Methane Production Potential of Fruit and Vegetable WastesIn Vitro

Urbanisation threats to dairy cattle health: Insights from Greater Bengaluru, India

Complex urbanisation dynamics, on the one hand, create a high demand for animal products, and on the other hand put enormous pressure on arable land with negative consequences for animal feed production. To explore the impact of accelerated urbanisation on dairy cattle health in urban farming systems, 151 farmers from different parts of the Greater Bengaluru metropolitan area in India were individually interviewed on aspects addressing cattle management and cattle health. In addition, 97 samples of forages from the shores of 10 different lakes, and vegetable leftovers used in cattle feeding were collected for nutritional analysis. Along with the use of cultivated forages, crop residues, and concentrate feed, 47% and 77% of the farmers occasionally or frequently used lake fodder and food leftovers, respectively. Nutritionally, lake fodder corresponded to high-quality pasture vegetation, but 43% of the samples contained toxic heavy metals such as arsenic, cadmium, chromium, and lead above official critical threshold levels. Therefore, lake fodder may affect cows' health if consumed regularly; however, heavy metal concentrations varied between lakes (P < 0.05), but not between fodder types (P > 0.05). Although 60% of the interviewed farmers believed that their cows were in good health, logit model applications revealed that insufficient drinking water supply and the use of lake fodder negatively impacted cattle health (P < 0.05). While it remains unknown if regular feeding of lake fodder results in heavy metal accumulation in animal products, farmers and farm advisors must address this and other urbanization-related challenges to protect cattle health.

Potential of Recycling Cauliflower and Romanesco Wastes in Ruminant Feeding: In Vitro Studies

Simple Summary

The use of vegetable wastes in animal feeding is increasing worldwide, but the knowledge of the nutritional value of some of them is still limited. In this study, the nutritive value for ruminants of different fractions of cauliflower and Romanesco wastes (leaves, stems and sprouts) was assessed using in vitro techniques. In addition, we analyzed the effect of increasing the substitution rate of cauliflower for commercial concentrate in a dairy sheep diet containing 40% of alfalfa hay and 60% of concentrate. All fractions of both vegetables had high amounts of water, but their dry matter was rich in protein and sugar and it was extensively fermented in vitro by ruminal microorganisms. Stems and sprouts were more rapidly fermented than leaves, but there were only minor differences between the two assessed vegetables. In an in vitro study with diets for dairy sheep with concentrates containing increased amounts of dried cauliflower, we observed that cauliflower can be included up to 24% of the concentrate without any negative effect on rumen fermentation. The results indicate that cauliflower and Romanesco wastes could be used in ruminant feeding, but in vivo trials are needed to confirm the in vitro results.

Abstract

The nutritive values for ruminants of cauliflower (CAU) and Romanesco (ROM) wastes (leaves, stems and sprouts) were assessed by analyzing their chemical composition, in vitro ruminal fermentation, and in vitro intestinal digestibility. In addition, the in vitro ruminal fermentation of diets containing increasing amounts of CAU was studied. The dry matter (DM) content of leaves, stems and sprouts of both vegetables was lower than 10%, but they contained high crude protein (CP; 19.9 to 33.0%) and sugar (16.3 to 28.7%) levels, and low neutral detergent fiber (21.6 to 32.3%). Stems and sprouts were more rapidly and extensively fermented in the rumen than leaves, but there were only minor differences the fermentation profiles of both vegetables. The estimated metabolizable energy content ranged from 9.3 (leaves) to 10.8 (sprouts) MJ/kg DM. The CP rumen degradability (12-h in situ incubations) was greater than 80.0% for all fractions, and the in vitro intestinal digestibility of CP ranged from 85.7 to 93.2%. The inclusion of up to 24% of dried CAU in the concentrate of a mixed diet (40:60 alfalfa hay:concentrate) increased the in vitro rumen fermentation of the CAU diet, but did not affect methane (CH₄) production, indicating the lack of antimethanogenic compounds in CAU.

Effect of pretreatment with organic solvent on enzymatic digestibility of cauliflower wastes

The present study investigated the operational conditions for different pretreatment approaches and subsequent enzymatic hydrolysis of cauliflower wastes (stalk and leaf) for better release of fermentable sugars. The structural analysis of raw and pretreated lignocellulosic biomasses was investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transforms infrared (FTIR) analysis. Results demonstrated that the highest cellulose conversion rate and removal of most of the hemicellulose and lignin were obtained with organosolvent pretreatment. Using methanol in presence of sodium (Na) acetate was most effective in delignification of cauliflower wastes. In the present study, methanol (100% v/v) in presence of 0.1 M Na-acetate at 121 °C for 45 and 60 min for stalk and leaf, respectively, gave maximum reducing sugar yield. Response surface methodology was used to optimize different process parameters for enzymatic saccharification using microbial cellulase and xylanase. The optimum operation condition of enzymatic hydrolysis of organosolvent pretreated cauliflower wastes were substrate loading (2.5% w/v for both stalk and leaf), enzyme loading (15 and 10 U/g for stalk and leaf, respectively), pH (4.46 and 5.48 for stalk and leaf, respectively), at 60 °C and for 180 min.