Effects of Supplemental Histamine on Gastric Acid Secretion, Digestive Enzyme Activities, Intestinal Microfloral of Early Weaned Piglets

Two experiments were conducted to study the effect of supplemental histamine in the diet of early-weaned piglets. In experiment A, 24 cross bred piglets with an average body weight of 6.10±0. 40 kg, weaned at the age of 28 days, were divided into four groups, fed with basal diet of low dietary copper without (control) or with supplemental histamine at 60, 120, 180μg kg-1 BW. During the two weeks and the third week after weaning, ADG(average daily gain) of piglets were increased by 15.8%(P<0. 05), 9.5%(P< 0.10) by addition of 60μg kg-1 BW histamine, but decreased by addition of 180μg kg-1BW histamine, which also increased the amount of E. coli in colon and the scour incidence. The secretion of gastric acid and pepsin were improved by both dose of supplemental histamine (60, 180μg kg-1BW) and gastric digesta pH were decreased by both. Addition of 60 μg kg-1 BW histamine improved the activities of trypsin, amylase in duodelum digesta. In experiment B, 12 cross bred piglets with an average body weight of 6. 85±0.35 kg, weaned at the age of 28 days, were divided into two groups, fed with basal diet of high dietary copper without (control) or with supplemental 60 μg kg-1 BW histamine. During the two weeks and the third week after weaning, ADG of piglets were increased by 9. 8% (P<0.05), 7. 0% (P<0. 10). The secretion of gastric acid, activities of trypsin and amylase in duodelum digesta, were also improved by addition of 60 μg kg-1BW histamine. The results showed that addition of histamine (60μg kg-1BW) in early weaned piglets could increase the secretion of gastric acid and pepsin, reduce gastric digesta pH and scour incidence, improve activities of trypsin, amylase in duodelum digesta, and the growing performance of early weaned piglets.

Breeding of Mycoplasmal pneumonia-negative Swine Population Using Combination Therapy,Segregated Early Weaning(SEW) and Three-point Production System

In order to explore a breeding method for mycoplasmal pneumonia-negative swine population, the purifying effects of combination therapy, SEW and three-point breeding and management system on Mycoplasma hyopneumoniae were investigated in this study. After the processes of screening pregnant sows, programmed therapy for sows, SEW, three-point breeding and management in the barrier isolation system and programmed therapy for piglets, the newly-bred piglets were monitored as long as four months by serum antibody detection of Mycoplasma hyopneumoniae and fluorescent quantitative PCR of nose swabs. The results showed that when the newlybred five batches of piglets were older than 35 d, they were all negative by serum antibody detection and nose swab antigen detection. Therefore, the combination therapy, SEW and three-point production and management system can effectively purify Mycoplasma hyopneumoniae, providing theoretical basis and clinical experience for the control and purification of domestic mycoplasmal pneumonia.

Distinct neuronal excitability alterations of medial prefrontal cortex in early-life neglect model of rats

Object:Early-life neglect has irreversible emotional effects on the central nervous system.In this work,we aimed to elucidate distinct functional neural changes in me-dial prefrontal cortex(mPFC)of model rats.Methods:Maternal separation with early weaning was used as a rat model of early-life neglect.The excitation of glutamatergic and GABAergic neurons in rat mPFC was recorded and analyzed by whole-cell patch clamp.Results:Glutamatergic and GABAergic neurons of mPFC were distinguished by typi-cal electrophysiological properties.The excitation of mPFC glutamatergic neurons was significantly increased in male groups,while the excitation of mPFC GABAergic neurons was significant in both female and male groups,but mainly in terms of rest membrane potential and amplitude,respectively.Conclusions:Glutamatergic and GABAergic neurons in medial prefrontal cortex showed different excitability changes in a rat model of early-life neglect,which can contribute to distinct mechanisms for emotional and cognitive manifestations.

Technical Measures for Rapid Propagation of Improved Beef Cattle

Based on early weaning in calves,hormone induction in young calves,intravital egg collection,in-vitro fertilization and embryo transfer which serve as major breakthroughs in livestock breeding technology,the techniques of hormone induction and in-vitro fertilization were integrated,not only to solve the problem of obtaining oocytes by hormone induction in adult cows in production practice,but also to obviously improve production efficiency.The application of this technology can help accelerate the cultivation process,shorten the generation interval,promote the industrialization and improve the economic benefits of beef cattle breed.This paper provides a reference for the research and application of new breeding and propagation techniques of beef cattle.

Effects of weaning age on growth, nutrient digestibility and metabolism,and serum parameters in Hu lambs

This study was conducted to investigate the effect of weaning age on growth performance, nutrient digestion and metabolism, and serological indicators, and to obtain an optimal weaning age in Hu lambs.Forty-eight newborn Hu lambs(birth weight, 2.53 ± 0.14 kg) were randomly divided into 4 groups. The lambs in control group(ER) suckled their dams. The lambs in other three experimental groups were weaned on milk replacer at 10.20, and 30 days of age(EW10, EW20, and EW30 groups),respectively. The results were as follows: 1) lambs in EW10 and EW30 groups had a lower(P < 0.05) ADG than those in ER group within 10 days post-weaning; the weaned lambs began to show a higher(P < 0.05) ADG than those in ER group after 20 days post-weaning. 2) EW10 and EW20 groups had a higher(P < 0.05) creep feed intake than EW30 and ER groups from 15 to 60 days of age. 3) The apparent digestibility of dry matter, organic matter, gross energy, nitrogen, ether extract and phosphorus, and the deposition of nitrogen and phosphorus did not differ(P > 0.05) among groups; however, the apparent digestibility and deposition of calcium in early weaned lambs were lower(P < 0.05) than those in ewe-reared lambs. 4)The albumin content in EW30 group was lower(P < 0.05) than that in ER group; the globulin content in EW30 group was higher(P < 0.05) than that in other groups; the content of serum insulin-like growth factor-1 in weaned lambs tended to increase compared with lambs in ER group. Finally, the growth rate of lambs decreased within 10 days post-weaning, but early weaning boosted creep feed intake, leading to better growth and health later in life. The Hu lambs can be weaned on milk replacer and creep feed at 10 days of age.

Oral administration of dibutyryl adenosine cyclophosphate improved growth performance in weaning piglets by enhancing lipid fatty acids metabolism

Dibutyryl adenosine cyclophosphate(dbc AMP-Ca), an analog of cyclic adenosine monophosphate(c AMP), plays greater roles in regulating physiological activities and energy metabolism than c AMP. The aim of this study was to investigate the effect of oral administration of dbc AMP-Ca on growth performance and fatty acids metabolism in weaning piglets. A total of 14 early weaning piglets(7 ± 1 d of age,3.31 ± 0.09 kg, Landrace ? Large White ? Duroc) were randomly divided into 2 groups: control group and dbc AMP-Ca group, and the piglets received 7 m L of 0.9% Na Cl or 1.5 mg dbc AMP-Ca dissolved in 7 m L of 0.9% Na Cl per day for 10 d, respectively. The results showed that the average daily gain(ADG)increased by 109.17%(P < 0.05) in the dbc AMP-Ca group compared with the control group. Besides,dbc AMP-Ca significantly decreased blood high density lipoprotein cholesterol(HDLC) concentration(P < 0.05) and significantly increased blood low density lipoprotein cholesterol(LDLC) concentration(P < 0.05) compared with the control group. Further, liver C18:2 n6 t content significantly increased in dbc AMP-Ca group(P < 0.05) compared with the control group. With the increase of C18:2 n6 t content,the m RNA expression levels of peroxisome proliferator-activated receptor a(PPARa) and hormone sensitive glycerol three lipase(HSL), of which genes are related to lipid metabolism, were also significantly increased(P < 0.05 or P < 0.01). All of the results indicated that dbc AMP-Ca improved the ADG, which was probably done by regulating fatty acids metabolism in the liver of weaning piglets.