Effects Of Different Energy Levels And Sources Body Composition, Age Of Puberty And On Estrus Ratio Of Gilts

属性不符 This study was conducted to determine the effects of different energy sources and energy levels on estrus ratio,age of puberty,body composition and estrus behavior of gilts.54(Landrace×Yorkshire) gilts with similar weight(59±4.2 kg) and age(147±3 day) were randomly allotted into 6 treatments with 9 replicates per treatment and 1 gilt per replicate in a 2(starch group and fat group)×3(low,middle and high level of energy)factorial experiment.Three energy levels:2.8,3.2 and 3.6 times the maintenance level were formulated in 60-80kg;2.45,2.8 and 3.15 times the maintenance level were formulated in 80-120kg(the maintenance level was 460kJ DE/kg BW^0.75).The middle level of energy refer to NRC(1998).The high and low level of energy were based on the middle leve to increase or decrease by 12.5%.Feed intake of high level of energy group was lower than ad-libitum feed intake,the amount of other nutritional ingredient was equally uptake except energy.This study calculated lipids content and lean content by butcher experiment.These results indicated that:1.Lipids content,backfat thickness,lean content,the ratio of lipids content to lean content and ADG increased with energy level enhancing.They were extremely significant higher at high level of energy group than low level of energy group (P＜0.01),however,they were no significant difference between middle and low level of energy group(P＞0.05),except ADG was significant higher at middle level of energy group than low level of energy group(P＜0.05).ADG and lipids content of high level of energy group were extremely significant higher than middle level of energy group,backfat thickness was significant higher than middle level of energy group(P＜0.05),while backfat thickness,lean content,the ration of lipids content to lean content were no significant difference(P＞0.05).In view of the energy source,lipids content,backfat thickness,lean content,the ration of lipids content to lean content and ADG were higher in fat group than starch group(P＞0.05).2.There was no significant effects of energy level on puberty age(p＞0.05).The puberty age was 208d,218d and 209d at low,middle and high level of energy, respectively,it was advanced 12 days in fat group compared to starch group whereas there was no significant difference between them(P＞0.05).Besides,the puberty age was advanced 11d,11d,12d at low,middle and high energy level of fat group compared to starch group.3.The estrus ratio of gilts increased with the increase of energy level(P＞0.05).The estrus ratio of high energy group was higher than of low and middle level of energy group,28.5%and 7.5%respectively.The estrus ratio were 77.8%both in starch and fat group at low level of energy;and it was 100%in both group at high level of energy,however,it was 88.9%and 100%in starch group and fat group respectively at middle level of energy(P＞0.05).4.Standing reflex ratio of gilt in estrus were affected by energy level and energy source.The puberty standing reflex ratio in high level of energy group was 72%,it was elevated,by12.5%and 1.4%,compared to low and middle level of energy group, respectively.The second standing reflex ratio in high level of energy group was 94% which was higher than low and middle level of energy group,however,it was not significant different(P＞0.05).The second standing reflex ratio was higher than the puberty standing reflex ratio in each level of energy group,however,there were no significant difference(P＞0.05).The puberty and the second standing reflex ratio of starch group were increased by 33.9%and 1%respectively in starch group,compared to fat group.The estrus interval at low level of energy group exceed 21days,but high and low level of energy group all exceed 22 days and the estrus interval of starch group was lower than fat group by 1.7%.5.Lipids content,backfat thickness,the ratio of lipids content to lean content, ovaries weight,uterus weight were extremely significant higher than anestrus gilts (P＜0.01).and estrogen level of estrus gilts were significant higher than anestrus gilts(P＜0.05),Oviduct weight was higher than anestrus gilts,whereas it was not...