Effect Of Different Level Of Starch And Fat During Late Gestation On The Reproductive Performance Of Multiparous Sows

A one-factor experiment was designed to investigate the effect of fat and corn starch as the source ofenergy during late gestation (from seventy days of gestation to farrowing ) on the reproductive performance of prolificacy multiparous sows under the same diets energy level . Fourteen LandranceX Meishan crossbred ,sixth-parity sows were blocked randomly to 4 treatments (2.0%, 8.0%, 14.0%, 20.0% of fat level with starch level 63.25%, 50.53%, 37.08%, 24.19% respectively) on d 70 of gestation by the body weight at mating . The sows were given semi-purity diets, which were consist of base diets and differential ratio of fat and corn starch .The digestable energy of diets were 3.3Mcal/kg and crude protein level were 12%.Three kinds of oils, rapeseed oil , soybean oil and lard , were blended as the fat source , in which the ratio were designed to 1:2:2 .Diets provided similar amounts of Ca, P .mineral, vitamin and fiber to all sows . During gestation, the sows in each treatment were fed the assigned amount of experimental diet, feed intake were 1.0, 1.2, 2.0 fold of energy for mantaince in early, mid- and late gestation All sows were allowed ad libitum access to lactational diet during lactation. The results showed :1 .Supplying same energy level to sows during late gestation , with the fat level increased in diets , the total number born .number born alive, litter weight at birth also increased.2.Supplying same energy level to sows during late gestation , with the fat level increased in diets , the ADF1 was significantly decreased during the first seven days of lactation (P>0.01) .Diets with 2.0 % of fat level compared to 8.0% ,14.0 % and 20.0 % of fat level , increased sows' ADFI during the first seven days of lactation by 20.1%, 30.1% and 36.7% respectively ..3. Supplying same energy level to sows during late gestation , diets with8.0% ,14.0% and 20.0 % of fat level compared to 2.0% of fat level significantly (P<0.05) increased the fat concentration ofcolostrum .Diets with 9.1% of fat and 48.1% of starch during late gestation , the fat concentration of colostrum was 5.7%. (P<0.05) .4. Supplying same energy level to sows during late gestation , diets with 20.0%of fat level decreased the digestibility of energy (P<0.05) ,but 8.0% and 14.0% of fat in diets increased the digestibility of energy (P<0.05) . Sows intaked diets with 8.0 - 9.0% of fat (fat intaked between 5.43 and 5.71g/BW0.75/d, with the same .starch intaked between 31.44 and 30.56 g/BW0.75/d ) during late gestation ,the ADE/GE and AME/GE of energy was optimal.5. Supplying same energy level to sows during late gestation , with the fat level increased in diets , the body weight and backfat of sows before farrowing increased,also increased body weight and backfat lost during lactation, and no significantly effects on WEI of sows . It is concluded that :1.Under the same energy level (3.3Mcal DE/kg) , fat or starch as the energy source of sows during late gestation has different nutritional effect on sow's reproductive performance ,fat compared to starch was more important to improve sow's reproductive performance.2. Under the same energy level (3.3Mcal DE/kg) in this experiment, the optimal fat level (8~ 10%) and starch level (50.5 ~ 45.9%) in sows diets ,or sows fat intaked between 5.12 and 6.39g/BW0.75/d, with the same .starch intaked between 32.32 and 29.46g/BW0.75/d during late gestation can improve sow's reproductive performance .