Net protein and metabolizable protein requirements for maintenance and growth of early-weaned Dorper crossbred male lambs

Abstract: Feedlot efficiency increases as technologies are adopted and new feed ingredients, especially byproducts, become available and incorporated into diets. Byproduct availability increased in response to the renewable fuels standard of 2005, creating substantial amounts of feedstuffs best used by ruminants. Cereal grains have been partially replaced with human-inedible byproducts, as they provide comparable levels of energy in cattle diets. To evaluate the effects of changes in diet and feedlot production practices on net protein contribution (NPC) and human-edible protein conversion efficiency (HePCE) across time, a deterministic NPC model was used. NPC was assessed for the feedlot industry using lot level production data from 2006 to 2017 for eight commercial feedlots. Ingredient and nutrient composition was collected for a representative starter and finisher diet fed for each year from each feedlot. NPC was calculated by multiplying human-edible protein (HeP) in beef produced per unit of HeP in feed by the protein quality ratio (PQR). Systems with NPC >1 positively contribute to meeting human protein requirements; NPC < 1 indicates competition with humans for HeP. NPC was regressed on year to evaluate temporal change in NPC. Feedlots were categorized as increasing NPC (INC; slope > 0) or constant NPC (CON; slope = 0) according to regression parameter estimates. Four feedlots were categorized as INC and four were CON. The rate of change in PQR was similar for CON and INC (P ≥ 0.79), although rates of change among INC and CON differed for byproduct and cereal grain inclusion (P ≤ 0.01) across years evaluated. Feedlots categorized as INC reduced HeP consumed by 2.39% per year, but CON feedlots did not reduce HeP consumed each year (0.28%). Cattle received and shipped by INC were lighter than those in CON feedlots (P < 0.01). Across years, INC produced more HeP (20.9 vs. 19.2 kg/hd) than CON (P < 0.01), and both feedlot types tended to improve HeP gained over time (0.1 kg per year; P = 0.10). Differences in slope over time for INC and CON were observed for conversion efficiency of HeP (P < 0.01). NPC increased 0.027 units per year for INC (P < 0.01) and was 0.94 in 2017. NPC by the feedlot sector improved from 2006 to 2017, decreasing the amount of human-edible feeds required to produce more high-quality protein from beef.

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Metabolizable protein requirements of lactating goats

Small Ruminant Research ◽

10.1016/j.smallrumres.2004.04.004 ◽

2004 ◽

Vol 53 (3) ◽

pp. 327-337 ◽

Cited By ~ 12

Author(s):

I.V Nsahlai ◽

A.L Goetsch ◽

J Luo ◽

Z.B Johnson ◽

J.E Moore ◽

...

Keyword(s):

Protein Requirements ◽

Metabolizable Protein ◽

Lactating Goats

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Net and metabolizable protein requirements for body weight gain in hair and wool lambs

Small Ruminant Research ◽

10.1016/j.smallrumres.2005.10.012 ◽

2007 ◽

Vol 67 (2-3) ◽

pp. 192-198 ◽

Cited By ~ 19

Author(s):

A.M.A. Silva ◽

A.G. Silva Sobrinho ◽

I.A.C.M. Trindade ◽

K.T. Resende ◽

O.A. Bakke

Keyword(s):

Body Weight ◽

Weight Gain ◽

Body Weight Gain ◽

Protein Requirements ◽

Metabolizable Protein

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Development of an equation to predict net protein requirements for the growth of Zebu beef cattle

animal ◽

10.1017/s1751731119002684 ◽

2020 ◽

Vol 14 (5) ◽

pp. 963-972

Author(s):

L.F. Costa e Silva ◽

S.deCamposValadares Filho ◽

P. Del Bianco Benedeti ◽

E. Detmann ◽

A.C.Baião Menezes ◽

...

Keyword(s):

Beef Cattle ◽

Protein Requirements ◽

Net Protein

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Estimation of the net energy and protein requirements for maintenance of male arctic foxes (Alopex lagopus) during the growth period12

Journal of Animal Science ◽

10.1093/jas/skz253 ◽

2019 ◽

Vol 97 (11) ◽

pp. 4579-4587

Author(s):

W Zhong ◽

L L Mu ◽

F F Han ◽

G L Luo ◽

X Y Zhang ◽

...

Keyword(s):

Linear Relationship ◽

Heat Production ◽

Feed Intake ◽

Metabolizable Energy ◽

Net Energy ◽

Protein Requirements ◽

Maintenance Requirement ◽

Arctic Foxes ◽

Energy Maintenance ◽

Net Protein

Abstract The maintenance requirements of net energy and net protein were assumed to represent the most accurate and important values totally for the animal’s utilization. The objective of this experiment was to determine the net energy and net protein requirements for maintenance of growing arctic foxes. The experiments was evaluated using regression models estimated from data collected by means of indirect calorimetry, nitrogen balance trials, and digestion and metabolism experiments. Thirty-six growing arctic foxes (3 487 ± 261.7 g) at the age of 85 days were randomly assigned to four groups with 9 animals in each group. Arctic foxes were fed a complete formula diet at four intake levels (100%, or 80%, 60%, and 40% of feed requirements) from 24 July 2017 to 23 September 2017. Arctic foxes in each treatment were kept individually in respiration chambers after 1-d adaptation at day 2 for a 3-d balance trial and then at day 5 followed by a 3-d fasting period. The metabolizable energy intake (MEI), heat production in the fed state (HP), and retained energy (RE) of arctic foxes significantly decreased (P < 0.01) as the feed intake level decreased. Fasting heat production (FHP) of arctic foxes was not influenced by feed intake level (P > 0.05). The metabolizable energy maintenance requirement (MEm) and net energy maintenance requirement (NEm) estimated from the linear relationship between RE and MEI were 230 and 217 kJ/kg of body weight BW0.75/d, respectively. The MEm and NEm estimated by logarithmic regression of HP on MEI were 225 and 209 kJ/kg BW0.75/d, respectively. The net N maintenance requirement (NNm) and net protein maintenance requirement (NPm) estimated from the linear relationship between retained nitrogen (RN) and daily nitrogen intake (NI) were 179.6 mg/kg BW0.75/d and 1.123 g/kg BW0.75/d, respectively. It is concluded that NEm and NPm values obtained fill the net energy and protein requirements shortage, and provide the basic data for establishing the standard of nutrition demand of breeding arctic foxes in China.

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Metabolizable Protein: 2. Requirements for Maintenance in Growing Saanen Goats

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.650203 ◽

2021 ◽

Vol 8 ◽

Author(s):

Anaiane P. Souza ◽

Julián A. C. Vargas ◽

Marcia H. M. R. Fernandes ◽

Amélia K. Almeida ◽

Kleber T. Resende ◽

...

Keyword(s):

Meta Analysis ◽

The Other ◽

N Balance ◽

Regression Equations ◽

Protein Requirements ◽

Metabolizable Protein ◽

Balance Technique ◽

Comparative Slaughter ◽

Different Levels ◽

Feeding Systems

This study aimed to estimate the protein requirements for the maintenance of growing Saanen goats of different sexes from 5 to 45 kg of body weight (BW) using two methods and applying a meta-analysis. For this purpose, two datasets were used. One dataset was used to evaluate the effects of sex on the protein requirements for maintenance using the comparative slaughter technique. This dataset was composed of 185 individual records (80 intact males, 62 castrated males, and 43 females) from six studies. The other dataset was used to evaluate the effects of sex on the protein requirements for maintenance using the N balance method. This dataset was composed of 136 individual records (59 intact males, 43 castrated males, and 34 females) from six studies. All studies applied an experimental design that provided different levels of N intake and different levels of N retention, allowing the development of regression equations to predict the net protein requirement for maintenance (NPM) and the metabolizable protein (MP) requirements for maintenance (MPM) in Saanen goats. The efficiency of MP use for maintenance (kPM) was computed as NPM/MPM. The efficiency of MP use for gain (kPG) was calculated using the equation of daily protein retained against daily MP intake above maintenance. A meta-analysis was applied using the MIXED procedure of SAS, in which sex was considered a fixed effect, and blocks nested in the studies and goat sex were considered as random effects. The NPM did not differ between sexes, irrespective of the approach used. The daily NPM estimated was 1.23 g/kg0.75 BW when using the comparative slaughter technique, while it was 3.18 g/kg0.75 BW when using the N balance technique for growing Saanen goats. The MPM estimated was 3.8 g/kg0.75 BW, the kPM was 0.33, and the kPG was 0.52. We observed that the NPM when using the comparative slaughter technique in growing Saanen goats is lower than that recommended by the current small ruminant feeding systems; on the other hand, the MPM was similar to previous reports by the feeding systems. Sex did not affect the protein requirements for maintenance and the efficiencies of use of metabolizable protein.

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Validation of the Equations Used in Determining Dry Matter Intake, and Metabolizable Protein Requirements for Finishing Lambs as used in the Sheep Companion Module to BRaNDS

10.31274/ans_air-180814-920 ◽

2010 ◽

Author(s):

Garland R. Dahlke ◽

Daniel G. Morrical ◽

Lauren J. Secor

Keyword(s):

Dry Matter ◽

Dry Matter Intake ◽

Protein Requirements ◽

Metabolizable Protein

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Influence of Salinity on Protein Requirements of Rainbow Trout (Salmo gairdneri) Fingerlings

Journal of the Fisheries Research Board of Canada ◽

10.1139/f73-298 ◽

1973 ◽

Vol 30 (12) ◽

pp. 1867-1873 ◽

Cited By ~ 56

Author(s):

I. H. Zeitoun ◽

J. E. Halver ◽

D. E. Ullrey ◽

P. I. Tack

Keyword(s):

Rainbow Trout ◽

Protein Efficiency Ratio ◽

Salmo Gairdneri ◽

Efficiency Ratio ◽

Protein Requirements ◽

Protein Levels ◽

Major Consequence ◽

Percentage Weight ◽

Net Protein ◽

Representative Samples

Rainbow trout (Salmo gairdneri) juveniles maintained at 10 and 20 ppt salinity were fed seven diet treatments from 30 to 60% protein in 5% increments for 10 weeks. The fish were stocked in cones, initially 50 fish per cone. Biweekly weights of diets and fish were determined and mortality was recorded daily. Percentage weight gain, gross diet efficiency, and protein efficiency ratio (P.E.R.) were computed. The minimum protein levels required for fish to achieve highest performance using these criteria were 40 and 45% for those maintained at 10 and 20 ppt, respectively. Mortality was significantly (P < 0.05) higher for fish maintained at the higher salinity. Analyses of the fish carcasses were conducted at the beginning and end of the experiment on representative samples to estimate the grams protein retained and apparent net protein utilization (N.P.U.) to verify the above findings. All the available data showed that dietary protein was of major consequence on all measurements until the minimum required level of protein in the diet was reached, while salinity was of minor consequence. P.E.R. and apparent N.P.U. were 2.10 and 34.4, respectively, for casein diets at the 40% protein level.

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