Control of Egg Size in Chickens through Dietary Amino-acid Balance

Nature ◽  
1963 ◽  
Vol 200 (4907) ◽  
pp. 702-703 ◽  
Author(s):  
B. E. MARCH ◽  
J. BIELY
Keyword(s):  
Amino Acid ◽  
Egg Size ◽  
Dietary Amino Acid ◽  
Amino Acid Balance

scholarly journals 84 Improving dietary amino acid balance reduces heat production in lactating sows exposed to heat stress

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 47-48
Author(s):  
Sai Zhang ◽  
Jay S Johnson ◽  
Nathalie L Trottier
Keyword(s):  
Heat Stress ◽  
Amino Acid ◽  
Gas Exchange ◽  
Positive Pressure ◽  
Metabolic Heat ◽  
Lactating Sows ◽  
Dietary Amino Acid ◽  
Conventional Diet ◽  
Diet Control ◽  
Amino Acid Balance

Abstract We hypothesized that lactating sows fed a reduced CP (RCP) diet with supplemental AA to improve AA balance produce less metabolic heat (HP) compared with feeding a conventional diet (control). The objective was to measure HP of sows (n = 24) fed control (19.6% CP) or RCP (14.2% CP) under thermoneutral (TN, 21 ± 1.5°C) or cycling heat stress (HS, 32 ± 1.5°C daytime and 24 ± 1.5°C nighttime). Diets contained 0.90% SID Lys and 2,580 kcal/kg. Positive pressure indirect calorimeters were used to measure gas exchange in individual sows with litters (sow + litter), and individual piglets on lactation d 4, 8, 14 and 18, and HP determined overnight (1900–0700) and during daytime (0700–1900). Sow and litter weights were recorded on d 1, 10 and 21. Sow HP was calculated by subtracting litter HP from sow + litter HP based on BW0.75. Model included the fixed effect of diet, random effects of block and sow, sow feed intake as a regression variable and day as the repeated measurement. Compared to control, HP (kcal/h·kg0.75) of RCP was lower (P < 0.01) overnight (5.25 vs. 5.96 ± 0.38), during daytime (6.33 vs. 6.94 ± 0.23), and over 24-h (5.78 vs. 6.46 ± 0.24) under HS. Under TN, HP of RCP tended to differ (P = 0.107) overnight (5.20 vs. 5.90 ±0.57) and over 24-h (5.93 vs. 6.48 ± 0.50) and did not differ (P = 0.190) during daytime (6.66 vs. 7.06 ± 0.52). Under HS, lactation day affected HP (P < 0.05) overnight and over 24-h, with HP increasing from d 1 to 14 and decreasing from d 14 to 18. Under TN, day of lactation did not affect sow HP. Feeding RCP diet to lactating sows decreased HP, and this effect was more pronounced in sows housed under HS.

scholarly journals Plasma urea nitrogen as an indicator of amino acid imbalance in rabbit diets

2020 ◽  
Vol 28 (2) ◽  
pp. 63
Author(s):  
Pablo Jesús Marín-García ◽  
María del Carmén López-Luján ◽  
Luís Ródenas ◽  
Eugenio Melchor Martínez-Paredes ◽  
Enrique Blas ◽  
...  
Keyword(s):  
Amino Acid ◽  
Feed Efficiency ◽  
Dry Matter ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Dietary Amino Acid ◽  
Amino Acid Imbalance ◽  
Ad Libitum ◽  
Amino Acid Balance ◽  
Current Guidelines

<p>In recent decades, recommendations on dietary protein content have been considerably reduced, while fibre content has been increased. Under these conditions, an adequate dietary amino acid balance could be crucial to optimise feed efficiency. Plasma urea nitrogen (PUN) level could be a good indicator of an amino acid imbalance and its potential has already been studied in other species, but not yet in rabbits. The main objective of the present work was to detect the possible interest of PUN in pinpointing amino acid deficiencies in rabbits. Two experimental diets were formulated from the same basal mixture, following all the recommendations for growing rabbits, except lysine, whose content was variable, following current guidelines in diet P8.1 or lower from those in P4.4 (with 8.1 and 4.4 g/kg dry matter of lysine and with 757 and 411 mg of lysine per MJ of digestible energy). Three different trials were designed: one where the animals were fed &lt;em&gt;ad libitum&lt;/em&gt; (AL) and two others in which fasting periods of 10 h were included; one where feeding was restored at 08:00 h (Fast8h) and the other at 18:00 h (Fast18h). A total of 72 three-way crossbred growing rabbits (24 animals for each trial in a split-plot trial) up to a total of 12 recordings were used. Blood samples were taken every 4 h in AL trial and every hour after refeeding up to a total of six controls, in trials Fast8h and<br />Fast18h. The differences between balanced and unbalanced diets in lysine were highest (&lt;em&gt;P&lt;/em&gt;&lt;0.001) between 04:00 h and 12:00 h in animals fed ad libitum, and at 3 h after refeeding (21:00 h) in Fast18h. These results suggest that PUN could be an adequate indicator to detect deficiencies in amino acids in growing rabbit<br />diets.</p>

scholarly journals Matching Dietary Amino Acid Balance to the In Silico-Translated Exome Optimizes Growth and Reproduction without Cost to Lifespan

2017 ◽  
Vol 25 (5) ◽  
pp. 1206 ◽  
Author(s):  
Matthew D.W. Piper ◽  
George A. Soultoukis ◽  
Eric Blanc ◽  
Andrea Mesaros ◽  
Samantha L. Herbert ◽  
...  
Keyword(s):  
Amino Acid ◽  
In Silico ◽  
Dietary Amino Acid ◽  
Amino Acid Balance ◽  
Growth And Reproduction
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