Long-term adaptation of sheep to low protein intake under simulated drought conditions

Farid, M. F. A.

doi:10.1016/s0140-1963(18)31340-5

Cited by 4 publications

(2 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several experiments around the world suggest a clear effect of supplementation on the performance of pen-fed sheep; however, responses in the field have been less clear (Tudor and Morris, 1971;Mulholland and Coombe, 1979;Butler et al, 1987). This discrepancy may arise from several causes: (1) diet selectivity is more important in field experiments (Tudor and Morris, 1971), (2) diet selection may change with supplementation (Hatfield et al, 1991), (3) urea often decreases forage palatability (Bhattacharya and Pervez, 1973;Butler et al, 1987), (4) unsupplemented sheep may show compensatory growth in the more favourable season (Entwistle and Knights, 1974;Mulholland and Coombe, 1979) and (5) N-restricted sheep may markedly increase their nitrogen use efficiency by reducing nitrogen excretion and increasing N recycling (Farid, 1985;Farid et al, 1989).…”

Section: Introductionmentioning

confidence: 99%

Urea supplementation effects on the utilization of low‐quality forage and lamb production in patagonian rangelands

Golluscio

Paruelo

Mercau

et al. 1998

Grass and Forage Science

View full text Add to dashboard Cite

The effect of feeding a urea-based supplement for the last 8 weeks of pregnancy was examined on ewes grazing the grass-shrub steppes of NW Patagonia, Argentina. The productivity of ewes and lambs and the utilization rate of the major, less preferred, grass species (Stipa speciosa, 27% cover) was analysed. In a paddockscale experiment, ewes grazed two areas of 450-500 ha from 15 August to 15 February at a stocking rate of 0·5 ewes ha Ϫ1 . From 15 August to 10 October, one group of ewes was given access to a urea-based supplement containing 300 g kg Ϫ1 urea, 320 g kg Ϫ1 salt, 30 g kg Ϫ1 molasses and 300 g kg Ϫ1 bone meal. Average supplement consumption was 3·5 g ewe Ϫ1 d Ϫ1 . The performance of 100 ewes in each of the two areas was evaluated. Supplemented ewes gained 4·2 kg more live weight than the control ewes between 15 August and 10 October (prepartum) (liveweight gain was 10·3 vs. 6·1 kg ewe Ϫ1 , P < 0·05). The number of live lambs at 8 weeks of age, as a proportion of ewes mated, was 15% higher in the supplemented than in the control group (0·634 vs. 0·553, P < 0·05). A similar increase in the live weight of lambs at 8 weeks of age in the supplemented group compared with the controls was also observed (12·1 vs. 10·6 kg, P < 0·05). In the paddock with the supplemented ewes, there was a significant increase in the proportion of Stipa speciosa plants defoliated (0·62 vs. 0·38, P < 0·05) and in the intensity of defoliation of these plants. It was concluded that urea-based supplements increased productivity of ewes and that this was likely to be associated with an increase in the intake, and possibly digestibility, of the less preferred species such as Stipa speciosa.

show abstract

Section: Introductionmentioning

confidence: 99%

Urea supplementation effects on the utilization of low‐quality forage and lamb production in patagonian rangelands

Golluscio

Paruelo

Mercau

et al. 1998

Grass and Forage Science

View full text Add to dashboard Cite

show abstract

“…Ruminants grazing arid and semi-arid rangelands are frequently exposed to different environmental stresses including, among other stress factors, the adverse climatic conditions and the shortage in quantity and quality of water and feed. Many studies Schmidt-Nielsen et al, (1957); Ben Goumi et al, (2003) Zine-Fillali and Show (2004) and Achaaban et al, (2000) were carried out to investigate adaptive responses under these conditions but stress factors were considered separately or in limited combinations, mainly the climate, water deprivation and water salinity (Farid, 1989), and without allowing for gradual and long-term adaptation characterising semi-arid and arid ecosystems (Farid, 1985). Different direct and indirect environmental stressors are known to interact and hence, adaptive responses might be modified.…”

Section: Introductionmentioning

confidence: 99%

Some Aspects of Thermo-Regulation in Water Deprived Camels Under the Semi-Arid Conditions of the North-Western Coastal Desert in Egypt

El-Zeiny

2007

Journal of Animal and Poultry Production

View full text Add to dashboard Cite

This study was conducted at Maryout Experimental Station near Alexandria, 32° latitude affiliated to the Desert Research Center in Cairo. In this study, the effect of heat stress resulting from the combined effect of water deprivation, the housing environment and season of the year on the changes of rectal (RT) and skin temperature (ST) and their amplitude (differences between morning and afternoon values), as well as gradients between core and surface temperatures and the ambient temperature were investigated in eight non-pregnant and non lactating female dromedary camels fed at the maintenance level. Half the animals were watered daily whereas the other half was intermittently watered, once every 7 days. Moreover, half the animals were kept outdoors and not sheltered whereas the other half was housed indoors. The experimental treatments were repeated three times between April and August to represent spring, early summer and late summer seasons. Climatic (ambient temperature (Ta), relative humidity (RH%) and temperature humidity index (THI) and animal data (RT and ST) were recorded twice daily at 7:00 am and 2:00 pm for seven consecutive days representing a complete water deprivation cycle.It was evident that the housing environment in the morning was a significant source of variation affecting both RT and ST and their amplitude, as well as core, skin and ambient temperature gradients. Water deprivation also represented another significant source of variation that affected (RT), both in the morning and in the afternoon. However, (ST) was significantly affected by season only in the morning. All the above parameters were significantly affected by days of the water deprivation cycle.It was noticeable that the RT of the water deprived camels kept outdoors was consistently lower than their control mates. Largest average RT amplitude was observed in the water deprived camels housed outdoors which was 4 folds of their water deprived mates housed indoors. On the other hand, ST behaved differently in such a way that in the water deprived camels it was frequently higher than in the daily watered controls. Evident was the capacity of camels to maintain constant, the overall rectal-air temperature gradient through varying rectal-skin and skin-air gradients, and invariably in opposite direction. This was aided by the fact that (Ta) were constantly lower than the (RT) and (ST). Hence, the temperature of the skin and its regulation determines to a large extent the core temperature of camels.

show abstract

Long-term adaptation of sheep to low protein roughage diets: effects of water deprivation and urea supplementation in the drinking water

Farid

Nasr

Hassan

et al. 1989

Journal of Arid Environments

View full text Add to dashboard Cite

Long-term adaptation of sheep to low protein intake under simulated drought conditions

Cited by 4 publications

References 13 publications

Urea supplementation effects on the utilization of low‐quality forage and lamb production in patagonian rangelands

Urea supplementation effects on the utilization of low‐quality forage and lamb production in patagonian rangelands

Some Aspects of Thermo-Regulation in Water Deprived Camels Under the Semi-Arid Conditions of the North-Western Coastal Desert in Egypt

Long-term adaptation of sheep to low protein roughage diets: effects of water deprivation and urea supplementation in the drinking water

Contact Info

Product

Resources

About