Goat as the ideal climate-resilient animal model in tropical environment: revisiting advantages over other livestock species.

In the agriculture sector, livestock are considered extremely resilient to climate change and are tipped to play a significant role in ensuring food security to meet the increased demands of growing human population by 2050. Compared to other domestic species, goats are considered the ideal animal model for climate change due to its high thermal and drought resilience, ability to survive on limited pastures, and high disease resistance. This review is therefore a revisit to the advantages of rearing goats over other livestock species under current and future trends of changes in climate, particularly to cope with recurrent multiple stressors such as heat load, and lack of water and feed. In summary, goats, also called as poor man's cow, are preferred by the small-scale landless farmers due to their low input and assured higher output system, as they require low initial investment, with minimum specialized facilities and labors. Furthermore, they perceive goats as better resilient animal to cope with multiple stressors such as heat load, and water and feed scarcity, and possess better skills to cope with bush, when compared with sheep and cattle. The unique capacity for employing behavioral plasticity and morphological features of goats gives them clear advantage over sheep and cattle, when coping with seasonal biotopes, and experiences of water and feed shortage. When facing with low-quality feed, they also are superior to cattle and sheep to digest dry matter and to recycle nitrogen. Additionally, goats have superior ability to desiccate feces and concentrate urine, when compared with sheep and cattle. These advantages make goat the go-to species for efficiently countering the adversities associated with climate change and to optimize appropriate economic return through sustained production. Therefore, goats are tipped to be the future animals with extreme potential to counter the projected alarming climate change impacts and expected to play a significant role in ensuring food security to meet the demands of the growing human population by the end of this century.

Analysis of carcass traits and quantitative expression patterns of different meat quality governing genes during heat stress exposure in indigenous goats.

A study was conducted to assess the impact of heat stress on various carcass traits, meat quality variables and gene expression patterns which governs meat quality in indigenous female Kodi Aadu breed. The study was conducted for 45 days in climate chamber with 12 animals randomly allocated into two groups of six animals each, KC (n = 6; Female; Control), KHS (n = 6; Female; heat stress). Majority of the major carcass traits and meat quality variables remained intact between KC and KHS groups. The myostatin (MSTN), calpain 1 (CAPN1) and Diacylglycerol Acyltransferase 1 (DGAT1) mRNA expression patterns were significantly (P < 0.01) lower in KHS group as compared to KC group. However, the calpain 2 (CAPN2), calpastatin (CAST) and Crytallin alpha (CRYA) mRNA expression patterns were significantly (P < 0.05) higher in KHS group. Thus, the study established that the major carcass traits and meat quality variables remained intact after heat stress exposure in female Kodi Aadu goats. Further, MSTN, HSP27, CRYA and HSP90 genes were identified as biomarkers for reflecting meat quality during heat stress exposure in female Kodi Aadu breed.

Ovarian expression, polymorphism identification and association of SIRT3 gene with reproduction traits in goats.

The NAD+-dependent protein deacetylase, Sirtuin3 (SIRT3), plays a role in fertility by preventing the activation of reactive oxygen species (ROS). A novel study was conducted on caprine SIRT3, to study its ovarian expression, explore the sequence variability in exon 7 and analyze its association with prolificacy in two native goat breeds of Kerala, Malabari and Attappady Black. The mRNA isolated from ovaries of six Malabari and Attappady Black goats were subjected to quantitative PCR (qPCR) using GAPDH and ß-actin as reference genes. Genomic DNA was isolated from 185 goats (99 Malabari and 86 Attappady Black) and subjected to PCR-SSCP to identify polymorphism in exon 7 of SIRT3 and association with litter size was analyzed. The ovarian expression of caprine SIRT3 was significantly higher (p ≤ 0.01) in Malabari than low prolific Attappady Black. PCR-SSCP analysis revealed, exon 7 of SIRT3 was polymorphic with three genotypes namely, AA, AB and BB with a novel SNP, g.154C > T in the 3'UTR. A significant association (p ≤ 0.05) was noticed between the genotypes of SIRT3 and litter size. The results obtained from this study highlight the role of SIRT3 in reproduction and hence SIRT3 may be considered as a potential candidate gene for genetic improvement in goats.

Heat stress and poultry production: impact and amelioration.

Globally, the poultry industry is gaining significant importance among the agricultural and its allied sectors. However, heat stress was found to negatively affect the poultry production particularly in the tropical regions. This review is therefore an attempt to generate information pertaining to the impacts of heat stress on poultry production and its amelioration. Heat stress reduces the growth, reproductive performance, and egg production in poultry birds. The reduction in productive potential of poultry birds on exposure to heat stress may be attributed to the deviation of energy resources from production to adaptation pathway. There are different approaches pertaining to relieving the adverse impacts of heat stress on poultry production. These approaches can be broadly categorized under genetic, management, and nutritional strategies. These approaches may reduce the negative effects of heat stress and enhance the productive performance of poultry birds. The management strategies include appropriate shelter design, providing shade, using sprinklers, implementing cooling devices, and using fans and ventilation systems. The recommended floor space for mature birds weighing 1.7 kg is 0.06 m2/bird while it is 0.13 m2/bird for the birds weighing 3.5 kg with 27.8 kg/m2 bird density in either case. The nutritional interventions comprise ration balancing and providing essential micronutrients to improve the productive and reproductive performance in poultry birds. Fat, antioxidants, yeast, and electrolyte supplementations are some of the most commonly used nutritional strategies to ensure optimum production in the poultry industry. Furthermore, providing adequate water supply and disease surveillance measures may help to ensure optimum meat and egg production in the birds. The advanced biotechnological tools may aid to identify suitable genetic markers in poultry birds which might help in developing new strains of higher thermo-tolerance by designing suitable breeding program involving marker-assisted selection. These strategies may help to optimize and sustain poultry production in the changing climate scenario.

Sirtuin3 (SIRT3) gene molecular characterization and SNP detection in prolific and low prolific goat breeds.

Sirtuin3 (SIRT3) is a member of the Sirtuin family of NAD+-dependent deacetylase. They have evolved as a vital protein in preventing the activation of reactive oxygen species (ROS) in oocytes. A novel study on caprine SIRT3 was conducted, to characterize caprine SIRT3, to detect potential polymorphisms in SIRT3 and to analyze their association with litter size in the two indigenous goat breeds of India viz., the prolific Malabari and low prolific Attappady Black goats. A 1070 bp mRNA sequence of SIRT3 cDNA comprised of an ORF of 1002 bp encoding 333 amino acids, having 96% identity with bovine SIRT3. The genomic DNAs from the goats (n = 222) were subjected to PCR and single strand conformation polymorphism (SSCP) of exon 5 fragment (213 bp) of caprine SIRT3. On analysis, two genotypes viz., DD and DE were observed with frequencies of 0.63 and 0.37 respectively. Further sequencing of the PCR products of the respective genotypes revealed a novel synonymous SNP (MF176159:c.691C > T). Genotypes of this fragment had a significant influence on number of kids born (P < 0.05) with DD genotype being superior to DE genotype. These results highlight the role of SIRT3 in reproduction traits and the detected novel SNP would aid in the Marker Assisted Selection programmes and thus SIRT3 can considered as a potential candidate gene for reproduction traits in goats.