Arth David Sol Valmoria Ortega

Heat stress (HS) can impair the pigs' intestinal integrity, jeopardizing nutrient and mineral digestibility. Our study aimed to investigate HSs' impact on the ileal digestibility of nutrients and minerals in pigs and whether high dietary antioxidants...

The gastrointestinal tract (GIT) is a complex, dynamic, and critical part of the body, which plays an important role in the digestion and absorption of ingested nutrients and excreting waste products of digestion. In addition, GIT also plays a vital role in preventing the entry of harmful substances and potential pathogens into the bloodstream. The gastrointestinal tract hosts a significant number of microbes, which throughout their metabolites, directly interact with the hosts. In modern intensive animal farming, many factors can disrupt GIT functions. As dietary nutrients and biologically active substances play important roles in maintaining homeostasis and eubiosis in the GIT, this review aims to summarize the current status of our knowledge on the most important areas.

In Laos, pork is the second most common meat source after fish and its demand is constantly growing annually. Recently, pork has been in short supply in urban and rural areas, forcing the Lao government to import thousands of tons from neighbouring countries, particularly Thailand, Vietnam, and China. In view of the earlier-mentioned, this study aimed to look at the current situation of pork production and supply in Vientiane Capital (VC) and the prospects for pork production in VC, Laos. In 2020, Laos had a pig population of about 4.3 million, with over 91.0% being native pigs and only 366,000 heads being European pig types, with over 54.0% being reared in VC. In 2019, Laos had 578 commercial pig farms, with 188 farms (33.0%) of which were located in VC. Despite the fact that most of the commercial pig farms are located in VC, pork demand is still high, with the consequence that consumers need to pay a high price. For example, in 2020, the average price of pork was 46,000 LAK/kg ($ 4.00); it rose up by 22.0% against 2019 and by 11.0% from 2015. Several feed raw materials (maize, cassava, and rice bran) are produced in VC, and nearby provinces, which the farmers can use to combat the dramatic changes or instabilities of feed price. We concluded that there is a high potential to develop pig production in VC, especially local breeds considering the high demand for premium pork and more available raw feed materials.

The physiological status of poultry can be disturbed by different stressors that may lead to oxidative stress conditions. Oxidative stress activates defense systems, which mitigates the adverse effects. Several lines of the poultry defense system exist, including enzyme systems such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and non-enzymatic antioxidants such as Glutathione (GSH). Methionine—a vital amino acid in poultry nutrition—plays a significant role in protein synthesis, transsulfuration, and transmethylation and is also involved in several biochemical pathway activations that can affect the antioxidant system. Therefore, this review aims to summarize the current knowledge on the role of methionine in poultry under heat stress or managing stress, on the antioxidants responsible for scavenging free radicals (GSH) and those responsible for detoxification (SOD, CAT, and GPx). Different levels of methionine supplementation above the requirement (up to 1% Met added on the basal diet) have been tested on the antioxidant status of poultry. It has been shown to improve the antioxidant status and reduce oxidative stress. The results of many experiments on poultry supplemented with diets of different methionine sources indicate that L-Met has good potential to stimulate the antioxidant status of poultry.

Heat stress (HS) can have detrimental effects on intestinal integrity and can jeopardize the digestibility performance in pigs. With prolonged exposure to heat, some thermoregulatory processes in pigs are potential causes for electrolyte imbalance. The adverse effects of HS on mineral digestibility and electrolyte balance are not widely studied and information on its abatement through vitamin and micro-mineral supplementation in combinations above the recommended level in pigs is limited. The aim of this study is to research this area. Thirty-six Danbred hybrid barrows (65.1 ± 2.81kg) were distributed among the four treatments (n = 9 per treatment): (1) thermo-neutral (19.5 ± 0.9 °C, RH- 85.9 ± 7.3%)+ control diet (TC) (NRC, 2012), (2) HS (28.9 ± 0.9 °C, RH- 60.4 ± 4.3%) + control diet (HC), (3) HS +diet with elevated levels of vitamins (vitamin E and C) and micro-minerals (Zn and Se) (HT1), and (4) HS + diet with further elevation of vitamins and micro-minerals (HT2). Plasma samples were collected on days 7 and 21 of the experiment to investigate electrolyte concentration. During the experimental period, feces samples were collected from pigs placed in digestibility cages (six pigs from each treatment) to investigate the digestibility of Ca, P, Na, Se, and Zn. HS did not decrease the digestibility of minerals, but elevated supplementation of the selected vitamins and trace minerals improved it significantly. HS caused a significant decrease of Cl⁻ (p < 0.01) in plasma, indicating an imbalance. In conclusion, pigs can have some resilience against heat stress in terms of mineral digestibility. Proper vitamin and trace mineral supplementation are key factors in the ability of pigs to overcome the negative effects of HS.

The Philippine livestock industry is a vital component in the country's agricultural sector. It contributes around 18.23 percent of the gross output value in agriculture and provides livelihood to many people living in rural areas, signifying its importance with regard to the country’s economy. The constantly increasing demand for animal protein associated with the increase of the world’s population led to the intensification of livestock production, realized through the various initiatives implemented by the government, such as the import of high producing purebreds of various species. This strategy greatly influenced the country's animal genetic resource's diversity and increased food animals' population; however, it impacted the native breeds of food animals. Understanding the characteristics, performance and value of native and exotic breeds is essential to prioritize their livestock industry existence. Thus, this paper aims to characterize various native and exotic breeds of livestock in the Philippines and assess the current conservation of native animals.

Heat stress (HS) significantly affects the performance of pigs by its induced stressors such as inflammation, hypoxia and oxidative stress (OS), which mightily strain the intestinal integrity and function of pigs. As heat stress progresses, several mechanisms in the intestinal epithelium involved in the absorption of nutrients and its protective functions are altered. Changes in these mechanisms are mainly driven by cellular oxidative stress, which promotes disruption of intestinal homeostasis, leading to intestinal permeability, emphasizing intestinal histology and morphology with little possibility of recovering even after exposure to HS. Identification and understanding of these altered mechanisms are crucial for providing appropriate intervention strategies. Therefore, it is this papers’ objective to review the important components for intestinal integrity that are negatively affected by HS and its induced stressors. With due consideration to the amelioration of such effects through nutritional intervention, this work will also look into the capability of dietary antioxidants in mitigating such adverse effects and maintaining the intestine’s integrity and function upon the pigs’ exposure to high environmental temperature.