It has been established that the synthesis of heat shock protein 70 (Hsp70) is temperature-dependent. The Hsp70 response is considered as a cellular thermometer in response to heat stress and other stimuli. The variation in Hsp70 gene expression has been positively correlated with thermotolerance in Drosophila melanogaster, Caenorhabditis elegans, rodents and human. Goats have a wide range of ecological adaptability due to their anatomical and physiological characteristics; however, the productivity of the individual declines during thermal stress. The present study was carried out to analyze the expression of heat shock proteins in different tissues and to contrast heat stress phenotypes in response to chronic heat stress. The investigation has been carried out in Jamunapari, Barbari, Jakhrana and Sirohi goats. These breeds differ in size, coat colour and production performance. The heat stress assessment in goats was carried out at a temperature humidity index (THI) ranging from 85.36-89.80 over the period. Phenotyping for heat stress susceptibility was carried out by combining respiration rate (RR) and heart rate (HR). Based on the distribution of RR and HR over the breeds in the population, individual animals were recognized as heat stress-susceptible (HSS) and heat stress-tolerant (HST). Based on their physiological responses, the selected animals were slaughtered for tissue collection during peak heat stress periods. The tissue samples from different organs such as liver, spleen, heart, testis, brain and lungs were collected and stored at -70 °C for future use. Hsp70 concentrations were analyzed from tissue extract with ELISA. mRNA expression levels were evaluated using the SYBR green method. Kidney, liver and heart had 1.5-2.0-fold higher Hsp70 concentrations as compared to other organs in the tissue extracts. Similarly, the gene expression pattern of Hsp70 in different organs indicated that the liver, spleen, brain and kidney exhibited 5.94, 4.96, 5.29 and 2.63-fold higher expression than control. Liver and brain tissues showed the highest gene expression at mRNA levels as compared to kidney, spleen and heart. HST individuals had higher levels of mRNA level expression than HSS individuals in all breeds. The Sirohi breed showed the highest (6.3-fold) mRNA expression levels as compared to the other three breeds, indicating the better heat stress regulation activity in the breed.

No abstract

Mortality patterns of two Zebu cattle breeds, Sahiwal and Tharparkar, and two crossbred strains, Karan Swiss and Karan Fries, maintained at the National Dairy Research Institute, Karnal were studied. Nine-year (1989--90 to 1997--98) data on mortality were analysed for year, season, age and cause effects on mortality rate. The overall mortality was 14.17%. The mortality in Sahiwal, Tharparkar, Karan Swiss and Karan Fries averaged 14.35%, 7.21%, 17.12% and 13.46%, respectively. The breed mortality rate did not vary significantly between years, seasons, age categories and causes of disease. However, the trends indicated appreciable difference in mortality rates. The mortality was highest in the year 1994--95 (19.53%) and lowest in 1991--92 (8.56%). There was very little variation in seasonal mortality rate and mortality rate averaged 4.53%, 4.81% and 4.84% in hot-dry (March-June), hot-humid (July-October) and cold (November-February) seasons, respectively. The mortality up to 2 months of age accounted for a major share (50-60% or higher) in different breed groups. Digestive problems followed by respiratory disorders together accounted for 70-80% of total deaths.

This study was conducted for establishment of the relationship of blood variables with growth rate of postweaned lambs. Eight lambs each of fast growth (FG; 11.6 ± 0.5 kg live wt. at weaning) and slow growth (SG; 7.7 ± 0.5 kg live wt. at weaning) were monitored fortnightly for endocrine and hematobiochemical variables along with parasitic load and growth performance. Recording of body weight (BW) and average daily gain (ADG) was performed monthly from birth to 180 days. Triiodothyronine (T3) and thyroxine (T4) were significantly (P < 0.05) higher while thyroid-stimulating hormone (TSH) and insulin-like growth factor-1 (IGF-1) were significantly (P < 0.05) lower in FG lambs compared to SG lambs. Blood cell counts, hematocrit, hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin were significantly (P < 0.05) higher in FG lambs compared to SG lambs. Except for the birth wt., the BW and ADG of FG lambs were significantly (P < 0.05) higher at all time points. Liver enzymes (alkaline phosphatase and alanine aminotransferase) and triglyceride were significantly (P < 0.05) higher in SG lambs compared to FG lambs. These findings indicate a significant influence of growth rate on peripheral concentrations of endocrine and some hematobiochemical variables in lambs. These selected variables can be used for early identification and culling of slow-growing lambs for better economic return to lamb producers.

The production performance of livestock is influenced by short-term variation in weather pattern. Goat adapts to varied ecological conditions and maintains productivity; however, wide variation has been observed among individual animals in response to environmental stimuli in a population. The objective of the present study was to identify the contrasting phenotypes on the basis of the physiological response in goats during heat stress. The study utilised 138 Jamunapari and 242 Barbari goats during peak heat-stress period and 82 Jamunapari and Barbari goats under thermo-neutral conditions. The physiological response of goats to different environmental conditions was evaluated by recording various parameters such as rectal temperature (RT), respiration rate (RR) and heart rate (HR). The temperature humidity index varied from 85.36 to 89.80 and from 65.32 to 73.12 during heat-stress and thermo-neutral assessments respectively. There was direct increase in HR and RR (>25%) due to heat stress in the animals, as compared with those in thermo-neutral conditions. On the basis of the distribution of RR and HR values across the breed in the population, the individuals having a RR of ≥50 and a HR of ≥130 are recognised as heat stress-susceptible phenotypes and those having a RR of ≤30 and a HR of ≤100 are recognised as heat stress-tolerant individuals. Different biomarkers were analysed in plasma, while heat-shock proteins and leptin were analysed in tissue extracts by ELISA. C-reactive protein and HSP90 concentrations were significantly (P < 0.05) different between heat stress-susceptible and heat stress-tolerant individuals. Heat-shock proteins HSP70, HSP 90, and C-reactive protein and triiodothyronine were reliable indicators of long-term heat stress. Identification of contrasting phenotypes in regard to heat stress is necessary so as to evaluate the expression pattern at a cellular level, as well as physiological and biochemical parameters.

No abstract

The invasion of the male urogenital tract by microorganisms, and its subsequent effects on sperm fertilising ability, has not been well discussed in bucks. The present study was conducted to assess the bacterial load in fresh semen of the 2–6 years old bucks. For conducting the experiment, semen ejaculates from 18 bucks (6 from each breed namely Jakhrana, Jamunapari and Barbari) were used. We collected 5 ejaculates from each buck in each season (Summer‐April to June, Rainy‐July to Sept and Winter‐November to January). Semen was collected with the artificial vagina (AV) method, and separate AV was used for each buck every time. The semen collection frequency was once in a week. Immediately after initial evaluation, collected semen samples were transferred to the microbiology laboratory of the institute. Thereafter, the semen samples were subjected to bacteriological examination to assess the microbial load. The results of the current study indicate that the microbial load in the semen was significantly (p < 0.05) higher in the Jamunapari bucks and in aged bucks. Bacteriospermia in different seasons was not significantly varied; however, nonsignificant increase in microbial load during the rainy season was observed. Overall, the average bacterial load in the semen of Jamunapari, Barbari and Jakhrana bucks was found 540.50 ± 55.88 CFU/ml, 391.81 ± 46.33CFU/ml and 388.93 ± 44.71 CFU/ml respectively. No significant difference in bacterial counts in the subsequent ejaculates among bucks was observed. Moreover, correlation analysis revealed that the proportions of motility, viability, plasma membrane integrity and acrosomal integrity were negatively influenced by the increased bacterial contamination of buck semen.

No abstract