Title of Research: Effects of Alfalfa Hay Particle Size and Feeding Frequency on Lamb Performance and Digestibility Traits PhD Degree Candidate: Hafiz A. Ibrahim

Particle Size Affects Rumination If too fine – chewing ↓, saliva ↓, buffering capacity ↓, pH ↓ If adequate – chewing ↑, saliva ↑, buffering capacity ↑, pH ↑

Objectives of the study To evaluate the effects of Alfalfa Hay Particle Size and Feeding Frequency on:- Lamb performance. Nutrient digestibility. Digesta Passage rate. Carcass characteristics.

MATERIALS AND METHODS 72 Najdi ram Lambs averaging 24kg were utilized. Long alfalfa hay and two chopping lengths were offered. Diet A= 9.5 mm-length hay in PCR. Diet B= 14 mm-length hay in PCR. Diet C= Long hay + PConc. Feed was offered as 95g.d.W 0.75

Alfalfa Hay Particle Length & Long Hay Diet A & B ( 9.5,14 mm)Diet C ( Long hay)

Two feeding frequencies were practiced: Once per day (8:00 am). Twice per day (8:00 am and 4:00 pm). Lambs were randomly allocated to six treatment groups (12 per group) in a 3x2 factorial arrangement. The feeding experiment were lasted for 14 wk; thereafter, all lambs were slaughtered.

Treatment Group

Table1. Ingredients and Composition of the Basal Diet. DM basis %Ingredient 69.76Barley 25.0Alfalfa hay 4.2Soybean meal 0.5Salt 0.5Limestone 0.04Trace mineral, vitamin premix 0.2%

Chemical analysis of the diets (g/kg) Diet CDiet BDiet ADescription Dry Matter Crude Protein Ether Extract Crude Fiber ADF NDF Ash ME For Ruminant Kcal/Kg

:Parameters Measured Daily feed intake. Average Daily Gain. Feed Efficiency. Nutrients Digestibility. Nitrogen Balance. Rumen Kinetics. Digesta Passage. Carcass Characteristics.

Statistical Analysis Lamb Performance, Digestibility Traits, Ruminal Parameters and Carcass Data were subjected to GLM models using The Statistical Analysis System Packages (SAS, 2000).

Effects of alfalfa hay particle size and feeding frequency on lamb performances. Frequency effectDiet EffectTraits TwiceOnceDiet CDiet BDiet A Initial body wt., kg b 48.5 ab 51.1 a Final body wt., kg c 254 b 272 a ADG, g/d 1352 b 1387 a Feed intake, g/d a 5.35 b 5.10 c Feed conversion ratio

Carcass characteristics

Effects of alfalfa hay particle size and feeding frequency on nutrient digestibility Frequency effectDiet EffectNutrient TwiceOnceDiet CDiet BDiet A Dry Matter % Crude Protein % a 68.4 b 66.8 b Ether Extract % 44.0 b 49.0 a 48.5 a 41.6 b 50.9 a ADF % 44.4 b 48.7 a 52.5 a 40.6 c 46.6 b NDF % N free Extract % TDN %

Effects of alfalfa hay particle size and feeding frequency on nitrogen balance Diet CDiet BDiet AItem TwiceOnceTwiceOnceTwiceOnce Body weight, kg DM intake, g/d Nitrogen intake, g/d Nitrogen excretion, g/d Fecal Urinary Nitrogen retention: g/d % of N intake

Effects of alfalfa hay particle size and feeding frequency on ruminal VFA concentrations Frequency effectDiet EffectVFA, mM TwiceOnceDiet CDiet BDiet A Acetic b 16.4 b 18.7 a 3 h 8.8 b 10.1 a 7.6 b 9.9 a 10.9 a 24 h Propionic b 17.7 a 18.4 a 3 h 10.6 a 8.2 b 7.1 c 12.0 a 9.1 b 24 h Butyric ab 5.4 a 3.7 b 3 h b 3.8 a 3.1 ab 24 h

h Post-feeding Figure 1. Effect of particle length on total VFA concentration in rumen liquor VFA concentration, mM

h Post-feeding Figure 2. Effect of feeding frequency on total VFA concentration in rumen liquor VFA concentration, mM

Effect of alfalfa particle size and feeding frequency on digesta passage rate and Cr MRT

Frequency effectDiet EffectItem TwiceOnceDiet CDiet BDiet A % Cr +++ Recovery Time post-dosing, mg Cr/h 9.6 a 8.5 b 6.1 c 9.4 b 11.5 a hr 12.5 a 10.7 b 10.3 b 11.0 b 13.5 a hr 3.1 a 3.0 b 3.4 a 2.9 b 2.8 b hr 57.1 b 60.9 a 63.1 a 58.5 b 55.6 c Mean Retention Time, hr

Conclusion Complete pelleted feed with reduced alfalfa particle size improved: - Average Daily Gain (ADG). - Dry Matter Intake (DM). - Decrease digestibility of NDF, ADF. - Lower rumen solid retention time. - Hot carcass weight. Feeding frequency

Recommendations More research is needed. Complete pelleted ration (75% concentrate Plus 25%chopped alfalfa hay) is recommended. Once daily feeding would reduce labor and equipment operation costs at the feedlot production