The effect of selection for fleece weight upon urea metabolism and digestive function in Romney sheep

1989 ◽  
Vol 40 (5) ◽  
pp. 1065 ◽  
Author(s):  
BC Thompson ◽  
DW Dellow ◽  
TN Barry
Keyword(s):  
Creatinine Clearance ◽  
Clearance Rate ◽  
Genetic Selection ◽  
Plasma Urea ◽  
Voluntary Feed Intake ◽  
Outflow Rate ◽  
Urea Metabolism ◽  
Selection For ◽  
Fleece Weight ◽  
Plasma Urea Concentration

The effect of 30 years genetic selection for greasy fleece weight upon rumen metabolism, apparent digestibility and nitrogen metabolism was investigated in Romney sheep.Fleece weight (Fwt) animals had a 1 mM lower plasma urea concentration than control (C) animals when fed on both diets given, but there was no difference in plasma urea IRL, urinary urea excretion or urea recycling to the digestive tract between the Fwt and C sheep when fed either diet. Relative to the C shccp, the Fwt animals had a higher creatinine clearance rate when fed the meadow hay diet, and a higher urea clearance rate when fed both diets.When fed the meadow hay diet there were no differences between the Fwt and C animals in voluntary feed intake (VFI) or apparent DM digestibility. However, when fed on the lucerne chaff diet the Fwt animals had a higher VFI than the C animals and a lower apparent DM digestibility. These changes were associated with an increase in the rumen fractional outflow rate (FOR) of lignin in the Fwt sheep, and a higher molar proportion of acetate and a lower proportion of propionate in rumen fluid.The differences in urea and creatinine clearance rates suggest that selection for fleece production may have altered kidney function, with expression of this and rumen FOR being related to nutritional level. A factor contributing to the superior wool production of the Fwt sheep is suggested.

Nitrogen metabolism and plasma urea concentrations in fleeceweight-selected and control Romney rams

1987 ◽  
Vol 38 (5) ◽  
pp. 917 ◽  
Author(s):  
SN McCutcheon ◽  
DDS Mackenzie ◽  
HT Blair
Keyword(s):  
Creatinine Clearance ◽  
Clearance Rate ◽  
Urine Output ◽  
Plasma Concentrations ◽  
Nitrogen Retention ◽  
Urea Concentration ◽  
Plasma Urea ◽  
Plasma Urea Concentration ◽  
And Control ◽  
Daily Period

Nitrogen retention and plasma urea concentrations were examined in 2-year-old Romney rams from fleeceweight-selection and control lines. In four experimental periods rams were fed chaffed lucerne hay (110% of maintenance energy requirements) three times daily (Period I), twelve times daily (Period II), twice daily (Period IV), or were fasted (Period 111). Nitrogen balance was measured in Period I, while plasma concentrations, urinary excretions and clearances of urea and creatinine were examined in Periods II-IV. Water intake and urine output were measured in all periods. Plasma urea concentrations were also measured in the same rams at grazing. Differences between the lines in water intake, urine output, faecal and urinary nitrogen excretion and nitrogen retention were not significant. Control rams maintained significantly higher plasma concentrations of urea and creatinine than fleeceweight-selected rams but only under controlled feeding conditions (particularly twelve times daily feeding). Differences between the lines in plasma urea concentration could be accounted for by the (non-significantly) greater urinary urea excretion, and lower creatinine clearance rate, of control rams. Measurement of plasma urea concentration in sheep may provide a useful predictor of genetic merit for fleeceweight. However, it will be necessary to measure plasma urea concentration under controlled feeding conditions to accurately rank animals. Concurrent measurement of creatinine clearance rate and urinary urea excretion should also enhance the accuracy of prediction of genetic merit.

Sheep of divergent genetic merit for wool growth do not differ in digesta kinetics while on restricted intakes

2014 ◽  
Vol 54 (9) ◽  
pp. 1243 ◽  
Author(s):  
I. De Barbieri ◽  
R. S. Hegarty ◽  
V. H. Oddy ◽  
M. C. Barnett ◽  
L. Li ◽  
...  
Keyword(s):  
Compartmental Model ◽  
Genetic Selection ◽  
Amino Nitrogen ◽  
Feeding Level ◽  
Wool Growth ◽  
Selection For ◽  
Fleece Weight ◽  
Estimated Breeding Values ◽  
Growth Differences ◽  
Weight Groups

Sheep selected for high wool growth were previously shown to exhibit higher microbial protein outflow from the rumen and higher uptake of amino nitrogen in portal blood than those selected for low wool growth. This suggests that genetic selection for wool growth may induce changes in foregut physiology. This study was undertaken to determine whether differences in digesta kinetics, especially mean retention mime (MRT), are associated with differences in fleece production between sheep with low or high estimated breeding values (EBVs) for fleece weight. Twenty mature Merino wethers with uniform EBVs for liveweight were allocated to two groups of 10 animals on the basis of high or low EBVs for yearling fleece weight. Five sheep with low-EBVs and five sheep with high-EBVs for fleece weight groups were allocated in a crossover design to low and high feeding-level treatments, which comprised a blended hay diet fed at maintenance or 1.5 times maintenance. All sheep were given single doses of chromium-mordanted fibre and cobalt-EDTA as inert, non-digestible markers. Digesta kinetics was determined by analysis of the faecal marker excretion patterns using a compartmental model. Higher feed intakes from animals fed 1.5 times maintenance were associated with higher rates of wool growth and higher masses of indigestible fibre in the gut, but reduced MRT of digesta. Although sheep with higher EBVs for fleece weight had higher wool growth rates, there was no indication that these wool growth differences were associated with differences in digesta kinetics. The lack of interaction between feeding level and genotype suggests that MRT did not contribute to genotype differences in wool growth in sheep fed restricted intakes. The differences in wool growth among commercial Merino sheep with divergent fleece weight EBVs achieved by multi-trait selection are not attributable to differences in digesta kinetics, at least when feed is not available ad libitum.

UREA DEGRADATION IN THE CAMEL

1976 ◽  
Vol 56 (3) ◽  
pp. 595-601 ◽  
Author(s):  
B. EMMANUEL ◽  
B. R. HOWARD ◽  
M. EMADY
Keyword(s):  
Crude Protein ◽  
Urea Concentration ◽  
Pool Size ◽  
Entry Rate ◽  
Plasma Urea ◽  
Dietary Nitrogen ◽  
Urea Metabolism ◽  
Plasma Urea Concentration ◽  
Kinetics Of ◽  
General Plasma

Following a single injection of 14C-urea, the kinetics of urea metabolism have been studied in two female Arabian camels (Camelus dromedarius) fed roughage diets containing 6.1 (diet A), 9.6 (diet B), and 13.6% (diet C) crude protein. In general, plasma urea concentration, urea pool size, urea entry rate and urinary urea excretion rate increased as the dietary nitrogen intake increased. The mean extents of urea degradation were approximately 86, 74 and 47% for diets A, B, and C, respectively, as calculated from the ratio of urea degradation rate to urea entry rate, or from the fraction of 14C-urea recovered in the urine. The following parameters were linearly related: urea entry rate and urea pool size, urea pool size and plasma urea concentration, percentage urea degraded and urea entry rate, and percentage urea degraded and crude protein intake.

Genetic selection for nonstructural carbohydrates and its impact on other nutritive attributes of alfalfa ( Medicago sativa ) forage

2021 ◽  
Author(s):  
Annie Claessens ◽  
Marie Bipfubusa ◽  
Caroline Chouinard‐Michaud ◽  
Annick Bertrand ◽  
Gaëtan F. Tremblay ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Genetic Selection ◽  
Nonstructural Carbohydrates ◽  
Selection For

Genome-wide association for plasma urea concentration in sheep

2021 ◽  
Vol 248 ◽  
pp. 104483
Author(s):  
Taiana Cortez de Souza ◽  
Tatiana Cortez de Souza ◽  
Gregorí Alberto Rovadoscki ◽  
Luiz Lehmann Coutinho ◽  
Gerson Barreto Mourão ◽  
...  
Keyword(s):  
Urea Concentration ◽  
Genome Wide Association ◽  
Plasma Urea ◽  
Genome Wide ◽  
Plasma Urea Concentration

scholarly journals Influence of Genetic Selection for Growth and Broodstock Diet n-3 LC-PUFA Levels on Reproductive Performance of Gilthead Seabream, Sparus aurata

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 519
Author(s):  
Shajahan Ferosekhan ◽  
Serhat Turkmen ◽  
Cathaysa Pérez-García ◽  
Hanlin Xu ◽  
Ana Gómez ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Egg Quality ◽  
Sparus Aurata ◽  
Genetic Selection ◽  
Growth Trait ◽  
High Growth ◽  
Gilthead Seabream ◽  
Commercial Diet ◽  
Selection For ◽  
Broodstock Diet

Genetic selection in gilthead seabream (GSB), Sparus aurata, has been undertaken to improve the growth, feed efficiency, fillet quality, skeletal deformities and disease resistance, but no study is available to delineate the effect of genetic selection for growth trait on GSB reproductive performance under mass spawning condition. In this study, high growth (HG) or low growth (LG) GSB broodstock were selected to evaluate the sex steroid hormones, sperm, egg quality and reproductive performance under different feeding regime of commercial diet or experimental broodstock diet containing either fish oil (FO) or vegetable oil (VO) based diet. Under commercial diet feeding phase, broodstock selected for either high growth or low growth did not show any significant changes in the egg production per kg female whereas egg viability percentage was positively (p = 0.014) improved by the high growth trait broodstock group. The experimental diet feeding results revealed that both growth trait and dietary fatty acid composition influenced the reproductive performance of GSB broodstock. In the experimental diet feeding phase, we observed high growth trait GSB males produced a higher number of sperm cells (p < 0.001) and also showed a higher sperm motility (p = 0.048) percentage. The viable egg and larval production per spawn per kg female were significantly improved by the broodstock selected for high growth trait and fed with fish oil-based diet. This present study results signifies that gilthead seabream broodstock selected on growth trait could have positive role in improvement of sperm and egg quality to produce viable progeny.

Developmental morphology and anatomy of the reproductive structures in sunflower (Helianthus annuus): a unified temporal scale

Botany ◽  
2015 ◽  
Vol 93 (5) ◽  
pp. 307-316 ◽  
Author(s):  
L.I. Lindström ◽  
L.F. Hernández
Keyword(s):  
Disease Resistance ◽  
Helianthus Annuus ◽  
Oil Content ◽  
Genetic Selection ◽  
Reproductive Development ◽  
Developmental Morphology ◽  
Male And Female ◽  
Reproductive Structures ◽  
Selection For ◽  
Growing Conditions

In sunflower (Helianthus annuus L.), there has been an intense genetic selection for achenes with agronomic value, such as greater mass, oil content, and disease resistance. However, the information regarding the anatomical events that control their growth and maturation is surprisingly scarce. The aim of the present work was to study sunflower male and female sporogenesis and gametogenesis, as well as cell division and enlargement and tissue differentiation in the ovary and the embryo, linking the timing of these events to two frequently used phenological scales and a thermal time scale. In addition, we propose an ontogenetic scale that integrates the results of the present work to that of previous studies on sunflower reproductive development. The unified scales presented here provide a framework for others to investigate the relationships uncovered in this study in different genetic backgrounds and under different growing conditions.

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