YIELD AND PHYSIOLOGICAL RESPONSES OF WALNUT TREES IN SEMI-ARID CONDITIONS: APPLICATION TO IRRIGATION SCHEDULING

A study of the physiological responses and energy expenditure of goats was carried out from June 1999 to May 2000 by conducting two experiments: one on bucks maintained on stall feeding in autumn 1999 (Expt 1) followed by year-round grazing on native ranges over three seasons: monsoon, winter and summer (Expt 2). Physiological responses and energy expenditure (EE) measurements of housed and grazing goats were recorded at 06.00 h and 14.00 h for 5 consecutive days in each season. Goats were fixed with a face mask and meteorological balloon for collection of expired air and measurement of EE. Respiration rate (RR) at 06.00 h was similar in all seasons (14 respiration/min) except in the monsoon, where a significantly (P<0.05) higher value (26 respiration/min) was recorded. At 14.00 h, RR was higher in monsoon and summer (81 and 91 respiration/min) than in winter (52 respiration/min). Irrespective of the season, heart rate (HR) was higher at 14.00 h (86 beat/min) than at 06.00 h (64 beat/min). The rise of rectal temperature (RT) from morning (06.00 h) to peak daily temperature (14.00 h) was 0.9 °C in housed goats in autumn and 1.0, 2.1 and 2.0 °C in grazing goats during monsoon, winter and summer, respectively. The mean value was 1.7 °C. Skin temperature (ST) was lowest in winter (30.1 °C) and highest at 14.00 h in summer (40.3 °C). Energy expenditure of goats at 06.00 h was 32.7 W in winter and significantly (P<0.05) increased to 52.0 W in summer and 107.8 W in monsoon. At 14.00 h, EE was 140.2 W in winter and increased to 389.0 W and 391.3 W respectively in monsoon and summer. It is concluded that monsoon and summer are both stressful seasons in semi-arid regions. Animals should be protected from direct solar radiation during the hottest hours of the day to ameliorate the effect of heat stress.

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Triazine carryover in semi-arid conditions

Crop Protection ◽

10.1016/0261-2194(90)90132-q ◽

1990 ◽

Vol 9 (6) ◽

pp. 429-432 ◽

Cited By ~ 2

Author(s):

O.A. Chivinge ◽

B. Mpofu

Keyword(s):

Arid Conditions ◽

Semi Arid

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Genetic parameters of Barki sheep raised under semi-arid conditions

Animal Science ◽

10.1017/s0003356100027008 ◽

1969 ◽

Vol 11 (3) ◽

pp. 361-367 ◽

Cited By ~ 9

Author(s):

M. H. Fahmy ◽

E. Salah E. Galal ◽

Y. S. Ghanem ◽

S. S. Khishin

Keyword(s):

Genetic Parameters ◽

Genetic Correlations ◽

Research Station ◽

Phenotypic Correlations ◽

Arid Conditions ◽

Body Weights ◽

Genetic And Phenotypic Correlations ◽

Fleece Weight ◽

Semi Arid ◽

Desert Research

SUMMARYRecords on 695 lambs were collected over a period of 5 years from 1961/62 to 1965/66, at Ras El-Hekma Desert Research Station, 230 km west of Alexandria. The characters studied were birth, weaning and yearling body weights, pre- and post-weaning daily gains and greasy fleece weight.Birth, 120-day and 365-day body weights were 3·4, 18·2 and 33·4 kg respectively. Greasy fleece weight at 16 months of age was 3·29 kg. Heritability estimates of birth, weaning, yearling weights, pre- and post-weaning daily gains and greasy fleece weight were 0·22, 0·45, 0·41,0·45 and 0·29 respectively. Genetic and phenotypic correlations between birth, weaning and yearling weights were all positive and significant. Genetic correlations between fleece weight and body characteristics were negative and low.

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