The use of alkanes as markers for estimating diet composition in sheep and goats

2006 ◽  
Vol 34 ◽  
pp. 15-20
Author(s):  
L.M.M. Ferreira ◽  
M. Oliván ◽  
M.A.M. Rodrigues ◽  
A. Dias-da-Silva ◽  
K. Osoro

SummaryAn experiment was carried out to evaluate the use of alkanes for estimating diet composition of goats and sheep offered three different dietary treatments. Twelve animals as two groups of 4 crossbred goats (G1, 24 kg live weight; G2, 22 kg) and 4 crossbred sheep (S, 26 kg live weight), were housed in metabolism pens. Animals were offered daily a total of 1 kg DM/100 kg live weight. G1 received 70% ryegrass (Lolium perenne) and 30% gorse (Ulex gallii), G2 received 70% ryegrass and 30% heather (Erica sp.) and S group ate 100% ryegrass. Diet composition was estimated from the alkane concentrations (using all alkanes from C23 to C36 or only odd-chain alkanes C27, C29, C31 and C33) in diet and faeces (with or without correction for incomplete faecal recoveries) using least-squares procedures.Dietary treatment and animal species significantly affected alkane faecal recoveries, except for C24 and C36. When applying the faecal recovery corrections, there were no significant differences between measured proportions of dietary components and those estimated using all alkanes or odd-chain alkanes. In contrast, the proportions calculated without faecal recovery correction differed significantly (P<0.05) from the actual proportions and over-estimated the amount in the diet of those plant components with higher concentrations of long-chain alkanes (Erica sp. and Lolium perenne). The results indicate that alkanes are useful markers to estimate diet composition, however, it was observed that animal species and diet composition influenced the faecal recovery of alkanes. This suggests that the use of the alkane methodology for estimating the diet selection of grazing animals should be preceded by a calculation of the actual alkane faecal recoveries for each experimental condition.

2016 ◽  
Vol 64 (4) ◽  
pp. 249 ◽  
Author(s):  
Emma L. Gray ◽  
Chris J. Burwell ◽  
Andrew M. Baker

The endangered black-tailed dusky antechinus (Antechinus arktos) was described in 2014, so most aspects of its ecology are unknown. We examined diet composition and prey selection of A. arktos and a sympatric congener, the northern form of A. stuartii, at two sites in Springbrook National Park. Overall, taxa from 25 invertebrate orders were identified in the diets from 252 scat samples. Dietary components were similar for each species, but A. arktos consumed a higher frequency and volume of dipteran larvae and Diplopoda, while A. stuartii consumed more Coleoptera, Lepidoptera, Orthoptera and Isopoda. Both species of Antechinus had a higher percentage of ‘empty’ scats (devoid of any identifiable invertebrate material) in 2014 compared with 2015. The former was a drier year overall. Lower rainfall may have reduced abundance and diversity of arthropod prey, causing both species to supplement their diet with soft-bodied prey items such as earthworms, which are rarely detected in scats. Comparison of prey in scats with invertebrate captures from pitfall traps showed both species to be dietary generalists, despite exhibiting distinct preference and avoidance of certain prey categories. The ability of an endangered generalist marsupial to switch prey may be particularly advantageous considering the anticipated effects of climate change on Gondwanan rainforests during the mid-late 21st century.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 345-346
Author(s):  
Jose Alvear ◽  
Jorge Ron ◽  
Hector Torrealba ◽  
Christian H Ponce

Abstract An experiment was conducted to evaluate the effects of corn protein concentrate (CPC) levels on performance, nitrogen digestibility, blood parameters, and visceral organ mass by newly weaned piglets. Forty piglets (6. 9 kg ± 1.2 kg of live weight) were allotted to 4 dietary treatments in a completely randomized block design. Piglets were fed individually 1 of 4 experimental diets containing different CPC levels (0%, 5%, 10% or 15%) during 44 d. Performance parameters were measured weekly. Total fecal and urine samples were collected on d 33 of the experiment for 4 consecutive days to determine N balance. At the end of the feeding period, blood samples were collected to measure blood parameters, and animals were slaughter to determine visceral organ mass. Data were analyzed as a randomized complete block designed using PROC MIXED in SAS. Final BW tended to decrease linearly (P = 0.065) as dietary CPC level increased. Overall, ADG tended to decrease linearly (P = 0.065), and ADFI was significantly reduced (P = 0. 038) as dietary CPC level increased. Nevertheless, FCR was not by dietary treatment (P = 0.1872). There were no differences on nitrogen intake, retention and digestibility across dietary treatments (P &gt; 0. 407). However, there was a tendency to decrease linearly N excretion on urine as CPC increased in the diet. Hematocrit and Serum Urea-N were linearly increased and reduced, respectively as CPC increased in the diet (P &lt; 0. 027). Empty BW at d 44 tended to linearly reduce as CPC increased. Pancreas weight was reduced by inclusion of CPC (linearly; P = 0. 005). In summary, it was demonstrated that, when CPC replaced partially traditional protein sources up to 5% of the diet, performance and N status of the animal are not altered. However, caution should be taken with higher levels of inclusion.


1970 ◽  
Vol 74 (3) ◽  
pp. 415-421 ◽  
Author(s):  
J. J. Robinson ◽  
T. J. Forbes

SUMMARYThirty-six Border Leicester x Scottish Blackface ewes were separated from their lambs after approximately 12 weeks lactation and brought indoors. They were allocated at random to nine dietary treatments comprising three dietary ratios of chopped roughage to concentrate, each offered at three levels of feeding. During the course of the experiment digestibility and nitrogen balance trials were carried out using three ewes from each dietary treatment.The daily nitrogen intakes required for nitrogen equilibrium were calculated from the regressions of nitrogen intake on nitrogen retained for each of the three ratios. The intakes increased from 0·47 g/kg W0·75 on the diet containing the lowest proportion of roughage to 0·59 g/kg W0·75 on the diet containing the highest proportion of roughage. The corresponding digestible organic matter intakes did not differ significantly from the pooled value of 18·8 g/kg W0·75.The daily digestible organic matter intakes required for the maintenance of live weight on the three ratios did not differ significantly from the pooled estimate of 26·9 g/kg W0·75 which is in close agreement with other published results. The nitrogen intakes required for the maintenance of live weight increased from 0·70 on the diet containing the lowest proportion of roughage to 0·84 g/kg W0·75/day on the diet containing the highest proportion of roughage.The coefficients for live-weight change in the regression equations relating digestible organic matter to live weight and live-weight change for each ratio did not differ significantly from the pooled estimate of 2·0 g DOMI/g live-weight change.The significance of the results are discussed in relation, to the nutritional status of the ewe and other research findings.


2007 ◽  
Vol 58 (11) ◽  
pp. 1013 ◽  
Author(s):  
M. Oliván ◽  
L. M. M. Ferreira ◽  
U. García ◽  
R. Celaya ◽  
K. Osoro

The present study aimed to test the effect of applying different sets of n-alkane faecal recoveries and different plant species grouping approaches on the estimates of the diet selected by goats and sheep when grazing/browsing complex vegetation communities composed of mosaics of heather-gorse vegetation interspersed with patches of perennial ryegrass. The use of different sets of n-alkane faecal recoveries significantly affected the estimated proportions of most vegetation components in both animal species. The diet estimates were also significantly affected by the calculation approach: A1 (using all individual plant species); A2 (grouping plant species with similar n-alkane profile, with equal weighting within the group); and A3 (grouping plant species with similar n-alkane profile, with different weighting according to the botanical composition of the plot). There was a significant interaction between calculation approach (A) and faecal recovery sets (FR) on the resulting estimates of the Ericaceae species in the diet of goats and of all diet components in sheep. When using A1 approach, the estimated proportion of Agrostis capillaris in the diets was high and seemed to be overestimated, compared with its low availability (1.1% of total cover) in the field. However, the application of calculation approaches A2 and A3 gave lower dietary proportions of component D2 (Agrostis capillaris and Ulex gallii) and higher proportions of components D1 (Lolium perenne and Pseudarrhenatherum longifolium), D3 (Erica umbellata, Erica cinerea, Erica australis, Calluna vulgaris) and Erica arborea. These results indicate that the application of the n-alkane technique for estimation of the diet composition in field with complex vegetation conditions is sensitive to the use of faecal recovery corrections and to the grouping of possible dietary components.


2017 ◽  
Vol 73 (2) ◽  
pp. 355-367 ◽  
Author(s):  
L. M. M. Ferreira ◽  
C. López López ◽  
R. Celaya ◽  
K. Osoro ◽  
M. A. M. Rodrigues

1969 ◽  
Vol 73 (3) ◽  
pp. 395-415 ◽  
Author(s):  
R. Blair ◽  
J. B. Dent ◽  
P. R. English ◽  
J. R. Raeburn

SummaryA total of 512 pigs were given from 50 lb live weight one of 16 diets (four lysine levels at each of 12, 14, 16 and 18% protein), at one of four levels of intake. They were killed at 100, 150, 200 or 250 lb live weight and the carcasses jointed in a standard manner and right sides dissected into lean meat, fat, skin and bone.Mean percentage proportion of shoulder, middle and ham joints in the dressed sides at the four weights was 36·3, 36·4 and 27·3; 35·4, 37·9 and 26·7; 34·5, 39·6 and 25·9; and 33·8, 40·7 and 25·5, respectively. Mean percentage lean meat at the four live weights was 61·5, 59·9, 56·7 and 54·2 and the mean percentage fat was 20·7, 24·4, 29·4 and 32·8.Carcass quality was influenced significantly by dietary treatment and sex. Increasing the level of protein in the diet up to 16, 16, 14–16 and 14%, respectively, for the four live weight groups gave a significant increase in carcass leanness. Increasing the level of lysine in the diet did not have a very marked effect on carcass composition, while increasing feed intake to the highest level produced fatter carcasses at all weights. Carcasses of males were fatter and with a lower proportion of ham than those of females. Interactions involving dietary treatments and sex were described.Chemical composition of the m. longissimus dorsi was not altered markedly by dietary treatment or sex but dry matter and intramuscular fat content rose with increasing weight. Protein content of the dry matter remained fairly constant at all weights, while colour and shear value rose with increasing weight but were not significantly influenced by dietary treatment or sex.The pH values of the m. multifidus dorsi just after slaughter or on the day following were not markedly affected by dietary treatment, sex or weight.


2006 ◽  
Vol 34 ◽  
pp. 1-7 ◽  
Author(s):  
H. Dove ◽  
M. Oliván

SummaryThe objective of the current study was to investigate the possible use of alkenes (unsaturated hydrocarbons) of plant waxes as diet composition markers in sheep. Twenty-four sheep (30 kg live weight) were housed in individual pens (n=16, “pen” sheep) or in metabolism crates (n=8, “crate” sheep) for the total collection of faeces. Once daily, sheep were fed 720 g DM of a two-component diet consisting of a roughage source (chaffed perennial ryegrass) and a high-quality supplement (unpelleted sunflower meal, SFM) in different proportions, 7:1, 6:2, 5:3 and 4:4 (4 pen sheep and 2 crate sheep/treatment). SFM was labelled with a solution of beeswax to provide an alkane/ alkene profile different from the chaff. Diet composition was estimated from C27, C29, C31 and C33 alkene concentrations in diet and faeces (total faeces or rectal grab samples), using the least-squares package ‘EatWhat’. Estimates were conducted with or without correction of faecal alkane concentrations for incomplete faecal recovery, calculated from the alkene intakes and faecal outputs in the crate sheep.Although the faecal alkene recoveries of alkenes were low, they did not differ between chain lengths for alkenes C27 to C33. Therefore in cage sheep, alkene-based estimates of SFM proportions, with or without faecal recovery correction, did not differ significantly from the proportions fed and were as accurate as earlier alkane-based estimates. In pen sheep, SFM proportions estimated from rectal grab samples were slightly but significantly over-estimated, regardless of whether or not recovery corrections were used. The over-estimates were not related to recovery corrections but to the small differences in concentrations between rectal grab samples from pen sheep and the total faeces from cage sheep. The lack of effect of recovery corrections does not mean they should be excluded from such calculations, as there may be situations in which there is an effect of carbon-chain length on alkene recovery. Use of recovery corrections also permits an estimate of whole-diet digestibility.The present results indicate that alkenes could be useful additional markers to the alkanes for estimating the proportion of two dietary components in diets offered to sheep.


1970 ◽  
Vol 75 (3) ◽  
pp. 403-411 ◽  
Author(s):  
J. J. Robinson ◽  
C. Fraser ◽  
Elizabeth L. Corse ◽  
J. C. Gill

SUMMARYAn experiment was carried out in which each of thirty-six ewes was offered one of six dietary treatments from the 30th to the 140th day of gestation. The treatments supplied two levels of metabolizable energy (ME) intake (128 and 116 kcal/kg W0.75/day) each at three patterns of protein intake, namely equal increments at 22 day intervals, equal decrements at the same intervals and a constant daily intake throughout. The protein intake patterns supplied a mean daily intake of digestible crude protein of 3·74 g/kg W0.75/day. Nitrogen balances were carried out on four ewes from each dietary treatment during the last 10 days of each 22 day period.Thirteen ewes randomly distributed on all dietary treatments were barren. Mean rate of live-weight gain in the pregnant ewes was 123 g/day compared with 66 g/day in the non-pregnant ewes and was not significantly affected by treatments. Lamb birth weights adjusted to the basis of twins were 3·83, 4·02 and 3·56 kg for the increasing, constant and decreasing patterns of protein intake respectively.Within patterns of protein intake there were no significant differences in nitrogen retention between pregnant and non-pregnant ewes until after 90 days of gestation. Thereafter retention increased in the pregnant ewes offered the constant and increasing patterns of crude protein and remained constant in the non-pregnant ewes. During the same period the retention of both pregnant and non-pregnant ewes on the decreasing pattern decreased.The effects of both energy and protein intake on nitrogen retention in early and late pregnancy were assessed by multiple regression analysis. The results are discussed in relation to other recent findings.


2021 ◽  
Vol 39 (1) ◽  
pp. 153-160
Author(s):  
G. S Bawa ◽  
L. H. Lombin ◽  
D. Shamaki ◽  
P. Karsin ◽  
U. Musa

A feeding trial was conducted to determine the effect of varying dietary levels of protein on performance of Japanese quail chicks. Six iso-caloric (2953-3078 kcal/kg, ME) diets were formulated to contain crude protein (CP) at 18, 20, 22, 24, 26 and 28% levels, respectively. Each of the dietary treatment was replicated three times with sixty (60) quail chicks per replicate. A total of 1080 day-old unsexed quail chicks were used for the study and distributed using completely randomized design. The experiment lasted 42 days during which data were collected. Feed and water were provided ad libitum throughout the experimental period. Feed intake, weight gain, feed conversion ratio and protein intake differ significantly (P<0.05) due to dietary treatments. Final live weight and cost per gain were not significantly (P>0.05) different across dietary treatments. Age at first egg and average weight of eggs at point of lay differed significantly (P<0.05) across dietary treatments. The haematological parameters (Total protein, haemoglobin, albumen and red blood cell) were significantly (P<0.05) affected by the dietary protein levels. Carcass weight, dressing percentage, prime cuts and the weight of major organs expressed as percentage of the live weight were not significantly (P>0.05) affected by the dietary treatments. It was concluded that Japanese quail chicks required up to 26% level of dietary protein for optimum performance. 


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