Effects of barley grain compared to commercial concentrate or rapeseed meal supplementation on performance of growing dairy bulls offered grass silage-based diet

Huhtanen

Joki‐Tokola

2014

Animal

Self Cite

The objective of this meta-analysis was to develop empirical equations predicting growth responses of growing cattle to protein intake. Overall, the data set comprised 199 diets in 80 studies. The diets were mainly based on grass silage or grass silage partly or completely replaced by whole-crop silages or straw. The concentrate feeds consisted of cereal grains, fibrous by-products and protein supplements. The analyses were conducted both comprehensively for all studies and also separately for studies in which soybean meal (SBM; n = 71 diets/28 studies), fish meal (FM; 27/12) and rapeseed meal (RSM; 74/35) were used as a protein supplement. Increasing dietary CP concentration increased ( P < 0.01) BW gain (BWG), but the responses were quantitatively small (1.4 g per 1 g/kg dry matter (DM) increase in dietary CP concentration). The BWG responses were not different for bulls v. steers and heifers (1.4 v. 1.3 g per 1 g/kg DM increase in dietary CP concentration) and for dairy v. beef breeds (1.2 v. 1.7 g per 1 g/kg, respectively). The effect of increased CP concentration declined ( P < 0.01) with increasing mean BW of the animals and with improved BWG of the control animals (the lowest CP diet in each study). The BWG responses to protein supplementation were not related to the CP concentration in the control diet. The BWG responses increased ( P < 0.05) with increased ammonia N concentration in silage N and declined marginally ( P > 0.10) with increasing proportion of concentrate in the diet. All protein supplements had a significant effect on BWG, but the effects were greater for RSM ( P < 0.01) and FM ( P < 0.05) than for SBM. Increasing dietary CP concentration improved ( P < 0.01) feed efficiency when expressed as BWG/kg DM intake, but decreased markedly when expressed as BWG/kg CP intake. Assuming CP concentration of 170 g/kg BW marginal efficiency of the utilisation of incremental CP intake was only 0.05. Increasing dietary CP concentration had no effects on carcass weight, dressing proportion or conformation score, but it increased ( P < 0.01) fat score. Owing to limited production responses, higher prices of protein supplements compared with cereal grains and possible increases the N and P emissions, there is generally no benefit from using protein supplementation for growing cattle fed grass silage-based diets, provided that the supply of rumen-degradable protein is not limiting digestion in the rumen.

Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 50%

Evaluation of protein supplementation for growing cattle fed grass silage-based diets: a meta-analysis

Huhtanen

Joki‐Tokola

2014

Animal

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“…In accordance with earlier meta-analysis and feeding experiments (Huuskonen, 2011 and2013;Pesonen et al, 2013b and, protein supplementation had no effects on the dressing proportion or carcass conformation score. Consistently with the present meta-analysis, Huuskonen et al (2014) observed that increased dietary CP concentration increased carcass fat score of growing cattle.…”

Section: Carcass Traitssupporting

confidence: 89%

The development of a model to predict BW gain of growing cattle fed grass silage-based diets

Huhtanen

2015

Animal

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The objective of this meta-analysis was to develop and validate empirical equations predicting BW gain (BWG) and carcass traits of growing cattle from intake and diet composition variables. The modelling was based on treatment mean data from feeding trials in growing cattle, in which the nutrient supply was manipulated by wide ranges of forage and concentrate factors. The final dataset comprised 527 diets in 116 studies. The diets were mainly based on grass silage or grass silage partly or completely replaced by whole-crop silages, hay or straw. The concentrate feeds consisted of cereal grains, fibrous by-products and protein supplements. Mixed model regression analysis with a random study effect was used to develop prediction equations for BWG and carcass traits. The best-fit models included linear and quadratic effects of metabolisable energy (ME) intake per metabolic BW (BW 0.75 ), linear effects of BW 0.75 , and dietary concentrations of NDF, fat and feed metabolisable protein (MP) as significant variables. Although diet variables had significant effects on BWG, their contribution to improve the model predictions compared with ME intake models was small. Feed MP rather than total MP was included in the final model, since it is less correlated to dietary ME concentration than total MP. None of the quadratic terms of feed variables was significant ( P > 0.10) when included in the final models. Further, additional feed variables (e.g. silage fermentation products, forage digestibility) did not have significant effects on BWG. For carcass traits, increased ME intake (ME/BW 0.75 ) improved both dressing proportion ( P < 0.01) and carcass conformation ( P < 0.001) and increased ( P < 0.001) carcass fat score. Increased dietary CP concentration had no significant ( P > 0.10) effect on dressing proportion or carcass conformation score, but it increased ( P < 0.01) carcass fat score. The current study demonstrated that ME intake per BW 0.75 was clearly the most important variable explaining the BWG response in growing cattle. The effect of increased ME supply displayed diminishing responses that could be associated with increased energy concentration of BWG, reduced diet metabolisability (proportion of ME of gross energy) and/or decreased efficiency of ME utilisation for growth with increased intake. Negative effects of increased dietary NDF concentration on BWG were smaller compared to responses that energy evaluation systems predict for energy retention. The present results showed only marginal effects of protein supply on BWG in growing cattle.

“…Compared to the recent Finnish experimental datasets for dairy bulls with typical Finnish grass silage-based diets (e.g. Huuskonen and Joki-Tokola 2010, Huuskonen 2009, 2011, 2013, the average lifetime carcass gain was approximately 10% lower in the present field data. This difference probably reflects variable feeding regimes and management factors at farm level compared to the controlled experimental environments.…”

Section: Resultscontrasting

confidence: 71%

A comparison of Nordic Red, Holstein-Friesian and Finnish native cattle bulls for beef production and carcass traits

2014

AFSci

The objective of this study was to determine beef production traits of purebred Nordic Red (NR), Holstein-Friesian (Hol), Eastern Finncattle (EF), Northern Finncattle (NF) and Western Finncattle (WF) bulls. The data collected from slaughterhouses included observations of 164 862 NR, 87 323 Hol, 283 EF, 523 NF and 1 728 WF bulls. For estimating valuable cuttings also a separate dataset was collected including observations of 16 036 NR, 8 806 Hol, 18 EF, 126 NF, and 133 WF bulls. NR and Hol had the highest carcass gain (532 and 542 g d-1, respectively). Overall, the data showed poorer gain of the Finnish native breeds compared to NR and Hol. Among the native breeds, WF (427 g d-1) showed better growth compared to EF (356 g d-1) and NF (385 g d-1). Less differences were observed in valuable cuttings as might be inferred based on the differences in carcass conformation scores.