The effect of subclinical intestinal nematode infection on the diet seletion of growing sheep

1994 ◽  
Vol 72 (5) ◽  
pp. 665-677 ◽  
Author(s):  
I. Kyriazakis ◽  
J.D. Oldham ◽  
R.L. Coop ◽  
F. Jackson
Keyword(s):  
Feed Intake ◽  
Live Weight ◽  
Diet Selection ◽  
Metabolizable Energy ◽  
Protein Requirements ◽  
Intestinal Nematode ◽  
Ewe Lambs ◽  
Daily Rate ◽  
Reduced Rate ◽  
Selection Of

To test the hypothesis that subclinical gastrointestinal parasitism, associated with an impairment in N digestion and metabolism and a reduction in the voluntary feed intake (VFI), could affect the diet selection of sheep given a choice between two feeds that differed in their crude protein (CP) content, twenty-four Texel ×Scottish Blackface ewe lambs growing from 28 to 48 kg live weight (LWT) were given a daily dose of 2500 larvae of the intestinal nematode Trichostrongylus colubriformis; twenty-four similar lambs were used as uninfected controls. Six infected and six control lambs were given a free choice between two pelleted feeds (10·4 MJ metabolizable energy/kg), wilh different CP contents (90 (L) and 214 (H) g CP/kg fresh feed respectively). In addition, eighteen parasitized and eighteen control sheep were given access ad lib. to either feed L, or feed H, or their mixture M (164 g CP/kg; twelve per feed), in order to quantify the effects of the feeds when offered alone, and to test for any interactions between feed CP content and parasitism on the performance of the lambs. Intestinal parasitism reduced significantly (P < 0·001) both the rates of LWT gain (by 30%) and VFI (by 10%). The adult and developing parasitic forms took 4 weeks to establish and develop to a significant adult worm population (as judged by the faecal egg counts and blood variables) and until then there was no effect of parasitism on the performance of the lambs. The diet selection of the lambs given a choice between two feeds was similar between the two groups in the first 4 weeks of the experiment, but differed significantly (P < 0·05) in the second part of the experiment (4th week to the end). Thus, while parasitized lambs had a reduced rate of feed intake, by changing their diet selection they achieved a daily rate of CP intake similar to the control ones. However, since the parasitized lambs had a reduced rate of LWT gain, they also consumed a higher total amount of CP to reach the same LWT. It is concluded that sheep infected daily with a small number of larvae of T. colubriformis and given a choice between two feeds that differ in their protein contents are able to modify their diet selection in order to meet the increased protein requirements resulting from such an infection.

scholarly journals Diet selection in sheep: The role of the rumen environment in the selection of a diet from two feeds that differ in their energy density

1995 ◽  
Vol 74 (1) ◽  
pp. 39-54 ◽  
Author(s):  
S. D. B. Cooper ◽  
I. Kyrizakis ◽  
J. V. Nolan
Keyword(s):  
Energy Density ◽  
Feed Intake ◽  
Latin Square ◽  
Live Weight ◽  
Diet Selection ◽  
Metabolizable Energy ◽  
Daily Rate ◽  
Carry Over ◽  
And Control ◽  
Selection Of

The effect of the energy density (ED) of feeds offered as a choice on the diet selection of sheep, and the relationship between the rumen environment and the diet selected from feeds of different ED were investigated in two experiments. In the first experiment two feeds, L and H, and their mixture M (3:1 w/w) were formulated. All feeds had similar calculated metabolizable protein: metabolizable energy (ME) ratios, but differed in ED (7·4, 8·1 and 10·1 MJ ME$sol;kg fresh feed for L, M and H respectively). The feeds were offered ad lib. either singly or in paired choices (L/M, L/H and M/H; n6 per treatment) to growing sheep. Although the rate of live-weight (Lwt) gain on feed H was higher than on feeds L or M, and the daily rate of feed intake lower, the sheep on feed choices did not consume only feed H. Instead they selected a mixture of both feeds offered, such that the total amount of H consumed per kg fresh feed was similar on choices L/H and M/H. The rate of Lwt gain of sheep on choices L/H and M/H was not different from that achieved on feed H alone. In the second experiment the choice L/H was offered to fistulated sheep (10 months of age, mean Lwt 57·5 kg) in an 8×8 Latin square, with 7 d periods. Treatments were infusions into the rumen (total volume 1 litre) over 4 h on days 1–4 of each period of acid (HC1; Acid 1, 400; Acid 2, 300 and Acid 3, 200 mmol/l), alkali (NaOH; Alk 1, 316; Alk 2, 212 and Alk 3, 109 mmol/l) and control (NaCl; Con 1, 315 and Con 2, 209 mmol/l). Infusate osmolalities (mOs/kg) were 795 (Acid 1), 585 (Acid 2, Alk 1 and Con 1), 390 (Acid 3, Alk 2 and Con 2) and 200 (Alk 3). Infusion treatment significantly affected the diet selection of the sheep (P < 0·05) according to the osmolality of infusate, but not according to rumen pH. During infusions intake of feed H tended to decline with increasing treatment osmolality, whereas intake of L remained constant. The effects on diet selection and feed intake were of a short duration with no carry-over effects. These results show that sheep given a choice between two feeds of different ED select a substantial quantity of the low-ED feed; this diet selection is affected by short-term manipulations of their rumen environment, in a manner that is consistent with the maintenance of effective rumen conditions.

Diet selection of sheep: sodium bicarbonate, but not the offering of hay, modifies the effect of urea on diet selection

2002 ◽  
Vol 74 (2) ◽  
pp. 357-367 ◽  
Author(s):  
S. M. James ◽  
I. Kyriazakis ◽  
G. C. Emmans ◽  
B. J. Tolkamp
Keyword(s):  
Sodium Bicarbonate ◽  
Live Weight ◽  
Diet Selection ◽  
Metabolizable Energy ◽  
Fresh Matter ◽  
Total Food Intake ◽  
Period 2 ◽  
Control Food ◽  
Selection Of

AbstractThe hypotheses tested were that the expected preference of sheep for a food with adequate rumen degradable protein (RDP) supplemented with urea would be reduced both by the addition of a buffer (sodium bicarbonate (SB)) and by offering ad libitum access to hay. A control food (C), calculated to be adequate in its ratio of effective RDP to fermentable metabolizable energy (fME), was formulated. Other foods were made by adding 12·5 (U1) or 25 (U2) g urea per kg fresh matter (FM) to C and 20 g SB per kg FM to C, U1and U2. The acid buffering capacity (ABC) of each food was measured in vitro. The experiment consisted of two successive periods, each of 4 weeks. Ninety-eight female, Texel ✕ Greyface sheep were randomly allocated to 14 groups each with seven animals. Groups 1 to 6 were offered one of: C, U2, C + SB, U2+ SB, C with hay or U2with hay throughout the experiment. Groups 7 to 10 were offered the choices of C v. U1or C v. U2, either with or without hay in a change-over design; animals that received hay during period 1 (groups 8 and 10) did not do so during period 2 and vice versa (groups 7 and 9). Groups 11 to 14 (no. = 7) were offered the choices of C v. U1or C v. U2, either with or without SB supplemented to both foods, in a change-over design. Adding either urea, or SB, or both to C had no effects on intake or live-weight gain when offered alone. Both supplements significantly (P 0·001) increased the ABC of food C. Throughout the experiment hay consumption was very low (overall mean: 23 (s.e. 2·5) g hay per sheep day). Offering hay caused no change in the preference for the urea-supplemented foods. Sheep offered the choices C v. U1or C v. U2, with neither hay nor SB, selected 0.466 (s.e. 0·036) and 0.588 (s.e. 0·025) kg/kg total food intake (TFI) of U1and U2respectively. The proportions of the urea-supplemented foods were significantly reduced (P 0.01) by SB supplementation: to 0.348 (s.e.0·045) and 0·406 (s.e.0·059) kg/kg TFI of U1and U2respectively. The effect of SB addition on the diet selection of sheep could be due to its buffering properties. When SB is added to both foods the need for urea to be used as a buffer is reduced with a consequent decrease in the proportion selected as the urea-supplemented food. Effects of diet on buffering may override other diet selection objectives, such as the avoidance of an excess intake of RDP.

scholarly journals Diet selection in sheep: the ability of growing lambs to select a diet that meets their crude protein (nitrogen × 6.25) requirements

1993 ◽  
Vol 69 (3) ◽  
pp. 617-629 ◽  
Author(s):  
I. Kyriazakis ◽  
J. D. Oldham
Keyword(s):  
Weight Gain ◽  
Feed Intake ◽  
Protein Intake ◽  
Crude Protein ◽  
Energy Content ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Protein Nitrogen ◽  
Se 33 ◽  
Selection Of

To test the proposition that sheep are able to select a diet that meets their crude protein (N × 6.25; CP) requirements, feeds L, A, B, C and H with the same energy content (11 MJ metabolizable energy/kg feed) but different CP contents (78, 109, 141, 172 and 235 g CP/kg fresh feed respectively) were formulated. In addition, feed U, which was feed L plus 21.4 g urea/kg (CP content 132 g/kg), was also made. The feeds were offered ad lib. either singly (n 4 per treatment) or as a choice between feed H and another feed (pairs LH, AH, BH, CH and UH; n 9 per feed pair) to individually penned Suffolk × Scottish mule wether lambs, over the live-weight range 25–45 kg. On the single feeds the rates of live-weight gain were 273, 326, 412, 418, 396 and 407 g/day (SE of difference (SED) 34; P < 0.01) and protein (excluding wool) gain were 27, 32, 44, 45, 41 and 39 g/d (SED 4; P < 0.001) for feeds L, A, B, C, H and U respectively. When sheep were given a choice between a feed below (L or A) and a feed above their CP requirements (H; as judged by the single-feeding treatments) the CP concentration selected was not different between the two pairs: 131 (SE 4) v. 133 (SE 4) g CP/kg feed for pairs LH and AH respectively. On the choices BH and CH (a choice between two feeds above requirements) the feed lower in CP was constantly preferred (874 (SE 33) and 910 (SE 33) g feed B and C respectively per kg total feed intake; CP selected was 157 and 178 g CP/kg respectively). However, this was not the case with the UH choice on which sheep consumed only 599 (SE 61) g feed U/kg total feed intake, resulting in a selection of a higher CP in their diet (173 g CP/kg). The live-weight gains of the animals given a choice between two feeds were 416, 387, 415, 410 and 383 g/d (SED 37) and protein gains were 45, 40, 46, 50 and 43 (SE 7) for pairs LH, AH, BH, CH and UH respectively, which were comparable with the best performance achieved on a single feed. The results suggest that sheep were able to select a diet that meets their CP requirements and avoid, at least to a certain extent, excess of protein intake. It is also possible that sheep discriminate against a property of feed U, such as an excess of urea, when this feed is paired with a feed high in CP.

The voluntary intake and utilization of roughage–concentrate diets by sheep. 1. Concentrate supplements for hay and straw

1971 ◽  
Vol 13 (1) ◽  
pp. 71-82 ◽  
Author(s):  
J. R. Crabtree ◽  
G. L. Williams
Keyword(s):  
Dry Matter ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Weight Changes ◽  
Ewe Lambs ◽  
Unit Increase ◽  
Level 3 ◽  
Voluntary Intake ◽  
Four Levels ◽  
Concentrate Level

SUMMARYFour levels of a proprietary concentrate (0, 100, 200 and 400 g/day) were offered to Welsh Mountain ewe lambs receiving hay or straw ad libitum for 14 weeks. The apparent digestibility of the energy and nitrogen in the various diets was determined in a concurrent digestibility trial.The voluntary intakes of the straw and hay dry matter when given alone were 242 and 451 g/day respectively (28·4 and 49·2 g/kg W0·73 per day). Straw intake increased with an increase in concentrate feeding up to a level of 25% concentrate in the total dry matter and then declined. Hay intake declined linearly with increasing concentrate level (3 g/day decline per unit increase in the percentage of concentrate). In each case the total intake of dry matter and digestible energy increased with an increase in concentrate level.There was a positive within-treatment relationship between initial live weight and voluntary intake, an additional 0·019 Meal ME/day being consumed per kg increase in live weight. Within treatment groups lambs consuming relatively more food also made relatively higher weight gains. Estimates based on published standards of the metabolizable energy intakes required to produce the live weight changes observed on each treatment were considerably higher than the intakes recorded in the trial.

Estimating forage intake and energy requirements of free-ranging wapiti (Cervus elaphus)

1992 ◽  
Vol 70 (4) ◽  
pp. 675-679 ◽  
Author(s):  
Z. Jiang ◽  
R. J. Hudson
Keyword(s):  
Single Dose ◽  
Cervus Elaphus ◽  
Feed Intake ◽  
Body Weight Gain ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Fecal Output ◽  
Summer Pasture ◽  
Free Ranging

A single dose marker method was calibrated to estimate intakes of pasture forage by wapiti. Each animal was offered 250 g of alfalfa–barley pellets labeled with chromic oxide (Cr2O3), and freshly voided fecal samples were collected before and for 6–7 days after administration. Dry fecal output was calculated by dividing the marker dosage by the average fecal marker concentration. Feed intake was then calculated from fecal output and feed digestibility as determined by total fecal collection or the ratio of acid-insoluble ash in feed and feces. The concordance of the marker estimate with measured feed intake was tested on penned wapiti fed alfalfa–barley pellets or herbage. On pasture, the marker method was compared with intakes estimated by the bite-count method. As an additional check, data from pen and field studies were pooled to establish the relationship between metabolizable energy intake and body-weight gain. The single dose marker method provided a practical way to assess feed intake of free-ranging animals. Metabolizable energy requirements for maintenance of live weight were 572 kJ/W0.75 for penned wapiti in winter and 936 kJ/W0.75 for wapiti on summer pasture. Tissues mobilized during winter provided 26 kJ/g, and metabolizable energy requirement per unit liveweight gain was 39 kJ/g on summer pasture.

Diet Selection of Weaned Piglets - Is a Training Period Necessary?

1994 ◽  
Vol 1994 ◽  
pp. 35-35
Author(s):  
J.A. Dalby ◽  
J.M. Forbes ◽  
M.A. Varley ◽  
S. Jagger
Keyword(s):  
Amino Acids ◽  
Diet Selection ◽  
Training Period ◽  
Food Protein ◽  
Weaned Piglets ◽  
Adequate Diet ◽  
Protein Requirements ◽  
Weaned Piglet ◽  
Potential Benefits ◽  
Selection Of

The requirements of a weaned piglet are expected to change systematically over the period 6kg-25kg. Commonly during this time animals will be offered two diets. However, initially on each diet the animal may be restricted because it's protein requirements are in excess of that supplied by the diet. Then latterly, amino acids may be oversupplied requiring deamination of the excess by the pig. This is a costly process, in terms of the energy required by the pig and commercially, in terms of food protein costs. This system also does not take into account differing individual requirements within a group of pigs due to genotype, sex, maturity and stage of growth. As a result potential benefits are to be obtained if weaned piglets can be shown to choose an adequate diet, meeting their individual requirements, when given a choice of feeds.

scholarly journals Estimation of the net energy and protein requirements for maintenance of male arctic foxes (Alopex lagopus) during the growth period12

2019 ◽  
Vol 97 (11) ◽  
pp. 4579-4587
Author(s):  
W Zhong ◽  
L L Mu ◽  
F F Han ◽  
G L Luo ◽  
X Y Zhang ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Heat Production ◽  
Feed Intake ◽  
Metabolizable Energy ◽  
Net Energy ◽  
Protein Requirements ◽  
Maintenance Requirement ◽  
Arctic Foxes ◽  
Energy Maintenance ◽  
Net Protein

Abstract The maintenance requirements of net energy and net protein were assumed to represent the most accurate and important values totally for the animal’s utilization. The objective of this experiment was to determine the net energy and net protein requirements for maintenance of growing arctic foxes. The experiments was evaluated using regression models estimated from data collected by means of indirect calorimetry, nitrogen balance trials, and digestion and metabolism experiments. Thirty-six growing arctic foxes (3 487 ± 261.7 g) at the age of 85 days were randomly assigned to four groups with 9 animals in each group. Arctic foxes were fed a complete formula diet at four intake levels (100%, or 80%, 60%, and 40% of feed requirements) from 24 July 2017 to 23 September 2017. Arctic foxes in each treatment were kept individually in respiration chambers after 1-d adaptation at day 2 for a 3-d balance trial and then at day 5 followed by a 3-d fasting period. The metabolizable energy intake (MEI), heat production in the fed state (HP), and retained energy (RE) of arctic foxes significantly decreased (P < 0.01) as the feed intake level decreased. Fasting heat production (FHP) of arctic foxes was not influenced by feed intake level (P > 0.05). The metabolizable energy maintenance requirement (MEm) and net energy maintenance requirement (NEm) estimated from the linear relationship between RE and MEI were 230 and 217 kJ/kg of body weight BW0.75/d, respectively. The MEm and NEm estimated by logarithmic regression of HP on MEI were 225 and 209 kJ/kg BW0.75/d, respectively. The net N maintenance requirement (NNm) and net protein maintenance requirement (NPm) estimated from the linear relationship between retained nitrogen (RN) and daily nitrogen intake (NI) were 179.6 mg/kg BW0.75/d and 1.123 g/kg BW0.75/d, respectively. It is concluded that NEm and NPm values obtained fill the net energy and protein requirements shortage, and provide the basic data for establishing the standard of nutrition demand of breeding arctic foxes in China.

scholarly journals The effect of rumen adaptation to oxalic acid on selection of oxalic–acid–rich plants by goats

2000 ◽  
Vol 83 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Alan J. Duncan ◽  
Pilar y ◽  
Sheila A. Young
Keyword(s):  
Oxalic Acid ◽  
Live Weight ◽  
Diet Selection ◽  
Adaptation Period ◽  
Gelatin Capsules ◽  
Secondary Plant Compounds ◽  
Internal Markers ◽  
Plant Compounds ◽  
Selection Of ◽  
Secondary Plant

Rumen microbial degradation is an important route for detoxification of secondary plant compounds encountered in the diets of free-grazing ruminants. Exposure to diets containing particular secondary plant compounds can lead to increased rates of secondary compound degradation in the rumen. An experiment was conducted to determine whether rumen adaptation to oxalic acid would influence the diet selection of goats offered choices between plant species differing in their oxalic acid content. Twelve adult female goats were divided into two groups of six animals each. One group received a daily oral dose, in gelatin capsules, of 0·6 mmol oxalic acid/kg live weight per d throughout the experiment while the other group received placebos consisting of empty gelatin capsules. After an adaptation period of 8 d, the animals were allowed to graze a mixture of spinach (rich in oxalic acid) and cabbage (low in oxalic acid) for 7 h/d on two consecutive days per week during four consecutive 1-week periods. Intervening days were spent on grass pasture. Diet composition and intake were measured using cuticular wax n−alkanes as internal markers. Results showed that adapted goats included a higher proportion of spinach in their diet (P < 0·05) although absolute intakes of spinach were the same for the two groups. Goats in the oxalic-acid-adapted group consumed less cabbage than control animals (P < 0·05) suggesting that adaptation to oxalic acid at the rumen level may have interfered with detoxification of cabbage-derived secondary plant compounds. Voluntary intake increased progressively through the four experimental periods (P < 0·001) with a tendency for higher intakes among control than among adapted animals (P < 0·1). The experiment demonstrates how differences in the rate of degradation of secondary plant compounds may influence diet selection in ruminants.

scholarly journals Protein requirements of growing lambs

1973 ◽  
Vol 30 (1) ◽  
pp. 45-60 ◽  
Author(s):  
J. L. Black ◽  
G. R. Pearce ◽  
D. E. Tribe
Keyword(s):  
Energy Intake ◽  
Protein Intake ◽  
Milk Proteins ◽  
Live Weight ◽  
Metabolizable Energy ◽  
N Balance ◽  
Net Energy ◽  
Protein Requirements ◽  
Reference Protein ◽  
Group 2

1. The protein requirements of lambs were established by measuring nitrogen balance in seventy-four animals given liquid diets which passed direct to the abomasum. Four groups of lambs weighing approximately 8 kg (group 1), 13 kg (group 2), 21 kg (group 3) and 30 kg (group 4) received diets in which 0·10, 0·15, 0·20, 0·25, 0·30, 0·35 or 0·40 of the digestible energy was provided as protein (DPE:DE ratio) and a gross energy intake of from 1·30 to 1·42 MJ/kg0·73 per d.2. When the protein requirements were taken to correspond to the protein intake at the point of intersection of the line describing the increase in N balance with increase in protein intake and the line representing the maximum N balance, values of 0·25, 0·23, 0·17 and 0·12 DPE:DE ratio were obtained for groups 1–4 respectively. The requirements expressed in these terms can be applied only to lambs fed on liquid diets which contain milk proteins and escape fermentation in the rumen. To enable the results to be applied to lambs given other diets, the requirements were expressed as g reference-protein (defined as a theoretical protein with the ideal pattern of amino acids) per MJ net energy and were 11·6, 10·4, 8·0 and 6·2 for groups 1–4 respectively. The relationship between protein requirement (Y, g reference protein/MJ net energy) and live weight (X, kg) was: Y = 13·4–0·242X.3. The influence of energy intake on protein requirements in lambs is discussed and it is concluded that the results obtained are applicable to lambs given a metabolizable energy intake of more than about 1·75 times their maintenance requirement.4. Application of the estimated requirements to ruminant lambs and methods of formulating diets to supply the required quantity of reference protein/MJ net energy are discussed.

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