Nutritional quality of wet distillers' grains co-ensiled with whole-plant maize and its feeding value for lambs

The high moisture content of wet distillers' grains with solubles (WDGS) has limited its feeding value despite the relatively high nutritive value. The co­ensiling with whole­plant maize, as a complementary feed, was evaluated for growing lambs by formulating diets whose contents were: whole plant maize silage (WPMS) + sunflower oilcake meal (SOM) (control, WPMS + SOM), whole plant maize silage + dried distillers' grains (WPMS + DDGS), and whole­plant maize (WPM) co­ensiled with WDGS (WPM ­ WDGS). Rumen fermentation parameters and in situ degradability of the diets were evaluated using three cannulated Merino wethers in a cross over 3 × 3 Latin square design experiment that lasted 39 days. Concurrently, feed intake and growth performance of South Africa Mutton Merino lambs (29.7 ± 3.6 kg) were evaluated over 45 days. The WPMS + DDGS diet had a lower rate of dry matter degradation (p < 0.05) compared to the WPMS + SOM and WPM­WDGS diets. However, the rapidly fermentable fraction, as well as the progressively fermentable fraction of the diet dry matter, was not different (p > 0.05). No differences in rumen volatile fatty acid, ammonia nitrogen concentration nor rumen pH of the wethers as a result of diet differences were observed. Lambs consuming the WDGS­based diet had a lower average daily intake and average daily gain (p < 0.05) compared to lambs consuming the DDGS and WPMS­based diets. However, the feed conversion ratio was not affected by diet differences (p > 0.05). In conclusion, co­ensiling WDGS with whole­plant maize provides the opportunity for the long­term storage and utilization of WDGS in lamb feeding.

Nutritional quality of wet distillers grains coensiled with wholeplant maize and its feeding value for lambs

ABSTRACT: The high moisture content of wet distillers grains with solubles (WDGS) has limited its feeding value despite the relatively high nutritive value. The coensiling with wholeplant maize, as a complementary feed, was evaluated for growing lambs by formulating diets whose contents were: whole plant maize silage (WPMS) + sunflower oilcake meal (SOM) (control, WPMS + SOM), whole plant maize silage + dried distillers grains (WPMS + DDGS), and wholeplant maize (WPM) coensiled with WDGS (WPM WDGS). Rumen fermentation parameters and in situ degradability of the diets were evaluated using three cannulated Merino wethers in a cross over 3 × 3 Latin square design experiment that lasted 39 days. Concurrently, feed intake and growth performance of South Africa Mutton Merino lambs (29.7 ± 3.6 kg) were evaluated over 45 days. The WPMS + DDGS diet had a lower rate of dry matter degradation (p 0.05) compared to the WPMS + SOM and WPMWDGS diets. However, the rapidly fermentable fraction, as well as the progressively fermentable fraction of the diet dry matter, was not different (p > 0.05). No differences in rumen volatile fatty acid, ammonia nitrogen concentration nor rumen pH of the wethers as a result of diet differences were observed. Lambs consuming the WDGSbased diet had a lower average daily intake and average daily gain (p 0.05) compared to lambs consuming the DDGS and WPMSbased diets. However, the feed conversion ratio was not affected by diet differences (p > 0.05). In conclusion, coensiling WDGS with wholeplant maize provides the opportunity for the longterm storage and utilization of WDGS in lamb feeding.

Substitution of rumen degradable nitrogen with urea in sheep fed low quality Eragrostis curvula hay

The aim of the present study was to determine whether sunflower meal (SFM), a highly rumen degradable protein (RDP) source, can be substituted with non-protein nitrogen (NPN, urea) without impacting negatively on intake, digestibility, rumen fermentation and microbial nitrogen (N) synthesis (MNS) in wethers consuming low quality Eragrostis curvula hay. Five wethers were fed ad libitum, low quality hay and supplemented twice-daily in equal proportions, via the rumen cannulae, one of five iso-nitrogenous and iso-energetic supplements in a 5 × 5 Latin square design experiment. The supplements differed in the ratios of rumen degradable N (RDN) supplied by either SFM and/or urea and is presented as percentage of RDN supplied by urea: T0 (100 % SFM, 0 % urea); T15 (85 % SFM, 15 % urea); T30 (70 % SFM, 30 % urea); T45 (55 % SFM, 45 % urea) and T60 (40 % SFM, 60 % urea). Forage intake and total tract dry matter (DM) digestibility did not differ; however, higher forage neutral detergent fiber (NDF) digestibilities were observed in the sheep supplemented with the higher urea-treatments (T45 and T60) compared to T15. Neither rumen pH nor total rumen volatile fatty acid (VFA) concentraions differed. The mean rumen ammonia nitrogen (RAN) concentration of the sheep supplemented with T60 was higher than T30 (9.35 mg dL1 vs. 7.41 mg dL1); however, no differences were observed in MNS or efficiency of MNS among treatments. Results suggest that up to 60 % of RDN supplied by SFM can be substituted with urea, without affecting intake, digestibility or MNS in wethers fed a low quality tropical hay.

Substitution of rumen degradable nitrogen with urea in sheep fed low quality Eragrostis curvula hay

The aim of the present study was to determine whether sunflower meal (SFM), a highly rumen degradable protein (RDP) source, can be substituted with non-protein nitrogen (NPN, urea) without impacting negatively on intake, digestibility, rumen fermentation and microbial nitrogen (N) synthesis (MNS) in wethers consuming low quality Eragrostis curvula hay. Five wethers were fed ad libitum, low quality hay and supplemented twice-daily in equal proportions, via the rumen cannulae, one of five iso-nitrogenous and iso-energetic supplements in a 5 × 5 Latin square design experiment. The supplements differed in the ratios of rumen degradable N (RDN) supplied by either SFM and/or urea and is presented as percentage of RDN supplied by urea: T0 (100 % SFM, 0 % urea); T15 (85 % SFM, 15 % urea); T30 (70 % SFM, 30 % urea); T45 (55 % SFM, 45 % urea) and T60 (40 % SFM, 60 % urea). Forage intake and total tract dry matter (DM) digestibility did not differ; however, higher forage neutral detergent fiber (NDF) digestibilities were observed in the sheep supplemented with the higher urea-treatments (T45 and T60) compared to T15. Neither rumen pH nor total rumen volatile fatty acid (VFA) concentraions differed. The mean rumen ammonia nitrogen (RAN) concentration of the sheep supplemented with T60 was higher than T30 (9.35 mg dL1 vs. 7.41 mg dL1); however, no differences were observed in MNS or efficiency of MNS among treatments. Results suggest that up to 60 % of RDN supplied by SFM can be substituted with urea, without affecting intake, digestibility or MNS in wethers fed a low quality tropical hay.(AU)

In-vitro screening of Kalahari browse species for rumen methane mitigation

The nutritional value of browse foliage from the Thorny Kalahari Dune Bush veld of South Africa is not characterized. Most of this browse species is rich in tannin, but still palatable, and is consumed by ruminants during the dry season, as well as having a role to play in mitigating enteric methane emission from ruminants. In this study, the rumen methane mitigation potential of 19 browse species foliage collected from the Thorny Kalahari Dune Bush veld, was analyzed in terms of chemical composition, in vitro fermentation, digestibility and methane production. In vitro gas and methane production and organic matter digestibility (IVOMD) were determined by using rumen fluid collected, strained and anaerobically prepared. A semi-automated system was used to measure gas production (GP) from each browse species by incubating 400 mg samples in a shaking incubator at 39 °C with or without inclusion of 400 mg of polyethylene glycol (PEG). Data for all the parameters collected were statistically analyzed using the SAS (9.0) general linear model (GLM) procedure, and differences between foliage species were determined using Duncans multiple-range test. Acacia luederitziiand Monechma incanumshowed the best potential for decreasing methane production by up to 90 % after 48 h of incubation. The secondary components (mainly tannins) of the browse species appeared to have a significant effect on volatile fatty acids (VFA), methane and gas production as judged by the comparison of samples incubated with or without PEG inclusion. The substantial amount of crude protein (CP) content coupled with their anti-methanogenic effect during fermentation would make these browses a potential mitigation option for small scale farmers and pastoralists in sub-Sahara Africa. However, it is also very important that systematic and strategic supplementation in a mixed diet should be looked at as the way forward in terms of best utilization.

In-vitro screening of Kalahari browse species for rumen methane mitigation

The nutritional value of browse foliage from the Thorny Kalahari Dune Bush veld of South Africa is not characterized. Most of this browse species is rich in tannin, but still palatable, and is consumed by ruminants during the dry season, as well as having a role to play in mitigating enteric methane emission from ruminants. In this study, the rumen methane mitigation potential of 19 browse species foliage collected from the Thorny Kalahari Dune Bush veld, was analyzed in terms of chemical composition, in vitro fermentation, digestibility and methane production. In vitro gas and methane production and organic matter digestibility (IVOMD) were determined by using rumen fluid collected, strained and anaerobically prepared. A semi-automated system was used to measure gas production (GP) from each browse species by incubating 400 mg samples in a shaking incubator at 39 °C with or without inclusion of 400 mg of polyethylene glycol (PEG). Data for all the parameters collected were statistically analyzed using the SAS (9.0) general linear model (GLM) procedure, and differences between foliage species were determined using Duncans multiple-range test. Acacia luederitziiand Monechma incanumshowed the best potential for decreasing methane production by up to 90 % after 48 h of incubation. The secondary components (mainly tannins) of the browse species appeared to have a significant effect on volatile fatty acids (VFA), methane and gas production as judged by the comparison of samples incubated with or without PEG inclusion. The substantial amount of crude protein (CP) content coupled with their anti-methanogenic effect during fermentation would make these browses a potential mitigation option for small scale farmers and pastoralists in sub-Sahara Africa. However, it is also very important that systematic and strategic supplementation in a mixed diet should be looked at as the way forward in terms of best utilization.(AU)