Influence of seasonal changes on physiological variables, haematology and serum thyroid hormones profile in male Red Sokoto and Sahel goats

Sex-based responses of heat stress and subsequent recovery on the growth performance, metabolic changes, and redox status of broilers at market age

This experiment investigated the sex responses of heat stress (HS) and subsequent recovery on growth performance, serum metabolic parameters, and redox status. Two hundred 38-day-old broilers were arranged in a completely randomized design with a 2 × 2 (temperatures and sexes) factorial arrangement in five replicates. Broilers were raised at 24 ± 1 °C or 32 ± 1 °C for 3 days and returned to 24 °C for 2 days. The study showed that HS decreased both average daily feed intake (ADFI), average daily gain (ADG), serum total glutathione peroxidase (GPx), and superoxide dismutase (T-SOD). However, it increased feed conversion ratio (FCR), rectal temperature (RT), respiratory rate (RR), serum glucose, blood urea nitrogen (BUN), low-density lipoprotein cholesterol, and the protein carbonyl group (PCG). Male broilers had higher ADFI, ADG, lactic acid (LA), high-density lipoprotein cholesterol (HDL-C), and PCG, but lower FCR, albumin, total antioxidant capacity, T-SOD, and GPx. Temperature and sex significantly interacted with ADFI, ADG, LA, and HDL-C. The effects of HS on RR, RT, glucose, albumin, BUN, PCG, T-SOD, and GPx recovered after 2 days. These results indicate that HS and subsequent recovery affect growth performance, which is accompanied by disturbances in serum nutrient metabolism and abnormalities in redox function and manifested by temporal and gender differences.

Assessment of the adaptation of Nguni goats to water stress

The recurring drought and limited rainfall patterns occasioned primarily by climate change in sub-Saharan African countries threaten sustainable animal agriculture. The irreversibility of this natural phenomenon calls for an intensive and urgent selection of adaptable breeds that can cope but with minimal compromise on production indices. A water scarcity simulation study was conducted to assess the adaptation potential of Nguni goats to regulated watering by evaluating their growth performance, tolerance to heat and water stress and blood indices during the dry summer months. Eighteen growing Nguni goats (average age: 1 year; BW: 19.25 ± 1.6 kg) were assigned equally to three treatments: W0, without water restriction (WR); W70, WR of 70% ad libitum water intake (WI); and W50, WR of 50% ad libitum WI. The experimental trial lasted for 75 d following a 14-day acclimatisation to the housing condition. Data on growth performance, body thermal gradient, skin temperature (ST) and rectal temperatures, respiratory rate (RR), body condition scores (BCs), linear body indices and blood biochemical indices were taken. The results showed that the final BW was not affected (P > 0.05) by the water restriction levels. The daily gain, DM intake and total BW gain were similar (P > 0.05) in groups W70 and W50. Body thermal gradient and ST were not affected (P > 0.05). The RR and BCs decreased (P < 0.05) with increasing water restriction levels. The body and rump lengths and sternum height were similar (P > 0.05) for groups W70 and W50. There is an haemocentration (W0 < W70 < W50; P < 0.05) of sodium, Chloride, urea, creatinine, total protein, and cholesterol with water restriction levels. Generally, most physiological variables assayed were similar (P > 0.05) in the water-stressed groups (W70 and W50). Overall, Nguni goats showed an adaptive capacity to tolerate limited water intake.

Endocrine, energy, and lipid status during parturition and early lactation in indigenous goats native to the Algerian Sahara

Background and Aim:

Goats are widely distributed in southwest Algeria. The Saharan goat is perfectly adapted to the harsh conditions of arid areas, and it is characterized by resistance to long photoperiod and reduced metabolic needs, allowing the survival of its offspring by maintaining lactation. Several studies have demonstrated that parturition and lactation are critical periods that induce hormone, energy, and lipid status changes in mammals. However, the relationship between the blood biochemical parameters of parturition control and lactation functions in the Algerian Saharan goat has not been thoroughly documented. Therefore, this study assesses hormone and metabolite levels during parturition and early lactation in Saharan goats reared in arid areas.

Materials and Methods:

Experiments were performed on 14 multiparous female goats, and blood samples were collected during parturition, 4 days postpartum (D1PP-D4PP), and during the first 12 weeks of lactation (W1-W12) to analyze prolactin, cortisol, glucose (GLU), total proteins (TP), cholesterol (CHO), triglycerides (TGs), total lipids (TL), low-density lipoproteins (LDLs), high-density lipoproteins (HDLs), and very LDLs (VLDLs).

Results:

Statistical data analysis revealed a significant (p<0.05) increase in plasma prolactin concentrations at W1 after parturition, reaching maximum values at W3 and W9, and remained high until W12 of lactation. Plasma cortisol levels were high at parturition, reaching two peaks at W3 and W9, and then decreased at W5, W7, and W12 of lactation. No significant changes were found in serum GLU levels during the first 7 weeks of lactation compared with parturition day; then, the levels became significantly (p<0.05) lower at W8, W11, and W12 of lactation. Plasma TP increased significantly (p<0.05) at D3PP, W1, and W4, then decreased significantly (p<0.05) at W8. In addition, this decrease coincided with that of GLU production. Serum CHO, TGs, TL, LDLs, and VLDLs, were low at parturition and high at D4PP and during the first 3 months of lactation. Furthermore, HDL levels were low at D3PP, 1^st, and 3^rd months and high at the 2^nd month of lactation.

Conclusion:

This study emphasized the impact of parturition and the 1^st weeks of lactation on endocrine and metabolic changes in indigenous goats living in the Algerian Sahara Desert. These results can be used to monitor and improve farming management and understand physiological adaptive strategies, mainly lactation function sustainability, of this goat living in marginal zones.

Physiological, oxidative and metabolic responses of lactating water buffaloes to tropical climate of South China

BACKGROUND

Heat stress in tropics is generally associated with significant economic losses resulting from reduced performance, morbidity, and mortality of livestock. To avoid serious consequences of heat stress, it is imperative to better understand the physiological responses and biochemical changes under the state of altered body homeostasis during different seasons of the year.

OBJECTIVES

This study aimed to evaluate the seasonal dynamics of physiological, oxidative and metabolic responses of lactating Nili-Ravi buffaloes to the tropical climate of South China.

METHODS

Physiological responses including rectal temperature (RT), body surface temperature (BST) and respiratory rate (RR) along with serum biochemical and antioxidant parameters of 20 lactating Nili-Ravi buffaloes were evaluated during different seasons of the year.

RESULTS

Higher temperature-humidity Index (THI) during the summer season (>80) resulted in a significant increases in RR and BST as compared to the winter season. Higher oxidative stress was observed in the summer season as revealed by significantly higher MDA while lower serum antioxidant enzyme (TAC, GSH-Px, SOD and CAT) contents. Moreover, serum cortisol was also significantly higher in summer and autumn. The levels of growth hormone and ACTH were also significantly (P < 0.05) lower in summer and autumn as compared to other seasons. The negative association of THI with physiological and antioxidant parameters was observed while it was positively associated with serum MDA and cortisol levels.

CONCLUSIONS

Our study revealed moderate heat stress in lactating buffaloes in the summer season which calls for attention to avoid economic losses and animal welfare issues.

Intake salinity water by creole goats in a controlled environment: ingestive behavior and physiological variables

The study aimed to verify the effect of water salinity and environmental temperature on the physiological variables (respiratory rate, heart rate, rectal temperature, and surface temperature) and ingestive behavior (rumination, feeding, drinking, and idle) of creole goats. Thirty-six males with an average age of 5.0 ± 0.6 months and an average weight of 20.0 ± 2.3 kg were housed in metabolic cages. The experimental design was a 2 × 3 type crossover (two temperatures and three levels of salinity). The two temperatures were: T1 = 26 ± 0.6 °C (thermoneutral) and T2 = 32 ± 1.2 °C (stress) and three levels salinity (1.0, 6.0, and 12.0 dS m^-1). Between the temperatures, the respiratory rate (RR) and surface temperature (ST) present a difference (P < 0,05), being higher in the high temperature. Between temperatures, respiratory rate and surface temperature show a difference (P < 0.05), being higher at high temperature, keeping heart rate and rectal temperature similar at both temperatures. Among the different salinity levels in the behavioral activities, the feeding and urination activity presented a significant difference (P < 0.05), increasing with the water's salinity level. Between temperatures, the rumination efficiency dray matter and neutral detergent fiber showed a significant difference (P < 0.05). With increasing air temperature, they decreased the rumination time-water salinity levels influence (P < 0.05) the feeding efficiency of dry matter. Therefore, water with up to 9.600 mg TDS L^-1 can be used strategically in the desedentation of goats in semi-arid regions.

Adaptive profiles of Nellore sheep with reference to farming system and season: physiological, hemato-biochemical, hormonal, oxidative-enzymatic and reproductive standpoint

This paper outlines the effect of farming systems with reference to season on the body condition score (BCS) and adaptive profile (physiological, hemato-biochemical, hormonal, enzymatic and reproductive parameters) of Nellore sheep. In trial 1, sixty ewe-lambs were allotted to extensive, semi-intensive, and intensive rearing systems (n = 20) and evaluated for BCS at puberty, mating, 2 weeks pre-lambing and 2, 4, 8, and 12 weeks post-lambing. In trial 2, eighteen rams were distributed evenly to three farming systems (n = 6) and evaluated for physiological, hemato-biochemical, hormonal, enzymatic, and reproductive parameters concerning three seasons. Although the scores did not differ among the groups, the Kruskal-Wallis ranks of BCS revealed a higher energy status of intensive ewes at different physiological conditions. The sheep reared under extensive and semi-intensive systems displayed higher temperature, pulse rate and respiratory rate with predominant effects in summer season. Similarly, both systems exhibited higher WBC and lower haemoglobin, PCV, and RBC contents without affecting MVC, MCH, MCHC, and differential leucocyte count. The percent haemoglobin and RBC count were higher in winter compared to summer months, whereas WBC count followed an exactly opposite pattern. The sheep reared in intensive system showed higher glucose, total protein, albumin, cholesterol, T3, T4, calcium, and phosphorus; however, the globulin, creatinine, uric acid, aspartate amino transferase (AST), alanine amino transferase (ALT), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase, and catalase levels were elevated in extensive and semi-intensive systems. The dartos muscle extension (DME) and scrotum sweating rate (SSR) were higher for the sheep reared under extensive system, especially during summer season; while the seminal parameters viz., total sperm count, progressive sperm motility, and plasma membrane integrity were lower for extensive and semi-intensive sheep. No interactions were noticed for any of the parameters, except for cortisol, DME, and SSR, which showed significant interactions for rearing system vs. season. Our results showed dynamic adaptive mechanisms of the Nellore sheep in relation to different stressors like grazing for long distances, inadequate nutrition, and heat stress, revealing the heat resilient ability in harsh environmental conditions. Further, the analyzed vector plot showed that the AST, GPx, Cortisol, SOD, Catalase, WBC, PR, T4, total abnormalities, and major abnormalities were the major contributors for adapting during combined stressors.

Performance, heat tolerance response, and blood metabolites of water-restricted Xhosa goats supplemented with vitamin C

Water restriction in small ruminants is usually accompanied by a drop in feed intake, body weight, and disturbances in the normal internal milieu. However, attempts to lessen the burden of water stress with vitamin C (VC) supplementation have been greeted with conflicting reports. Therefore, this experiment was conducted to evaluate the effect of single and/or multiple VC supplementations in water-restricted Xhosa goats by evaluating their performance, heat tolerance, and blood metabolites. In total, 42 does, 12 mo old and with an average weight of 15.92 ± 2.12 kg were evaluated for 75 d. The does were distributed according to a complete randomized design into seven groups of six comparable animals: W0, without water restriction (control); W70, water restriction of 70% of ad libitum water intake (WI); W50, water restriction of 50% ad libitum WI; W70⁺, water restriction of 70% of ad libitum WI plus 3 g VC daily; W50⁺, water restriction 50% of ad libitum WI plus 3 g VC daily; W70⁺⁺, water restriction of 70% of ad libitum WI plus 3 g VC and extra 5 g VC given every eighth day; and W50⁺⁺, water restriction of 50% of ad libitum WI plus 3 g VC and extra 5 g VC given every eighth day. Goats under the W50 group were the most affected (P < 0.05) and the effect was more pronounced in their body condition scores (BCs). Weight loss due to water restriction was reduced by VC supplementation in treated groups. Changes in body thermal gradient, rectal temperature, cholesterol, and bilirubin were similar (P > 0.05) across the various experimental groups. The attenuation effect of VC was significant (P < 0.05) in responses to respiratory rate, Na⁺, K⁺, Mg²⁺, Cl⁻, Ca²⁺, and urea. Supplementation of VC (either single or multiple) did not significantly (P > 0.05) improve the effect of water restriction on BCs, FAMACHA, glucose, globulin, alanine aminotransferase, and high-density lipoprotein. The additive effect of multiple VC significantly influenced (P < 0.05) Na⁺ and Mg²⁺. Limited WI affects growth and other physiological parameters in Xhosa goats. However, supplementation of VC may be beneficial at modulating the stressful stimuli imposed by water stress.

Ameliorative effects of L-glutamine on haematological parameters in heat-stressed Red Sokoto goats

The aim of the study was to evaluate haematological responses in Red Sokoto goats (RSGs) administered with L-glutamine during the hot-dry season. Experimental animals included 28 clinically healthy RSGs divided into treated group (n = 14); each administered L-glutamine at 0.2 g/kg body weight, dissolved in 10 mL distilled water, and control group (n = 14); each administered 10 mL distilled water, per os once daily for 21 days. The ambient temperature and relative humidity recorded daily for 4 weeks were used to calculate the temperature-humidity index. Three millilitres of blood sample was collected from each goat by jugular venipuncture for haematology, while rectal temperature (RT), heart rate (HR) and respiratory rate (RR) were also measured once weekly at weeks 0 (before), 1, 2, 3 (during) and 4 (after L-glutamine administration). The haematological, RT, HR and RR data obtained weekly were analysed using repeated-measures one-way ANOVA, followed by Tukey's post-hoc test to evaluate differences between periods, and between treated and control groups. The PCV, haemoglobin concentration and RBC count were higher (P < 0.05) in the treated group compared to the control group during the period of L-glutamine administration. These differences were sustained till week 4. Beginning from week 1 of the study, the total leucocyte count in treated group (10.10 ± 0.25 × 10³/μL) was higher (P < 0.05) than the count in control group (7.23 ± 0.41 × 10³/μL), this trend was also maintained throughout the study. The neutrophil:lymphocyte ratio during weeks 3 and 4 of the experiment was lower (P < 0.05) in the treated compared to the control group. RT was lower (P < 0.05) in treated group than the control group. In conclusion, L-glutamine administration ameliorated the adverse effects of heat stress on the haematological parameters in RSGs during the hot-dry season.

Variations in serum metabolites in response to season, cyclicity, and pregnancy in estrus-synchronized Damascus goats

The current study was carried out to determine the changes in serum electrolytes, liver enzymes, and hormones during breeding and non-breeding seasons in estrus-synchronized goats. Forty goats (n = 40) were synchronized by inserting the sponges intravaginally for 12 days; PMSG and PGF₂α were injected on day of sponge removal. Blood samples were collected from the goats at the time of sponges insertion (day -12), estrus day (day 0), and at 15 day after sponge withdrawal (day 15). The blood samples were analyzed for glucose, cholesterol (CHO), aspartate aminotransferase (AST), alanine aminotransferase (ALT), thyroid stimulating hormone (TSH), triiodothyronine (T₃), thyroxine (T₄) and progesterone (P₄), calcium (Ca), phosphate (PO₄), magnesium (Mg), sodium (Na), potassium (K), and chlorine (Cl) levels. Repeated measurements ANOVA of general linear model were used as statistical model. The results showed that seasons have an effect (p < 0.05) on glucose, Ca, Na, K, Cl, CHO, T₃, and T₄ levels. There was an effect (p < 0.05) of cyclicity only on P₄ level. Whereas, nonpregnant, or goats carrying singlet and twin fetuses have shown variation (p < 0.05) in glucose, Ca, and P₄ levels. Although, the correlations existed between different serum metabolites but strong correlations (p < 0.05) were observed either between Ca and Na or T₃ and T₄. In conclusion, the serum electrolytes and liver enzymes are correlated with hormones during the different seasons, pregnancy status, and fecundity. In recommendation, the results of the study could be as managemental tool to monitor the reproductive activity across seasons and to maintain pregnancy carrying twining in goat breeds.

Sensitivity, Impact and Consequences of Changes in Respiratory Rate During Thermoregulation in Livestock – A Review

This review discusses the thermal conservative and heat dissipating roles of one of the most sensitive thermoregulatory variables (respiratory rate) with the aim of enhancing its application in evaluating both cold and heat adaptation. During cold exposure, livestock enhance the economy of body heat through reduction in respiratory rate with the extent of reduction being greater and commencing at relatively higher ambient temperature in poorly adapted phenotypes. This is accompanied by an increase in tidal volume and alveolar oxygen uptake, but a decrease in partial pressure of oxygen. On the other hand, heat stress induces increase in respiratory rate to enhance evaporative heat loss with the magnitude of such increase being greater and commencing at relatively lower ambient temperature in phenotypes that are poorly-adapted to heat. This is accompanied by a decrease in tidal volume and the development of hypocapnia. The increase in respiratory rate is observed to be greater, moderate and lesser in livestock that are mainly (pigs, rabbits and poultry), moderately (sheep, goats and Bos taurus) and less (Zebu cattle) dependent on respiratory evaporative heat loss, respectively. The changes during chronic heat stress may cause acid-base crisis in all livestock, in addition to reduction in eggshell quality in birds; due to marked decrease in partial pressure of carbon dioxide and a compensatory increase in elimination of bicarbonate. Within and between breed variations in sensitivity of respiratory rhythm to both cold and heat stress has shown high applicability in identifying phenotypes that are more susceptible to thermal stress; with some cellular and metabolic changes occurring to protect the animal from the consequences of hypo- or hyper-thermia. The information in this review may provide basis for identification of genes that support or suppress thermoregulation and may also be of great use in animal breeding, genomics and selective thermal stress mitigation to provide maximum protection and comfort to poorly-adapted phenotypes.

Hair coat characteristics and thermophysiological stress response of Nguni and Boran cows raised under hot environmental conditions

Breed, age, coat colour, month and temperature humidity index (THI) influence on body weight (W), body condition score (BCS), thermophysiological variables (rectal temperature (Tr), skin temperature (Tsk)) and hair length was studied in Nguni (n = 19) and Boran (n = 16). As a result of this study, breed influenced W, BCS and Tsk on the neck and belly (P < 0.05). The BCS and W of Nguni cows were higher than the Boran cows. Hair length of both breeds increased from February to August. The THI influenced thermophysiological variables (P < 0.05). Increased Tr for both breeds was recorded in February and April, respectively (P < 0.05). Month influenced Tsk and June recorded lower values (P < 0.05). Younger cows (3-8 years) had lower weight and high Tr and Tsk (P < 0.05). Nguni cows had high neck and thurl temperatures in June while Boran cows had the highest in August (P < 0.05). Red, dun and white-black Boran cows had increased BCS. Nguni cows with red, fawn and white cows had high BCS. Fawn-coloured Nguni cows and white-brown Boran cows had the more weight than cows with other colours compared in the study. White-red Nguni and Boran cows recorded the highest Tr. For Nguni cows, neck and belly temperatures were significantly (P < 0.001) correlated to thurl temperature. Boran cows had significant (P < 0.001) correlations for THI and neck, belly and thurl temperatures. The current study found that Nguni cows were more adapted to the prevailing bioclimatic changes. However, Boran cows have the potential of performing well under heat stress conditions over time.

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  <  0.05) packed cell volume (PCV) and red blood cell (RBC) count but lower (P  <  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  <  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  <  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.