Comparative assessment of native, crossbred and exotic pigs during different seasons (winter, spring and summer) based on rhythmic changes in the levels of serum cortisol, lactate dehydrogenase levels and PBMC HSP70 mRNA expression pattern

A systematic review on the trend of transcriptomic study in livestock: An effort to unwind the complexity of adaptation in a climate change environment

Heat stress has been proven to cause negative effects on livestock leading to lower productivity and economic value. Understanding how heat stress manifests within an animal's body is the first step in devising a heat stress mitigation strategy; transcriptomic studies are one of the methods used. Here, using a systematic literature review methodology, we examine the recent decade of transcriptomics' application to the study of livestock adaptation. We identified 152 studies that met our criteria for using transcriptome methods to heat stress adaptation and were published within the last ten years. Our analysis demonstrates the growing popularity and application of transcriptome approaches in the investigation of the response of ruminants, pigs, and poultry livestock to heat stress. Majority of the works was done in chicken and cattle using multiple organs as the sample, with qRT-PCR as the most employed technique. It has been established that a variety of biomarkers can be used to assess animals under heat stress, such as the HSPs, ILs, and TLRs. Although transcriptomics has lately been employed extensively to uncover the mechanism of heat adaptation, this adaptive feature's complex mechanism remains unclear, leaving many knowledge gaps for investigation. A more complex studies involving more various cell types, organs, or even model organisms using multi-omics approach could be the future research direction in understanding the heat stress effects on livestock better.

Tracing the genetic footprints: India's role as a gateway for pig migration and domestication across continents

This study explored the maternal genetic diversity in the pig genetic resources of India by analyzing a mitochondrial D-loop fragment and comparing it with the corresponding sequences of previously published studies involving domestic pigs and wild boars. Sequencing of 103 samples representing different domestic pig populations revealed existence of 32 maternal haplotypes. The indices of haplotype and nucleotide diversity in Indian domestic pigs were 0.9421 and 0.015, respectively. Median-Joining network revealed that Indian pigs belong to Clade A and show conformity to 6 haplogroups reported worldwide (D1a, D1a1, D1a2, D1e, D1h and D3a). Among these, D1e and D1a2 were shared with Asian wild boars too. Interestingly, haplotype sharing was evident between Indian pigs and samples from other countries representing Africa, Asia, Europe and Oceania. This study substantiates India's contribution as a possible pig domestication center and highlights the importance of the Indian subcontinent in dispersal of the species to other continents. Additionally, genetic evidence suggested the influence of trading routes and historical interactions in shaping pig genetic exchange. Overall, this investigation provides valuable insights into the genetic diversity, historical migration, and domestication of Indian domestic pigs, contributing to the broader understanding of global pig genetic resources and their evolutionary history.

Physiological, blood-biochemical and behavioural changes of Ghoongroo pigs in seasonal heat stress of a hot-humid tropical environment

The present study investigated the effect of seasonal heat stress on the physiological, behavioural and blood bio-chemical profile of adult Ghoongroo pigs (1.5-2 years of age) of different physiological groups. Thirty Ghoongroo pigs (10 boars, 10 non-pregnant sows and 10 pregnant sows) were allotted to individual pens. The study continued for 1 year covering three main seasons, i.e. summer (March-June), rainy (July-October) and winter (November-February) season. Temperature humidity index was significantly (P < 0.05) higher in summer (83.2 ± 0.47) followed by rainy (68.5 ± 1.13) and winter (66.8 ± 0.67) seasons, which indicated that pigs were exposed to heat stress during summer. Rectal temperature and pulse rate were not affected by group × season interaction but were affected by group (P = 0.002) and season (P < 0.001), which were usually greater during summer than during winter and in boars than in pregnant sows. Respiration rate was affected by group × season interaction (P = 0.002), which was greater in boars than in non-pregnant and pregnant sows during summer and rainy season but was similar in winter among the groups. Total erythrocytes, leucocytes counts, and cortisol levels were influenced by group (P < 0.001), season (P < 0.001) and group × season interaction (P < 0.001), which increased in summer compared with winter. Sodium and potassium concentrations in serum were not affected by group and group × season interaction but were affected by season (P < 0.001), which were lower in summer than in winter. All behaviour activities (standing, resting and roaming time, urination, fighting and drinking frequency) were affected by group (P < 0.001), season (P < 0.001) and group × season interaction (P < 0.001), except eating time that was only influenced by season. The present study suggested that Ghoongroo pigs experienced heat stress during summer, which was reflected in physiological, blood-biochemical and behavioural alterations.

Modeling of Heat Stress in Sows Part 2: Comparison of Various Thermal Comfort Indices

Heat stress has an adverse effect on the production performance of sows, and causes a large economic loss every year. The thermal environment index is an important indicator for evaluating the level of heat stress in animals. Many thermal indices have been used to analyze the environment of the pig house, including temperature and humidity index (THI), effective temperature (ET), equivalent temperature index of sows (ETIS), and enthalpy (H), among others. Different heat indices have different characteristics, and it is necessary to analyze and compare the characteristics of heat indices to select a relatively suitable heat index for specific application. This article reviews the thermal environment indices used in the process of sow breeding, and compares various heat indices in four ways: (1) Holding the value of the thermal index constant and analyzing the equivalent temperature changes caused by the relative humidity. (2) Analyzing the variations of ET and ETIS caused by changes in air velocity. (3) Conducting a comparative analysis of a variety of isothermal lines fitted to the psychrometric chart. (4) Analyzing the distributions of various heat index values inside the sow barn and the correlation between various heat indices and sow heat dissipation with the use of computational fluid dynamics (CFD) technology. The results show that the ETIS performs better than other thermal indices in the analysis of sows' thermal environment, followed by THI2, THI4, and THI7. Different pigs have different heat transfer characteristics and different adaptability to the environment. Therefore, based on the above results, the following suggestions have been given: The thermal index thresholds need to be divided based on the adaptability of pigs to the environment at different growth stages and the different climates in different regions. An appropriate threshold for a thermal index can provide a theoretical basis for the environmental control of the pig house.

Study on the effect of seasonal variation on expression of serum biochemicals in pigs

Pigs are particularly susceptible to heat stress because of their more sub-cutaneous fat with little or non-functional sweat glands. Pigs depend on panting as primary mechanism of heat dissipation and/or wallowing. Therefore, a study was conducted to generate basic information on certain blood biochemicals of pigs reared in high humid climatic condition. For the purpose, blood samples were collected randomly from 400 female pigs (6–12 month of age) during summer and winter of the year. The analysis of THI has shown an increase in the study area since 2012 to 2018. The hematological study of the pigs revealed a variation in respect of Hb and TEC with the season. Estimation of different enzymes showed increase with the increase of THI. The activity of enzyme, hormones except leptin was accelerated. Expression of IGF 1, HSP 70 and HSP 90 was also affected with the change of THI. The level of Kisspeptin and FSH β receptor showed difference between two seasons of the year. However, the level of Kisspeptin and FSH β receptor in serum of the experimental animals was found to be insufficient to initiate puberty till 12 months of age. It can be concluded that the pigs reared in semi-intensive system under high humid climatic condition did not attain puberty up to one year of age.