Cold Dry Season Research Articles

Browse silage as potential feed for captive wild ungulates in southern Africa: A review.

The objective of the review was to assess the potential of indigenous browse trees as sustainable feed supplement in the form of silage for captive wild ungulates. Several attempts to use silage as feed in zoos in temperate regions have been conducted with success. Information on silage from the indigenous browse trees preferred by wild ungulates in southern Africa is scanty. The use of silage from the browse trees is of interest as it has potential to reduce or replace expensive feed sources (pellets, fruits and farm produce) currently offered in southern African zoos, game farms and reserves, especially during the cold-dry season. Considerable leaf biomass from the indigenous browse trees can be produced for silage making. High nutrient content and minerals from indigenous browsable trees are highly recognised. Indigenous browse trees have low water-soluble carbohydrates (WSC) that render them undesirable for fermentation. Techniques such as wilting browse leaves, mixing cereal crops with browse leaves, and use of additives such as urea and enzymes have been studied extensively to increase WSC of silage from the indigenous browse trees. Anti-nutritional factors from the indigenous browse preferred by the wild ungulates have also been studied extensively. Indigenous browse silages are a potential feed resource for the captive wild ungulates. If the browse trees are used to make silage, they are likely to improve performance of wild ungulates in captivity, especially during the cold-dry season when browse is scarce. Research is needed to assess the feasibility of sustainable production and the effective use of silage from indigenous browse trees in southern Africa. Improving intake and nutrient utilisation and reducing the concentrations of anti-nutritional compounds in silage from the indigenous browse trees of southern Africa should be the focus for animal nutrition research that need further investigation.

One-year review of pityriasis rosea among outpatients in Kano, Northwestern Nigeria

Background: Pityriasis rosea (PR) is an acute self-limiting papulo-squamous skin disorder commonly observed in otherwise healthy children and young adults. Objective: To describe the clinical pattern of PR in Kano, Northwest Nigeria. Materials and Methods: This was a descriptive cross-sectional study that was carried out between June 2010 and May 2011 among out-patients attending three dermatology clinics in Kano, Nigeria. Patients with rashes that met the clinical diagnostic criteria of PR were recruited and followed up until there was resolution of lesions. The demographic characteristics of the patients were recorded along with the clinical manifestations of the lesions. All the data obtained were analysed using SPSS for Windows. Results: Out of 1,528 patients seen over the 12 months study period, 56 patients had PR out of which 23 (41.1%) were males and 33 (58.9%) were females, giving a male:female ratio of 1:1.4. PR, therefore, accounted for 3.6% of all dermatology out-patient visits in Kano. The patients' ages ranged from 6 years to 55 years with most of them in the age range of 11–20 years. The peak month of incidence was January in which about a quarter (21%) of the patients were seen. Only 5 (8.9%) patients had prodromal symptoms preceding the onset of the rash. Herald patch, which was mainly located on the trunk, was present in 45 (80%) of the studied patients. Secondary eruptions appeared within 7 days after the herald patch in 69% and had a typical Christmas tree pattern of distribution along the line of skin cleavage in 70% of the patients. Approximately three-quarter (73 %) of the patients had complete resolution of the rash by the 4th week. Recurrence was not reported 24 weeks after the last patient was seen. Conclusion: The pattern of presentation of PR was not different from that observed by other researchers. However, contrary to earlier reports from south Nigeria, our study shows that PR occurs more frequently during the cold dry season.

Influence of irrigation and fertilisation management on the seasonal distribution of water and nitrogen in a semi-arid loamy sandy soil

Increased use of irrigation on semi-arid sandy soils requires optimisation of irrigation and fertilisation practices to reduce water and nitrogen (N) losses. Field experiments were conducted on a semi-arid loamy sandy soil in two consecutive cropping periods, one in a cold-dry season (CP-cd) and one in a hot-wet season (CP-hw). The effects of individual treatment factors and their interactions, including two different irrigation methods (furrow – F or drip – D), two irrigation levels (full – If or reduced – Ir) and two top dressing N fertiliser types (quick – Nq or slow – Ns release), on water and N distribution in the soil profile, potential water fluxes to the zone below the roots and N losses from the 0–90 cm soil profile were studied. The concentrations of NO3-N and NH4-N in soil water (from suction cups) and soil (from bulk soil samples) tended to be higher at greater depth in the treatments with lower soil water tension, resulting from the interactions between the factors F or D with If and Nq, most probably resulting from net downward redistribution of N. The IrNs treatments resulted in longer soil water NO3-N and NH4-N residence time at 30 and 60 cm depth, and throughout the two cropping periods NO3-N was higher in Ns than in Nq treatments. Potential faster downward water flux, and thus water losses and the N leaching risk, was concentrated to the first 50–75 days after sowing in FIr and DIr treatments, while it was spread throughout the cropping periods in FIf and DIf. Hence, treatments FIfNq and DIfNq in both CP-cd and CP-hw resulted in the highest estimated N losses from the 0–90 cm soil profile. Based on these results, a combination of D irrigation, Ir irrigation level and Ns fertiliser type should preferably be applied, to avoid the risk of excessive water losses, downward N redistribution and subsequent leaching.

Seasonal food habits of the endangered Indochinese leopardPanthera pardus delacouriin a protected area of North West Thailand

The Indochinese leopard Panthera pardus delacouri has experienced a sharp decline in numbers and distribution, especially in Thailand. We have analyzed its diet in Om Koi Wildlife Sanctuary of North West Thailand, where only wild prey species were present. Scats were collected during the dry-hot and the dry-cold seasons. The Indian muntjac appeared to be the staple of the leopard's diet, particularly in the dry-cold season, and consumed equally with the Indian wild boar in the dry-hot one. The occurrence of the Indochinese hog deer in the diet of the leopard in Om Koi represents the first detection record of this endangered species in North West Thailand, after being long extirpated. During the dry-hot season, poachers slashed and burnt portions of forest to flush game and to provide space for poppy fields. Muntjacs are sensitive to both forest fires and poaching, whereas Indian wild boar are resilient to disturbance, which may explain their alternation in diet.

Altitudinal distribution of two sibling species of the Drosophila tripunctata group in a preserved tropical forest and their male sterility thermal thresholds

Variation of ecophysiological traits may help to explain geographic distribution patterns of Drosophila sibling species. Many traits in ectotherms have optimal performance within specific temperature ranges. Altitudinal gradients are potentially informative for characterizing differences of sibling species distributions. We collected two sibling species of the tripunctata group – Drosophila mediopunctata (MPT) and D. unipunctata (UNI) – at eight altitudes (ranging from 593 to 1185m above sea level) located at a continuous Atlantic Rainforest reserve in consecutive years (2009–2011), with two collections at the hot-rainy season and two at the cold-dry season. Mean altitude was significantly different between species and seasons. Their distributions showed a consistent pattern with MPT always occurring at higher altitudes than UNI. A significant correlation was found between altitude and species relative abundance. We characterized the thermal range of fertility, an important fitness component, for each species and found evidence for differential thermal adaptation. Our results suggest that the two species altitudinal distributions and seasonal relative abundances are consistent with their differential thermal adaptations: MPT seems to be adapted to lower temperatures, occupies higher altitudes and occurs at higher relative abundances in the cold-dry season; while UNI tolerates higher temperatures and occurs at lower altitudes and higher relative abundances in the hot-rainy season. However, their thermal ranges overlap at most temperatures, suggesting that additional variables (e.g. habitat choice, competition, differential survival etc.) may also play a role to determine their distribution in the field.

Spatiotemporal distribution and impact of diamondback moth parasitoids in the Dakar Niayes in Senegal

Conservation biological control, which fosters the optimal use of indigenous natural enemies, is a promising way for reducing pesticide reliance in horticultural systems. The objective of this study is to determine the distribution of parasitoid species, their parasitism rates on pest populations in relation to environmental conditions in the main Senegalese market garden area (Niayes). To do this, one hundred and sixteen cabbage plots, distributed in the Niaye segmented into three areas, along a South-North transect, are chosen. These plots were observed during four crop seasons from October 2012 to May 2014. Pest larvae were counted every three weeks using 24 randomly chosen cabbage plants per plot. Four hymenopteran parasitoid species were identified; Oomyzus sololowskii (Kurdjumov), (Eulophidae), Brachymeria sp. (Chalcididae), Apanteles litae Nixon and Cotesia vestalis (Haliday) both Braconidae. The percentage of parasitism varied between the plots, the geographical locations and the sampling period. O. sokolowskii and A. litae species were predominant and were affected by the growing season. The species distribution in the three sampling areas revealed that O. Sokolowskii was more efficient during the cold dry season, whereas A. litae was more efficient during the hot dry season. These results aim at identifying conditions favorable to the regulation of populations of cabbage moth by natural enemies. Parasitoids can play a promising role as biological control agents in Senegal. In order to do this, studies such as these must be carried out and the results communicated to farmers who often misunderstand the primordial role that natural enemies can play in pest control. Keywords : Cabbage, parasitism percentage, dry season, West Africa, Plutella xylostella .

Association between Childhood Diarrhoeal Incidence and Climatic Factors in Urban and Rural Settings in the Health District of Mbour, Senegal.

We assessed the association between childhood diarrhoeal incidence and climatic factors in rural and urban settings in the health district of Mbour in western Senegal. We used monthly diarrhoeal case records among children under five years registered in 24 health facilities over a four-year period (2011–2014). Climatic data (i.e., daily temperature, night temperature and rainfall) for the same four-year period were obtained. We performed a negative binomial regression model to establish the relationship between monthly diarrhoeal incidence and climatic factors of the same and the previous month. There were two annual peaks in diarrhoeal incidence: one during the cold dry season and one during the rainy season. We observed a positive association between diarrhoeal incidence and high average temperature of 36 °C and above and high cumulative monthly rainfall at 57 mm and above. The association between diarrhoeal incidence and temperature was stronger in rural compared to urban settings, while higher rainfall was associated with higher diarrhoeal incidence in the urban settings. Concluding, this study identified significant health–climate interactions and calls for effective preventive measures in the health district of Mbour. Particular attention should be paid to urban settings where diarrhoea was most common in order to reduce the high incidence in the context of climatic variability, which is expected to increase in urban areas in the face of global warming.

Spatiotemporal patterns of clinical bovine dermatophilosis in Zimbabwe 1995-2014.

A retrospective study of clinical bovine dermatophilosis outbreaks and cases for the period 1995–2014 was conducted, using data obtained from the Division of Veterinary Services (DVS). A total of 3856 outbreaks and 26 659 cases of dermatophilosis were reported countrywide during this period. The post rainy season accounted for 37.9% of the outbreaks followed by the rainy season (26.7%), cold dry season (22.1%) and the hot dry season (13.2%). A retrospective space–time scan statistic in SaTScan™ was used to detect clusters. From this study, it was evident that dermatophilosis was spreading from the north-west of Zimbabwe through the central to the north-east during the period 2010–2014. Five clusters were identified mainly in the central and north-western regions of Zimbabwe. The primary cluster was centred at Ungwe, Gokwe district in Midlands; the second, third, fourth and fifth likely clusters were centred at Bonga (Mashonaland Central), ARDA (Mashonaland West), Nsenga (Matabeleland North) and Zanda in Gokwe, respectively. The findings of this study suggest the continued spread of dermatophilosis across the country; as such the Department of Livestock and Veterinary Services are advised to develop measures aimed at managing this spread such as dipping, quarantine, movement control and raising farmer awareness.

Assessing patterns and determinants of latrine use in rural settings: A longitudinal study in Odisha, India.

IntroductionMonitoring of sanitation programs is often limited to sanitation access and coverage, with little emphasis on use of the facilities despite increasing evidence of widespread non-use.ObjectivesWe assessed patterns and determinants of individual latrine use over 12 months in a low- income rural study population that had recently received latrines as part of the Government of India’s Total Sanitation Campaign (TSC) in coastal Puri district in Odisha, India.Materials and methodsWe surveyed 1938 individuals (>3 years) in 310 rural households with latrines from 25 villages over 12 months. Data collection rounds were timed to correspond with the seasons. The primary outcome was reported use by each member of the household over the prior 48 h. We classified use into three categories—“never”, “sometimes” and “always/usually”. We also assessed consistency of use over six days across the three seasons (dry cold, dry hot, rainy). We explored the association between individual and household-level variables and latrine use in any given season and longitudinally using multinomial logistic regression. We also inquired about reasons for non-use.ResultsOverall, latrine use was poor and inconsistent. The average response probability at any given round of never use was 43.5% (95% CI = 37.9, 49.1), sometimes use was 4.6% (95% CI = 3.8, 5.5), and always/usual use was 51.9% (95% CI = 46.2, 57.5). Only two-thirds of those who reported always/usually using a latrine in round one reported the same for all three rounds. Across all three rounds, the study population was about equally divided among those who reported never using the latrine (30.1%, 95% CI = 23.0, 37.2), sometimes using the latrine (33.2%, 95% CI = 28.3, 38.1) and always/usually using the latrine (36.8%, 95% CI = 31.8, 41.8). The reported likelihood of always/usually versus never using the latrine was significantly greater in the dry cold season (OR = 1.50, 95% CI = 1.18, 1.89, p = 0.001) and in the rainy season (OR = 1.34, 95% CI = 1.07, 1.69, p = 0.012), than in the dry hot season.Across all three seasons, there was increased likelihood of always/usually and sometimes using the latrine versus never using it among females and where latrines had a door and roof. Older age groups, including those aged 41–59 years and 60+ years, and increase in household size were associated with a decreased likelihood of always/usually using the latrine versus never using it. The leading reason for non-use was a preference for open defecation.ConclusionResults highlight the low and inconsistent use of subsidized latrines built under the TSC in rural Odisha. This study identifies individual and household levels factors that may be used to target behavior change campaigns to drive consistent use of sanitation facilities by all.

Comparative evaluation of haematological parameters and erythrocyte membrane stability in pregnant and lactating goats in different seasons of tropical Savannah

Haematological parameters and erythrocyte osmotic fragility (EOF) are commonly used as indicators of health status and erythrocyte membrane integrity. Variations in haematological parameters and EOF in late gestation and early lactation during the cold-dry (CDS), hot-dry (HDS) and rainy (RAS) seasons were studied in sixty (n = 60) Red Sokoto goats (20 goats for each season). The ambient temperatures and temperature-humidity index recorded were higher in the afternoon hours of the HDS and RAS, but lower in the morning hours of the CDS as compared with the thermoneutral zone of goats. Results revealed that the pregnant goats had significantly (P < 0.05) lower PCV and RBC, but higher haemoglobin parameters (Hb, MCH and MCHC) in RAS. Unlike in the pregnant goats, higher (P < 0.05) values of PCV and RBC were observed during the HDS as compared with the CDS and RAS in lactating goats. The EOF was significantly higher during lactation than pregnancy in the CDS and HDS. Similarly, the magnitude of the left shift in fragiligram during the CDS was more marked in pregnant compared with lactating goats. During gestation, the CDS had lower (P < 0.05) EOF than HDS and RAS, with a marked left shift in the fragiligram of both pregnant and lactating goats during the CDS. In conclusion, seasonal variations exist in physiology of erythrocytes of goats during the peri-partum period, with an increase in PCV and RBC, but a decrease in haemoglobin parameters in pregnant compared with lactating goats during the RAS. Erythrocyte stability and membrane integrity were higher in pregnant than lactating goats, and also higher during the CDS than the HDS and RAS, irrespective of reproductive status. This information may be useful in the design of animal breeding and is of value in animal welfare, research, diagnosis and management of haematological conditions during the peri-partum period.

Variations in Platelet Count and Total Protein in Relation to Differences in Sex, Age, Breed and Reproductive Status of Goats during the Cold-Dry Season (Harmattan)

Variations in Platelet Count and Total Protein in Relation to Differences in Sex, Age, Breed and Reproductive Status of Goats during the Cold-Dry Season (Harmattan)

Influences of breed, sex and age on seasonal changes in haematological variables of tropical goat kids

Abstract. The influences of breed, sex and age on seasonal changes in haematological variables of kids (1–4 months old) belonging to Red Sokoto (n = 60) and Sahel (n = 60) goats were studied at the peaks of the cold-dry, hot-dry and rainy seasons in a West Africa Guinea savanna climate. The results showed that, during the hot-dry season, Sahel goat kids had significantly higher (P &lt; 0.05) packed cell volume (PCV) and red blood cell (RBC) count but lower (P &lt; 0.05) mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and total leucocyte count than Red Sokoto kids. Similarly, younger kids of both breed had significantly higher (P &lt; 0.05) PCV and RBC but lower MCV, MCH and MCHC compared with the older kids during the hot-dry season. Younger kids (1–2 months) of both breeds exhibited significantly (P &lt; 0.05) high PCV and RBC but low MCH and MCHC during the hot-dry season as compared with the cold-dry and rainy seasons, with the magnitude of the change being greater in Sahel kids. More remarkable seasonal fluctuations in haematological parameters were observed in buck kids than doe kids of both breeds. Multivariate analysis revealed a clear distinction between the change in haematological parameters during the cold-dry as compared with the hot-dry and rainy seasons, with MCV having the strongest discriminating power (0.91*). In conclusion, breed, age and sex variations in haematological variables of goats were more pronounced in the hot-dry season, during which the seasonal changes were more dramatic in kids of Sahel goats, as well as in younger and male kids of both breeds. These findings may be useful in the management of tropical goat kids in different seasons.

Seasonal drought ensemble predictions based on multiple climate models in the upper Han River Basin, China

An experimental seasonal drought forecasting system is developed based on 29-year (1982–2010) seasonal meteorological hindcasts generated by the climate models from the North American Multi-Model Ensemble (NMME) project. This system made use of a bias correction and spatial downscaling method, and a distributed time-variant gain model (DTVGM) hydrologic model. DTVGM was calibrated using observed daily hydrological data and its streamflow simulations achieved Nash–Sutcliffe efficiency values of 0.727 and 0.724 during calibration (1978–1995) and validation (1996–2005) periods, respectively, at the Danjiangkou reservoir station. The experimental seasonal drought forecasting system (known as NMME-DTVGM) is used to generate seasonal drought forecasts. The forecasts were evaluated against the reference forecasts (i.e., persistence forecast and climatological forecast). The NMME-DTVGM drought forecasts have higher detectability and accuracy and lower false alarm rate than the reference forecasts at different lead times (from 1 to 4 months) during the cold-dry season. No apparent advantage is shown in drought predictions during spring and summer seasons because of a long memory of the initial conditions in spring and a lower predictive skill for precipitation in summer. Overall, the NMME-based seasonal drought forecasting system has meaningful skill in predicting drought several months in advance, which can provide critical information for drought preparedness and response planning as well as the sustainable practice of water resource conservation over the basin.

A new classification of large-scale climate regimes around the Tibetan Plateau based on seasonal circulation patterns

This study aims to develop a large-scale climate classification for investigating the characteristics of the climate regimes around the Tibetan Plateau based on seasonal precipitation, moisture transport and moisture divergence using in situ observations and ERA40 reanalysis data. The results indicate that the climate can be attributed to four regimes around the Plateau. They situate in East Asia, South Asia, Central Asia and the semi-arid zone in northern Central Asia throughout the dryland of northwestern China, in addition to the Köppen climate classification. There are different collocations of seasonal temperature and precipitation: 1) in phase for the East and South Asia monsoon regimes, 2) anti-phase for the Central Asia regime, 3) out-of-phase for the westerly regime. The seasonal precipitation concentrations are coupled with moisture divergence, i.e., moisture convergence coincides with the Asian monsoon zone and divergence appears over the Mediterranean-like arid climate region and westerly controlled area in the warm season, while it reverses course in the cold season. In addition, moisture divergence is associated with meridional moisture transport. The northward/southward moisture transport corresponds to moisture convergence/divergence, indicating that the wet and dry seasons are, to a great extent, dominated by meridional moisture transport in these regions. The climate mean southward transport results in the dry-cold season of the Asian monsoon zone and the dry-warm season, leading to desertification or land degradation in Central Asia and the westerly regime zone. The mean-wind moisture transport (MMT) is the major contributor to total moisture transport, while persistent northward transient eddy moisture transport (TEMT) plays a key role in dry season precipitation, especially in the Asian monsoon zone. The persistent TEMT divergence is an additional mechanism of the out-of-phase collocation in the westerly regime zone. In addition, the climate-mean MMT and TEMT are associated with the atmospheric stationary wave and storm track, which results from the uplift of orography and land-sea thermal contrast. Therefore, the paleoclimate changes in mid-latitude arid-semi-arid regions are linked to the different phases of uplift of mountains and plate motion tied to the evolution of the Mediterranean.

AMS14C and Chemical Composition of Atmospheric Aerosols from Mexico City

AbstractAir pollution in Mexico City, which has more than 22 million inhabitants, continues to be one of the main environmental issues. Aerosol samples (PM10) collected in Mexico City and the city of Cuernavaca (a clean reference site) have been characterized using different techniques. This multifaceted approach addresses the source apportionment of the carbonaceous matter in PM10, as well as the airborne elements and ions. Accelerator mass spectrometry (AMS) radiocarbon analysis of total carbon, X-ray fluorescence (XRF), and ion chromatography were performed on aerosols collected at three sites in Mexico City and one site in Cuernavaca, during 2 months of the cold-dry season (November–December) in 2012. New results obtained for Mexico City are compared with previous reports. Average levels of PM10were higher in Mexico City sites (43.3–60.8 μg/m3) than in Cuernavaca (32.2 μg/m3). According to the material balance, PM10collected in Mexico City had a lower contribution of crustal material (31.2–36.8%) than Cuernavaca (46.9%). Average contributions of particulate carbonaceous matter to PM10were similar in both cities, but much higher contributions of mineral salts, trace elements, and ions were observed in Mexico City in comparison to Cuernavaca. Total organic carbon (OC) and elemental carbon (EC) contents were higher in aerosols from Mexico City than those from Cuernavaca. The temporal variation results showed that within all locations studied the OC concentration was high compared to the EC. Results from a theoretical calculation of fossil carbon (FC) and biogenic carbon (BC) concentrations showed that FC and BC levels depend on the site: at Mexico City sites, FC was equal or higher than BC. At Cuernavaca, BC was always higher than FC.

SEASONAL ABUNDANCE AND SPOROZOITE RATES IN MALARIA VECTORS IN NCHELENGE INCLUDING ISLANDS OF LAKE MWERU AN AREA WITH A HIGH BURDEN OF MALARIA IN NORTHERN ZAMBIA

BackgroundNchelenge district is a holoendemic malaria transmission zone in northern Zambia. The district occurs in a region characterised by a mix of water, marshes, islands and lagoons presenting a uniquely...

Cattle landscape selectivity is influenced by ecological and management factors in a heterogeneous mountain rangeland

Few studies addressing drivers of cattle selectivity focus on the combination of ecological (biotic and abiotic) and management factors such as rotational systems, paddock sizes and paddock shapes. As a consequence, it is difficult to prioritise management practices integrating information of different driving factors. In a heterogeneous mountain rangeland in Central Argentina we established a total of 419 square study plots of 1 ha located in 18 paddocks with differing sizes, shapes and cattle grazing management. Plots were small samples of landscapes, covering all existing variability in vegetation and physiography. For each plot we estimated the annual cattle use, average seasonal cattle density, forage types and abiotic characteristics. We used general linear models to show that selectivity was mainly driven by biotic variables. Cattle selected landscapes dominated by short palatable plants, but the strength of this influence differed among paddocks. Selectivity was strongest in paddocks with low abundance of lawns dominated by short palatable plants and low annual stocking rate. As stocking rate and the availability of lawns increased, selectivity strength decreased. Abiotic variables had far less influence than biotic variables, showing that cattle tended to avoid rough landscapes with steep terrain in the wet-warm season; and to be attracted by permanent water sources during the dry-cold season. Seasonal stocking density and paddock size had no detectable influence on cattle selectivity and distribution. Paddock shape influenced distribution but not the strength of forage selectivity. We conclude that in our system, cattle selectivity is mainly driven by biotic factors, and the most effective methods of changing the consequent distribution pattern is by manipulating forage types and paddock shape. The role of stocking rate remains controversial as it was correlated with the proportion of lawns in the paddock.

Effects of Cold-Dry (Harmattan) and Hot-Dry Seasons on Daily Rhythms of Rectal and Body Surface Temperatures in Sheep and Goats in a Natural Tropical Environment.

Studies on daily rhythmicity in livestock under natural conditions are limited, and there is mounting evidence that rhythm patterns differ between chronobiological studies conducted in the laboratory and studies conducted under pronounced natural seasonality. Here, we investigated the influence of cold-dry (harmattan) and hot-dry seasons on daily rhythmicity of rectal (RT) and body surface temperatures (BST) in indigenous sheep and goats under natural light-dark cycles. The RT and BST of the animals, and the ambient temperature (AT) and relative humidity (RH) inside the pen, were measured every three hours for a period of two days, twice on separate days during the hot-dry and the harmattan seasons, respectively. The AT and RH had minimum values of 16°C and 15% recorded during the harmattan and maximum values of 32°C and 46% recorded during the hot-dry season, respectively. A trigonometric statistical model was applied to characterize the main rhythmic parameters according to the single cosinor procedure. The result showed that RT and BST exhibited different degrees of daily rhythmicity, and their oscillatory patterns differed with the seasons (larger amplitude during the harmattan season than during the hot-dry season). The goats displayed greater (p < 0.05) amplitude of BST than the sheep in all seasons. The acrophases were restricted to the light phase of the light-dark cycle. The mesor of RT in goats was not affected by the season, but mesors of BST in both species were significantly higher (p < 0.05) during the hot-dry than the harmattan season. The goats had a more robust RT rhythm (70%) as compared to the sheep (56%). Overall, the results demonstrated that seasonal changes influenced considerably the daily rhythmicity of RT and BST in sheep and goats under natural light-dark cycle. Awareness of these changes may be useful in the improvement of diagnosis, treatment and prevention of diseases, and welfare and productivity of sheep and goats under cold-dry and hot-dry conditions.

Response of maize root growth to irrigation and nitrogen management strategies in semi-arid loamy sandy soil

Strategies to promote dense, deep root systems are important for the efficient use of water and nitrogen fertilisers in subtropical loamy sandy soil. This study assessed the effect of interactions between irrigation method (drip and furrow), irrigation level (full and reduced), and nitrogen fertiliser type (quick-release and slow-release) on root growth of maize (Zea mays L.) and the associated effect on grain yield, aboveground biomass and leaf area index. Factorial field experiments on semi-arid loamy sandy soil in Mozambique was carried out in four cropping periods (two in the hot-wet season, two in the cold-dry season). The response to the management factors at three growing stages of coarse (≥0.7mm diameter) and fine (<0.7mm diameter) root density (RD) (two cropping periods) and maximum rooting depth (four cropping periods) were measured in situ by modified profile wall method. The interactions between management factors did not explain the variation in maize RD or maximum rooting depth. However, seasonal variation between the cropping periods affected the distribution of coarse RD. Drip irrigation gave 33–153% higher coarse RD and 26–55% higher fine RD than furrow irrigation in deeper layers (16–64cm), whereas furrow irrigation gave 21–40% higher coarse RD than drip at a shallow depth (0–16cm). Irrigation level had little effect on RD, whereas slow-release fertilisation resulted in overall higher RD, aboveground biomass and grain yield than quick-release fertilisation in the cold-dry season. RD or maximum rooting depth showed few significant correlations with grain yield, biomass and leaf area index, respectively, but higher RD generally tended to result in higher yield. Overall, drip irrigation combined with reduced irrigation and slow-release N fertiliser appeared to be the most promising strategy to promote maize rooting and increase yield, especially in the cold-dry season.

Seasonal variation in body mass index, cardinal physiological variables and serum thyroid hormones profiles in relation to susceptibility to thermal stress in goat kids

The influence of seasonal changes and susceptibility to thermal stress on body mass index (BMI), cardinal physiological variables (respiratory rate; RR, pulse rate; PR and rectal temperature; RT) and circulating thyroid hormone profiles (T3 and T4) was studied in Red Sokoto (n=60) and Sahel (n=60) goats during the cold-dry (CDS), hot-dry (HDS) and rainy (RAS) seasons. Using the RR, goats were grouped into cold stress susceptible (CSS) and cold stress tolerant (CST) phenotypes in the season with lower temperature humidity index (CDS) or heat stress susceptible (HSS) and heat stress tolerant (HST) phenotypes in the seasons with higher THI (HDS and RAS). Results revealed that the PR and RT were lower (P<0.05), while circulating thyroid hormones and BMI were higher (P<0.05) in Red Sokoto compared with Sahel goats. The RR, PR, RT and T3:T4 were significantly lower, while circulating T3 was higher during the CDS as compared with the HDS. Higher population of the goats were susceptible to cold and heat stress. Discriminant analysis showed higher misclassification of goats into HSS and HST phenotypes as compared with classification into CSS and CST phenotypes. The CSS phenotypes had significantly lower RT, but higher PR than the CST phenotypes. The HSS phenotypes had lower (P<0.05)T3 than the HST phenotypes. Total variation in susceptibility to thermal stress was mainly explained by the RT, T3 and PR. In conclusion, unlike RT, PR and T3, BMI seems to have less influence on the susceptibility of kids to thermal stress. In addition, this study demonstrates the role of the thermogenic effect of T3 in the susceptibility and tolerance of kids to thermal stress.