Feedlot Nutrition: Moving the Boundaries P. H. Henning & F. M. Hagg SAFA Cattleman’s Conference 2011

Feedlot Nutrition: Moving the Boundaries Introduction The boundaries Dietary adaptation (step-up) Promising new technology Parting thoughts

Introduction (1) “Change is the only certainty”

Introduction (2) Changing numbers – human population ↑ – food / beef requirement ↑ – agricultural land ↓ Changing views (consumer) – global village; competitiveness – sustainability – animal welfare – natural / organic

Introduction (3) “For the Feedlot Industry change is not a choice but a matter of survival” Initiative rather than defensive Need to move boundaries – 4-minute mile

The boundaries (1) Feedlot objectives – produce desired carcass in most cost-effective manner – maximize carcass weight per unit feedlot (people, facilities, overheads) – maximize price / value per kg carcass FCR (F:G) Feed cost per kg gain

The boundaries (2)

The boundaries (3)

Dietary adaptation (1) Definition: Gradual (sequential) increase in diet grain concentration, over 2 to 4 week period USA 65 → 94% concentrate in 28d SA 80 → 92% concentrate in 14d Substantial variation !!!

Dietary adaptation (2) Elements of adaptation – microbiological change – physiological change – behavioral change Change in rumen microbial population is the rate-limiting step ?!

Dietary adaptation (3) Change from high-forage to high-concentrate diets → marked changes in rumen environment – rapidly fermentable carbohydrate (RFC) ↑ – fibrolytic bacteria ↓ – amylolytic bacteria ↑ – pH ↓ Time is required to establish a stable microbial population

Dietary adaptation (4) Typical step-up strategies – sequential (concentrate ↑, roughage ↓) – restricted feeding of finishing diet – limited maximum feeding of step-up diets – Two-diet blending starter-finisher

Dietary adaptation (5)

Dietary adaptation (6) Implications of dietary adaptation – higher roughage use manure ↑ methane ↑ handling ↑ risk ↑ – delay of desired high energy intake

Promising new technology (1) Dietary adaptation = change in rumen microbial population – Megasphaera elsdenii – key lactic acid utilizer – numbers low on high roughage diets – slow growing → requires time to reach adequate levels in rumen

Postulated (1975) to use M. elsdenii as DFM to facilitate adaptation Thwarted by – loss of viability during freeze-drying – sensitivity to oxygen (strict anaerobe) Promising new technology (2)

Promising new technology (3) Concept received new impetus with isolation of M. elsdenii NCIMB – fast-growing – wide pH optimum – tolerant of ionophores and in-feed antibiotics – novel approach to its application

Megasphaera elsdenii NCIMB 41125

Promising new technology (4) Novel application – give live M. elsdenii as a single oral dose to cattle on the first day of the adaptation period Hypothesis 1: live M. elsdenii, given as a single oral dose, will: – rapidly colonise in the rumen – prevent accumulation of lactic acid – improve rumen pH

Promising new technology (5) Trials to test hypothesis – rumen-fistulated cattle / sheep – changed from high-roughage to high-concentrate diet – given single oral dose of M. elsdenii NCIMB to coincide with diet change – ca ≥10 IO viable cells per animal – McDaniel et al (2008a,b); Henning et al (2010); Aikman et al (2011)

Promising new technology (6) Log of viable cells per ml P < 0.05

Promising new technology (7) Lactic acid (mM) P < 0.05

Promising new technology (8) pH P < 0.05

Rumen pH :4510:4512:4514:4516:4518:4520:4522:4500:4502:4504:4506:45 Time Rumen pH Placebo NCIMB P<0.1 at this time point Animals fed Animals fed

Promising new technology (9) Hypothesis 2: Live M. elsdenii, given as a single oral dose at start of concentrate feeding, will allow more rapid step-up Trials to test hypothesis – Kansas State University (Thompson et al, 2010) – ARC-Irene (Henning et al, 2009)

KSU trial Objective: – To evaluate the effect of a single oral dose of Megasphaera elsdenii NCIMB on performance of cattle fed either a traditional or an accelerated diet step-up regime The study was conducted as a 2 x 2 factorial design with dietary step-up rate (traditional or accelerated) and addition of M. elsdenii or placebo as treatment factors

Dietary treatments DietTraditional 5-stepAccelerated 3-step 55% concentrate/45% roughageDays 1 to 4Days 1 to 3 65% concentrate/35% roughageDays 5 to % concentrate/25% roughageDays 9 to 12Days 4 to 7 85% concentrate/15% roughageDays 13 to % concentrate/6% roughageDays 17 to 95Days 8 to 95 No Tylan included

Experimental 80 crossbred beef cattle Animals were kept in individual pens 95-day experimental period Me-treated animals received a single oral dose of M. elsdenii NCIMB (10 11 viable cells) on Day 1 (first day of step-up) whilst each control animal received a placebo

Results Item 5 – step (16d)3 – step (7d) ControlMe-treatedControlMe-treated No of head 20 Start LW (kg) 408 FCR (kg DM / kg LW) Carcass weight (kg) (P < 0.10) Liver abscess (%)

ARC-Irene trial Hypothesis: Orally dosing cattle with M. elsdenii at start of feeding period will allow them to go onto the top diet sooner Objective: To determine how rapid newly- arrived feedlot cattle may be stepped-up when they are orally dosed with M. elsdenii Approach: followed a regression approach with 6 step-up rates, increasing with equal increments

Treatment number Starting roughage level on Day 1 Roughage level of Top Diet Day reaching Top Diet Dietary treatments with different starting roughage levels (% of DM) and subsequent different number of days required to reach the Top Diet containing 5% roughage.

IngredientStarterGrower Eragrostis curvula hay Ground maize (corn) Wheat bran Commercial HPC Molasses meal5.0 Feed lime1.0 Salt0.5 Urea1.0 Vit-min premix0.1 Ingredient composition (% A-F) of the basal diets used in the trial.

NutrientsStarterGrower CP Starch NDF ADF EE3.4 ME (MJ/kg DM)(calculated) Nutrient composition of the experimental diets (%DM).

Experimental 36 Bonsmara steers (W = 231 ± 9.9 kg) No previous exposure to concentrate diets Kept in single pens Fed ad libitum at 08:00 and 15:00 Roughage for 2 weeks, fast for 18h, feeding of experimental diets from Day 1 to Day ml oral dose of M. elsdenii NCIMB (10 11 cfu) at 08:00 on Day 1, just prior to feeding concentrate diets for the first time

The effect of diet step-up rate on performance (Days 1 to 35) of feedlot steers receiving a single oral dose of M. elsdenii. 1 Feed conversion ratio 2 Animals showing symptoms of digestive or respiratory health problems Day reaching Top DietRegression P-value DMI (kg/d) ADG (kg/d) FCR No. of pulls

Conclusions 1.In cattle dosed with M. elsdenii it was possible to increase step-up rate, without compromising performance 2.Higher energy intake plus M. elsdenii benefitted performance 3.Increasing step-up rate reduced the need for roughage

Promising new technology (10) M. elsdenii is a promising tool to move boundaries in feedlot nutrition Further trials currently in progress – large experimental pen trial at KSU – large-pen commercial feedlot trials

Promising new technology (11) Important considerations – applying M. elsdenii with current step-up = defeating the object; greatest advantage expected when used in conjunction with accelerated step- up – need to adjust revised starter diet(s) for content of other critical nutrients and therapeutic agents – concern about early finishing

Parting thoughts Awareness of the need to move boundaries, and willingness to try new technologies Step-up is a very real boundary, and one which may be moved Megasphaera elsdenii is a promising new tool in the hand of the Feedlotter As with other tools it requires strategic application to be beneficial

Thank you