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Featured researches published by K.J. Hammond.


Journal of Dairy Science | 2016

Effects of diet forage source and neutral detergent fiber content on milk production of dairy cattle and methane emissions determined using GreenFeed and respiration chamber techniques

K.J. Hammond; A.K. Jones; D.J. Humphries; L.A. Crompton; C.K. Reynolds

Strategies to mitigate greenhouse gas emissions from dairy cattle are unlikely to be adopted if production or profitability is reduced. The primary objective of this study was to examine the effects of high maize silage (MS) versus high grass silage (GS) diets, without or with added neutral detergent fiber (NDF) on milk production and methane emission of dairy cattle, using GreenFeed (GF) or respiration chamber (RC) techniques for methane emission measurements. Experiment 1 was 12wk in duration with a randomized block continuous design and 40 Holstein cows (74d in milk) in free-stall housing, assigned to 1 of 4 dietary treatments (n=10 per treatment), according to calving date, parity, and milk yield. Milk production and dry matter intake (DMI) were measured daily, and milk composition measured weekly, with methane yield (g/kg of DMI) estimated using a GF unit (wk 10 to 12). Experiment 2 was a 4×4 Latin square design with 5-wk periods and 4 dairy cows (114d in milk) fed the same 4 dietary treatments as in experiment 1. Measurements of DMI, milk production, and milk composition occurred in wk 4, and DMI, milk production, and methane yield were measured for 2d in RC during wk 5. Dietary treatments for both experiments were fed as total mixed rations offered ad libitum and containing 500g of silage/kg of dry matter composed (DM basis) of either 75:25 MS:GS (MS) or 25:75 MS:GS (GS), without or with added NDF from chopped straw and soy hulls (+47g of NDF/kg of dry matter). In both experiments, compared with high GS, cows fed high MS had a higher DMI, greater milk production, and lower methane yield (24% lower in experiment 1 using GF and 8% lower in experiment 2 using RC). Added NDF increased (or tended to increase) methane yield for high MS, but not high GS diets. In the separate experiments, the GF and RC methods detected similar dietary treatment effects on methane emission (expressed as g/d and g/kg of DMI), although the magnitude of the differences varied between experiments. Overall methane emission and yield were 448g/d and 20.9g/kg of DMI for experiment 1 using GF and 458g/d and 23.8g/kg of DMI for experiment 2 using RC, respectively.


British Journal of Nutrition | 2016

Influence of ruminal methane on digesta retention and digestive physiology in non-lactating dairy cattle.

Marie T. Dittmann; K.J. Hammond; P. Kirton; D.J. Humphries; L.A. Crompton; Sylvia Ortmann; T.H. Misselbrook; Karl-Heinz Südekum; Angela Schwarm; Michael Kreuzer; C.K. Reynolds; Marcus Clauss

Enteric methane (CH4) production is a side-effect of herbivore digestion, but it is unknown whether CH4 itself influences digestive physiology. We investigated the effect of adding CH4 to, or reducing it in, the reticulorumen (RR) in a 4×4 Latin square experiment with rumen-fistulated, non-lactating cows, with four treatments: (i) control, (ii) insufflation of CH4 (iCH4), (iii) N via rumen fistula, (iv) reduction of CH4 via administration of bromochloromethane (BCM). DM intake (DMI), apparent total tract digestibility, digesta mean retention times (MRT), rumen motility and chewing activity, spot breath CH4 emission (CH4exhal, litre/kg DMI) as well as CH4 dissolved in rumen fluid (CH4RRf, µg/ml) were measured. Data were analysed using mixed models, including treatment (or, alternatively, CH4exhal or CH4RRf) and DMI relative to body mass0·85 (rDMI) as covariates. rDMI was the lowest on the BCM treatment. CH4exhal was highest for iCH4 and lowest for BCM treatments, whereas only BCM affected (reduced) CH4RRf. After adjusting for rDMI, CH4RRf had a negative association with MRT in the gastrointestinal tract but not in the RR, and negative associations with fibre digestibility and measures of rumination activity. Adjusting for rDMI, CH4exhal had additionally a negative association with particle MRT in the RR and a positive association with rumen motility. Thus, higher rumen levels of CH4 (CH4exhal or CH4RRf) were associated with shorter MRT and increased motility. These findings are tentatively interpreted as a feedback mechanism in the ruminant digestive tract that aims at mitigating CH4 losses by shortening MRT at higher CH4.


Journal of Dairy Science | 2015

Effects of forage source and extruded linseed supplementation on methane emissions from growing dairy cattle of differing body weights

K.J. Hammond; D.J. Humphries; L.A. Crompton; P. Kirton; C.K. Reynolds

Changes in diet carbohydrate amount and type (i.e., starch vs. fiber) and dietary oil supplements can affect ruminant methane emissions. Our objectives were to measure methane emissions, whole-tract digestibility, and energy and nitrogen utilization from growing dairy cattle at 2 body weight (BW) ranges, fed diets containing either high maize silage (MS) or high grass silage (GS), without or with supplemental oil from extruded linseed (ELS). Four Holstein-Friesian heifers aged 13 mo (BW range from start to finish of 382 to 526 kg) were used in experiment 1, whereas 4 lighter heifers aged 12 mo (BW range from start to finish of 292 to 419 kg) were used in experiment 2. Diets were fed as total mixed rations with forage dry matter (DM) containing high MS or high GS and concentrates in proportions (forage:concentrate, DM basis) of either 75:25 (experiment 1) or 60:40 (experiment 2), respectively. Diets were supplemented without or with ELS (Lintec, BOCM Pauls Ltd., Wherstead, UK; 260 g of oil/kg of DM) at 6% of ration DM. Each experiment was a 4 × 4 Latin square design with 33-d periods, with measurements during d 29 to 33 while animals were housed in respiration chambers. Heifers fed MS at a heavier BW (experiment 1) emitted 20% less methane per unit of DM intake (yield) compared with GS (21.4 vs. 26.6, respectively). However, when repeated with heifers of a lower BW (experiment 2), methane yield did not differ between the 2 diets (26.6g/kg of DM intake). Differences in heifer BW had no overall effect on methane emissions, except when expressed as grams per kilogram of digestible organic matter (OMD) intake (32.4 vs. 36.6, heavy vs. light heifers). Heavier heifers fed MS in experiment 1 had a greater DM intake (9.4kg/d) and lower OMD (755 g/kg), but no difference in N utilization (31% of N intake) compared with heifers fed GS (7.9 kg/d and 799 g/kg, respectively). Tissue energy retention was nearly double for heifers fed MS compared with GS in experiment 1 (15 vs. 8% of energy intake, respectively). Heifers fed MS in experiment 2 had similar DM intake (7.2 kg/d) and retention of energy (5% of intake energy) and N (28% of N intake), compared with GS-fed heifers, but OMD was lower (741 vs. 765 g/kg, respectively). No effect of ELS was noted on any of the variables measured, irrespective of animal BW, and this was likely due to the relatively low amount of supplemental oil provided. Differences in heifer BW did not markedly influence dietary effects on methane emissions. Differences in methane yield were attributable to differences in dietary starch and fiber composition associated with forage type and source.


Proceedings of the 69th Conference of the New Zealand Society of Animal Production, Canterbury, New Zealand, 24-26 June 2009. | 2009

The variation in methane emissions from sheep and cattle is not explained by the chemical composition of ryegrass.

K.J. Hammond; S. Muetzel; G. G. Waghorn; C.S. Pinares-Patiño; Burke Jl; S. O. Hoskin


Animal Feed Science and Technology | 2013

Effects of feed intake on enteric methane emissions from sheep fed fresh white clover (Trifolium repens) and perennial ryegrass (Lolium perenne) forages

K.J. Hammond; Burke Jl; John Koolaard; S. Muetzel; C.S. Pinares-Patiño; Garry Waghorn


Animal Feed Science and Technology | 2015

Methane emissions from cattle: Estimates from short-term measurements using a GreenFeed system compared with measurements obtained using respiration chambers or sulphur hexafluoride tracer

K.J. Hammond; D.J. Humphries; L.A. Crompton; Colin Green; C.K. Reynolds


Animal Feed Science and Technology | 2016

Review of current in vivo measurement techniques for quantifying enteric methane emission from ruminants

K.J. Hammond; L.A. Crompton; A. Bannink; J. Dijkstra; D.R. Yáñez-Ruiz; P. O’Kiely; E. Kebreab; Maguy Eugène; Zhongtang Yu; Kevin J. Shingfield; Angela Schwarm; A.N. Hristov; C.K. Reynolds


Agriculture, Ecosystems & Environment | 2014

The Inclusion of Forage Mixtures in the Diet of Growing Dairy Heifers: Impacts on Digestion, Energy Utilisation, and Methane Emissions

K.J. Hammond; D.J. Humphries; Duncan Westbury; A. Thompson; L.A. Crompton; P. Kirton; C. Green; C.K. Reynolds


Journal of Dairy Science | 2016

GreenFeedと呼吸チャンバ技術を用いて決定した乳牛とメタン放出の乳生産に及ぼす粗飼料源と中性デタージェント繊維含量の影響【Powered by NICT】

K.J. Hammond; A.K. Jones; D.J. Humphries; L.A. Crompton; C.K. Reynolds


70th conference 8th-10th March 2016 in Hannover: review, abstracts, workshop = 70. Tagung vom 8.-10.03.2016 in Hannover | 2016

The effect of methane on properties of digestive physiology in dairy cow

Marie T. Dittmann; K.J. Hammond; P. Kirton; D.J. Humphries; L.A. Crompton; T.H. Misselbrook; Karl-Heinz Südekum; Angela Schwarm; Michael Kreuzer; C.K. Reynolds; Marcus Clauss

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P. Kirton

University of Reading

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A. Bannink

Wageningen University and Research Centre

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J. Dijkstra

Wageningen University and Research Centre

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D.R. Yáñez-Ruiz

Spanish National Research Council

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