Semi-arid Tropical Environment Research Articles

Whole-genome resequencing reveals genomic variation and dynamics in Ethiopian indigenous goats

Ethiopia has about 52 million indigenous goats with marked phenotypic variability, which is the outcome of natural and artificial selection. Here, we obtained whole-genome sequence data of three Ethiopian indigenous goat populations (Arab, Fellata, and Oromo) from northwestern Ethiopia and analyzed their genome-wide genetic diversity, population structure, and signatures of selection. We included genotype data from four other Ethiopian goat populations (Abergelle, Keffa, Gumuz, and Woyto-Guji) and goats from Asia; Europe; and eastern, southern, western, and northern Africa to investigate the genetic predisposition of the three Ethiopian populations and performed comparative genomic analysis. Genetic diversity analysis showed that Fellata goats exhibited the lowest heterozygosity values (Ho = 0.288 ± 0.005 and He = 0.334 ± 0.0001). The highest values were observed in Arab goats (Ho = 0.310 ± 0.010 and He = 0.347 ± 4.35e−05). A higher inbreeding coefficient (FROH = 0.137 ± 0.016) was recorded for Fellata goats than the 0.105 ± 0.030 recorded for Arab and the 0.112 ± 0.034 recorded for Oromo goats. This indicates that the Fellata goat population should be prioritized in future conservation activities. The three goat populations showed the majority (∼63%) of runs of homozygosity in the shorter (100–150 Kb) length category, illustrating ancient inbreeding and/or small founder effects. Population relationship and structure analysis separated the Ethiopian indigenous goats into two distinct genetic clusters lacking phylogeographic structure. Arab, Fellata, Oromo, Abergelle, and Keffa represented one genetic cluster. Gumuz and Woyto-Guji formed a separate cluster and shared a common genetic background with the Kenyan Boran goat. Genome-wide selection signature analysis identified nine strongest regions spanning 163 genes influencing adaptation to arid and semi-arid environments (HOXC12, HOXC13, HOXC4, HOXC6, and HOXC9, MAPK8IP2), immune response (IL18, TYK2, ICAM3, ADGRG1, and ADGRG3), and production and reproduction (RARG and DNMT1). Our results provide insights into a thorough understanding of genetic architecture underlying selection signatures in Ethiopian indigenous goats in a semi-arid tropical environment and deliver valuable information for goat genetic improvement, conservation strategy, genome-wide association study, and marker-assisted breeding.

Modelling the spatial variability of soil micronutrients for site specific nutrient management in a semi-arid tropical environment

Deficiency of micronutrients in the soils of semi-arid tropical (SAT) environments is a major limiting factor for crop production. This study aims to model the spatial variability of soil micronutrients in croplands of Thimmajipet block, Mahabubnagar, Telangana, India. We collected 1508 georeferenced surface (0–15 cm) soil samples at a grid interval of 325 × 325 m and analysed them for DTPA extractable fractions of iron (Fe), manganese (Mn), copper (Cu), zinc (Zn) and boron (B). Landform and topographic variables were derived from the digital elevation model of the study area. Results showed that all the micronutrients varied highly (CV > 35%) in the order of Zn > Fe > Cu > B > Mn. The Q–Q plots indicated non-normal frequency distribution for all the micronutrients, and log transformation improved them. We compared spherical, circular, exponential, and Gaussian models of ordinary kriging interpolation to define the spatial variability structure. The spherical model with the lowest RMSE and better r2 values was selected to map the spatial distribution of the micronutrients. The nugget to sill ratio (N:S > 0.75) indicated that the micronutrients were weakly spatial dependent. Multiple regression analysis (p < 0.05) indicated that the micronutrient concentration and spatial distribution were controlled by (1) parent material; (2) CaCO3; (3) OC; and (4) antagonistic nutrient interaction. Further, critical deficiency zones of Zn, Cu, B and Fe were delineated by integrating cadastral map on the spatial distribution maps. Our study demonstrates that the large scale spatial variability mapping of soil micronutrients is a prerequisite for implementing site-specific nutrient management in the SAT regions.

Plant Available Water Capacity (PAWC) for Deep-Rooted Crops in Cracking Clay Soils (Vertisols) of Semi-Arid Central India

Smectite is the dominant clay mineral in the cracking clay soils (mainly Vertisols) in the semi-arid tropical (SAT) region (Vidarbha andMarathwada).Amongst the crystalline clay minerals, smectite has the highest soil moisture retention capacity depicted as the available water between field capacity and wilting point, which increases with soil depth. But in SAT Vertisols of Vidarbha and Marathwada regions, the release of this soil water is unavailable to deep-rooted crops, causing loss of crop yield is frequently observed. Thus, the water holding between33 and 1500 kPa tension is not in reality available soil moisture in these soils. The release of soil moisture is, however, seriously constrained by the dispersion of smectitic clay colloids due to the presence of both Mg and Na ions on soil exchange complex. In reality, in calcareous Vertisols of non-sodic nature, soil moisture is held at 100 kPa while in calcareous Vertisols of sodic nature it is held at 300 kPa. Based on this field observation the concept of plant available water content, which relates to profile water content, was adopted earlier to calculate the plant available water capacity (PAWC) considering the soil moisture held between 100-1500 kPa for non-sodic and 300-1500 kPa for sodic soils. This pragmatic PA WC method showed a significant positive correlation between the PA WC and the yield of cotton (lint + seed) of 32 Vertisols of the Vidarbha region, however, it did not address the status of soil moisture release at higher tensions. It is apprehended that at higher tensions, the release of soil moisture is not enough during the dry period of the season that can prevent the extension of vertical cracks in the slickensided horizons at deeper depth of 100 cm and beyond. Less amount of soil water in the subsoils is due to the decrease of saturated hydraulic conductivity(sHC) with depth preventing the free flow of rainwater in the subsoils. This makes subsoils as more water constraint horizons but enriches subsoils with pH > 8.0, more amount of Mg2+ and Na+ ions on soil exchange complex. Such Vertisols do not support the second crop during the winter months. In view of this predicament in agricultural land use plan of SAT Vertisols, the present study was undertaken to understand the cause and effect relationship between soil moisture and relevant soil parameters that prevent the release of soil moisture at higher tensions. In order to find an insight into this queer issue, soil moisture retention and release curves at 33, 100, 300, 500, 800, 1000 and 1500 kPa, were obtained for each genetic horizon of 33 representative Vertisols ofVidarbha andMarathwada region. In Vidarbha, Vertisols are Aridic/Typic/Sodic Haplusterts and Calciusterts, and in Marathwada, they are Typic/Sodic Haplusterts. Moisture tension curves indicate that the release of water beyond 800 kPa is negligible. Failure in the release of soil water beyond 800 kPa is due to the dispersion of fine clay size smectite (< 200 nm) consisting primarily of nano-size smectite (<100 nm), caused by the Mg2+ and Na+ ions present on the soil exchange complex. The dispersed nano-size smectite blocks the macropores and simultaneously increase the micropores, where soil moisture is held very tightly. In the present study, PA WC calculation was done considering the soil water held between 100-800 kPa for soils of non-sodic nature, and for sodic soils, it was between 300-800 kPa. The revised PAWC data showed a better significant positive correlation with yields of cotton on farmers ’field, in comparison to correlation obtained earlier. Thus, it stands as a robust index parameter of soil abiotic stress in SAT environment. This unique parameter having a legacy to major pedogenetic processes in SAT Vertisols. In Indian states under SAT, PAWC emerges as a formidable biophysical parameter for evaluation of rain-fed Vertisols for growing deep-rooted crops.

Impact of heat stress, nutritional stress and their combinations on the adaptive capability of Malpura sheep under hot semi-arid tropical environment

Impact of heat stress, nutritional stress and their combinations on the adaptive capability of Malpura sheep under hot semi-arid tropical environment

Seasonal rhythmicity of thermoregulatory physiological responses in fat-rumped sheep under semi-arid tropical environment

ABSTRACTThe immediate response of animals to fluctuations in environmental temperature is an alteration in their physiological responses. For those who failed to cope, their production performance is affected greatly. Fat-rumped sheep is phenotypically different from the commonly available sheep breeds of the semi-arid tropical environment in India. For assessment of thermoregulatory rhythmicity under extreme seasonal variations of the semi-arid tropical region, six adult fat-rumped (Dumba) rams were selected. The study was carried out in the year 2016–2017. All the rams were maintained under stall-feeding condition with a fixed dietary regime. Respiration rate (RR), pulse rate (PR), skin temperature (ST) and rectal temperature (RT) were recorded at morning (08:00 h), and afternoon (14:00 h) in summer (May–June), winter (December–January) and spring (March–April) for six times in each season at 7 days interval. Body weight was taken at the start and end of each season under study. The meteorological data were recorded twice daily at 8:00 h and 14:00 h for the entire study period. The study indicated significant (p < 0.05) variation in RR, PR and ST with respect to season. RT and body weight showed no significant variation among seasons. The result indicated fat-rumped sheep altered their thermoregulatory physiological responses as per the change of season to cope with environmental extremes under semi-arid tropical region.

A conceptual model of natural land degradation based on regressive pedogenesis in semiarid tropical environments

AbstractLand degradation occurs in all the climatic regions, however, the adverse effects are more pronounced in the semiarid tropical (SAT) environments due to increasing aridity and water scarcity. Though natural processes can also cause land degradation, it is generally attributed to anthropogenic factors. In this study, we elucidate the role of climate and landscape driven soil forming processes in land degradation through a conceptual model. For this, morphological, physical, and chemical properties of the soils occurring in a part of the SAT Deccan Plateau region, India, were characterized. The trend of climatic variables, namely, the mean annual rainfall, potential evapotranspiration, and maximum summer temperature during the last century (1901–2010) showed that the increase in aridity negatively influenced the soil forming processes. The results showed that rainfall variability, temperature, potential evapotranspiration, and hydrological behaviour of the SAT soils were the primary drivers of the soil forming processes and they were identified through examination of the soil variability by factor analysis. The depth distribution of selected indicators (% clay, pH, calcium carbonate, exchangeable sodium percentage, exchangeable magnesium percentage, and hydraulic conductivity) indicated that the current pedogenic processes operating in the SAT environment caused the undesirable modification in soil properties. Through our conceptual model, we discuss the mechanism of the formation of pedogenic carbonate, subsoil sodicity, and subsequent reduction in hydraulic conductivity which leads to the land and vegetation degradation in the SAT environments.

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

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.

Physiological rhythmicity in Malpura ewes to adapt to cold stress in a semi-arid tropical environment

A study was conducted to assess the rhythmic pattern of physiological parameter in Malpura ewes to adapt to cold stress in a semi-arid tropical environment. Eighteen adult Malpura ewes were selected for the present study. These ewes were randomly allocated into two groups: GI (Open shed; n=9) and GII (Protected; n=9). The study was conducted for a period of 30 days during the peak winter season (December 2011) during which the animals were stall fed. Blood samples were collected at fortnightly interval. The growth, physiological response, blood biochemical response and endocrine response parameters were studied. The results reveal that cold stress had significant negative influence on all the parameters studied in the ewes. In conclusion, it can be said that cold stress had significant influence on the biological functions in the ewes that would result in the impairment of their production and reproductive efficiency as well. The study also indicates the relevance of provision of appropriate protective measures to foster cold during the extreme winter months in the arid and semi-arid tropical areas.

Effect of protection against hot climate on growth performance, physiological response and endocrine profile of growing lambs under semi-arid tropical environment.

In the hot semi-arid tropical region, extreme summer is a major constraint in sheep production. The growth performance of growing lambs is impaired during the summer. Therefore, the present study was conducted to assess the effect of protection against hot climate on growth performance, physiological response, and endocrine profile of growing lambs under semi-arid tropical environment. All the data in the experiment were presented as mean±SE. Thirty Malpura lambs with the age of 122.7±6.05days and body weight of 19.52±0.42kg were allotted into three groups, viz. G1 (control, lambs kept in open area under tree shade), G2 (lambs kept in conventional asbestos-roofed shed), and G3 (lambs kept in designed shed). The allotment was based on their initial body weight so that the mean body weight of each group was similar. In all three types of protection, lambs were provided with sufficient space to move and social interaction. In asbestos-roofed shed (G2), all the four sides from ground to the roof were fenced with strong galvanized iron chain link. But in G3, all the four sides were constructed in a manner that there was 0.13m air space between inner and outer solid brick columns of the wall up to 1.37m height, and rest up to the roof was fenced with bamboo splint net. The air space between the two columns of the wall was filled with sand, and it was kept in moist condition by continuous water drips which provide extra evaporative cooling. The designed shed was basically constructed with bamboo. Tree shade was assured under the natural shades of large trees. The shaded area was protected by wire fences. The experiment was conducted for 45days during very high temperature (May-June). The lambs were provided with ad libitum green fodder, dry roughage, 300g concentrate, and ad libitum drinking water. The respiration rate at morning and afternoon, pulse rate at morning and afternoon and rectal temperature at afternoon was significantly (P<0.05) lower in lambs of G3 as compared to other groups. The final body weight did not differ significantly between the groups, but average daily gain (g/day) was higher in G3 (150.06±11.13) as compared to the G1 (109.69±18.10). The feed conversion rate (FCR) was significantly (P<0.05) better in G3 (5.49±0.08) as compared to G1 (7.65±0.08) and G2 (6.60±0.08). The hemoglobin level was significantly (P<0.05) higher in G1. The endocrine profile did not vary significantly (P>0.05) among the groups, but insulin-like growth factor-1 (IGF-1) was higher in G3. It can be concluded from this study the lambs provided with better protection during summer remained in more comfortable condition, showed better FCR, and although not statistically significant showed better growth performance.

Impact of drip irrigation and N-fertigation scheduling on wheat (Triticum aestivum) under semi-arid tropical environment

The efficient use of water by modern irrigation systems is becoming increasingly important in arid and semi-arid regions with limited water resources. A field experiment was conducted at Jain Hi-Tech. Agri. Institute, Jalgaon, Maharashtra during rabi season of 2012-13 and 2013-14, to study the impact of drip irrigation and N-fertigation scheduling on growth and yield of winter wheat (Triticum aestivum L.). The results revealed that all growth traits, yield components, grain and straw yield of wheat increased significantly at each higher levels of drip irrigation up to DI - 1.0 Epan with water application of 511 and 446 mm and fertigation of 120 kg N/ha in both the years. The highest water productivity was recorded with 0.8 Epan and N160 in both the years of study. The predicted maximum grain yield was 4838 kg/ha in the 2012-13 with an input level of 171.1 kg N/ha, 4451 kg/ha in the 2013-14 with an input level of 154.7 kg N/ha and 4642 kg/ha on pooled basis with an input level of 162.6 kg N/ha, respectively beyond which the yield decrease. However, the maximum grain yield (Ymax) in 2012-13 and on pooled basis was not bracketed within the tested range of nitrogen levels (0 to 160 kg/ha). The economic optima of N level that will maximize the net return under prevailing prices considered above worked out to be 156.8 kg N/ha with the resultant grain yield of 4640 kg/ha.

Biological functions as affected by summer season-related multiple environmental stressors (heat, nutritional and walking stress) in Malpura rams under semi-arid tropical environment

The study was conducted with the primary objective to establish the impact of simultaneously imposed multiple stressors (thermal, nutritional and walking) on various biological functions in Malpura rams. The study was conducted for a period of 45 days. Twenty adult Malpura rams (average BW 44.9 Kg) were used in the present study. The rams were divided into two groups, CON (n = 10; Control) and MS (n = 10; multiple stressors). Both body weight (p < 0.05) and body condition scoring (p < 0.01) were lower in MS compared with CON rams. All the scrotal measurements reduced significantly (p < 0.01) in MS rams. All the testicular measurements also reduced significantly (p < 0.01) in MS as compared to CON rams. The seminal attributes, individual motility (p < 0.05), rapid motility (p < 0.05) and curvilinear velocity (p < 0.05) were significantly reduced in CON rams. However, slowness (p < 0.05), linearity (p < 0.05) and straightness (p < 0.05) parameters significantly increased in MS as compared to CON rams. In addition, plasma testosterone concentration was lower (p < 0.05) in MS rams. The study established the impact of multiple stressors on growth and reproductive performance of Malpura rams. Further, the results revealed that the only semen quality was affected by multiple stressors, but the semen production remained intact between the groups, indicating the extreme adaptive capability of Malpura rams to hot semi-arid tropical environment.

Effect of selenium-yeast feeding on amelioration of simulated heat stress and reproductive performance in Malpura ewe under semi-arid tropical environment

The present study was carried out for 35 days to assess the effect of selenium (Se)-yeast feeding on amelioration of simulated heat stress and reproductive performance of sheep. Twelve adult Malpura ewes were divided into two groups viz., G1 (n=6, control) and G2 (n=6, Se-yeast supplemented). The ewes of G2 were provided with Se at 0.3 mg/kg feed dry matter (DM) through Se-enriched yeast (Saccharomyces cerevesiea). The animals were stall fed individually with a diet consisting of 70% roughage (Cenchrus ciliaris) and 30% concentrate. All the ewes were estrus synchronized using intra-vaginal progesterone sponges+eCG protocol. To simulate heat stress, the ewes were kept inside the psychometric chamber and were exposed to different temperature at different hours of the day. Supplementation of Se-yeast had no significant effect on physiological response. Higher glucose and a lower protein level was found in the Se-yeast supplemented group under heat stress. Plasma metabolic hormone and cortisol level was higher in G1 as compared to Se-yeast supplemented ewes. Plasma glutathione peroxidase (GPx) was 10.62% higher in G2 as compared to the G1. Estrus percentage and estradiol level was higher in G2 as compared to the G1. From the findings of the present experiment, it is pertinent to conclude that the level of Se enriched yeast fed in this study have limited potential to ameliorate heat stress. However, different doses of Se could be tried in sheep to improve resilience against heat stress.

Effect of high ambient temperature on behavior of sheep under semi-arid tropical environment.

High environmental temperature is a major constraint in sheep production under semi-arid tropical environment. Behavior is the earliest indicator of animal's adaptation and responses to the environmental alteration. Therefore, the objective of this study was to assess the effects of high ambient temperature on the behavior of sheep under a semi-arid tropical environment. The experiment was conducted for 6weeks on 16 Malpura cross (Garole × Malpura × Malpura (GMM)) rams. The rams were divided equally into two groups, designated as C and T. The rams of C were kept in comfortable environmental conditions served as control. The rams of T were exposed to a different temperature at different hours of the day in a climatic chamber, to simulate a high environmental temperature of summer in semi-arid tropic. The behavioral observations were taken by direct instantaneous observation at 15-min intervals for each animal individually. The feeding, ruminating, standing, and lying behaviors were recorded twice a week from morning (0800 hours) to afternoon (1700 hours) for 6weeks. Exposure of rams to high temperature (T) significantly (P<0.05) decreased the proportion of time spent in feeding during the observation period in most of the hours of the day as compared to the C. The proportion of time spent in rumination and lying was significantly (P<0.05) lower in the T group compared to the C. The animals of T spent significantly (P<0.05) more time in rumination in standing position as compared to the C. The overall proportion of time spent in standing, panting in each hour, and total panting time was significantly (P<0.05) higher in the T as compared to the C. The result of the study indicates that the exposure of sheep to high ambient temperature severely modulates the behavior of sheep which is directed to circumvent the effect of the stressor.

Study of circadian rhythmicity of physiological response and skin temperature of sheep during summer and winter in semi-arid tropical environment

The present study aimed to evaluate the circadian rhythmicity of some physiological variables, including rectal temperature (RT), respiration rate (RR), heart rate (HR) and skin temperature (ST) in sheep during the summer and winter in semi-arid tropical environment. Eight Malpura rams of 3–4year of age with an average body weight of 37.1±1.99kg were selected for the study. All the animals were fed individually for a maintenance requirement on a body weight basis. The RT, RR, HR and ST values were measured in each animal at 3hour intervals for 24 consecutive hours. Ambient temperature (DBT) and relative humidity (RH) was also recorded inside the shed at the time of physiological parameter study. The cosinor analysis showed a daily circadian rhythm (P<0.01) in RR, HR and ST values during the summer and winter in sheep under semi-arid environment. The RR, HR and ST differ significantly (P<0.05) between summer and winter. The amplitude of RR, RT and ST differ significantly (P<0.05) between the seasons. The results indicate that the circadian rhythmicity of RR, HR, RT and ST during summer and winter changed as expected in compliance to the seasonal requirements of animal's adaptability.

Effect of multiple environmental stressors on the adaptive capability of Malpura rams based on physiological responses in a semi-arid tropical environment

A 45-day study was conducted where the primary objective was to evaluate the effect of simultaneously imposed multiple stressors (thermal, nutritional, and walking) on the adaptive capability of Malpura rams based on changes in ingestive behavior, physiological, blood biochemical, and endocrine responses. Twenty adult Malpura rams (average body weight 44.9 kg) were used in the study. The rams were divided into 2 groups, CON (n = 10; control) and multiple stressors (MS; n = 10; multiple stressors). All of the rams were stall fed with a diet consisting of 70% roughage and 30% concentrate. The CON rams were maintained in a shed under ambient conditions with ad libitum feeding without walking, whereas MS rams were subjected to multiple stressors (thermal, nutritional, and walking). The feed intake (P < 0.01) was lower and water intake (P < 0.01) was higher in MS compared to CON rams. Among the physiological measurements, respiration rate afternoon (P < 0.01), pulse rate morning (P < 0.01), rectal temperature afternoon (P < 0.01), skin temperature afternoon (P < 0.05), and both morning and afternoon scrotum temperature (P < 0.01) increased significantly in MS rams. Both hemoglobin (P < 0.05), packed cell volume (P < 0.01), increased and plasma glucose (P < 0.01) reduced significantly (P < 0.01) in MS as compared to CON rams. Among the endocrine parameters, the plasma cortisol increased and plasma thyroxin reduced significantly (P < 0.05) in MS rams. The study indicates that Malpura rams have the capability to adjust their physio-biochemical and endocrine responses to cope with multiple stressors in a hot semi-arid environment. Furthermore, the study also indicated that respiration rate, rectal temperature, scrotal temperature, hemoglobin, packed cell volume, and cortisol may act as ideal biological markers for quantifying the impact of multiple stressors in Malpura rams.

Models to predict both sensible and latent heat transfer in the respiratory tract of Morada Nova sheep under semiarid tropical environment.

The aim of this study was to build a prediction model both sensible and latent heat transfer by respiratory tract for Morada Nova sheep under field conditions in a semiarid tropical environment, using easily measured physiological and environmental parameters. Twelve dry Morada Nova ewes with an average of 3±1.2years old and average body weight of 32.76±3.72kg were used in a Latin square design 12×12 (12days of records and 12 schedules). Tidal volume, respiratory rate, expired air temperature, and partial vapor pressure of the expired air were obtained from the respiratory facial mask and using a physiological measurement system. Ewes were evaluated from 0700 to 1900h in each day under shade. A simple nonlinear model to estimate tidal volume as a function of respiratory rate was developed. Equation to estimate the expired air temperature was built, and the ambient air temperature was the best predictor together with relative humidity and ambient vapor pressure. In naturalized Morada Nova sheep, respiratory convection seems to be a mechanism of heat transfer of minor importance even under mild air temperature. Evaporation from the respiratory system increased together with ambient air temperature. At ambient air temperature, up to 35°C respiratory evaporation accounted 90% of the total heat lost by respiratory system, on average. Models presented here allow to estimate the heat flow from the respiratory tract for Morada Nova sheep bred in tropical region, using easily measured physiological and environmental traits as respiratory rate, ambient air temperature, and relative humidity.

Effect of multiple stress factors (thermal, nutritional and pregnancy type) on adaptive capability of native ewes under semi-arid environment

This study was conducted to evaluate the effect of multiple stress factors (thermal, nutritional and pregnancy type) on two different native track breeds of ewes as reflected by their adaptive capability under semi-arid environment. The multiple stressor experiment was conducted in twenty-four ewes (12 Santa Inês and 12 Morada Nova ewes). Both heat stress and pregnancy stress was common to all four groups. However, the animals were divided into further two groups within each breed on the basis of nutrition regimen. According the groupings were: Group 1 (Six Santa Ines ewes; heat stress; nutrition at 0.5% of BW; single pregnancy); Group 2 (Six Santa Ines ewes; heat stress; nutrition at 1.5% BW; twin pregnancy); groups Group 3 (Six Morada Nova ewes; heat stress; nutrition at 0.5% of BW; single pregnancy); Group 4 (Six Morada Nova ewes; heat stress; nutrition at 1.5% BW; twin pregnancy). All the animals in the experiment were pregnant. Heat stress was induced by exposing all animals to summer heat stress in outside environment while the nutritional regimen followed was at 0.5% and 1.5% level of body weight (BW) respectively in each breed. The experiment was conducted in a completely randomized design with two breeds, two nutritional treatments and two pregnancy types, 10 repetitions for physiological parameters and six for blood parameters, with repeated measures over time. Physiological parameters (respiratory rate, pulse rate and rectal temperature) were measured with the animals at rest in the morning and afternoon, 0600-0700 and 1300–1400h, respectively, every seven days. Blood samples were collected every 14d for determination of serum glucose, triglycerides, cholesterol, urea and creatinine. We found interaction effect between breed and pregnancy type on respiratory rate and rectal temperature with greater values in Santa Inês ewes than Morada Nova ewes. However, there was no significant fixed effect of pregnancy type and supplementation level on physiological responses of breeds. Environmental factor (period of the day) had influenced the physiological responses of ewes during all gestational period. Santa Inês ewes had greater serum glucose concentration at 105d and 120d of gestation compared to the Morada Nova ewes. Morada Nova ewes had greater concentrations of triglycerides, urea at 120d, 150d and also greater cholesterol at 105d, 135d and 150d of gestation compared with Santa Inês ewes. The present result indicates that thermal condition was most important factor that modified the physiological responses of ewes in a semi-arid tropical environment.

Effect of water restriction on physiological responses and certain reproductive traits of Malpura ewes in a semiarid tropical environment

Other than high temperature and feed shortage, water scarcity is a major problem in semiarid tropical region during summer. Water is considered as an essential nutrient and is involved in every metabolic function of the body. Considering its importance in sheep productivity, twenty-eight nonpregnant Malpura ewes were randomly and equally divided into 4 groups, viz., GI (control; ad libitum water), GII (20% less than ad libitum water intake), GIII (40% less than ad libitum water), and GIV (ad libitum water on alternated day) to see the effect of water restriction on physiological responses and certain reproductive traits of Malpura ewes in semiarid tropical environment. This study was conducted for a period of 35 days covering 2 estrous cycles. All the animals were provided with ad libitum feed consisted of 70% roughage and 30% concentrate. All the ewes were synchronized for estrus at the starting of the experiment and reproductive parameters were recorded. The feed intake of all the ewes was recorded individually daily during the study period. All the ewes were weighed individually every week before morning feeding. Physiological responses were recorded twice daily at 0700 h and 1400 h on weekly basis. Blood samples were collected at weekly interval. The feed intake was lower (P 0.05) during afternoon. All the water-restricted groups showed a trend of lower respiration rate and pulse rate both in morning and afternoon compared with GI, although the difference was not significant. Hemoglobin, packed cell volume, glucose, cholesterol, and chloride level were significantly (P < 0.05) lower in GIV compared with GI. The glucose and cholesterol levels were (P < 0.05) lower in GIII compared with GI. Estrus percentage was lower (85.7%) in the water-restricted ewes compared with control (100%). Estrogen level was significantly (P < 0.05) lower in GIII and GIV compared with GI, whereas progesterone level showed a reverse trend. The present study reveals the effect of water stress on biological functions of Malpura ewes during summer. The results suggest that Malpura ewes can adjust their physiochemical response and reproduction up to 20% of water restriction during hot summer.

The effect of nutritional stress on sperm motion characteristics and sexual behaviour of rams in a semi-arid tropical environment

The effect of nutritional stress on sperm motion characteristics and sexual behaviour of rams in a semi-arid tropical environment

Effect of different types of housing on behavior of Malpura lambs during winter in semi-arid tropical environment

Abstract During winter, different types of sheds were constructed to reduce lamb mortality. A study was conducted to assess the effect of different types of housing on the behavior of Malpura lambs during the winter in semiarid tropical condition in terms of suckling, feeding, lying, standing, social interaction, and oral stereotype. Sheds are constructed to reduce winter mortality. This study was carried out for a period of 1 month during winter (January-February). Twenty-one lambs of aged 3-5 weeks were divided into 3 groups of 7 animals each such as G-I (control, n = 7), G-II (bamboo dome, n = 7) and G-III (thermocol-insulated cold-protected shed, n = 7). The G-I lambs were maintained in normal asbestos roofed shed (side wall wire net, curtains at night time), whereas G-II lambs were maintained in a local hand-made bamboo dome structures. G-III lambs were kept in thermocol-insulated (roof and doors were made up of asbestos, thermocol, and polyvinyl chloride sheet, brick side wall) roofed shed from 6:30 pm to 7 am. The lambs were exposed to their mother in the morning (7 am to 7:30 am) and evening (5:30 pm to 6 pm) for suckling. Lambs were provided with ad libitum green fodder, dry roughage, and concentrate in an open area from 8 am to 5:30 pm. Behavioral recording was carried out for 1 animal from each group daily (once weekly for each animal) by 3 people (1 person for 1 lamb). G-III lambs showed higher weekly body weight gain and higher milk intake. Total feeding time was 22.44% higher in G-III compared to G-I lambs. Drinking time was higher in G-I lambs compared with those in the other groups. Standing time was significantly higher ( P