Evaluating by-products for inclusion in ruminant and monogastric diets

Overall project objective To improve the characterisation of the nutritive value of feeds to allow better diet formulation for improved animal productivity, product quality and reduced nutrient excretion. This project has a particular focus on the assessment and dietary inclusion of by-product feeds in both ruminant and monogastric diets.

Background

Irish Institute of European Affairs

International Livestock Research Institute

Dairy Feeding Trials The effect of increasing levels of by-products on milk production, milk composition, energy and nutrient partitioning in early-mid lactation grazing dairy cows Researchers: K. Pierce, T. Boland UCD Post-Graduate: Billy Carey, Sarah Condren (M.Agr.Sc. student)

Objectives To investigate the effect of increasing dietary inclusion of by-products (soya hulls, palm kernal and distillers) from 35-95% of concentrate on: Milk Yield and Composition Energy Partitioning N & P Balance

Dietary Treatments Diet BP35 (Control) Barley % Soyabea n Meal % Distillers DG % Palm Kernel Expeller % Soya Hulls % Other % 45 15 11.6 11.6 11.6 5 BP55 30 10 18.3 18.3 18.3 5 BP75 15 5 25 25 25 5 BP95 0 0 31.6 31.6 31.6 5 Other: Vitamins and minerals, molasses

Nutrient Composition (calculated) Nutrient BP35 BP55 BP75 BP95 Dry Matter % 86.75 87.19 87.62 88.06 Crude Protein % 15.91 15.90 15.98 15.88 UFL 0.95 0.94 0.93 0.92 PDIA (g/kg) 55.8 58.3 60.9 63.4 PDIE (g/kg) 108.7 108.4 108 107.7 PDIN (g/kg) 110.9 111.3 111.7 112.1 Ash % 6.71 6.91 7.11 7.31 Oil % 3.9 4.7 5.5 6.3 Fibre % 9.05 11.98 14.91 17.84

The impact of by-product inclusion level on daily milk yield (kg) 35 Trt; P = 0.78 32.5 30 27.5 25 Control BP55 BP75 BP95 22.5 20 Milk Yield

The impact of by-product inclusion level on daily milk fat and protein yield(kg) 1.2 1.1 Trt; P = 0.82 Trt; P = 0.57 1 0.9 0.8 0.7 Control BP55 BP75 BP95 0.6 0.5 Fat Protein

The impact of by-product inclusion level on milk constituents (%) 5 Trt; P = 0.62 4.5 4 3.5 3 2.5 2 1.5 Trt; P = 0.49 Trt; P = 0.87 Trt; P = 0.86 Control BP55 BP75 BP95 1 Fat Protein Lactose Casein

The impact of by-product inclusion level on milk fatty acid profile 2.5 P = 0.85 2 1.5 1 P = 0.45 a,x a ac, bc Control BP55 BP75 0.5 ac a bc bc BP95 0 Saturated Fatty Acids Unsaturated Fatty Acids Mono Unsaturated Fatty Acids Poly Unsaturated Fatty Acids

Summary Inclusion of up to 95% by-products in concentrates fed at 6 kg/day is achievable without negative effects on milk production variables, N excretion, diet digestibility or body condition score

Characterisation of the feeding value of imported by-product feedstuffs for beef cattle Researchers: M. McGee, A.P. Moloney & E.G. O Riordan Teagasc, AGRIC, Grange A. Kelly UCD Post-Graduate: David Magee (M.Agr.Sc. student)

PHASE 1: Objectives: Determine the feed intake & feed efficiency characteristics of by-product feedstuffs for beef cattle Beef production studies 1. Replacement of barley with increasing levels of maize dried distillers grains: intake, growth and carcass characteristics of beef cattle 2. Effect of replacing barley with increasing levels of wheat dried distillers grains on intake, growth and carcass traits of beef cattle 3. Intake and performance of beef cattle offered barley-based concentrates with increasing inclusion levels of soya hulls

Materials and Methods Animals: Late-maturing crossbred steers Concentrate rations: Barley/soya-based concentrate = control Rations containing 20, 40, 60 and 80% fresh weight of respective feed ingredients compared Concentrate feeding: 2 phases 1. Growing phase: ~70 days Supplement to moderate digestibility grass silage - 3 kg concentrate DM daily 2. Finishing phase: ~70-84 days Measurements: Concentrates offered ad libitum + restricted grass silage (3 kg fresh wt. daily) Feed chemical composition & nutritive value Individual intake, growth, feed efficiency & carcass traits

Study 1: Maize distillers - Conclusion Maize distillers grains had a superior feeding value to barleysoybean meal when offered as a supplement to moderate digestibility grass silage BUT not when offered as a high concentrate diet Results indicated that the optimum inclusion level of wheat distillers in the concentrate is: - up to 800g/kg supplement to grass silage - up to 400g/kg offered ad libitum

Study 2: Wheat distillers - Conclusion Wheat distillers had a superior feeding value to barley-soybean meal when offered as a supplement to moderate digestibility grass silage BUT not when offered as a high concentrate diet. Results indicated that the optimum inclusion level of wheat distillers in the concentrate is: up to 800g/kg supplement to grass silage up to 200g/kg offered ad libitum

Study 3: Soya hulls - Conclusion Soya hulls had an inferior feeding value to barley-soya bean meal when offered both as a supplement to moderate digestibility grass silage and as a high concentrate diet. Results indicated that the maximum inclusion level of soya hulls in a barley-based beef concentrate ration is ca. 200g/kg.

Pig feeding trials Objective To investigate the performance response, carcass characteristics, nitrogen and phosphorus excretion and odour emissions of growing-finishing pigs offered varying levels of by-products Researchers: J. O Doherty UCD Post-Graduate: Micheal O Leary (M.Agr.Sc. student) and Louise Clarke (PhD student)

Treatments A Control Diet B Low By-Product Diet C Medium By-Product Diet D High By-Product Diet *Diets are formulated on an ileal digestible amino acid and net energy

Composition of Diets (g/kg) Ingredient Control Low By- Product Medium By- Product High By- Product Wheat 340 340 340 340 Maize 250 250 250 250 Barley 210 140 70 - Soyabean Meal 160 120 60 - Rapeseed Meal - 70 140 210 Maize Distillers - 50 100 150 Minerals & Vitamins 2.5 2.5 2.5 2.5 *Diets are formulated on an ileal digestible amino acid and net energy *All diets have a NE of 10MJ/kg and 10g/kg of lysine

The impact of by-product inclusion level on animal performance Control Low Medium High S.E.M. Significance ADG D 0-62 (kg/day) 0.87 0.90 0.89 0.91 0.019 NS Intake D 0-62 (kg/day) 2.23 2.22 2.25 2.20 0.069 NS FCR D 0-62 (kg/kg) 2.56 a 2.46 bc 2.55 ac 2.44 b 0.030 0.0089

The impact of by-product inclusion level on nitrogen balance Control Low Medium High S.E.M. Significance N intake (kg) N Excretion (kg) N Retention (g/day) N Utilisation value 3.81 a 3.80 a 4.02 ac 4.10 bc 0.083 0.0205 2.32 a 2.31 a 3.53 b 3.58 b 0.068 0.0058 23.02 23.93 23.91 23.81 0.628 NS 0.394 a 0.396 a 0.376 b 0.372 b 0.0058 0.0052

The impact of by-product inclusion level on phosphorous utilisation P Intake (g) P Retention (g) P Output (g) Control Low Medium High S.E.M. Significance 531 a 558 a 683 b 737 c 13.5 <0.0001 311 312 310 325 7.4 NS 220 a 244 a 372 b 412 c 9.3 <0.0001

Summary High by-product inclusion level in the diet of grower finisher pigs improves FCR but leads to increased nitrogen and phosphorous excretion

Overall conclusion Increased potential for inclusion of By-product feeds in diets of ruminant and monogastric animals. Care required in relation to environmental impact of by-product inclusion Impacts on product quality need to be considered and work is ongoing in this regard