| The study was conducted to investigate the effect of maternal dietary concentrate feeding levels during late gestation on the production performance,embryo development of ewes,and growth and blood metabolites of offspring lambs.Sixty-six primiparous Hu ewes of bigeminal pregnancy were assigned to three treatments with various concentrate to forage in the late gestation.Several parameters were used to examine the effect on the development of ewes and lambs including the growth performance,nutrient digestion,blood metabolites,and embryo development.This study included three experiments and were showed as follows: Experiment 1: Effects of maternal dietary concentrate levels on the growth,embryo development and blood metabolites of ewes in late gestationThe purpose of this study was to investigate the effect of concentrate supplement level on the growth,nutrient digestion,embryo development and blood metabolites of ewes in late gestation.A total of 66 primiparous ewes with two lambs were selected and randomly divided into three groups according to the dietary concentrate levels(50%,40%,and 30% on DM basis,respectively).The forage was consisted of corn silage and peanut vine and fed separately from concentrate until delivery.The experiment commenced on d 90 of gestation and the total feed offered to animals maintained same throughout the experiment.The body weight and abdominal circumference were measured at d 90,120 and 140 of gestation;the blood samples were collected via jugular vein at d 120 and 140 of gestation;on d 120 and 140 of gestation,the nutrient digestion and slaughtered experiment was conducted for nutrient utilization of ewes and body size and embryo development of lambs.The results showed that: 1)the body weight gain of ewes significantly decreased when the concentrate feeding level decreased(P<0.05),while no difference was observed among the three treatments in terms of body weight and abdominal circumference values.2)There was little effect of dietary concentrate levels on pregnancy appendages,amniotic fluid and fetal weight in late gestation of ewes,while the fetal weight had a decreasing trend(0.05?P<0.10)when the concentrate levels decreased.3)Body size and organs weight of fetal in late gestation were similar among the three treatments(P>0.05),while there were decreasing trend in terms of body height,body length and the weight of liver,lung,stomach,small intestine(0.05<P<0.10).However,the heart weight was significant affected(P<0.05).4)The apparent digestibility of DM,gross energy,neutral detergent fiber,and ash of the 30% group was significantly lower than that of the 50% and 40% groups(P<0.05).The apparent digestibility of crude protein of the 40% group was significantly lower than that of the 50% group,but higher than that of the 30% group(P<0.001).5)The serum glucose concentrate of the 40% and 30% group was significantly lower when compared with 50% group on d 120 of gestation(P<0.05).The serum concentrations of acetone and acetoacetate of the 30% group were greater than those for the 50% or 40% group on d 120 and 140 gestation(P<0.05).The serum insulin concentration of the 40% group was greater than that of the 30% group on d 140 of gestation(P<0.05).6)No significant difference was found on lamb birth weight(P>0.05)or body dimensions(P>0.05),expect for body length(P<0.05).Experiment 2: Effects of material dietary concentrate levels in late gestation on the growth performance and serum biochemical parameters of postpartum lambsThe purpose of this study was to investigate the effects of maternal concentrate levels in late gestation on the growth,organ development and serum biochemical parameters of postpartum lambs delivered from the ewes in the Experiment 1,the lambs were fed with the mother milk,and the postpartum ewes were fed the same TMR.At the age of 10 days,per ewe was left only one lamb sucking mother milk until the lambs were 60 days old.Every 10 days,the lambs were weighted,at 20 and 60 days of age,each group was selected 4 males and 4 females for blood collection,and the body size of all the lambs were measured in 0 and 60 days of age.At the 60 days of age,every group was selected 3 male lambs for slaughter experiment.The results showed that: 1)there were no significant effects of maternal dietary concentrate level in late gestation on birth weight and body weight at suckling period(0 to 60 days after birth)(P>0.05),but with the concentrate level decreased,lamb birth weight had a decreased trend(0.05?P<0.10)and body weight at d 40 and 50 after birth had an increased trend(0.05?P<0.10).2)At d 0 after birth,as the concentrate level creased of ewes in late gestation,the body length was significantly decreased(P<0.05);at d 60 after birth,chest depth and curved crown-rump length of lambs were significantly increased with decrease of concentrate(P<0.05).3)At d 10 after birth,with the decrease of dietary concentrate level of ewes in late gestation,lung and liver weights of lambs were significantly decreased(P<0.05);at d 60 after birth,there was no significant difference in organ weight(P>0.05).4)At d 20 and 60 after birth,with the decreasing of dietary concentrate feeding level of ewes in late gestation,serum total antioxidant capacity,superoxide dismutase activity and glutathione peroxidase content of lambs were significantly increased(P<0.05),and serum malondialdehyde content was significantly decreased(P<0.05).Experiment 3: Effects of material dietary concentrate level in late gestation on the growth performance and serum biochemical parameters of postpartum early weaning ewes milk lambsThe purpose of this study was to investigate the effect of material dietary concentrate level in late gestation on the growth performance,nutrient digestion and serum biochemical parameters of postpartum early weaned lambs.The experiment animals were the lambs which were left out in 10 days old at experiment 2,and weaned maternal milk and fed the milk replacer at 10 days old.At the age of 15 days,the lambs were fed the starter,at the age of 20 days were fed alfalfa hay until 60 days of age.Body weight was measured every 10 days,and the body size indexes was measured at the age of 20 and 40 days old of lambs.At d 20 and 60,the blood samples were collected and the serum antioxidant capacity was determined.When the lambs were at 50 days of age,the digestion and metabolism tests were carried out.The results showed that the ewes dietary concentrate levels during late gestation had no significant effect on the birthweight and the weight of the postpartum early weaned lambs at d 10,20,30,40,50,and 60(P>0.05);there was no significant difference in the body size index of body height,chest depth,chest circumference,abdominal circumference,head breadth,head length,straight crown-rump length,curved crown–rump length and body length at d 20 and 60(P>0.05);the lamb apparent nutrient digestibility of DM,OM,GE,CP,EE,NDF,ADF,Ca,P and Ash also differ significantly among the three treatments(P>0.05);with the decreasing of maternal concentrate feeding level,the activity of lambs serum T-AOC and GSH-Px at d 20 and 60 significantly increased(P<0.01),the activity of SOD at d 20 significantly increased(P<0.01),and the SOD activity of 50% group was significantly lower than the 40% group and 30% group at d 60(P<0.05),the content of serum MDA at d 20 significantly decreased with the concentrate level decreased(P<0.01),the MDA content of 50% group was significant higher than the 30% group(P<0.01).In summary,with the decreasing of the dietary concentrate level of ewes in late gestation,the nutrient digestibility decreased,and weight gain was restricted,which resulted in lower blood glucose and higher serum ketone content of the ewes.Under the adjustment of ewe' physiology conditions,the embryonic developments of each treatment group was also effected.There was no significant difference in the postpartum lamb growth,but the level of serum antioxidant significantly increased with the concentrate level decreased no matter in sucking lambs or the early weaning lambs. |
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