Cattle are susceptible to heat stress, especially those kept on high levels of nutrition for the purpose of maximising growth rates, which leads to a significant heat increment in their bodies. Consequences include compromised health and productivity and mortalities during extreme events, as well as serious economic loss. Some measures of heat stress, such as plasma cortisol and temperature in the rectum, vagina, or rumen, are invasive and therefore unlikely to be used on farms. These may cause additional stress to the animal due to handling, and that stress in itself can confound the measure. Consequently, it is desirable to find non-invasive alternatives. Panting score (PS), cortisol metabolites in faeces, milk, or hair, and the infrared temperature of external body surfaces are all potentially useful. Respiratory indicators are difficult and time consuming to record accurately, and cortisol metabolites are expensive and technically difficult to analyse. Infrared temperature appears to offer the best solution but requires further research to determine the thresholds that define when corrective actions are required to ensure optimal health and productivity. Research in this area has the potential to ultimately improve the welfare and profitability of cattle farming.

The efficacy of tulsi (Ocimum sactum) and neem (Azadirachta indica) leaves extract as a growth promoter were studied in broiler. A total of 40 day-old broiler chicks were purchased from Kazi hatchery and after three days of acclimatization the chicks were randomly divided into four groups (n=10). No vaccination schedule was practiced and no antibiotic was added in ration of group A, B, C, and D respectively. Group A served control without any supplements while group B, C and D were supplemented with combination of tulsi and neem extract @ 1 ml, 2ml and 3 ml/liter of drinking water. Live body weight gain was recorded weekly up to 6th weeks and hematological studies were performed at 21st and 42nd day of experiments. At the end of 42nd day of experiment final body weight of group A, B, C and D were 1561± 12.10 g, 1698± 12.87 g, 1608± 12.04 g and 1763± 13.28 g, respectively. The birds of group D utilized their feed more efficiently among the treatment groups (p<0.05). The net body weight gain were, 1533± 11.98 g, 1443± 11.32 g and 1588± 12.10 g in treated groups compared to control group (1393± 11.07 g ) and total net profit per broiler was 19.08, 40.10, 20.68 and 45.07 Taka , respectively. Hematological parameterss (TEC, PCV, Hb and ESR) were not significantly changed among the treated and control group suggesting no side effects of herbal extracts in broiler. It can be concluded that tulsi and neem extract is economic and safe in broiler production.DOI: http://dx.doi.org/10.3329/bjvm.v11i1.17728 Bangl. J. Vet. Med. (2013). 11 (1): 1- 5