Effects of early intermittent maternal separation on behavior, physiological, and growth performance in piglets.

In pig production, the management of piglets by batch lactation due to the increase in litter sizes of sows may result in intermittent early neonatal maternal separation (NMS). We speculated that NMS may affect the piglets cognitive growth performance and health. To determine the extent of the effect, 12 litters of crossbred piglets (Large White × Duroc × Min-pig) were used in this trial. Piglets in the control (Con) group (n = 6) were given a standard feeding method during lactation. Piglets in the experimental group (n = 6) were subjected to the NMS model, in which sows were led out of the enclosure with food every day (8:00-11:00 and 13:00-16:00) starting from postnatal day (PND) 7. During the separation, the piglets were supplemented with milk. All experimental piglets were weaned on PND 35. The piglets were observed for aggression, play, mutual sniffing, and exploratory behavior on PNDs 7, 8, 21, 22, 34, 35, 38, 39, 51, 52, 64, and 65. Physiological indicators, namely serum adrenaline, cortisol, interleukin (IL)-1ß, IL-4, IL-6, and tumor necrosis factor (TNF)-α were measured on PNDs 35, 38, and 65, while piglet growth performance was evaluated during suckling and 1 month after weaning. The results showed that aggressive behavior in the MS group was significantly higher than that in the Con group (P < 0.05). Playful and mutual sniffing behaviors in the MS group were significantly lower than those in the Con group except for PNDs 38 and 39 (P < 0.05). Active exploratory behavior in the MS group was significantly higher than that in the Con group on PNDs 7 and 8, and PNDs 21 and 22 (P < 0.05). The frequency of belly-nosing behavior was significantly higher in the MS group than that in the Con group except for PNDs 64 and 65 (P < 0.05). Compared with the Con group, epinephrine, IL-1ß, IL-6, and TNF-α concentrations on PNDs 35, 38, and 65 were significantly increased in the MS group (P < 0.01), while IL-4 concentration was significantly decreased (PND 35: P < 0.05; PNDs 38 and 65: P < 0.01). Compared with the Con group, the piglet diarrhea rate in the MS group during suckling was significantly increased (P < 0.01), the weaning weight was significantly decreased (P < 0.05), and it had no significant effect on the body weight at the end of the trial (P > 0.05). In conclusion, the early intermittent NMS created stress and affected the growth performance of piglets during suckling. However, the growth rate was improved by compensatory measures during late weaning.

Although management methods, such as split-suckling and foster care, in pig production can improve piglet survival rates, these methods inevitably lead to neonatal maternal separation which is an early stress on the body, and can have serious negative effects on the body. In this experiment, we investigated the effect level of neonatal maternal separation on behavior, physiology, and growth performance of piglets. The study found that early intermittent maternal separation leads to anxiety and behavioral changes in piglets, negatively affecting diarrhea rates and weaning weights in suckling piglets, but the effects on growth performance in lactating piglets can be ameliorated during the nursing period.

[Effect of shuganjianpifang on the expression of BCL-2 and BAX in rats livers with hepatic fibrosis].

OBJECTIVE: To observe the effect of shuganjianpifang on BCL-2, BAX expressions in livers of hepatic fibrosis rats and its mechanism. METHODS: Sixty SD rats were randomly divided into six groups. Rat liver fibrosis was induced by CCl4 twice a week for 12 weeks. Shuganjianpifang was used daily via lavage at 7th week for 6 weeks. The contents of ALT, AST, T-BiL and Alb in serum were measured. Liver samples were taken to examine the degree of liver fibrosis by HE staining. The experessions of BCL-2 and BAX were detected by immunohisto chemistry. The expression of BCL-2, BAX mRNA was detected by RT-PCR technology. RESULTS: As compared with the fibrotic model group, shuganjianpifang significantly reduced histopathological change, such as steatosis, deposition, decreased the contents of ALT, AST and T-BiL, up-regulated the expression of Alb. Meanwhile shuganjianpifang could effectively inhibit the expression of BAX, significantly enhanced the expression BCL-2 in liver fibrosis rats. CONCLUSION: Shuganjianpifang can resist hepatic fibrosis possibly by up-regulating BCL-2 expression and down-regulating BAX expression.