Effect of dietary protein level and salinity on growth, survival, enzymatic activities and amino-acid composition of the white shrimp Litopenaeus vannamei (Boone, 1931) juveniles

Crustaceana ◽  
2015 ◽  
Vol 88 (1) ◽  
pp. 82-95 ◽  
Author(s):  
Liying Sui ◽  
Guannan Ma ◽  
Yuangao Deng

Litopenaeus vannamei (Boone, 1931) postlarvae with average initial body weight of 0.089 g were reared in 75-litre PVC tanks for 40 days at salinities of 30 and 60 g l−1. The shrimps were fed compound feed containing protein levels of 35, 40, 45 and 50%, respectively. Salinity had a remarkable effect on growth and survival of L. vannamei juveniles. Higher survival rate and lower growth were observed at 60 g l−1 salinity. Dietary protein level affected the survival and growth of juveniles at both salinities, increased with dietary protein levels in the range of 35 to 45%, but decreased slightly with 50% dietary protein. Broken line analysis showed that the estimated optimal dietary protein levels at salinities of 30 and 60 g l−1 were 45.93 and 46.74%, respectively. Higher salinity resulted in an increased moisture content, ash and crude protein content in the shrimp muscle tissue. The amino acid contents in the shrimp muscle tissue were generally higher at 60 g l−1 salinity and increased dietary protein level led to higher protein content, except with 50% dietary protein. At salinity 60 g l−1, the soluble protein content and activities of glutamic oxalacetic transferase (GOT) and glutamic pyruvic transaminase (GPT) in shrimp muscle tissue were higher, while catalase (CAT) activities were lower. Farming of L. vannamei at a marginal culture salinity (60 g l−1) is feasible though the shrimps were likely exposed to stressful conditions. Reduced growth rate at higher salinity may be attributed to the higher total ammonium (TAN) concentration in the culture medium and extra energy consumption for osmoregulation at hypersaline conditions.

2020 ◽  
Vol 28 (3) ◽  
pp. 1227-1241 ◽  
Author(s):  
Bruno Silva Olier ◽  
Jiovani Sergio Bee Tubin ◽  
Giovanni Lemos de Mello ◽  
Marcel Martínez-Porchas ◽  
Maurício Gustavo Coelho Emerenciano

2007 ◽  
Vol 38 (4) ◽  
pp. 475-485 ◽  
Author(s):  
Martin Perez-Velazquez ◽  
Mayra L. González-Félix ◽  
Fernando Jaimes-Bustamente ◽  
Luis R. Martínez-Córdova ◽  
Denisse A. Trujillo-Villalba ◽  
...  

2000 ◽  
Vol 80 (4) ◽  
pp. 633-642 ◽  
Author(s):  
Palle V. Rasmussen ◽  
Christian F. Børsting

The effect of different and shifting dietary protein levels on hair growth and the resulting pelt quality in mink was studied. Two groups of pastel female mink were fed either 59% (high protein, HP) or 40% (low protein, LP) of metabolisable energy (ME) from protein during pregnancy and lactation. Shortly after weaning, kits from females fed the LP diet were put on a new LP diet (21% protein of ME). Kits from females fed HP were randomly distributed to four experimental groups fed a new HP diet (34% protein of ME) and three of these groups were shifted to diets with 21% protein at different times during June until September. Skin biopsies were taken at 4, 6, 23 and, 29 wk of age. Histological techniques and computer-assisted light microscopy were used to determine the ratio of activity (ROA) of underfur and guard hairs, respectively, defined as the number of growing hairs as a percentage of the total number of hairs. The hair fibre length and thickness were determined by morphometric methods and correlated with fur properties of dried pelts judged by sensory methods. It was documented that 40% of ME from protein during pregnancy and lactation was sufficient for mink kits to express their genetic capacity to produce hair follicles. In males, a reduced protein level from the age of 15 wk or 22 wk until pelting disturbed moulting, indicated by a low ROA of underfur hairs at 23 wk, and consequently reduced the growth and development of the winter coat. A constantly low protein level from conception until the age of 29 wk did not disturb moulting, but led to a reduction of primeness and especially of the underfur length and fibre thickness of the winter coat. A low protein level from the age of 9 wk only reduced the thickness of the underfur fibres. Hair growth, final fur volume, and general quality of the winter coat of males were influenced negatively and to the same degree in all groups fed the LP diet in part of the growth period. The number of underfur hairs per area (hair density) of the winter coat was not influenced by the dietary treatment meaning that the protein content of 21% of ME in the LP diet was high enough for the mink to express its genetic capacity to develop hair follicles. However, this low protein content led to a reduction of hair fibre length and hair fibre thickness of the underfur. Overall, this study demonstrated that hair growth and hair properties in pelts are very dependent on the dietary protein supply in the period from 22 wk of age until pelting, irrespective of the supply in the preceding periods. Key words: Fur properties, hair fibres, nutrition, pelage, protein requirement


1963 ◽  
Vol 41 (1) ◽  
pp. 1871-1877
Author(s):  
John R. Beaton

Male, albino rats were fed diets containing 5%, 20%, and 40% casein by weight for 7 days at environmental temperatures of 22 °C and 2–3 °C. In one experiment, food was provided ad libitum; in a second experiment, all groups were provided with equal amounts of food. At 22 °C, the activities in liver of alanine-glutamic transaminase, phosphate-activated glutaminase, and arginase increased with increasing dietary protein level. At 2–3 °C, activities of the last two enzymes increased with increasing dietary protein level from 5% to 20% but not from 20% to 40% whereas transaminase activities increased throughout the dietary protein range 5% to 40%. No relationship of glucose-6-phosphatase activity to dietary protein level was evident at either environmental temperature. Cold exposure per se increased the activities of alanine-glutamic transaminase and glucose-6-phosphatase in all dietary protein groups but increased the activities of arginase and phosphate-activated glutaminase only in rats fed the 5% and 20% protein diets. It is postulated that increased activities of these liver enzymes during cold exposure result from augmented catabolism of substrates to meet increased energy requirements. As previously observed with respect to other metabolic alterations, it is apparent that cold exposure modifies the response of liver enzymes to changing dietary protein levels.


1978 ◽  
Vol 12 (2) ◽  
pp. 109-112 ◽  
Author(s):  
S. S. Ajayi ◽  
O. O. Tewe

The growth performance of 24 weanling giant rats was studied in 2 experiments of 30 weeks duration with commercial livestock rations and graded levels of protein. Daily average liveweight gain was 5·1-7·3 g, food consumption 26·9-36·3 g on 6 diets. Food intake, growth rate and food efficiency ratio were very similar using the different commercial diets. Growth performance improved as the dietary protein level was raised from 10 to 13%, but a further increase to 16% did not result in greater growth. The commercial pig ration and the experimental diet containing 13% dietary protein level were found to give satisfactory growth, and are recommended for studies with these animals.


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