Corncob biochar supplementation improves nutrient digestibility, fattening performance and carcass characteristics of fattening sheep

BACKGROUND

Corncob is a cheap source for biochar in developing countries. No studies reported on use of biochar as sheep fattening supplement.

OBJECTIVES

The goal of this study is to determine the effect of corncob biochar supplementation on growth performance and carcass characteristics of sheep.

METHODS

Twenty-four Horro yearling rams (18.6 ± 0.938 kg live weight) were randomly distributed to four groups, control (300 g/day concentrate + local hay ad libitum), BC1.5 (control +1.5 g/day biochar), BC3 (control +3 g/day biochar) and BC4.5 (control +4.5/day biochar). The experimental concentrate consisted of 200 g/day wheat bran and 100 g/day Noug cake. The study consisted of a growth trial of 111 days followed by a digestibility trial of 10 days. Carcass characteristics for all rams were recorded at the end of the trial.

RESULTS

Dry matter intake, crude protein intake, dry matter digestibility and acid detergent fibre digestibility of BC1.5 were significantly higher than the control. Corncob biochar supplementation significantly improved daily weight gain and feed conversion ratio of the rams. Supplementation sheep with corncob biochar improved significantly dressing percentage, hindquarters weight, forequarters weight, ribs weight, brisket weigh and rib eye muscle area. There was a significant effect of the dietary treatment on weight of internal organs; however, they were all within the normal range of sheep.

CONCLUSIONS

Corncob biochar supplementation would be recommended at a level of 1.5 g/day to improve growth performance and carcass characteristics of sheep.

Effects of brewers' spent grain protein hydrolysates on gas production, ruminal fermentation characteristics, microbial protein synthesis and microbial community in an artificial rumen fed a high grain diet

Background

Brewers’ spent grain (BSG) typically contains 20% – 29% crude protein (CP) with high concentrations of glutamine, proline and hydrophobic and non-polar amino acid, making it an ideal material for producing value-added products like bioactive peptides which have antioxidant properties. For this study, protein was extracted from BSG, hydrolyzed with 1% alcalase and flavourzyme, with the generated protein hydrolysates (AlcH and FlaH) showing antioxidant activities. This study evaluated the effects of AlcH and FlaH on gas production, ruminal fermentation characteristics, nutrient disappearance, microbial protein synthesis and microbial community using an artificial rumen system (RUSITEC) fed a high-grain diet.

Results

As compared to the control of grain only, supplementation of FlaH decreased (P < 0.01) disappearances of dry matter (DM), organic matter (OM), CP and starch, without affecting fibre disappearances; while AlcH had no effect on nutrient disappearance. Neither AlcH nor FlaH affected gas production or VFA profiles, however they increased (P < 0.01) NH₃-N and decreased (P < 0.01) H₂ production. Supplementation of FlaH decreased (P < 0.01) the percentage of CH₄ in total gas and dissolved-CH₄ (dCH₄) in dissolved gas. Addition of monensin reduced (P < 0.01) disappearance of nutrients, improved fermentation efficiency and reduced CH₄ and H₂ emissions. Total microbial nitrogen production was decreased (P < 0.05) but the proportion of feed particle associated (FPA) bacteria was increased with FlaH and monensin supplementation. Numbers of OTUs and Shannon diversity indices of FPA microbial community were unaffected by AlcH and FlaH; whereas both indices were reduced (P < 0.05) by monensin. Taxonomic analysis revealed no effect of AlcH and FlaH on the relative abundance (RA) of bacteria at phylum level, whereas monensin reduced (P < 0.05) the RA of Firmicutes and Bacteroidetes and enhanced Proteobacteria. Supplementation of FlaH enhanced (P < 0.05) the RA of genus Prevotella, reduced Selenomonas, Shuttleworthia, Bifidobacterium and Dialister as compared to control; monensin reduced (P < 0.05) RA of genus Prevotella but enhaced Succinivibrio.

Conclusions

The supplementation of FlaH in high-grain diets may potentially protect CP and starch from ruminal degradation, without adversely affecting fibre degradation and VFA profiles. It also showed promising effects on reducing CH₄ production by suppressing H₂ production. Protein enzymatic hydrolysates from BSG using flavourzyme showed potential application to high value-added bio-products.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-020-00531-5.

The use of biochar in animal feeding

Biochar, that is, carbonized biomass similar to charcoal, has been used in acute medical treatment of animals for many centuries. Since 2010, livestock farmers increasingly use biochar as a regular feed supplement to improve animal health, increase nutrient intake efficiency and thus productivity. As biochar gets enriched with nitrogen-rich organic compounds during the digestion process, the excreted biochar-manure becomes a more valuable organic fertilizer causing lower nutrient losses and greenhouse gas emissions during storage and soil application. Scientists only recently started to investigate the mechanisms of biochar in the different stages of animal digestion and thus most published results on biochar feeding are based so far on empirical studies. This review summarizes the state of knowledge up to the year 2019 by evaluating 112 relevant scientific publications on the topic to derive initial insights, discuss potential mechanisms behind observations and identify important knowledge gaps and future research needs. The literature analysis shows that in most studies and for all investigated farm animal species, positive effects on different parameters such as toxin adsorption, digestion, blood values, feed efficiency, meat quality and/or greenhouse gas emissions could be found when biochar was added to feed. A considerable number of studies provided statistically non-significant results, though tendencies were mostly positive. Rare negative effects were identified in regard to the immobilization of liposoluble feed ingredients (e.g., vitamin E or Carotenoids) which may limit long-term biochar feeding. We found that most of the studies did not systematically investigate biochar properties (which may vastly differ) and dosage, which is a major drawback for generalizing results. Our review demonstrates that the use of biochar as a feed additive has the potential to improve animal health, feed efficiency and livestock housing climate, to reduce nutrient losses and greenhouse gas emissions, and to increase the soil organic matter content and thus soil fertility when eventually applied to soil. In combination with other good practices, co-feeding of biochar may thus have the potential to improve the sustainability of animal husbandry. However, more systematic multi-disciplinary research is definitely needed to arrive at generalizable recommendations.