| Fluorine is necessary for living things.Appropriate amount of fluoride can promote the calcification of teeth and bones,the transmission of nerve excitement and the metabolism of the enzyme system,but excess and deficiency of fluorine can cause disease.There are many high-fluoride regions in china.Excessive fluoride has serious effects on human health.At the same time,high fluorine also affects livestock production.According to national standards,the maximum allowable amount of fluoride in pig compound feed is 100 mg/kg.In order to study the effects of high fluoride on sow reproductive performance and ovarian development,we built a high-fluorine sow model by adding NaF to the feed of the sow herd.In the experiment,100 healthy 1-month-old piglets were selected from the group of weaned pigs,and 60pigs were selected twice at the age of 2 months.They were randomly divided into 2groups with 5 repetitions in each group and 6 repetitions in each.Starting at 2 months of age,the control group was fed a basic diet(fluorine content 8 mg/kg),the test group were added 500 mg/kg NaF.And there was a slaughter test at 4 months of age.Ovarian tissue was used to analyze differences in the expression levels of genes and proteins related to oxidation and apoptosis,and ocular muscle tissue was used to determine the area of the ocular muscles,muscle system hydraulic power,flesh color,and marbling.At 6 months of age,a biopsy was performed to determine the backfat thickness,eye muscle area,and lean mass rate.Stop feeding at 7 month of age,started to check estrus,artificial insemination and breeding at 8 month of age.After sows Farrowing,recorded the number of births and the piglet’s birth weight.Porcine ovarian granulosa cells were cultured in vitro,and the effects of sodium fluoride on granulocyte survival rate,oxidation level and mitochondrial membrane potential were examined.The experimental results are as follows:1.Production performance:Add 500 mg/kg NaF to the diet,body weight was72.29±2.38 Kg,daily weight gain(ADG)was 0.67±0.02 kg,feed weight ratio(FCR)was 2.96±0.1,backfat thickness(correction)was 21.36±1.03 mm,the muscle system hydraulic power was 37.66±1.85%,the flesh color score was 2±0.63,and the marbling score was 1,and there had no significant difference compared with the control group(P>0.05)at 4 months of age.Eye muscle area(correction)was42.95±1.29 cm~2,and was significantly different from the control group(correction)58.81±2.15 cm~2(P<0.05)at 4 months of age;The body weight was 116.3±2.39 kg,ADG was 0.69±0.01 kg,FCR was 3.57±0.11,backfat thickness(correction)was21.06±0.67 mm,eye muscle area(correction)was 45.48±1.65 cm~2,lean rate was56.69±1.22%,and there had no significant difference compared with the control group(P>0.05)at 6 months of age.2.Reproduction performance:With 500 mg/kg NaF added to the diet in the test group,25 sows were bred,15 sows were pregnant,and the pregnancy rate was 60%.In the control group,25 sows were bred,18 sows were pregnant,and the pregnancy rate was 72%.Compared with the control group,the conception rate was reduced by12%;The litter size was 10.33±0.48,the number of live births in a litter was 10.08±0.63,and the number of healthy births was 9.58±0.56,which had no significant difference with control group(P>0.05).3.Oxidative apoptosis in ovarian tissue:Using qPCR to detect transcript levels of apoptosis marker genes,we found that BAX and BCL2 in ovarian tissue increased by29.04%(P>0.05),16.06%(P>0.05),BAX/BCL2 significantly increased by 12.05%(P<0.05),The mRNA transcription level of CAT and SOD1 decreased by 36.8%(P<0.05)and 30.33%(P<0.05)respectively;Using Western to detect the protein expression levels in ovarian tissue,we found that expression level of BAX,BCL2,CAT and SOD1 were significantly increased by 17.46%(P<0.05)and 34.47%(P<0.05),45.79%(P<0.05)and 33.21%(P<0.05)..4.Impact on ovarian granulosa cells:Porcine ovarian granulosa cells were isolated and cultured in vitro,and NaF was added to the culture medium at different concentrations(0,1,2,3,4,5 mM).The results showed that with the increase of NaF concentration,the survival rate of granular cells showed a downward trend.When the concentration reached 2 mM,the survival rate of ovarian granulosa cells was significantly reduced by 44.28%(P<0.05),the mitochondrial membrane potential was significantly reduced by 84.45%(P<0.05);when the concentration reaches 5 mM,the ROS level of granulosa cells was significantly increased by 43.16%(P<0.05),the GSH level was significantly decreased by 2.05%(P<0.05).Conclusion:Adding 500 mg/kg NaF in the feed to the gilts before mating had no significant effect on production performance and meat quality indicators;the conception rate during estrus was reduced by 12%;the piglet’s birth weight,average litter size had no significant effect.NaF treatment can significantly increased the level of ovarian tissue apoptosis,significantly reduced the expression of antioxidant genes,and significantly increased the content of antioxidant proteins;NaF treatment can reduce the survival rate of ovarian granulosa cells cultured in vitro,reduced the level of mitochondrial membrane potential,and increased the level of ROS,reduced the level of GSH.It is recommended that pig farms in high-fluorine areas pay attention to the detection of fluoride in drinking water and feed.If the fluorine concentration in the feed exceeds the national feed standard of 100mg/kg for a long time,measures need to be taken to remove the fluoride ion. |
