Nutritive value of maize and sorghum silages: fibre fraction degradation and rumen microbial density in buffalo cows

Abstract

Sorghum could be a potential substitute to maize in Mediterranean buffaloes feed in order to improve sustainability of buffalo-based agriculture, due to its reduced water and nitrogen requirements compared with maize, which is currently fed primarily. The aim of this study is to obtain information on rumen degradability of fibre fraction of maize and sorghum silages and to investigate the relationship between degradability and rumen microbial populations. As such four cannulated buffalo milking cows were fed ad libitum two different iso-energetic and iso-proteic diets based on maize silage (MS) and sorghum silage (SS). Based on plate counts, values of cellulolytic bacteria showed to be higher within the rumen of SS fed buffaloes compared to MS fed buffaloes (4.4 × 10 9 vs 1.9 × 10 9 cfu/ml, P <0.05), on the contrary, those of xylanolytic bacteria (3.2 × 10 9 vs 1.3 × 10 9 cfu/ml, P < 0.01) were higher in MS possibly due to the different fibre degradability. Real-time PCR of total bacteria, Fibrobacter succinogenes, Ruminococcus albus, and Ruminococcus flavefaciens revealed no statistical difference in their 16S rDNA concentrations between diets. MS and SS were subsequently utilized for a degradability experiment. For this trial three cannulated Mediterranean dry buffalo cows were used (body weight 580 ± 8.5 kg). The MS was found to have an effective degradability of acid detergent fibre, hemicelluloses, and cellulose which were always lower than SS. Maize neutral detergent fibre degradability and slowly degradable fraction were significantly (P < 0.01) higher, on the contrary the immediately degradable fraction was found to be significantly (P < 0.001) lower compared with sorghum. The better sorghum relative feed value (P < 0.001) was related to the major content of fibre fraction compared to maize. As recommended by the IPCC Guidelines, Tier 2 was chosen to estimate the enteric CH 4 emission factor. The estimate of methane production is significantly lower in animals eating sorghum rather than maize (63.48 and 103.00 kg CH 4 /head/ year respectively, P < 0.001). In conclusion, as no difference was observed in animal weight gain and milk yield, rumen microbiota or degradability, it could be possible to substitute MS with SS in buffalo diet.

Forage Potential of Pearl Millet and Forage Sorghum Alternatives to Corn under the Water-Limiting Conditions of the Texas High Plains: A Review

“…Similarly, in vitro dry matter digestibility for BMR sorghum was 6 and 18% greater than for non‐BMR sorghum and PS sorghum, respectively. Similarly, Sarubbi et al (2014) also showed slightly lower digestible energy values in non‐BMR sorghum and similar energy values in BMR sorghum compared with corn. This study also reported greater NDF (60 vs. 57%) and ADF (54 vs. 46%) in corn silage than in sorghum silage.…”

“…Harinarayana et al (2005) reported grain fractions of 25 to 30% and 6 to 18% in grain sorghum and forage sorghum on a dry matter basis, respectively. In addition, the relatively small and hard sorghum and pearl millet kernels escape rumen digestion, and are largely excreted in the manure (Sarubbi et al, 2014). Further, corn does not have any potential toxic constituents except for nitrate.…”

Nutritive value for ruminants of different fresh and ensiled sorghum (Sorghum bicolor (L.) Moench) varieties harvested at varying maturity stages

“…Earlier studies also found higher NDF content and lower NFC content in WCSS than in ensiled forage maize, while CP content was not different (Grant et al 1995;Colombini et al 2010;Sarubbi et al 2014). Furthermore, DM and OM digestibility, ruminal NDF degradability and energy content were also lower in WCSS than in ensiled forage maize (Colombini et al 2010;Sarubbi et al 2014).…”

“…Earlier studies also found higher NDF content and lower NFC content in WCSS than in ensiled forage maize, while CP content was not different (Grant et al 1995;Colombini et al 2010;Sarubbi et al 2014). Furthermore, DM and OM digestibility, ruminal NDF degradability and energy content were also lower in WCSS than in ensiled forage maize (Colombini et al 2010;Sarubbi et al 2014). In the experiments by Grant et al (1995) and Oliver et al (2004), WCSS from conventional sorghum varieties had lower and WCSS from bmr varieties had similar DM and NDF digestibility like ensiled forage maize.…”

Increasing the Sustainability of Maize Grain Production by Using Arbuscular Mycorrhizal Fungi Does Not Affect the Rumen of Dairy Cattle (Bos taurus) and Buffalo (Bubalus bubalis)

“…An increase in Methanobrevibacter in buffalo compared to cattle is consistent with the higher VFA production in these animals, which will also result in more hydrogen being available for methane production. Predictive equations have been used to estimate the enteric methane production in buffalo, however, this needs to be directly assessed in vivo (55,56).…”