The aim of this study was to assess the effects of feeding Atriplex halimus (AH) silage treated with two developed enzyme cocktails to sheep on feed intake, nutrient digestibility and ruminal fermentation. The AH silage was treated without or with 2 L of ZAD1(®) or ZAD2(®) /1000 kg with 5% molasses and ensiled for 30 days. Barley grain (300 g/head/day) was fed as an energy supplement once daily at 10.00 hours and AH silage with or without enzyme treatment was offered ad libitum to animals twice daily at 09.00 and 16.00 hours. Sheep were fed on four experimental forage diets comprised of AH silage and barley (D1), AH silage treated with ZAD1(®) and barley (D2), AH silage treated with ZAD2(®) and barley (D3) and AH silage treated with a combination of ZAD1(®) and ZAD2(®) (1:1) and barley (D4). Ensiling AH with enzymes reduced its contents of neutral detergent fiber and acid detergent fiber. The dry matter intake of AH of D2, D3 and D4 decreased (P < 0.001) as compared to D1. However, enzyme-treated diets had greater total digestible nutrients intake (P < 0.001) as compared to D1. The nutrients digestibility for D2, D3 and D4 were higher than those for D1 (P < 0.001), and were higher for D3 as compared to both D2 and D4. Sheep fed on D3 had highest (P < 0.001) ruminal total volatile fatty acids concentration, ammonia nitrogen concentration and microbial protein yield. It could be concluded that AH silage treated with ZAD1(®) or ZAD2(®) improved digestibility and rumen fermentation in sheep.

ABSTRACT:The effects of feeding Atriplex halimus treated with three developed enzyme cocktails to Barki sheep on feed intake, nutrient digestibility, N utilization, and ruminal fermentation were assessed. A. halimus was ensiled with two developed enzyme cocktails of ZAD1 ® (Z1) and/or ZAD2 ® (Z2) as liquid enzyme preparations (2 l/t) with 5% molasses and ensiled for 30 days. Three Barki rams (45 ± 3.2 kg) were used per treatment in five consecutive digestibility trials, while three ewes fitted with a permanent rumen fistula were used as source of inoculum for in vitro rumen fermentation trials. Barley grain (300 g/animal/day) was fed as energy supplement during the experimental trial for all diets. Five diets were composed as follows: A. halimus (leaves and stems) (D1); untreated A. halimus plus 4 g/animal/day ZADO ® (Z) (enzyme preparation in powder form) (D2); A. halimus ensiled with Z1 and barley plus 4 g/animal/day Z (D3); A. halimus ensiled with Z2 and barley (D3) plus 4 g/animal/day Z (D4); A. halimus ensiled with a combination of Z1 and Z2 (1 : 1) and barley plus 4 g/head/day Z (D5). For all trials, ad libitum A. halimus was offered twice a day at 9:00 and 16:00 h while barley grain was given once a day at 10:00 h. Both D1 and D2 diets increased (P <0.001) dry matter intake of A. halimus and total dry matter intake. Addition of 4 g/day of Z to Z1 and/or Z2 ensiled diets improved (P < 0.0001) organic matter, crude protein, crude fibre, and neutral detergent fibre digestibilities. Diets D1 and D2 increased (P < 0.001) N intake, whereas the direct addition of Z to D3, D4, and D5 decreased (P < 0.001) N balance and N balance/N absorption ratio. Sheep fed on Z in addition to Z2 ensiled A. halimus showed higher improvements for total volatile fatty acids (P < 0.001), ammonia N (P = 0.007), and microbial protein production (P = 0.003). It can be concluded that feeding sheep on A. halimus ensiled with Z1 and Z2 with direct feeding of Z enzyme preparation improved intake, digestibility, nitrogen balance and utilization, as well as rumen fermentation.

a b s t r a c tThis study was conducted to assess effects of sun-drying and/or addition of an exogenous enzyme (ENZ) preparation on intake, digestibility of nutrients and recovery values of secondary metabolites (SM) in the gastrointestinal tract of sheep fed Atriplex halimus (AH) foliages. A randomized block design for 28 d was used for four experimental treatments based on either fresh (AH-F) or sun-dried (AH-S) A. halimus foliages in the absence (−ENZ) or presence (+ENZ) of 10 g/sheep/d of the exogenous of ZADO ® enzyme preparation. Three adult sheep weighing 51 ± 2.7 kg were fed for each experimental treatment. The ENZ was added daily with a small amount of concentrate to help balance the dietary metabolizable energy concentration. Nutrient intake and digestibility, N balance and recovery of SM (i.e., total phenolics (TP), saponins (SP), alkaloids (AK), aqueous fraction (AF)) in the gastrointestinal tract were determined. Levels of most nutrients did not differ between AH-F and AH-S foliages, but the AH-S contained less than half of the SM in AH-F. Drying of A. halimus and ENZ addition increased (P=0.001) intake as well as OM and NDFom digestibility (P=0.02). Feed intake and digestibility were higher (P=0.01) in AH-S with ENZ addition. Intake of N by sheep fed the treatment diets depended on DM intake as the dietary concentration of N in the diets was similar. Thus AH-S sheep supplemented with ENZ had higher (P=0.001) N intake. Digestibility of N was similar to DM and OM digestibility, and was higher (P=0.03) in AH-S sheep supplemented with ENZ. Drying and ENZ addition to the diet increased (P=0.004) recovery of all SM. The fate of these compounds in the rumen needs to be evaluated considering that SM have been implicated in fiber and protein degradation in the rumen. The study showed that there are beneficial impacts of sun-drying and/or dietary exogenous enzyme addition for sheep fed A. halimus.

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