Acute heat stress and dietary methionine effects on IGF-I, GHR, and UCP mRNA expression in liver and muscle of quails

Effects of Transport Duration and Environmental Conditions in Winter or Summer on the Concentrations of Insulin-Like Growth Factors and Insulin-Like Growth Factor-Binding Proteins in the Plasma of Market-Weight Pigs

In previous work using market-weight pigs, we had demonstrated that insulin-like growth factors (IGFs) and insulin-like growth factor binding proteins (IGFBPs) are regulated during shipment characterized by changing conditions of stress due to loading or unloading, transportation, lairage, and slaughter. In addition, we found in a previous study that IGFBP-2 concentrations were lower in pigs transported for longer periods of time. Therefore, we performed a more detailed study on the effects of transport duration and season on the plasma concentrations of IGFs and IGFBPs in adult pigs. For the study, exsanguination blood was collected from 240 market-weight barrows that were transported for 6, 12, or 18 h in January or July. IGF-I and -II were detected using commercial ELISAs whereas IGFBPs were quantified by quantitative Western ligand blotting. In addition, established markers of stress and metabolism were studied in the animals. The results show that plasma concentrations of IGFBP-3 were significantly reduced after 18 h of transport compared to shorter transport durations (6 and 12 h; p < 0.05). The concentrations of IGF-I in plasma were higher (p < 0.001) in pigs transported 12 h compared to shorter or longer durations. Season influenced plasma concentrations of IGFBP-3 and IGF-II (p < 0.05 and p < 0.01, respectively). Neither transport duration nor differential environmental conditions of winter or summer had an effect on glucocorticoids, albumin, triglycerides, or glucose concentrations (p > 0.05). However, low-density lipoprotein concentrations decreased after 18 h compared to 6 h of transport (p < 0.05), whereas high-density lipoprotein concentrations were higher (p < 0.05) in pigs transported for 12 or 18 h compared to those transported for only 6 h. Our findings indicate differential regulation of IGF-compounds in response to longer transport duration or seasonal changes and support current evidence of IGFs and IGFBPs as innovative animal-based indicators of psycho-social or metabolic stress in pigs.

A comparison of two sources of methionine supplemented at different levels on heat shock protein 70 expression and oxidative stress product of Peking ducks subjected to heat stress

The aim of this study was to examine the effects of different sources and levels of methionine (Met) on Heat shock proteins HSP70 expression and protein carbonylation in liver, HSP70 expression and malondialdehyde (MDA) concentration in intestine under heat stress conditions during summer. A total of 720 (4 days old) Peking ducks were placed 20 per pen into six replicates for each of the six treatments with a 2 × 3 factorial arrangement, such that two sources of Met (DL-methionine [DLM] and DL-2-hydroxy-4-methylthiobutyrate [HMTBA] were supplemented at three different levels (0.05%, 0.20%, or 0.35% on as-fed basis respectively). The experiment was divided into a starter (day 4-16) and a grower (day 17-35) period. Diet supplemented with 0.35% Met significantly up-regulated the HSP70 mRNA expression in duodenum, jejunum and ileum on day 16 and 35 as well as in liver on day 35 (p < .05) of ducks. HMTBA-supplemented diets increased the HSP70 mRNA expression in duodenum, jejunum, ileum and liver on day 35 (p < .01). An increased MDA concentration was detected in jejunum of birds in 0.35% DLM-supplemented treatment on day 16 (p < .05). And decreased protein carbonylation concentration was found in DLM-supplemented treatment on day 16 (p < .01). The birds fed with 0.35% Met supplemental diet displayed lower hepatic protein carbonylation on day 16 (p < .05). In conclusion, supplementation of 0.35% Met in the duck diet showed up-regulated HSP70 expression in small intestine and liver, which may provide new perspective to the mechanism of Met function. At the same time, DLM supplemented in diet may ameliorate oxidative status of liver, while HMTBA supplementation may partially improve the intestinal oxidative status of Peking ducks.

Short-term methionine supplementation during the early post-partum period in primiparous rabbits improves prolificacy associated with an increase in serum concentrations of IGF-I

The aim of this study was to evaluate the effects of methionine supplementation on energy metabolism and reproductive performance during the early post-partum period in primiparous does. Forty nulliparous New Zealand White does were used. Females were randomized in two groups at calving: the control group (n = 20) was fed with the basal diet, and the methionine group (n = 20) was fed the basal diet plus 1 g/animal/day of methionine from the day of calving to 4 days post-partum. Results showed that methionine supplementation increased (p = 0.032) the concentration of insulin-like growth factor-1 with respect to control group 4 days post-partum. It similarly increased the prolificacy (p = 0.03), the number of kits born alive per litter (p = 0.06) and the body gain weight of the litter during supplementation (p = 0.035). These results were observed despite the does in the methionine group having a deeper negative energy balance than the does in the control group. Finally, methionine supplementation did not affect receptivity (p = 0.23), fertility (p = 0.49), the number of kits born dead per litter (p = 0.86) insulin and metabolites as glucose, non-esterified fatty acids and triglycerides. In conclusion, our results show that methionine supplementation during the first 4 days of the post-partum period in rabbits increases total litter size and the corporal weight of kits and is associated with an increase in blood concentration of IGF-1.