ABSTRACT
The increase in global temperature and consumers' welfare has increased the use of phytogenic feed additives (PFA) to mitigate the negative effects of heat stress on chickens in recent years. Various bioactive compounds capable of improving the thermotolerance of broiler chickens during exposure to thermal challenges have been identified in different plant species and parts. This review is an overview of the roles of bioactive compounds of different PFA, such as polyphenols and flavonoids, antioxidants, growth-promoting and immune-modulating agents, in heat stress management in broiler chickens. Common PFA in use, particularly in tropical environments, are also discussed. An understanding of the roles of the PFA in chickens' thermotolerance could further stimulate interest in their use, thereby improving the birds' productivity and addressing consumers' concerns. This review collates the existing data on the roles of herbs in mitigating heat stress on chickens and highlights future research perspectives.
Subject(s)
Biodiversity , Chickens , Animals , Temperature , Antioxidants , Animal Feed/analysisABSTRACT
The aim of the study was to investigate the effects of dietary alpha-ketoglutarate (AKG) on the faecal bacteria composition of suckling piglets after supplementation of AKG to the diet of lactating sows. After farrowing, the sows were assigned to either a normal lactation diet (control group, n = 12) or a diet supplemented with 0.25% AKG (AKG group, n = 12) based on body weight (BW) and parity. During the 21-d suckling period, BW and diarrhoea occurrences of piglets were recorded daily, while faeces were sampled weekly from sows and piglets. The levels of pH, ammonia, short-chain fatty acids (SCFA) and lactate in the faeces of piglets were determined. In particular, bacteria profiles in faeces of sows and their suckling piglets were examined by Illumina sequencing. The results showed that the AKG diet altered the faecal bacteria composition in sows during the 21-d lactation period, leading to increases (p < 0.05) in the abundances of genera Prevotella, Lactobacillus, Bacteroides and Methanobrevibacter, but decreases (p < 0.05) in the abundances of genera Oscillospira and Dorea. AKG supplement to the sows during lactation indirectly enhanced (p < 0.05) bacterial richness and SCFA levels (especially, acetate) in the faeces of piglets during the 21-d suckling period. It is suggested that maternal AKG supplementation alters the composition of faecal bacteria in the sows, and increases the faecal bacteria richness and acetate levels in the piglets, which might be associated with an enhanced growth performance of piglets.
Subject(s)
Feces/microbiology , Ketoglutaric Acids/metabolism , Sus scrofa/microbiology , Animal Feed/analysis , Animals , Animals, Newborn , Diet/veterinary , Dietary Supplements/analysis , Dose-Response Relationship, Drug , Female , Ketoglutaric Acids/administration & dosage , Lactation , Random Allocation , Sus scrofa/metabolismABSTRACT
The aim of the study was to investigate if dietary alpha-ketoglutarate (AKG) supplementation may improve the performance of lactating sows and their suckling piglets. After farrowing, 24 lactating sows (Large White × Landrace) with similar body weight (BW) were assigned to the control and AKG groups based on parity, and their lactation diets were supplemented with 0.00 or 0.25% AKG, respectively. It was found that supplementing the diet of lactating sows with 0.25% AKG enhanced growth performance of the suckling piglets from d 7 to d 21 of the lactation period, improved villus height of ileum and tended (p = 0.085) to increase mean volumetric bone mineral density of femur in the weanling piglets. In the lactating sows, dietary supplementation of AKG decreased plasma urea level on d 14 of lactation, decreased plasma calcium (Ca) concentrations from d 7 to d 21 of lactation and increased lactose and Ca levels in ordinary milk. Thus, it was proposed that AKG supplementation stimulates the capacity for lactose synthesis and Ca uptake in the mammary gland, thereby altering the composition of the ordinary milk which might be associated with the enhanced performance of piglets during the suckling period. These findings could lead to a better application of AKG in lactating nutrition, and therefore, promoting pork production.
