Effects of feeding nutritionally balanced rations on animal productivity, feed conversion efficiency, feed nitrogen use efficiency, rumen microbial protein supply, parasitic load, immunity and enteric methane emissions of milking animals under field conditions

Energy and Protein Requirements of Growing Lambs in Colombian Highlands

Determining the nutritional requirements of lambs is necessary to formulate balanced rations and contribute to sustainable sheep production systems. However, limited information is available regarding the nutritional requirements of growing lambs in the Colombian highlands. Twenty-two Romney Marsh males were used. Initially, four lambs were slaughtered at 20 kg body weight (BW). The remaining 18 lambs were distributed into two groups, according to BW (light: 20 BW and heavy: 30 kg BW). Lambs were randomly allocated into one of three different nutritional schemes, according to voluntary intake (no restriction, and 25 and 50% restriction). All the animals received a totally mixed ration. When a voluntary-fed lamb gained 10 kg BW, the two other lambs restricted to 25 and 50% were slaughtered and dissected into components to determine protein and gross energy concentration. Energy and protein accumulation were analyzed through regression analysis. The net energy for maintenance was 82.3 kcal/kg BW0.75, while the energy efficiencies for maintenance and gain were 0.72 and 0.29, respectively. Crude protein for maintenance was 1.78 g/kg BW0.75, and the nitrogen efficiencies for maintenance and gain were 0.41 and 0.27, respectively. The maintenance requirement of energy was greater, while protein was similarly related to values reported in the literature; however, the efficiency of energy and protein use was lower in growing lambs. These results suggested that estimating energy and nitrogen requirements for growing lambs must be adjusted in Colombian highland conditions.

Invited review: Advances in nutrition and feed additives to mitigate enteric methane emissions

Methane, both enteric and from manure management, is the most important greenhouse gas from ruminant livestock, and its mitigation can deliver substantial decreases in the carbon footprint of animal products and potentially contribute to climate change mitigation. Although choices may be limited, certain feeding-related practices can substantially decrease livestock enteric CH4 emission. These practices can be generally classified into 2 categories: diet manipulation and feed additives. Within the first category, selection of forages and increasing forage digestibility are likely to decrease enteric CH4 emission, but the size of the effect, relative to current forage practices in the United States dairy industry, is likely to be minimal to moderate. An opportunity also exists to decrease enteric CH4 emissions by increasing dietary starch concentration, but interventions have to be weighed against potential decreases in milk fat yield and farm profitability. A similar conclusion can be made about dietary lipids and oilseeds, which are proven to decrease CH4 emission but can also have a negative effect on rumen fermentation, feed intake, and milk production and composition. Sufficient and robust scientific evidence indicates that some feed additives, specifically the CH4 inhibitor 3-nitrooxypropanol, can substantially reduce CH4 emissions from dairy and beef cattle. However, the long-term effects and external factors affecting the efficacy of the inhibitor need to be further studied. The practicality of mass-application of other mitigation practices with proven short-term efficacy (i.e., macroalgae) is currently unknown. One area that needs more research is how nutritional mitigation practices (both diet manipulation and feed additives) interact with each other and whether there is synergism among feed additives with different mode of action. Further, effects of diet on manure composition and greenhouse gas emissions during storage (e.g., emission trade-offs) have not been adequately studied. Overall, if currently available mitigation practices prove to deliver consistent results and novel, potent, and safe strategies are discovered and are practical, nutrition alone can deliver up to 60% reduction in enteric CH4 emissions from dairy farms in the United States.

Do human-wildlife interactions predict offspring hiding strategies in peri-urban fallow deer?

Human activities can induce significant behavioural changes in wildlife. Often explored through extractive interactions (e.g. hunting) that can favour certain behavioural traits, the implications of non-extractive ones, such as wildlife feeding, remain understudied. Research shows that people tend to favour bolder individuals within populations despite their dynamics and consequences being unclear. Using fallow deer in a peri-urban environment, we studied whether mothers that show reduced fear of humans and consistently approach them for food adopt weaker anti-predator strategies by selecting less concealed fawning bedsites closer to human hotspots. This would provide the advantage of additional feeding opportunities in comparison with shyer mothers while keeping their fawns close. Our dataset encompassed 281 capture events of 172 fawns from 110 mothers across 4 years. Surprisingly, mothers that regularly accepted food from humans selected more concealed bedsites farther from human hotspots, giving their offspring better protection while also benefitting from additional food during lactation. Our results show behavioural adaptations by a subset of females and, for the first time, link the tendency to approach humans and strategies to protect offspring. Given previous findings that these begging females also deliver heavier fawns at birth, our research further investigates human-wildlife feeding interactions and their behavioural implications.

Life cycle assessment of greenhouse gas emission from the dairy production system - review

Climate change is altering ecological systems and poses a serious threat to human life. Climate change also seriously influences on livestock production by interfering with growth, reproduction, and production. Livestock, on the other hand, is blamed for being a significant contributor to climate change, emitting 8.1 gigatonnes of CO2-eq per year and accounting for two-thirds of global ammonia emissions. Methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) are three major greenhouse gases (GHG) that are primarily produced by enteric fermentation, feed production, diet management, and total product output. Ruminants account for three-quarters of total CO2-equivalent (CO2-eq) emissions from the livestock sector. The global dairy sector alone emits 4.0% of global anthropogenic GHG emissions. Hence, dairy farming needs to engage in environmental impact assessment. Public concern for a sustainable and environmentally friendly farming system is growing, resulting in the significant importance of food-based life cycle assessment (LCA). Over the last decade, LCA has been used in agriculture to assess total GHG emissions associated with products such as milk and manure. It includes the production of farm inputs, farm emissions, milk processing, transportation, consumer use, and waste. LCA studies on milk production would assist us in identifying the specific production processes/areas that contribute to excessive greenhouse gas emissions when producing milk and recommending appropriate mitigation strategies to be implemented for a clean, green, and resilient environment.

Scientific characterization methods for better utilization of cattle dung and urine: a concise review

Cattle are usually raised for food, manure, leather, therapeutic, and draught purposes. Biowastes from cattle, such as dung and urine, harbor a diverse group of crucial compounds, metabolites/chemicals, and microorganisms that may benefit humans for agriculture, nutrition, therapeutics, industrial, and other utility products. Several bioactive compounds have been identified in cattle dung and urine, which possess unique properties and may vary based on agro-climatic zones and feeding practices. Therefore, cattle dung and urine have great significance, and a balanced nutritional diet may be a key to improved quality of these products/by-products. This review primarily focuses on the scientific aspects of biochemical and microbial characterization of cattle biowastes. Various methods including genomics for analyzing cattle dung and gas chromatography-mass spectroscopy for cattle urine have been reviewed. The presented information might open doors for the further characterization of cattle resources for heterogeneous applications in the production of utility items and addressing research gaps. Methods for cattle's dung and urine characterization.

Diagnosing and treating esophageal obstruction in camels (Camelus dromedarius)

Background and Aim

Esophageal obstruction is a common occurrence and a serious condition in camels. This study aimed to assess the effects of mineral deficiency on esophageal obstruction rates in dromedary camels and describe their clinical presentation and treatment outcomes.

Materials and Methods

Twenty-eight camels were allocated to two groups. Group 1 (control) was composed of 10 sound camels. Group 2 included 18 camels with esophageal obstruction which were based on clinical and imaging evaluations. Hematobiochemical examinations in control and affected camels were compared and statistically analyzed.

Results

In camels with esophageal obstruction when compared with controls, hematological analyses showed significant increases (p < 0.05) in neutrophils, lymphocytes, and monocytes, along with significantly decreased total white blood counts. Aspartate transaminase, alanine transaminase, alkaline phosphatase, creatine phosphokinase, glucose, albumin, creatinine, and blood urea nitrogen concentrations were significantly higher in affected camels when compared with controls. Furthermore, gamma-glutamyl transferase, globulin, sodium, chloride, cobalt, iron, manganese, and selenium concentrations were significantly reduced. Affected camels were treated by stomach tube or surgery and were completely recovered, except for one camel with an esophageal fistula.

Conclusion

A lack of trace elements could have a significant role in esophageal obstruction in dromedaries. Clinical, ultrasonographic, and hematobiochemical evaluations are useful for the accurate diagnosis, prognosis, and treatment of esophageal obstruction in camels.

Does artificial feeding impact neonate growth rates in a large free-ranging mammal?

Variation and disparity in resource access between individuals in an animal population within human-dominated landscapes require attention as artificial selection processes may be at work. Independent, recreational human-wildlife feeding interactions constitute an increasingly prevalent, yet understudied, food resource for birds and mammals living in our cities. However, only a limited number of risk-taking individuals may access it. Using urban fallow deer as our model species, we hypothesized that if these interactions result in positive effects for the engaging individual, e.g. increased milk quality and yield, then this would result in the increased growth rates of their offspring. Alternatively, if these individuals were prioritizing investing time in engagement with humans, resulting in decreased maternal care, then this would result in slower growth rates in their offspring. We found that the offspring of those females that regularly interacted with humans displayed significantly faster growth rates than their risk-adverse counterparts. This advantage for fearless mothers in terms of boosted neonatal growth rates could be mirrored in birds accessing garden feeders, seagulls or pigeons utilizing urban resources, or seals approaching city harbours. Here, we add a new piece to the complex puzzle of how humans are impacting wildlife living within human-dominated landscapes.

Feeding Strategies to Mitigate Enteric Methane Emission from Ruminants in Grassland Systems

Ruminants produce approximately 30% of total anthropogenic methane emissions globally. The objective of this manuscript was to review nutritional enteric methane abatement practices for ruminants that are applicable under grazing conditions. A total of 1548 peer-reviewed research articles related to the abatement of enteric methane emissions were retrieved and classified into four categories: non-experimental, in vitro, in vivo confined, and in vivo grazing. The methane abatement strategies for grazing systems were arranged into grazing management and supplementation practices. Only 9% of the retrieved papers have been conducted under grazing conditions. Eight grazing management practices have been evaluated to reduce methane emissions. Decreasing the pre-grazing herbage mass reduced the methane emission per unit of product. Other grazing management practices such as increased stocking rate, decreased forage maturity, rotational stocking, and incorporating tannin-containing or non-tannin-containing feeds showed contradictory results. Nitrogen fertilization or silvopastoral systems did not modify methane emissions. Conversely, supplementation practices in grazing conditions showed contradictory responses on methane emissions. Lipid supplementation showed promising results and suggests applicability under grazing conditions. Identifying and implementing grazing strategies and supplementation practices under grazing conditions is required to increase efficiency and reduce the environmental impact of these systems.

Exploring dietary quality characteristics related to milk yield of crossbred cows in Ethiopian smallholder farms: a clustering and multivariate analysis approach

The study, conducted on 70 smallholder dairy farms in Northern Ethiopia, aimed to evaluate whether variation in milk yield (in early and mid-lactation) of multiparous Holstein-Friesian crossbred cows is related to diet composition and quality. At early stage (1-120 days in milk (DIM)), a total of 70 dairy farms were used, while at mid-lactation (121-240 DIM), 54 dairy farms continued to be part of the study. K-means clustering was applied to group the cows based on energy-corrected milk yield (ECMY) into three milk production farm clusters (MPFC): Low MPFC (5.7-9.3 L/day), medium MPFC (9.4-12.8 L/day), and high MPFC (12.9-17.6 L/day). The dry matter intake (DMI) of cows during early lactation for high MPFC and low MPFC was 14.1 and 11.2 kg/day, respectively. The dietary proportion of crop residues in diets offered to crossbred cows tended to be lower in the high MPFC during early as well as in mid-lactation. Cows from the high MPFC consumed diets with higher (rumen degradable) protein levels both in early and in mid-lactation, while dietary fiber fractions and in vitro dry matter digestibility (IVDMD) only differed in early lactation. Multiple regression models indicated that DMI (kg/day) in combination with either neutral detergent fiber, crude protein, or IVDMD (g/kg DM) explained about 25% of the variation in daily ECMY expressed relative to body weight (mL/kg). Hence, higher milk production is linked to both increased DMI and better quality of diets.

Metabolic and endocrine responses to short-term nutrient imbalances in the feed ration of mid-lactation dairy cows

Short-term imbalances of dietary nutrients occur during natural fluctuations in roughage quality (e.g. on pasture) or temporal shortages of supplementary feed components. In contrast to a deficiency, macronutrients (i.e. carbohydrates, proteins, lipids) beyond the adequate supply with other nutrients may, for instance, alter milk composition, increase BW or result in a greater excretion of nitrogen. Especially dairy cows with a moderate performance, in mid- or late lactation, or in extensive farming systems may be exposed to imbalanced rations. A better understanding of metabolic and endocrine responses depending on macronutrient supply may help to precisely feed dairy cows. The present study investigated short-term metabolic and endocrine responses to different levels of concentrates formulated to particularly provide one major macronutrient source (carbohydrates, proteins or lipids). Based on parity number, lactational stage, milk yield and BW, nine mid-lactating cows (211 ± 19 days in milk) were grouped into three blocks of three animals each. Concentrates (aminogenic: rich in CP and nitrogen sources; glucogenic: high content of carbohydrates and glucogenic precursors; lipogenic: high lipid content) were fed in addition to hay in a factorial arrangement at increasing levels from 2.5 to 7.5 kg/d during 9 d. Milk yield, BW and feed intake were recorded daily. Blood and milk were sampled every 3 d at the end of each concentrate level. Milk fat, protein, lactose and urea contents were determined. In blood, concentrations of various metabolites, endocrine factors and enzyme activities (e.g. glucose, non-esterified fatty acids (NEFAs), β-hydroxybutyrate, urea, cholesterol, triglycerides, insulin, glucagon, aspartate aminotransferase (ASAT), gamma-glutamyltransferase (GGT) and glutamate dehydrogenase activity (GLDH)) were measured. Milk yield, milk composition and BW were not affected by type and level of concentrates. Feed intake increased in cows with greater amounts of the aminogenic and lipogenic concentrate compared with the glucogenic concentrate. Milk and plasma urea concentrations were elevated in the aminogenic and to a lesser extent in the lipogenic treatment compared with the glucogenic treatment. Glucose concentrations in plasma were not affected by treatments, whereas insulin and glucagon increased, and NEFA concentrations decreased only in cows fed 7.5 kg/d aminogenic concentrate compared with the glucogenic and lipogenic treatment. Activities of ASAT, GGT and GLDH as well as the total antioxidant capacity were not affected by diets. In conclusion, immediate metabolic and endocrine responses were observed due to the short-term dietary changes. Particularly, a surplus of nitrogen supply via the aminogenic diet affected metabolic responses and stimulated insulin and glucagon secretion.

Effects of oat hay and leguminous forage mixture feeding on enteric methane emission, energy utilization, and feed conversion efficiency in male crossbred Simmental beef cattle

Dietary manipulation has the potential to mitigate methane (CH₄ ) emission and to maintain or enhance livestock productivity. We conducted two experiments to investigate the effects of replacing oat hay by leguminous forages (alfalfa hay [AH], 0, 8, 16, and 24%, experiment 1; common vetch hay [CVH], 0, 10, 20, and 30%, experiment 2) on energy metabolism of crossbred Simmental cattle. In experiment 1, total volatile fatty acid (VFA) concentrations increased quadratically with increasing AH proportions (p = .006) with a forage-to-concentrate ratio of approximately 50:50, whereas the CH₄ energy to gross energy intake ratio (CH₄ -E:GEI) was significantly lower with 16% AH compared with 24% AH diet (p < .05). In experiment 2, there were no differences in the total VFA concentrations among the four diet groups with a forage-to-concentrate ratio of around 60:40 (p > .05); however, CH₄ -E:GEI was significantly lower in the 30% CVH diet compared with the 10% CVH diet (p < .05). There was no significant difference in feed conversion efficiency among the four diet groups in each experiment. The results suggest that substituting 16 and 30% oat hay by AH and CVH provide optimal diets with forage-to-concentrate ratios of 50:50 and 60:40, respectively, which may reduce CH₄ emission without compromising the feed conversion efficiency of crossbred Simmental cattle.

Improving adoption of technologies and interventions for increasing supply of quality livestock feed in low- and middle-income countries

The global increase in the demand for and production of animal-source foods (four-to five-fold increase between 1960 and 2015), which has been mostly concentrated in low- and middle-income countries (LMIC), provides smallholder livestock producers with an opportunity for improving their livelihoods and food and nutrition security. However, across livestock production systems in many LMIC, limited supplies and high cost of good quality feed severely constrains exploitation of this opportunity. In many of such countries, feeds and feeding-related issues are often ranked as the primary constraint to livestock production and increased consumption of animal-source foods. Here we review the complex biophysical, socio-economic and technological challenges related to improving quality feed supply and the reasons for generally low adoption of apparently proven feed enhancement technologies. We describe also successful interventions and conclude by recommending strategies for improving quality feed supply in LMIC that account for and overcome the prevailing challenges.

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Livestock production in developing countries is constrained by limited supply of quality feeds.

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There are many technologies that can improve supply of quality feed for small holder producers.

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Complex set of bio-physical and socio-economic factors limit the adoption of technologies and thus limit the improvement in supply of quality feed.

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The failures of adoption of feed improvement technologies result from systemic constraints and inadequate attention to sociocultural and economic factors.

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Success is often driven either by market incentives and or an innovative affordable approach that provides solutions to multiple problems.

Factors affecting levels of volatile 4-alkyl branched-chain fatty acids in sheep milk from 2 contrasting farming systems in New Zealand

Knowledge of factors influencing the levels of 4-alkyl branched-chain fatty acid (vBCFA), and consequently the "sheepy flavor" intensity of New Zealand sheep milk, is currently limited. In this study, we investigated the effects of 2 contrasting farming systems (fully housed/mid-lactation or pasture-grazed/late lactation) on the levels of vBCFA in sheep milk on a commercial farm in the North Island of New Zealand. Fully housed/mid-lactation ewes were housed 24 h/d and fed a total mixed ration. Pasture-grazed/late-lactation ewes were grazed 24 h/d and offered approximately 40% supplements because of poor pasture growth resulting from dry and hot climatic conditions. Any effects of genetics, age, lactation stage, feed composition, lambing date, or the environment in the housing barn or outdoors were confounded. The results obtained in this study were descriptive rather than definitive, because of the limitations of the experimental design. Levels of 4-methyloctanoic acid and 4-methylnonanoic acid in milk from fully housed/mid-lactation ewes increased during the trial period, but remained low in milk from pasture-grazed/late-lactation ewes. Levels of 4-ethyloctanoic acid in milk from the 2 groups of ewes were comparable throughout the trial. Increases in levels of 4-methyloctanoic acid and 4-methylnonanoic acid in sheep milk were associated with lactation stage and the proportion of lucerne silage fed to ewes. The level of free-form 4-ethyloctanoic acid was positively correlated with the proportion of soy meal in the diet and negatively correlated with the proportion of barley. Milk from fully housed/mid-lactation ewes had a higher flavor values than milk from pasture-grazed/late-lactation ewes because of its higher total amounts of vBCFA.

Greenhouse gas emission intensity based on lifetime milk production of dairy animals, as affected by ration-balancing program

Smallholder dairying in India and other developing countries relies on low- and medium-productive animals, and the feeding is mainly based on crop residues and other agro-industrial by-products. The diets are generally nutritionally imbalanced, resulting in productive and reproductive inefficiencies. This also negatively affects the emission intensity (Ei). For the past 3 years, the National Dairy Development Board of India has been implementing large-scale ration-balancing (RB) program in field animals. The effect of feeding balanced rations on Ei was explored. A cradle to farm-gate life-cycle assessment, taking into account the lifespan milk production, was conducted on 163 540 lactating cows and 163 550 buffaloes in northern, southern, eastern and western India. The life-cycle assessment boundary included feed production, enteric fermentation and manure management during various stages of life. On the basis of economic allocation, emissions of methane (CH4) from enteric fermentation, CH4 from manure management, nitrous oxide from manure management and greenhouse gas (GHG), i.e. carbon dioxide (CO2), CH4 and nitrous oxide from feed production, contributed 69.9%, 6.3%, 9.6% and 14.2% in cows, and 71.6%, 7.4%, 12.6% and 8.4% in buffaloes, respectively, to the baseline (before RB) lifetime total GHG emissions. Average Ei based on economic, mass and digestibility allocation for ‘baseline versus after RB’ were 1.6 versus 1.1, 1.8 versus 1.2 and 1.7 versus 1.2 kg CO2-equivalent/kg fat and protein-corrected milk in cows and 2.3 versus 1.5, 2.5 versus 1.6 and 2.4 versus 1.5 kg CO2-equivalent/kg fat and protein-corrected milk in buffaloes, respectively. Feeding-balanced rations significantly improved milk production, but reduced Ei of milk on lifetime basis by 31.2% and 34.7% in cows and buffaloes, respectively. Implementation of RB program has shown considerable potential to reduce GHG emission intensity under smallholding dairy production system of India.

Study on minerals status of dairy cows and their supplementation through area specific mineral mixture in the state of Jharkhand

Background

Deficiency of macro and micro-minerals in the ration of dairy cows adversely affects growth, milk production and reproduction efficiency. It is essential to examine mineral concentrations in feeds offered to dairy cows in practical farms.

Methods

Two villages from each taluka were selected at random for taking representative samples of feeds, forages and hair. Within the village, help was sought from village milk producers and district animal husbandry officer for identification of 4 to 5 farmers and collection of representative samples. All the samples were processed and analyzed for chemical composition as well as major macro and micro-minerals, using Inductively Coupled Plasma-Optical Emission Spectrometer.

Results

Ca content in wheat straw (0.29%), crushed maize (0.02%) and wheat bran (0.12%) was found to be below the critical level (0.30%). The P content in concentrate ingredients was high (0.26–0.96%), but low in dry roughages (0.06–0.12%). Cereal straws (0.14%) and grains (0.12%) were deficient in Mg. Feeds and forages were found to be adequate in K (1.50%). Cereals straws were found to be deficient in S (0.11%). Greens were good source of Cu (12.02 ppm). Wheat straw was found to be low in Zn (18 ppm), but high in Mn (225 ppm) and Fe (509 ppm). Local grasses and azolla green were found to be rich source of Co (>1.00 ppm). Se (0.63 ppm) was present in appreciable quantities in most of the feedstuffs.

Conclusions

From the present study, it was apparent that the feeds and forages available in the state of Jharkhand may not meet the requirements for Ca, P, Mg, Cu, Zn and Co in order to sustain a milk production of ~10 kg/day. Therefore, it is necessary to supplement these deficient minerals through area specific mineral mixture in the ration of dairy cows for improving productivity and reproduction efficiency.

Proficiency Testing of Feed Constituents: A Comparative Evaluation of European and Developing Country Laboratories and Its Implications for Animal Production

Proficiency tests, with two feed samples each year, for various constituents (proximate, macro- and microminerals, feed additives, and amino acids) were conducted in 2014 and 2015. A total of 40 and 50 European and 73 and 63 developing country feed analysis laboratories participated in the study in 2014 and 2015, respectively. The data obtained from these two sets of laboratories in each year enabled a comparison of the performance of the European and developing country laboratories. Higher standard deviation and several-fold higher coefficients of variation were obtained for the developing country laboratories. The coefficients of variation for chemical composition parameters, macrominerals, microminerals, and amino acids were higher by up to 9-fold, 14-fold, 10-fold, and 14-fold, respectively, for the developing country laboratories compared with the European laboratories in 2014, while the corresponding values for 2015 were 4.6-fold, 4.4-fold, 9-fold, and 14-fold higher for developing county laboratories. Also, higher numbers of outliers were observed for developing countries (2014, 7.6-8.7% vs 2.9-3.0%; 2015, 7.7-9.5% vs 4.2-7.0%). The results suggest higher need for developing country feed analysis laboratories to improve the quality of data being generated. The likely impact of higher variability of the data generated in developing countries toward safe and quality preparation of animal diets, their impact on animal productivity, and possible ways to improve the quality of data from developing countries are discussed.

Carbon footprint of milk production under smallholder dairying in Anand district of Western India: a cradle-to-farm gate life cycle assessment

In recent years, the concept of life cycle assessment (LCA) has proven to be useful because of its potential to assess the integral environmental impacts of agricultural products. Developing countries such as India are good candidates for LCA research because of the large contribution of smallholder dairy system to the production of agricultural products such as milk. Therefore, the aim of the present study was to explore the carbon footprint of milk production under the multi-functional smallholder dairy system in Anand district of Gujarat state, western India. A cradle-to-farm gate LCA was performed by covering 60 smallholder dairy farms within 12 geographically distinct villages of the district. The average farm size was 4.0 animals per farm, and the average number of each category of animal was 2.5 lactating cows, 1.4 lactating buffaloes, 1.8 replacement cows, 1.6 replacement buffaloes, 2.0 retired cows, 1.3 retired buffaloes and 1.0 ox per farm. The emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) on CO2-equivalent (CO2-eq) basis from feed production, enteric fermentation and manure management were allocated to fat- and protein-corrected milk (FPCM) on the basis of mass balance, price and digestibility. Emissions of CO2, CH4 and N2O from cattle contributed 11.0%, 75.4% and 13.6%, respectively, to the total greenhouse gas (GHG) emissions. The contribution of CO2, CH4 and N2O from buffalo was 8.2%, 80.5% and 11.3%, respectively, to the total GHG emissions of farms. The average carbon footprint (CF) of cow milk was 2.3, 1.9 and 2.0 kg CO2-eq/kg FPCM on mass, economic and digestibility basis, respectively, whereas for buffalo, milk CF was 3.0, 2.5 and 2.7 kg CO2-eq/kg FPCM, respectively. On the basis of digestibility allocation, emissions from retired (>10 years of age and incapable of or ceased producing milk) cows and buffaloes were 1571.3 and 2556.1 kg CO2-eq/retirement year, respectively. Overall, the CF of milk production under the smallholder dairy system in Anand district was 2.2 kg CO2-eq/kg FPCM, which reduced to 1.7 kg CO2-eq/kg FPCM when milk, manure, finance and insurance were considered as economic functions of the smallholder system. The CF was lower by 65% and 22% for cow and buffalo milk, respectively, than were the estimates of FAO for southern Asia, and this was mainly attributed to difference in the sources of GHG emissions, manure management systems, feed digestibility and milk production data used by FAO.

Smart livestock feeding strategies for harvesting triple gain – the desired outcomes in planet, people and profit dimensions: a developing country perspective

Of the total greenhouse gas emission from the livestock sector, 45% relates to feed production and processing. Enteric methane (35%), land-use change (9%) and manure nitrous oxide and manure methane together (9.5%) are the other sources of greenhouse gas emissions, which to a large extent depend on feed types. Inefficient use of feeds reduces profitability. Increasing future feed demand and food-feed-fuel competition have environmental and social impacts. The growth for demand in livestock products comes with social, economic and environmental challenges. This paper argues that the efficient utilisation of feed resources and application of appropriate feeding strategies are vital for strengthening the three conventional pillars of sustainability (environment, social and economic). Towards this end, it identifies and explores a series of promising innovations and practices in feed production and feeding including balanced and phased feeding; increase in the quality and level of use of forages in diets; reduction in use of grains; harvesting forages when nutrient availability per unit of land is maximum; targeted mineral feeding; reduction in feed losses; use of straw-based densified feed blocks; better recycling of human food wastes and human-inedible food components to feed; new business models for production and use of urea-ammoniated straws, urea-molasses blocks, forages and silages in smallholder farms; and use of underutilised locally available feed crops linked with strengthening of seed development and distribution infrastructure. The development of simple tools and on-site assays for correcting nutritional imbalances also offers interesting opportunities. Collection of data on feed availability at the national level, and generation of sound chemical composition and nutritional value data of feeds, are a prerequisite to innovate. The focus of the discussion will be on low-input livestock systems in developing world. A large number of livestock are found in such systems and small improvements can have high global impact. In addition to the technological aspects, policy and institutional building options required to realise large impact are also discussed.

Milk traits of lactating cows submitted to feed restriction

Data from five experiments with dairy cows where feed was restricted to 0, 40, and 50% of the ad libitum amount, with 259 observations, were subjected to multivariate analyses to determine the effects of severity and duration of feed restriction on production, physical-chemical characteristics, ethanol stability, and somatic cell score of milk. A negative relationship was seen between the severity and duration of feed restriction with milk production, lactose content, titratable acidity, and milk stability to the ethanol test. The milk stability to the ethanol test, protein content, milk yield, and somatic cells score were the most important attributes retained by the discriminant analysis. Milk stability to the ethanol test, live weight, days in restriction, and pH were the most important characteristics explaining the variance within the different levels of feed restriction. Milk production and ethanol stability were significantly lower in both levels of feed restriction compared with the group fed ad libitum. When feed restriction was followed by refeeding, the difference observed in ethanol stability was the first discriminant variable, followed by the difference in unstable milk frequency and titratable acidity. Increments in the severity and duration of feed restriction negatively affect milk production and milk ethanol stability.

Effect of feeding a balanced ration on milk production, microbial nitrogen supply and methane emissions in field animals

Dairy animals in developing countries produce more methane (CH4), primarily on account of feed rations imbalanced in nutrients. A field study on early lactating cows (n = 80) and buffaloes (n = 82) was conducted to evaluate the effect of feeding a balanced ration on milk production, microbial nitrogen (N) supply and CH4 emissions in different agroclimatic regions of India. CH4 emissions was measured using the sulfur hexafluoride tracer technique, before and after feeding a balanced ration. Feeding practices revealed that intake of protein was adequate in the ration of experimental animals in most of the regions, except for the buffaloes of the western region. Metabolisable energy (MJ/cow.day) intake was higher by 7.6% and 13.6% in cows of western and northern regions, respectively. In buffaloes, energy intake (MJ metabolisable energy/buffalo.day) was higher by 11.5% in the western region but lower by 17.7% in the central region. Average calcium intake was deficient by 23.5% and 35.1%, whereas phosphorus intake was deficient by 33.2% and 56.2% in cows and buffaloes, respectively. Feeding a balanced ration increased (P < 0.05) average daily milk production by 6.7% and 7.6%, whereas cost of production decreased by 13.7% and 9.9% in cows and buffaloes, respectively. Fat-corrected milk increased from 9.1 to 9.8 kg/cow.day and from 6.9 to 7.7 kg/buffalo.day. Intestinal flow of microbial N improved significantly by 25.5% and 26.7% in cows and buffaloes, respectively. Balanced feeding reduced CH4 emissions (g/kg milk yield) by 17.3% (P < 0.05) in cows and 19.5% (P < 0.01) in buffaloes. The present study indicates that feeding a balanced ration improves milk production and microbial N supply, and reduces CH4 emissions in field animals.

Technical options for the mitigation of direct methane and nitrous oxide emissions from livestock: a review

Although livestock production accounts for a sizeable share of global greenhouse gas emissions, numerous technical options have been identified to mitigate these emissions. In this review, a subset of these options, which have proven to be effective, are discussed. These include measures to reduce CH4 emissions from enteric fermentation by ruminants, the largest single emission source from the global livestock sector, and for reducing CH4 and N2O emissions from manure. A unique feature of this review is the high level of attention given to interactions between mitigation options and productivity. Among the feed supplement options for lowering enteric emissions, dietary lipids, nitrates and ionophores are identified as the most effective. Forage quality, feed processing and precision feeding have the best prospects among the various available feed and feed management measures. With regard to manure, dietary measures that reduce the amount of N excreted (e.g. better matching of dietary protein to animal needs), shift N excretion from urine to faeces (e.g. tannin inclusion at low levels) and reduce the amount of fermentable organic matter excreted are recommended. Among the many 'end-of-pipe' measures available for manure management, approaches that capture and/or process CH4 emissions during storage (e.g. anaerobic digestion, biofiltration, composting), as well as subsurface injection of manure, are among the most encouraging options flagged in this section of the review. The importance of a multiple gas perspective is critical when assessing mitigation potentials, because most of the options reviewed show strong interactions among sources of greenhouse gas (GHG) emissions. The paper reviews current knowledge on potential pollution swapping, whereby the reduction of one GHG or emission source leads to unintended increases in another.

Special topics--Mitigation of methane and nitrous oxide emissions from animal operations: I. A review of enteric methane mitigation options

The goal of this review was to analyze published data related to mitigation of enteric methane (CH4) emissions from ruminant animals to document the most effective and sustainable strategies. Increasing forage digestibility and digestible forage intake was one of the major recommended CH4 mitigation practices. Although responses vary, CH4 emissions can be reduced when corn silage replaces grass silage in the diet. Feeding legume silages could also lower CH4 emissions compared to grass silage due to their lower fiber concentration. Dietary lipids can be effective in reducing CH4 emissions, but their applicability will depend on effects on feed intake, fiber digestibility, production, and milk composition. Inclusion of concentrate feeds in the diet of ruminants will likely decrease CH4 emission intensity (Ei; CH4 per unit animal product), particularly when inclusion is above 40% of dietary dry matter and rumen function is not impaired. Supplementation of diets containing medium to poor quality forages with small amounts of concentrate feed will typically decrease CH4 Ei. Nitrates show promise as CH4 mitigation agents, but more studies are needed to fully understand their impact on whole-farm greenhouse gas emissions, animal productivity, and animal health. Through their effect on feed efficiency and rumen stoichiometry, ionophores are likely to have a moderate CH4 mitigating effect in ruminants fed high-grain or mixed grain-forage diets. Tannins may also reduce CH4 emissions although in some situations intake and milk production may be compromised. Some direct-fed microbials, such as yeast-based products, might have a moderate CH4-mitigating effect through increasing animal productivity and feed efficiency, but the effect is likely to be inconsistent. Vaccines against rumen archaea may offer mitigation opportunities in the future although the extent of CH4 reduction is likely to be small and adaptation by ruminal microbes and persistence of the effect is unknown. Overall, improving forage quality and the overall efficiency of dietary nutrient use is an effective way of decreasing CH4 Ei. Several feed supplements have a potential to reduce CH4 emission from ruminants although their long-term effect has not been well established and some are toxic or may not be economically feasible.