V.P. Maurya

Walking Stress Influence on Livestock Production

The food available to grazing animals, particularly during the dry season, in the tropics, is often of very low quality and, in addition, is frequently available at low densities per unit area. Grazing ruminants attempt to adapt to these adverse conditions by increasing the time for which they graze each day and also by dispersing more widely. However, the time for which animals can graze may be limited by solar radiation and fly irritation during the day. Depending on management conditions, livestock are required to walk long distances. When walking is restricted (1–3 km/day), animal performance is generally not reduced. However, under certain conditions (scarce or hilly pasture) the distances walked by livestock can be substantially greater. Unusual physical activity is considered a stress factor in all species since it induces neuroendocrine and metabolic changes which in turn alter the physiological responses, endocrine and enzymes’ release status and productivity in animals. In addition, there are both breed and interspecies differences in locomotory efficiency as a result of morphological, physiological and behavioural adaptations in livestock. The significant changes in physiological responses, adrenal and thyroid hormone concentrations after subjecting the livestock species to walking stress shows that they are capable to adapt to long-distance walking and adrenal and thyroid gland hormones play a significant role in such adaptation. Though, while trying to adapt to long-distance walking scenario in search of food, animals compromise their productive performance. This is reflected as significant reduction in growth, milk and reproductive performance of different livestock species. The reason for this low production could be a major proportion of the energy is shifted to combating the walking stress as any counter measures need energy source for its implementation. The repercussions of walking or work on production performances have been studied by various researchers and reported that livestock energy requirement increases significantly during walking exercise. Further, most of the increase in energy expenditure of physical activity results from grazing and locomotion costs. The energy expenditure of locomotion during grazing contributes significantly to the energy requirement of animals in free-living conditions and must be included for accurate evaluation of the energy needs of the grazing animal.

Expression analysis of Toll like receptors and interleukins in Tharparkar cattle during acclimation to heat stress exposure

Six male Tharparkar cattle of 2-3 years old were selected for the study. After 15 days acclimation at thermo neutral zone (TNZ) in psychrometric chamber, animals were exposed at 42°C for 6h up to 23 days followed by 12 days of recovery period. Blood samples were collected during control period at TNZ (day 1, 5 and 12), after heat stress exposure (day 1-10, Short Term Heat Stress Acclimation - STHSA; day 15-23, Long Term Heat Stress Acclimation - LTHSA) and recovery period (day 7 and 12) and peripheral blood mononuclear cells (PBMCs) were isolated for RNA and protein extraction. Serum cortisol concentration was assessed by RIA. The mRNA and protein expression in PBMCs were determined by qPCR and western blot respectively. Samples at TNZ were taken as control. Serum cortisol concentration was increased (P<0.05) during STHSA and gradually declined during LTHSA. Toll like receptor 2 (TLR 2) expression was up regulated (P<0.05) during STHSA and declined to basal level during LTHSA and recovery phase. However, toll like receptor 4 (TLR 4) expression was up regulated (P<0.05) during STHSA and LTHSA while declined in recovery phase. Interleukin 2 (IL2) and interleukin 6 (IL 6) were up regulated (P<0.05) during STHSA and reduced to basal level during LTHSA. PBMCs culture study was conducted to study transcriptional abundance of TLR2/4 and IL2/6 at different temperature-time combinations. The present findings indicate that TLR 2/4 and IL 2/6 could possibly play a vital role in thermo tolerance in Tharparkar cattle during short term and long term heat stress exposure.

Fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor A (VEGFA) synergistically promote steroidogenesis and survival of cultured buffalo granulosa cells

The present study investigated the combined effect of fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor A (VEGF-A) on estradiol (E2) secretion and relative abundance of mRNA for aromatase enzyme (CYP19A1), proliferating cell nuclear antigen (PCNA) and BCL-2 associated X protein (BAX) in cultured buffalo granulosa cells (GCs). Follicles were isolated and classified into four groups based on size and E2 concentration in follicular fluid (FF): Small, 4-6mm diameter, E2<0.5ng/ml; Medium, 7-9mm, E2=0.5-5ng/ml; Large, 10-13mm, E2=5-40ng/ml; Preovulatory (PFs), >14mm, E2>180ng/ml. The GCs of PF were cultured in 24 well cell culture plates and allowed to become 75-80% confluent. Then cultured GCs were treated with FGF2 (200ng/ml) and VEGF-A (100ng/ml) separately and in combination for three incubation periods (24, 48 and 72h). Estradiol secretion was greater in GCs treated with FGF2+VEGF-A compared to FGF2 or VEGF-A at all incubation periods and was greatest (P<0.05) at 72h of incubation. The relative abundance of CYP19A1 and PCNA mRNA were relatively consistent with the amount E2 secretion. In contrast, the relative abundance of Bax mRNA was less in GCs treated with the combination of FGF2 and VEGF-A as compared to either FGF2 or VEGF-A alone and the least concentration (P<0.05) was at 72h of incubation. Findings with use of immunocytochemistry of cells treated with these factors were consistent to the relative abundance of mRNA transcript for the factor. The present findings indicate that FGF2 and VEGF-A may function in a synergistic manner to promote steroidogenesis and survival of cultured buffalo GCs.

Overview on Adaptation, Mitigation and Amelioration Strategies to Improve Livestock Production Under the Changing Climatic Scenario

Livestock production is thought to be adversely affected by detrimental effects of extreme climatic conditions. Consequently, adaptation, mitigation and amelioration of detrimental effects of extreme climates have played a major role in combating the climatic impact in livestock production. While measures to reduce the growth of greenhouse gas emissions are an important response to the threat of climate change, adaptation to climate change will also form a necessary part of the response. The salient adaptation strategies are developing less sensitive breeds, improving water availability, improving animal health, promoting women empowerment, developing various policy issues, establishing early warning systems and developing suitable capacity building programmes for different stakeholders. Developing adaptation strategies is therefore an important part of ensuring that countries are well prepared to deal with any negative impacts that may occur as a result of climate change. The integration of new technologies into the research and technology transfer systems potentially offers many opportunities to further the development of climate change adaptation strategies. Adapting to climate change and reducing GHG emissions may require significant changes in production technology and farming systems that could affect productivity. Many viable opportunities exist for reducing CH4 emissions from enteric fermentation in ruminant animals and from livestock manure management facilities. To be considered viable, these emission reduction strategies must be consistent with the continued economic viability of the producer and must accommodate cultural factors that affect livestock ownership and management. This chapter also elaborates on ameliorative strategies that should be given consideration to prevent economic losses incurred due to environmental stresses on livestock productivity. Reducing the impact of climatic stresses on livestock production requires multidisciplinary approaches which emphasise animal nutrition, housing and animal health. Therefore, emphasis should be given to all three aspects of adaptation, mitigation and amelioration strategies to sustain livestock production under the changing climate scenario.

Stimulatory effect of luteinizing hormone, insulin-like growth factor-1, and epidermal growth factor on progesterone secretion and viability of cultured bubaline luteal cells

We evaluated the temporal (24, 48 and 72 hours) and dose-dependent (5, 10, and 100 ng/mL of LH, IGF-1, and EGF, respectively) production and secretion of progesterone (P4) in cultured luteal cells from different stages of estrous cycle as well as the expression of steroidogenic acute regulatory protein (STARD1), cytochrome P450 cholesterol side-chain cleavage (CYP11A1), and 3β-hydroxysteroid dehydrogenase (HSD3B), anti-apoptotic gene PCNA, and pro-apoptotic gene BAX in luteal cells of mid-luteal phase in buffalo. Samples from early luteal phase (ELP; Day 1 to 4; n = 4), mid-luteal phase (MLP; Day 5 to 10; n = 4), and late luteal phase (LLP; Day 11 to 16; n = 4) of estrous cycle were collected. Progesterone was assayed by RIA, whereas mRNA expression was determined by quantitative real-time polymerase chain reaction. Results depicted that highest dose (100 ng/mL) of LH, IGF-1, and EGF and longer duration of time brought about a (P < 0.05) rise in P4 level and expression of steroidogenic enzymes and PCNA compared with the lower level(s) and control while, all treatments (P < 0.05) inhibited BAX expression in a time dependent-manner. Analysis of interaction between stage and treatments revealed that LH treatment (P < 0.05) increased P4 production compared with IGF-1 and EGF in ELP and MLP. However in LLP, treatment with IGF-1 and EGF significantly (P < 0.05) increased P4 production compared with LH treatment. Summarizing, our study explores the steroidogenic potential of LH and growth factors across different luteal stages in buffalo, which on promoting steroidogenic enzyme expression and cell viability culminated in enhanced P4 production in luteal cells.

Effect of Controlled and Uncontrolled Rate of Cooling, Prior to Controlled Rate of Freezing, on Motion Characteristics and Acrosomal Integrity of Cryopreserved Ram Spermatozoa

A programmable cell freezer provides ideal cryobiological conditions for controlled-rate cooling and freezing of ram spermatozoa. The purpose of this study was to investigate the effects of controlled (Group 1) and uncontrolled (Group 2) cooling conditions prior to programmable freezing of ram semen on post-thaw sperm motion characteristics and acrosomal integrity of ram spermatozoa. Semen samples of good initial motility obtained from adult Malpura rams were pooled, diluted to 1 × 10(9) spermatozoa per milliliter with Egg yolk-TEST-glycerol extender, and packaged in 0.25 mL straws. Straws representing Group 1 were cooled in a programmable cell freezer from 25°C to 5°C at the rate of -0.15°C per minute followed by a holding time of 2 h for equilibration, while straws of Group 2 were allowed to cool slowly up to 5°C and equilibrate for 2 h in the cold cabinet. After equilibration, straws of Group 2 were also loaded in the cell freezer for freezing straws of both the treatment groups simultaneously from 5°C to -125°C at the rate of -25°C per minute. Thawing of straws was done at 50°C for 10 s and the quality of frozen-thawed spermatozoa was objectively assessed by using sperm motility analyzer. Thawed samples were also evaluated for acrosomal integrity after staining the dried semen smears with Giemsa stain. The average post-thaw motility of straws was significantly higher (P < 0.05) in samples frozen after controlled cooling, compared with samples frozen after uncontrolled rate of cooling. The percent of spermatozoa with normal acrosome was also significantly (P < 0.05) higher in Group 1, compared to Group 2. The results indicate that controlled-rate cooling has a significant effect on post-thaw motility and acrosomal integrity of frozen-thawed ram spermatozoa, compared to uncontrolled-rate cooling prior to programmable freezing.

Concept of Multiple Stresses and Its Significance on Livestock Productivity

Animals reared in tropical environments are generally subjected to more than one stress at a time. This greatly influences the animal production and reproduction under such environmental conditions. Nearly all studies on the effect of environmental stress on farm animal productivity have generally implicated one stress at a time since comprehensive, balanced multifactorial experiments are technically difficult to manage, analyze, and interpret. Hence, few reports evaluating effects of multiple stresses on farm animals are available in the literature. However, researchers have described several hypothetical schemes highlighting how two stressors can synergistically influence normal physiologic functions in mammalian species. Thermal stress in livestock is aggravated when feed restriction is involved. These effects are often manifested in changes in the blood biochemical parameters, enzymes, and thyroid hormone levels in livestock. Generally, when nutrition is not compromised, livestock species cope with heat stress better. Further, several findings have shown that livestock species tolerate and adapt to nutritional stress more than thermal stress. However, when both stresses are present, severe impacts on all the biologic functions in the livestock have been observed. Hence, it may be pertinent to conclude that the combined effects of two stressors may have severe impact on biologic functions in livestock species. Further studies involving more than one stress at a time emphasized the importance of providing optimum nutrition to livestock for counteracting thermal stress during summer. These types of investigations will be instrumental in gaining a thorough understanding of the role of nutrition in mitigating adverse effects of environmental stress on livestock and how the knowledge garnered can be used to develop rational managerial strategies for optimizing productivity in livestock farms.

Biological ability of Malpura rams to counter heat stress challenges and its consequences on production performance in a semi-arid tropical environment

Abstract A study was conducted to assess the biological ability of Malpura rams to counter heat stress challenges and its impact on the productive performance in a semi-arid tropical environment. The eighteen adult Malpura rams (average body weight 55.0 kg) were divided into two groups, GI (n = 9; Control) and GII (n = 9; heat stress). The study was conducted for a period of 60 days. The results showed that body weight, body condition score, heart girth and feed intake were significantly (p < 0.05) lower in GII as compared to GI rams. The physiological responses i.e. respiration rate, pulse rate, rectal temperature and sweating rate (body and scrotum) were significantly (p < 0.05) higher in rams exposed to heat stress. Among the endocrine parameters, plasma T3, T4 and testosterone concentrations were significantly (p < 0.05) lower in GII rams, while cortisol concentration was significantly (p < 0.05) higher in GII rams. In addition, heat stress significantly (p < 0.05) reduced semen volume, total sperm motility, sperm concentration and progressive sperm motility in GII rams. The results indicated that Malpura rams adapted to the heat stress condition, however, while doing so their production performances were compromised.

Adaptive Mechanisms of Livestock to Changing Climate

In the current scenario, climate change is occurring all over the world, which directly or indirectly affecting the agricultural production as well as the production of livestock. The arid and semiarid region of the world, where more than 75 % population of livestock exists, will be going to have pronounced effect of climatic change. Amongst the other stresses, heat stress is the most vital climatic stress which drastically affects the productive potential of livestock, and sometimes it is lethal to animal survival in harsh conditions. High ambient temperature, air movement, solar radiation, wind speed and relative humidity are important attributes of the climatic variables. Amongst the above-mentioned variables, high temperature, radiation and humidity are the most important factors, which drastically affect the overall performance of livestock with substantial reduction in meat, milk and egg production. In this context, the chapter highlights the significance of studying the impact of multiple stresses impacting livestock production simultaneously. The different adaptive means by which livestock respond to fluctuation of climatic changes are physiological, blood-biochemical, neuroendocrine, cellular and molecular mechanisms, respectively. In present climate change scenario, several mitigation strategies are to be implemented by which the production of livestock may be sustained to an extent even in harsh climatic conditions.

Transcriptional and translational abundance of Bone morphogenetic protein (BMP) 2, 4, 6, 7 and their receptors BMPR1A, 1B and BMPR2 in buffalo ovarian follicle and the role of BMP4 and BMP7 on estrogen production and survival of cultured granulosa cells

BMPs and their receptors modulate the granulosa cell (GC) function in the follicle of domestic animals. Since little is known on BMPs in the buffalo, the present study was aimed to investigate the expression of BMP2, 4, 6, 7 and their receptors BMPR1A, BMPR1B, BMPR2 in the GC and theca cells (TC) of ovarian follicles and the role of BMP4 and BMP7 on buffalo GC. Follicles were classified into four groups based on size and E2 level in the follicular fluid as follows: (i) Group1(4-6 mm; <0.5 ng/mL) (ii) Group 2 (7-9 mm; 0.5-5 ng/mL) (iii) Group 3 (10-13 mm; 5-40 ng/mL) and (iv) Group 4 (dominant follicle) (>13 mm; >180 ng/mL). The results revealed that except BMP6, BMP2, 4 7 and receptors BMPR1A, BMPR1B and BMPR2 showed a minimum of 1.5-2 fold increase in mRNA expression in the GC of dominant follicle as compared to other follicle classes. In the dominant follicle, a two-fold increase in BMP4 and BMP7 expression was observed in the TC. At 100 ng/mL, the BMP4 and BMP7 either alone or in combination maximally down-regulated CASPASE3 and stimulated the transcripts of PCNA, FSHR and CYP19A1 that was supported by E2 secretion in the granulosa cell culture suggesting their role in cell survival and E2 production. In conclusion, GC and TC of dominant follicles express BMP 2, 4, 6, 7 and their receptors BMPR1A, BMPR1B and BMPR2. BMP4 and BMP7 stimulate E2 production and promote GC survival.