Goutam Mondal

Life Cycle Assessment of Greenhouse Gases for Milk Production: A Review

In India, dairy sector has important impacts on the economy and ecosystem services and contributes to essential societal needs for food. Economic survey (2015–16) noted that India ranks first in milk production with an annual output of 146.3 million tonnes with a growth of 6.26% during 2014–15 accounting for 18.5% of world milk production. Whereas, FAO (2014) reported a 3.1% increase in world milk production from 765 million tonnes in the year 2013 to 789 million tonnes in the year 2014. The per capita availability of milk in India has increased from 176 g/d in the year 1990–91 to 322 g/d by 2014–15 which was more than the world average of 294 g/d during the year 2013. This represents a sustained growth in availability of milk and milk products for the growing population. As the public concern about climate change and environmental sustainability continues to grow and societal pressures on the dairy industry to reduce its environmental impact are rising, therefore, the concept of life cycle assessment (LCA) of GHG emissions for milk production helps in quantifying the environmental impact of dairy sector and furnishing a method of identifying mitigation options suited to reduce those environmental burdens. The process of LCA is generally composed of 4 components including goal and scope, life cycle inventory (LCI) analysis, life cycle impact assessment and interpretation. Creating an LCI of emissions to the environment (e.g. GHG emissions) for an animal agricultural system such as dairy sector, is challenging. The diversity of management systems across operations and segments of the dairy sector contribute to the challenges of creating LCI analyses. The purpose of this article was to assess the current LCA methodologies being used in analysis of the dairy sector and to compare the complexity and variations among LCA studies. It is also emphasised that more of such studies are required under different livestock rearing systems for different species under different agro-climatic zones of India.

Dietary supplementation of monensin for methane mitigation in non pregnant dry murrah buffaloes

The present study was conducted to evaluate the effect of dietary monensin supplementation on nutrient digestibility and enteric methane (CH4) emission in non pregnant dry Murrah buffaloes. Fourteen Murrah buffaloes were randomly divided into two groups of seven animals each based on body weight (597.62 kg). Both groups were fed as per ICAR (2013) without and with monensin supplementation (350 mg/head/d) in control and treatment groups, respectively for sixty days. The daily nutrient intake (kg/d) and apparent digestibility (%) of nutrients were similar in both the groups. However, enteric CH4 emissions (g/d) was reduced by 10.09% in monensin supplemented group as compared to control and lowered (P<0.05) by 6.34% for g/kg DM intake (19.78 vs. 21.12) in monensin supplemented group as compared to control. Energy loss in the form of methane as % of gross energy, digestible energy and metabolizable energy was reduced (P<0.05) in monensin supplemented group by 6.36, 9.24 and 9.79%, respectively. In conclusion, dietary monensin supplementation to non pregnant dry Murrah buffaloes could reduce enteric methane emissions without affecting nutrient intake and digestibility which will reduce the contribution of buffaloes to the global methane inventory and its negative impact on environment.

CNCP Fractions and in Vitro Rumen Fermentation of Straw Based Total Mixed Rations Supplemented with Leucaena leucocephala Leaves

An in vitro study was conducted to evaluate the effect of the different ratios of Leucaena (Leucaena leucocephala) leaves (L), wheat straw (W) and concentrate mixture (C) on total gas production, methanogenic potential and other rumen fermentation parameters using in vitro gas production technique. Four total mixed ration (TMR) were prepared using dried ground samples of W, C and L: WC (90W: 10C), WCL10 (80W: 10C: 10L), WCL25 (65W: 10C: 25L) and WCL50 (40W: 10C: 50L). For estimation of fermentation parameters, TMR samples (200 mg) were incubated with 30 mL buffered rumen liquor at 39±0.5oC for 24 h. As the level of Leucaena leaves increased in the substrate, total gas production increased (P<0.05) while CH4 production (mL/100 mg DDM) decreased (P<0.05) by 15, 24 and 36% in WCL10, WCL25 and WCL50, respectively. In vitro DM and OM digestibility was also higher (P<0.05) as the levels of Leucaena increased in the ration. Thus, this study indicated that with the inclusion of Leucaena to straw based ration, there was improved utilization of nutrients and reduced methane production.

Growth performance, and enteric and manure greenhouse gas emissions from Murrah calves fed diets with different forage to concentrate ratios

The present study investigated the effects of different dietary forage to concentrate ratios on animal performance, and enteric and manure greenhouse gas emissions in growing calves. Fifteen male Murrah calves (153.5 ± 18.17 kg; 6 to 12 months) were randomly assigned to 3 dietary treatments and fed corn fodder, wheat straw and concentrate in 3 different proportions: 20:60:20 (C20); 20:40:40 (C40) and 10:30:60 (C60), for a period of 120 days. Increasing dietary concentrate proportion had no significant (P > 0.05) effect on dry matter intake (DMI) but increased crude protein (CP) and total digestible nutrient intake (P < 0.05). Average daily gain and feed conversion efficiency were significantly higher (P < 0.05) for C60 compared with C20 and for C40, these did not differ with C20 and C60 (P > 0.05). The apparent digestibility of dry matter, organic matter and CP were higher (P < 0.05), but acid detergent fiber digestibility was lower (P < 0.05) for C60 compared with C20 whereas, ether extract and neutral detergent fiber digestibilities were not affected (P > 0.05). Daily methane (CH4) emission (g/d), CH4 energy loss (MJ/d) and CH4 yield (CH4 g/kg organic matter intake [OMI], CH4 g/kg digestible OMI, and CH4 % of metabolizable energy intake) were significantly higher for C20 compared with C60 (P < 0.05). Methane yield as g/kg DMI although lower for C60 compared with C20 but the difference was not significant (P > 0.05). Manure CH4 (g/kg DMI) and nitrous oxide (N2O mg/kg nitrogen) emissions were not affected (P > 0.05), but N2O emission on mg/kg DM basis was significantly higher (P < 0.05) from the manure of calves fed C60 than that for C20. Thus, increasing dietary concentrate proportion improved animal performance, and reduced enteric CH4 emission (g/day) without any significant effect on manure N2O (mg/kg nitrogen) and CH4 emissions.

Significance of Probiotics as Feed Additives in Livestock and Poultry Nutrition

A number of feed additives such as antibiotics, probiotics, oligosaccharides, enzymes and organic acids have been used in livestock feeds for improving productivity and maintaining gut eubiosis. Antibiotics have been widely used in livestock diets, however, development of antimicrobial resistance to these antibiotics urged scientists to find viable alternatives to the use of antibiotics that could enhance the productivity as well as natural defense mechanisms of animals. Probiotics are technically viable alternatives to antibiotics in livestock feed. Probiotics are the live culture of host-friendly microbes which upon ingestion exert health effects to the host. Probiotics have been established as a good alternative which can enhance intestinal health by stimulating the development of a healthy microbiota (predominated by beneficial bacteria), competing with pathogenic bacteria for nutrients in the gut, preventing enteric pathogens from colonizing the intestine, increasing digestive capacity and lowering the pH and altering mucosal immunity. Moreover, nutritional intervention through probiotics supplementation seems be a natural and holistic strategy to combat such challenges. The beneficial response to probiotics supplementation seems to be affected by both source and dose of probiotics supplemented in particular species. The present review is an attempt to explore the use of different probiotics in livestock feed and thetr probable mode of actions through which they exhibit their beneficial effects in animals.

Quantification of methane emissions from Murrah buffaloes fed different energy diets during various temperature humidity index periods in a tropical environment

The objective of the present study was to quantify the enteric methane emission in Murrah buffalo heifers at high (summer) and low (winter) temperature humidity index (THI) period fed different energy level diets. Thirty-six growing Murrah buffalo heifers of average bodyweight (158.51 ± 16.5 kg) were distributed into three groups of six animals each separated based on their bodyweight and fed for the period of 120 days each during summer (high THI, 78–85) and winter (low THI, 50–61). The animals were fed on three different levels of metabolisable energy (ME) content and the Control ration (T1) having ME content according to ICAR (2013) and T2 and T3 were having 115% and 85% ME than the Control respectively, in total mixed-based ration. The SF6 tracer gas technique was used to quantify the enteric methane emission by the animals. Methane emission (g/day) of Control and the high energy (T1 and T2) group was lower (P < 0.05) than the low energy (T3) fed group in both seasons. Methane losses as percentage of gross energy intake was lower (P < 0.01) during the winter season. However, in the low energy treatment group (T3) at both seasons these values are higher than the IPCC recommended value (6.5%) for calculation of national inventory of greenhouse gas emission from enteric sources. In between season average daily gain (kg) was higher (P < 0.01) in the winter season and among the treatment groups it was higher (P < 0.01) in the high energy group (T1, T2). Higher (P < 0.01) digestibility of dry matter, organic matter, neutral detergent fibre and acid detergent fibre was reported in the Control and high energy-fed group. Whereas in the summer season digestibility of dry matter, organic matter, crude protein and acid detergent fibre was higher (P < 0.01) than in the winter season. It can be concluded that energy levels significantly (P < 0.05) affect methane emissions and was lower in the Control and high energy-fed group (T1 and T2). However, while quantifying methane emission in changing THI period at different seasons it did not show any significant variation.

Effect of Tree Leaves and Malic Acid Supplementation to Wheat Straw Based Substrates on in Vitro Rumen Fermentation Parameters

This experiment was conducted to study the effects of addition of malic acid (MA) and tree leaves in straw based total mixed ration on in vitro rumen fermentation parameters. Four experimental substrates were prepared: Control (C-wheat straw and concentrate in 1: 1 ratio), T1 (45% wheat straw + 45% concentrate + 10% Leucaena leucocephala leaves), T2 (T1 diet + 1% MA), T3 (T1 diet + 2% MA). Inclusion of tree leaves increased (P<0.05) in vitro true dry (IVTMD) and organic matter (IVOMD) digestibility, however, no effect was observed on other fermentation parameters. Addition of MA in conjunction with tree leaves increased (P<0.05) total gas production, IVTDMD, IVTOMD and individual VFA concentrations. There was significant (P<0.05) reduction in CH4 production in MA supplemented groups. Therefore, addition of tree leaves improved the nutrient availability from straw based rations and malic acid further improved digestibility and reduced methane production.