken and 6-week-old Wister rat), not only daily gain and total gain were raised ,but also feed conversion rate were enhanced significantly.Of all experimental animals,chicken had best feeding effects, average daily gain and feed conversion rate were raised by 26.2% and 29.5 %, respectively when supplemented with 10 % alfalfa dust rich in Se and Co. Next to rabbit, average daily gain and feed conversion rate were raised by 12.4 % and 7.6 % respectively when supplemented with 10 % alfalfa dust(rich in Co). and raised by 11.0 % and 6.1 % respectively when supplemented with 10 % alfalfa dust(rich in Se and Co). Feed conversion rate of milk cow was raised by 13.9 % when supplemented with 5 % alfalfa dust(rich in Se). Feed conversion rate of sheep was raised by 28.3 % and 27.7 %, respectively when supplemented with 15 % alfalfa dust(rich in Se). and 10% dust(rich in Se and Co).All diets could enhance pepsin activities, decrease gastric remains feed, increase intake rate of Wister rat in early stage and enhance feed conversion efficiency(8.5 %～9.0 %) without harmful side effects compared with common alfalfa dust when application rates of alfalfa dusts with high contents of Se being 4 % and 6 %.(2)The effects of Se and Co fertilization on the quality of milk quality while transmitted through SPFAC Although alfalfa hay (rich in Se) could enhance cows forage conversion efficiency,they affect milk qualities, fat and protein in milk were decreased by 5 %-10 %, Lactose and SNF kept relative stable. Alfalfa hay( rich in Se and Co) could enhance fat 22.15%, protein kept stable, Lactose and SNF were dicreased significantly.(3)The effects of Se and Co fertilization on the quality of animal products while transmitted through SPFAC Alfalfa dust( rich in Se and Co) had no significant effects on contents protein, fat and Carbohydrate on rabbit and chicken, contents of some trace elements ,such as Fe,Cu and Zn were raised to some extent, contents of Se was enhanced more significantly.(4)The effects of Se and Co fertilization on Se content of animal products while transmitted through SPFAC When additive contents of alfalfa meal (rich in Se and Co)account for 5% of ration, Se contents of animal products (rabbit , chicken and rat)could be enhanced significantly, there were more significant conrelation(P﹤0.01)among Se accumulation amount in animal products, Se accumulation amount in pasture and Se applied amount in soil .This paper analysed additional benefits and critical techniques of Se and Co utilization in SPFAC, aims of which was to not only secure application of trace elements in forage and animal production, but also realize their multiple benefits in SPFAC. The results have great theoritical meaning and pratical value for safe production of forage and animal food products, which also was vital important to set up standardization production regulations as well as promote animal husbandry industrialization. |
