Agriculture and livestock are fundamental to the economies of developing countries. A substantial portion of crop harvests is allocated for animal feed. Thus, more technological advancements are necessary to enhance agricultural productivity and provide affordable feed. Future biotech crops are expected to play a crucial role in this area. The goal is often to introduce traits into plants that do not naturally occur in these species. These new traits may include resistance to pests, diseases, or environmental conditions, or the production of specific nutrients or pharmaceutical agents. GM crops have indirectly benefited the livestock sector by increasing the yield of feed ingredients and improving quality traits. These crops are primarily used in livestock feed rations as energy and/or protein sources. Numerous animal feeding studies have been conducted to demonstrate that genetically modified crops are as nutritious and wholesome as compared to their conventional counterparts. No biological relevant differences in animal performance, health, or animal product (meat and milk) composition had been observed in various studies conducted. Overall, no significant differences in gain, intake, and feed conversion have been reported. Since the GM crop’s composition is not different from its conventional counterpart [except for the introduced transgene(s) and expressed protein(s)] and the expressed transgenic protein is rapidly digested in the digestive system, one would not expect any unintended effects. The introduction of genetically modified (GM) crops into the market undergoes extensive testing and a rigorous approval process to ensure food, feed, and environmental safety. This process includes thorough analyses before GM crops are deemed safe for commercial use. GM livestock feed is assessed for its nutritional composition and digestibility by comparing it with conventional crops. Therefore, while GM crops have the potential to enhance the efficiency of animal agriculture by improving nutritional content, reducing pesticide use, and increasing crop yields, it is essential to approach their adoption with caution.

Poultry production is one of the most important livestock sectors as it provides the cheapest animal protein in the form of eggs and meat for human consumption in the shortest period. Feed cost typically accounts for 60-75% of the total cost of poultry production. However, feed availability is decreasing due to the increasing demands of an expanding human population and significantly increased levels of biofuel production. Therefore, finding economical, cost-effective, and locally available alternatives to conventional feed sources could be one way to reduce poultry feed costs. Mulberry leaves, which have a high nutritional value, can be added to the list of feed alternatives for poultry feeding. Mulberry leaf fodder can be employed successfully in the poultry diet. They are readily digestible (70-90 %) by herbivorous animals as well as monogastric and are found to contain little or no anti-nutritional factor or toxic compounds. It positively influences the growth performance and nutrient utilization in broiler and laying hens. It has been found that mulberry leaves contain a variety of active substances, including polysaccharides, flavonoids, and polyphenols, which can reduce blood glucose and triglycerides, and have the function of antioxidation and regulation of lipid metabolism. The yolk colour has been improved in the eggs of the birds fed with mulberry leaf powder, which can be due to excessive amounts of xanthophylls in the leaves. Mulberry leaves also have an enormous potential to reduce feed cost as they can be used instead of expensive protein sources such as soybean meal and fish meal in poultry diets. Studies conducted with poultry indicated that addition of mulberry leaves are possible up to certain limits in poultry diets without any adverse effect on their performance.

The present experiment was designed to study the effect of dietary incorporation of eucalyptus leaf powder on the average weekly feed intake and egg production of commercial laying hens. A 12-week feeding experiment was conducted on 72 White Leghorn laying chickens of 28 weeks of age. Hens were randomly assigned to one of four treatment groups, each having 18 birds and three replicates of six birds. Four treatments were included as a control (T1): basal diet, (T2): Incorporation of 0.3% eucalyptus leaf powder in the basal diet containing phytase, (T3): Incorporation of 0.45% eucalyptus leaf powder in the basal diet containing phytase, (T4): incorporation of 0. 6% eucalyptus leaf powder in the basal diet containing phytase. Daily feed intake and egg production were recorded. The results revealed that Supplementing Eucalyptus (Eucalyptus Globulus) Leaf powder did not affect the cumulative performance of laying hens in terms of feed intake and egg production (P>0.05). Based on the above findings, it was determined that adding 0.3 percent eucalyptus leaf powder to the basal diet containing phytase improves egg production. Furthermore, because Eucalyptus leaves can be procured at no cost, their incorporation is cost-effective and can help reduce feed expenditures.

This study evaluated the influence of varying dietary levels of selenium (Se) and Zinc (Zn) on the performance index, carcass characteristics, and immune response in broiler chicken. The experimental trial was carried for 42 days with a 3 × 3 factorial design involving three levels of each Se (0.15, 0.30, and 0.45 mg/kg diet) and Zn (40, 80, and 120 mg/kg diet) resulting in nine treatments. Six replicate groups with eight birds in each were assigned to each treatment (48 birds/treatment). During starter phase (0-3 weeks), optimum growth performance and growth efficiency of chicken was observed at 0.30 mg Se/kg diet. However, during finisher phase (4-6 week) and overall growth phase (0-6 week), 0.15 mg Se/kg diet was found to be optimum. Similarly, weight gain during starter phase was higher in birds fed at least 80 mg Zn/kg diet. The carcass characteristics did not reveal significant effect of Se and Zn supplementation in broiler chicken. And, on similar lines, cell mediated immunity remained unaffected. However, better humoral immunity was observed in birds supplemented with NRC recommended Se level in diet, but the NRC recommendation of 40 mg Zn/kg diet was inadequate for better humoral immune response compared to 80 or 120 mg level. Further, higher spleen and thymus weight was observed at 0.3 mg Se/kg diet and higher spleen weight at 80 mg Zn/kg diet. In conclusion, Se supplementation of 0.30 mg /kg diet and Zn supplementation of 80 mg/kg diet resulted in optimum growth performance, efficiency, and immunity of broiler chicken.

A study on bone development under the influence of selenium and vitamin E supplementation was under taken in broiler chicken. Three levels of each selenium (0.15, 0.35, and 0.45 mg/kg diet) and vitamin E (50, 100, and 150 IU/ kg diet) were taken to formulate nine treatment groups in the form of broiler starter and finisher to evaluate the bone morphometry and bone mineralization of broiler chicken. The experiment was conducted in a high temperature humidity index (83.94) during the August-September period. The results revealed that bone morphometry parameters such as tibia bone proximal width, mid shaft width, distal width, and length were not influenced by dietary selenium and vitamin E supplementation. Similarly, the mean tibia bone weight (g), bone moisture (%), bone calcium (%), bone phosphorus (%), total ash (%), and bone Zn content (mg/kg) did not differ significantly due to selenium and vitamin E levels in the diet. Therefore, it can be concluded that the bone morphometry and bone mineralization in broiler chicken is not affected by different levels of selenium and vitamin E in the diet.

The outbreak of coronavirus disease 2019 (COVID-19) as a pandemic has shaken the global health system and economy by their roots. This epidemic is still spreading and showing no signs of decreasing trend. Vaccination could be the only effective and economical means to control this pandemic. A number of research institutions and pharmaceutical companies have plunged into the race of vaccine development against COVID-19 which are in various stages of development. An intriguing fact of coronavirus infections is that in every decade of the 21st century there is a new major coronavirus epidemic, namely, severe acute respiratory syndrome (SARS) in 2002, Middle East respiratory syndrome (MERS) in 2012, and now COVID-19; and such epidemics are expected in future too. Since most of the biological characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are still obscure, the scientists are relying on the information available on SARS-CoV and to some extent on MERS-CoV for designing and developing COVID-19 vaccines. But there is a need of vigorous testing for immunogenicity, safety, efficacy, and level of protection conferred in the hosts. This review focuses on the challenges and prospects of vaccine development against COVID-19. It highlights seriousness, bottlenecks in vaccine development, possible vaccine candidates, different vaccine strategies, safety evaluation issues, and vaccine production processes pertaining to COVID-19 based on the knowledge acquired on SARS and MERS vaccine development in the past.

Nine dietary treatments using three levels of each selenium (0.15, 0.35 and 0.45 mg/kg diet) and Vitamin E (50, 100 and 150 IU/kg diet) were formulated as broiler starter (0–3 weeks) and finisher (4–6 weeks) diets to evaluate growth performance and hematology of broiler chicken. The experiment was carried out in an ambience of relatively higher temperature humidity index (83.94) during the August-September period. The results of the present study revealed that under heat stress better growth performance was recorded in the birds fed higher vitamin E levels (100 and 150 IU/kg diet) and 0.3 mg Se/kg diet. The RBC count, Hb (%), packed cell volume (%), and lymphocyte (%) were significantly better in birds supplemented with 0.3 mg Se/kg diet and 100 IU vitamin E/kg diet. Better H: L ratio was observed in birds fed 0.3 mg Se/kg diet with 100 IU vitamin E/kg diet. It can be concluded that the supplementation of the 0.3 mg Se/kg diet and 100 IU vitamin E/kg diet resulted in better growth performance and blood homeostasis in broiler chicken.

A total one ninety two day old chick of CARIBRO Vishal broiler chicken were housed in multi-tier brooder cages up to five weeks of age and reared under uniform husbandry conditions. On 36th day divided into 6 groups with three treatments (32 birds in each group’s) including control, enhancer and inhibitor, receiving normal saline, glutamine @ 0.75 mg kg-1 BW and quercetin @5 mg kg-1 BW respectively. After, 24 hours of administration each of the six groups were again divided into two with three groups in each, one being exposed to acute heat stress (40±1 °C; 55% RH) for different duration of 0, 2, 5 and 10 hours in psychometric chamber and another one were kept as unexposed to heat stress. The result indicated that concentrations of lipase (91.88 ± 2.25), amylase (111.49 ± 3.06), pepsin (71.66 ± 1.33) and trypsin (85.10 ± 2.84) were significantly (*p<0.05) higher in enhancer group. Heat stress has significantly (*p<0.05) increased the activity of trypsin (71.96 ± 2.98) and pepsin (61.01 ± 1.88) in jejunum and simultaneously decreased the amylase activity; however the lipase activity did not show any change in response to acute heat stress exposure. A significant difference observed (*p<0.05) on enzymatic activity of pepsin and trypsin and the activity of amylase and lipase was not significant under different duration of heat stress exposure. It can be concluded that protein synthesis modulator; glutamine significantly increases digestive enzymes activity and improve performance of broiler chicken under acute heat stress condition.

An experiment was conducted to study the effect of using butyric acid (BA) in place of antibiotic growth promoter (AGP) on performance and intestinal microflora in broiler chickens. Two hundred (200) day-old broiler chicks were housed and distributed randomly into four groups containing five replicates of 10 chicks in each replicate (4 treatmentsx5 replicates). The experiment had a randomized design. Four experimental diets T1, T2, T3 and T4 were formulated to contain no additive, Bacitracin Methylene Disalicylate (BMD) at 20 mg/kg diet and BA at 0.3 and 0.4%, respectively. Body weight gain (g) increased (P < 0.05) by the feeding of diets containing different levels of BA, but feed intake (g), feed conversion ratio (FCR) and mortality (%) did not differ significantly (P>0.05). Significant reduction was observed in coliforms and Lactobacillus counts in cecal contents (28 and 42 d) and excreta (42 d), whereas, total plate counts (TPC) at 42 d were significantly reduced in BA supplemented groups as compared to other groups. From the results, it can be concluded that, BA could be a good alternative to AGP for growth performance and improving gut microbial status in broiler chickens.

The present study was conducted to assess the effects of thermal stress on the serum biochemical and haematological parameters in broiler chicken. Forty CARIBRO- Vishal broiler chicken were divided into two groups with twenty birds each. The control group was kept at room temperature and treatment group was exposed to thermal stress under 40±1 °C for 4 hours at 35 day of age. The exposure of thermal stress significantly increased (P less than 0.05) the value of serum biochemical parameters (glucose, cholesterol and triglyceride), heterophills, H/L ratios and basophills, however the value of total leukocyte, haemoglobin, haematocrit value, and monocytes decreased significantly (P less than 0.05).

A study was conducted to determine the effect of egg weight on hatchability and chick weight in CARIBRO Vishal broiler chicken. In the present study a total of 600 eggs were selected and allocated into three treatments 200 each: small (<49g), medium (50-59g), and large (60-69g) and incubated at stranded incubation temperature and humidity. The result showed that hatchability percentage of large sized egg was significantly higher (P<0.05) in compare to medium and small sized eggs, however higher embryonic mortality were recorded in small egg size groups. Percent moisture loss were significantly (P<0.05) higher in small sized egg group. Higher chick weight and lower embryonic mortality was observed in large sized egg group in compared to medium and small sized group.