246 Over-feeding metabolizable protein supply in late gestation beef cattle: Effects on colostrum composition, milk and milk component yield, and pre-weaning growth of calves

Abstract In 1996, the NASEM beef cattle committee developed and published an equation to estimate cow feed intake using results from studies conducted or published between 1979 and 1993 (Nutrient Requirements of Beef Cattle). The same equation was recommended for use in the most recent version of this publication (2016). The equation is sensitive to cow weight, diet digestibility and milk yield. Our objective was to validate the accuracy of this equation using more recent published and unpublished data. Criteria for inclusion in the validation data set included projects conducted or published within the last ten years, direct measurement of forage intake, adequate protein supply, and pen feeding (no tie stall or metabolism crate data). The validation data set included 29 treatment means for gestating cows and 26 treatment means for lactating cows. Means for the gestating cow data set was 11.4 ± 1.9 kg DMI, 599 ± 77 kg BW, 1.24 ± 0.14 Mcal/kg NEm per kg of feed and lactating cow data set was 14.5 ± 2.0 kg DMI, 532 ± 116.3 kg BW, and 1.26 ± 0.24 Mcal NEm per kg feed, respectively. Non intercept models were used to determine equation accuracy in predicting validation data set DMI. The slope for linear bias in the NASEM gestation equation did not differ from 1 (P = 0.07) with a 3.5% positive bias. However, when the NASEM equation was used to predict DMI in lactating cows, the slope for linear bias significantly differed from 1 (P < 0.001) with a downward bias of 13.7%. Therefore, a new multiple regression equation was developed from the validation data set: DMI= (-4.336 + (0.086427 (BW^.75) + 0.3 (Milk yield)+6.005785(NEm)), (R-squared=0.84). The NASEM equation for gestating beef cows was reasonably accurate while the lactation equation underestimated feed intake.

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The effect of metabolisable protein supply at constant energy intake on the liveweight gain of bovines

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200591492 ◽

1995 ◽

Vol 1995 ◽

pp. 154-154

Author(s):

P N Johnson ◽

E R Deaville

Keyword(s):

Beef Cattle ◽

Theoretical Basis ◽

Initial Step ◽

Official Method ◽

Constant Energy ◽

Protein Requirements ◽

Metabolisable Energy ◽

The Uk ◽

Protein Supply ◽

Degradable Protein

The metabolisable protein (MP) system (AFRC, 1992), adopted as the official method of describing the protein requirements of ruminants in the UK, introduces the concepts of effective rumen degradable protein (ERDP), digestible undegradable protein (DUP) and fermentable metabolisable energy (FME). For effective protein rationing, the aim is to match the supply of FME and ERDP, and to supply further protein requirements as DUP. This should lead to a better balance of energy and protein to meet the requirements of the animal. Diets are likely to have lower total protein contents than those presently available, leading to reductions in diet costs and nitrogen (N) excretion. The MP system was constructed primarily on a theoretical basis and this experiment was an initial step in validating it for beef cattle.

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Influence of dietary rumen-degradable protein supply on rumen characteristics and carbohydrate fermentation in beef cattle offered high-grain diets

Animal Feed Science and Technology ◽

10.1016/s0377-8401(00)00191-7 ◽

2000 ◽

Vol 88 (1-2) ◽

pp. 59-77 ◽

Cited By ~ 19

Author(s):

S.M Martı́n-Orue ◽

J Balcells ◽

F Vicente ◽

C Castrillo

Keyword(s):

Beef Cattle ◽

Carbohydrate Fermentation ◽

Protein Supply ◽

Degradable Protein

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Changes in mammary metabolism in response to the provision of an ideal amino acid profile at 2 levels of metabolizable protein supply in dairy cows: Consequences on efficiency

Journal of Dairy Science ◽

10.3168/jds.2014-8656 ◽

2015 ◽

Vol 98 (6) ◽

pp. 3951-3968 ◽

Cited By ~ 17

Author(s):

M.N. Haque ◽

J. Guinard-Flament ◽

P. Lamberton ◽

C. Mustière ◽

S. Lemosquet

Keyword(s):

Amino Acid ◽

Dairy Cows ◽

Amino Acid Profile ◽

Metabolizable Protein ◽

Protein Supply ◽

Mammary Metabolism

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Development of the laser remote caliper as a method to estimate surface area and body weight in beef cattle

SURG Journal ◽

10.21083/surg.v1i2.402 ◽

2008 ◽

Vol 1 (2) ◽

pp. 57-72

Author(s):

Sarah Core ◽

Stephen Miller ◽

Matthew Kelly

Keyword(s):

Body Weight ◽

Beef Cattle ◽

Surface Area ◽

Digital Imaging ◽

Late Gestation ◽

P Value ◽

Side View ◽

Linear Measurements ◽

Indirect Measures ◽

Area And Volume

Linear measurements combined with surface area and volume calculations were used to develop formulas to estimate body weight (BW) in beef cattle. These measurements were evaluated directly or estimated using a laser remote caliper (LRC) and digital imaging software. Seventy-two dry, late gestation beef cows aged 3-13 years were measured and weighed Six measurements for each cow were taken; the cattle were weighed, a body condition score (BCS) was assigned, heart girth (HG), hip width (HW), and hip height (HH) were measured directly and 3 digital pictures were taken. The digital pictures portrayed three different views; side view (restrained), rear view (restrained), and side view (free-stall). Body length, HW, HH, surface area and volume were indirectly calculated from the digital images. For each view a complete (C-) formula (direct and indirect measures) and remote (R-) formula (only indirect measures) to estimate BW was developed. The R-squared values 0.7459, 0.7937, 0.8078, 0.5016, 0.611, 0.5553 were attained for C-side view free-stall, C-side view (restrained), C-rear view (restrained), R-side view free-stall, R-side view (restrained), and R-rear view (restrained). The accuracy of these formulas was 81% on average. BCS, HG and HW were the most significant factors when developing a formula for BW (p-value < 0.001). Side view (restrained) image measurements were most accurate in estimating BW. These measurements were highly correlated with the direct measurements and digital linear body measurements were not distorted (due to poor posture/positioning) as seen with the other views. The results or this study show that linear measurements collected by digital imaging methods can be a useful tool for estimating BW.

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