National Institute of Animal Nutrition and Physiology

Semen cryopreservation results in decreased viability and fertilizing ability due to temperature variation-mediated cryodamage limiting its practical application. Though many factors play a role in the success of semen cryopreservation, ice crystal formation plays an important role in post-thaw viability because of the position and surface area to semen volume ratio of the container. The present study was to compare the post-thaw cryo-survivability of sheep semen cryopreserved in cryovials with a smaller surface area to semen volume ratio in the vertical position versus straws with a larger ratio in both horizontal and vertical positions. Significantly (p < 0.05) higher post-thaw functional parameters and subsequent embryo production were observed in the semen cryopreserved in cryovials with LN2 vapour than cryopreserved in straws with a bio-freezer and LN2 vapour. The study concluded that higher post-thaw viability of the sperm cryopreserved in cryovials in the vertical position might be due to gravity-supported settling of the sperm at the bottom, creating a small air gap, and resulting in less ice crystal formation and subsequent embryo production in vitro. Whereas the straws in the horizontal position created a large air gap and faster ice crystal formation, and uneven distribution of temperature along the length of the straw in the vertical position leads to significant (p < 0.05) sperm damage for subsequent embryo production.

The study was conducted to assess the effects of a postbiotic, Saccharomyces cerevisiae fermentation product (SCFP) and a commercial phytogenic feed additive (PFA) as alternative to antibiotic growth promoter(AGP) on growth performance, gut microbiota, intestinal morphology, and immune response of commercial broiler chickens at a Food and Agriculture Organization (FAO) classified sector 3 commercial poultry farm. One-day-old mixed sex Vencobb 430 Y chicks (n=4800) were randomly divided into four dietary treatment groups for 35 days experimentation encompassingT1 (positive control, PC) basal diet supplemented with bacitracin methylene disalicylate as an AGP at 500 g/MT; T2 (negative control, NC) basal diet without a growth promoter; T3 basal diet supplemented with commercial PFA at 500 g/MT; T4 basal diet supplemented with SCFP at 1.25 kg/MT.At day 35, ADG and FCR were significantly improved in PFA and SCFP groups compared to the NC group. The levels of blood glucose, total protein, albumin, triglyceride, cholesterol, and uric acid in serum showed no significant variation across different dietary treatments. From day 21 of the study, log cfu count and DNA concentration of pathogens (Enterohaemorrhagic Escherichia coli, Salmonella) decreased significantly in the AGP, PFA, and SCFP groups compared to the NC group. Whereas the log cfu count and average DNA concentration of Lactobacillus was significantly increased in PFA and SCFP groups, but not in AGP group. Increased Lactobacillus concentration in PFA and SCFP groups downregulated the virulence gene expression of pathogens (Enterohaemorrhagic E. coli and Salmonella). The duodenal and jejunal villi height was significantly higher in PFA and SCFP groups, although ratio of villi height to crypt depth in the duodenum, jejunum and ileum did not show significant differences among the groups. On day 28, antibody titers against the IBDV and NDV were significantly higher in SCFP groups than other groups. The present study did not identify any modulation of the cell mediated immune response in the chickens. In conclusion, addition of SCFP at 1.25 kg/MT or PFA at 500 g/MT in diet could produce better nutrient utilization ability, reduction of pathogens and their virulence gene expression, increased Lactobacillus count, but incorporation of SCFP increased antibody titre against two fatal viral infections such as NDV and IBDV which was not detected with PFA.

Maternal diet plays a vital role in the development of the offspring and their post-hatch performance. The present study was conducted to evaluate the effect of supplementary organic zinc to the basal diet of broiler breeder chickens on the bird’s fertility, hatchability, production performance of the progenies and their intestinal morphological attributes. Broiler breeders (128) were grouped into four as control, fed basal diet containing 40 mg inorganic Zn/kg feed and groups of T1, T2 and T3 fed control diet with 20, 40 and 60 mg/kg organic Zn respectively, fed according to the breeder’s nutrient specifications except zinc content. The organic zinc was supplemented as zinc-methionine. Group-wise fertility and hatchability of the breeder birds were determined. The group-wise hatched chicks were reared for 42 days to assess their production performance, intestinal length and histo-morphology including villi length, diameter, crypt depth and corresponding absorptive surface. The hatchability was higher in 40 and 60 mg/kg supplemented groups. The hatch weight (g) and post-hatch growth performance of chicks were similar (P > 0.05) among the groups and were not influenced by the level of organic zinc supplementation. However, the intestinal histo-morphological attributes (villi length, diameter and mucosal cells) showed significant (P < 0.05) improvement in chicks hatched from the breeder’s fed with organic Zn supplemented (60 mg/kg of Zn) birds followed by 20, 40 mg and control group. The results indicated that the maternal zinc supplementation had positive impact on breeder’s fertility, hatchability, and intestinal histo-morphological attributes of the offspring but not on the performance of the offspring’s.

Buffaloes are the main milk producing units of India and are the backbone of Indian milk industries. Due to their significant contribution to reasonably priced and nutrient-dense animal protein, which will assist address global nutritional security, the demand for wholesome buffalo food items is still rising worldwide. Early estrus identification is one of the most crucial factors for buffaloes to reproduce more successfully. Buffaloes are seasonal polyestrous breeders and silent heat animals. This review article aims to highlight the importance of traditionally available methods and the non-invasive methods which are being attempted to detect estrus in buffaloes keeping in view the various factors influencing the estrus cycle and visualizing the molecular events associated with the ovarian physiology leading to the estrus cycle. Detection of silent estrus with the combinatorial use of traditionally available methods only may be difficult to identify individual animal in estrus by the farmer alone. Interventions in existing management practices can manifest estrus nicely. Many non-invasive methods/ assays/ tools to aid estrus detection have been attempted, but none have been proven efficient or reliable to be used at the field level by the small and/ marginal farmers. Therefore, a detailed study of the multiple factors influencing the estrus behaviour, reproductive endocrinology and expression of genes associated with molecular pathways related to estrus is required. This may in turn pave the way for not only the identification of new molecules related to estrus behaviour but also enhances the efficiency of non-invasive methods to detect estrus in buffaloes.

The livestock sector, a crucial source of revenue and global food security, is facing serious challenges due to climate change driven by global warming. This leads to serious effects on animal health and productivity, making it difficult for the livestock industry to meet the global demand and sustain the livelihoods of farmers. The main factor affecting livestock's productivity is heat stress. However, animals develop various adaptive mechanisms to cope with the effects of heat stress. Cellular and molecular responses act as key defense mechanisms, enabling animals adapt to environmental changes. The recent advancements in molecular biology have opened up opportunities for extensive research on epigenetics, which has a key role in regulating gene expression in animals in response to environmental stimuli. Such studies have gained considerable attention regarding heat acclimation in animals due to the fact that epigenetic mechanisms have been recognized as key players in long-term adaptation to high temperatures in farm animals. This review summarizes the different mechanisms and methodologies used to assess heat stress-associated epigenetic changes, including DNA methylation, which is an extensively studied epigenetic regulatory mechanism in relation to gene expression. The review also highlights the mechanisms and regulation of adaptation to heat stress in animals and collates information related to various epigenetic markers to assess the heat stress response, thereby aiding in improving thermal resilience in animals.

The spermatogonial stem cells (SSCs) are unique stem cells of the adult body having the power of self-renewal and differ entiation into spermatozoa. Due to their distinct advantages over other stem cell types, the field of cell based regenerative medicine is exploring the potential of SSCs for its various applications in biotechnology and animal reproduction. Here we discuss about several approaches for SSC isolation, enrichment and characterization. Given the low percentage of SSCs in the testis, it is difficult to obtain an enriched population of SSC for further research. Differentiation and apoptosis over time is another challenge in establishing a long term SSC culture system. Hence, optimization of the culture media and culture conditions along with cryopreservation is a prerequisite for the downstream application of SSC technology in livestock. Although several markers have been identified for SSCs in animals, an appropriate species specific marker is still lacking. Suitable recipients for SSC transplantation are generated through surrogate sire technology in livestock. SSC transplantation has been experimentally successful in numerous livestock species with donor derived spermatogenesis and production of offspring. Such advancement coupled with genome editing may open new avenues for augmenting livestock production in near future. We emphasize that a deeper understanding of the SSCs characteristics and the fac tors that influence their differentiation and stemness is essential for the wider application of SSC technology in animals.

An investigation was conducted to assess the efficacy of a novel antioxidant supplementation, Transcare, in alleviating transportation-induced stress among Bannur sheep. Thirty female Bannur sheep of 10-12months, were selected and randomly assigned to two groups: Bannur Non-supplemented (BNS) (n = 15) and Bannur Supplemented (BS) (n = 15). The BS was supplemented with antioxidant powder (Transcare) orally at a dose of 10g/animal, dissolved in 10mL drinking water, 45-60min preload. The antioxidants supplementation significantly (P < 0.01) influenced the variables such as pulse rate (after transportation), mean corpuscular volume (after transportation), glucose (after transportation) and HSP70 (after transportation), when juxtaposed between the BNS and BS cohorts. Marked reductions in transportation-induced stress were observed in Bannur sheep following antioxidant supplementation, as manifested by discernible alterations in stress-responsive metrics. These findings underscore the promising role of the novel oral antioxidant supplementation in alleviating transportation stress among Bannur sheep. Thus, advocating for the adoption of such supplementation strategies, particularly among economically constrained farmers, may present a viable approach to mitigate the economic ramifications associated with transportation-induced stress in sheep husbandry practices.

This study aimed to assess the prevalence of multidrug-resistant E. coli in poultry farms of Kozhikode district, Kerala. Cloacal swab samples (N=20) were collected from three broiler farms, with five samples taken from birds aged 11, 28, 36, and 41 days. Samples were processed for E. coli isolation and identification, with molecular confirmation by polymerase chain reaction using uidA gene. Out of 20 samples, 17 showed typical green metallic sheen colonies, of which 16 (94.11%) were confirmed positive by polymerase chain reaction. Kirby-Bauer antibiotic susceptibility testing revealed that 10 isolates (62.5%) were multidrug-resistant, showing (100%) resistance to tetracycline, followed by resistance to ampicillin (62.5%), enrofloxacin (56.25%), erythromycin (50%), cotrimoxazole (43.75%), doxycycline (37.5%), streptomycin (18.75%), and cefotaxime/clavulanic acid (6.25%).The high antibiotic resistance in E. coli poses risks to poultry health and potential human transmission, highlighting the need for strict biosecurity, responsible antibiotic use, and effective monitoring in poultry production.