Ewes increase their intake when offered a choice of herbage species at pasture

2006 ◽  
Vol 82 (2) ◽  
pp. 183-191 ◽  
Author(s):  
C. Cortes ◽  
J. C. Damasceno ◽  
J. Jamot ◽  
S. Prache
Keyword(s):  
Festuca Arundinacea ◽  
Foraging Behaviour ◽  
Latin Square ◽  
Intake Rate ◽  
Food Diversity ◽  
Resource Degradation ◽  
Digestible Organic Matter ◽  
Effect Of Food ◽  
Free Grazing ◽  
Preferred Species

AbstractIn stall-feeding conditions, food diversity has been shown to increase an animal's motivation to eat and its level of food intake. This effect has also been suggested, but not demonstrated, for free-grazing animals. In free-grazing conditions, however, animals may have to search for the preferred plant species and this may reduce their intake rate. Moreover, the management of diverse swards faces a risk of overgrazing the preferred species and undergrazing the less preferred species, leading to resource degradation. We investigated the effect of food diversity on foraging behaviour and intake in grazing sheep, in interaction with the type of diversity (conterminal monocultures v. mixtures) and management (two monocultures offered simultaneously v. successively over time). Five treatments were compared with five groups of five dry INRA 401 ewes for five periods, using a Latin-square design: LOL=grazing a monoculture of Lolium perenne cv. Herbie (L); FES=grazing a monoculture of Festuca arundinacea cv. Florine (F); STRIPS=grazing conterminal monocultures of L and F, 0·5:0·5 by ground area, with animals having a free choice between both species; TIME=grazing L from 16:00 to 09:00 h and F from 09:00 to 16:00 h; MIX=grazing an intermeshed mixture of L and F. Sward height was maintained at 9 cm. Each period comprised a 5-day adaptation subperiod followed by a 5-day measurement subperiod. Dietary choices and intake were measured using n-alkanes, and grazing time was assessed using the Ethosys® recording system. Intake rate was calculated as the ratio of intake to grazing time. Intake in the monoculture treatments were higher than predictions made for housed animals given similar forages ad libitum, demonstrating that sward conditions were favourable for the expression of voluntary intake in all treatments. Intake was higher in LOL than in FES, this result being consistent with predictions for stall-feeding conditions. There was no difference in diet composition, foraging behaviour and intake between the bispecific treatments (STRIPS, TIME and MIX). Intake was higher in the bispecific treatments than in LOL (1666 v. 1492 g digestible organic matter per day, P<0·001). Grazing time was higher in STRIPS and MIX than in LOL (420 and 430 min respectively v. 366 min, P<0·01). Dry ewes increase their intake when offered a choice of herbage species at pasture, this being mediated via an increase in grazing time rather than an increase in intake rate. There was no interaction with type of diversity or type of management.

Foraging behaviour of Armadillidium vulgare (Isopoda: Oniscidea) in heterogeneous environments

Behaviour ◽  
2004 ◽  
Vol 141 (2) ◽  
pp. 233-244 ◽  
Author(s):  
Joanne Tuck ◽  
Mark Hassall
Keyword(s):  
Leaf Litter ◽  
Foraging Behaviour ◽  
Walking Speed ◽  
Optimal Foraging Theory ◽  
Heterogeneous Environments ◽  
Intake Rate ◽  
High Quality ◽  
Turning Angle ◽  
Quality Food ◽  
Armadillidium Vulgare

AbstractForaging behaviour of Armadillidium vulgare was observed in laboratory arenas in which the spatial distribution of patches of high quality food (powdered dicotyledonous leaf litter) was varied within a background of low quality food (powdered grass leaf litter). The hypotheses that the foraging behaviour and foraging path of A. vulgare would be influenced by food quality and the patchiness of high quality food resources were tested. More time was spent in high quality food patches than in low quality food backgrounds than expected by chance in all heterogeneity treatments, but an increasingly higher percentage of time was spent in low quality food as the high quality food became more clumped in space. More time was spent searching, but less time was spent feeding in low quality food backgrounds than in high quality food patches in all the treatments. Walking speed was found to be lower in high quality food patches than in low quality food backgrounds and this was not affected by treatment. Turning frequency and turning angle were found to be higher in high quality food patches than in low quality backgrounds. Turning frequency in low quality food backgrounds decreased as the high quality food became more clumped in space, whereas turning angle in high quality food patches significantly increased in the patchy, but then decreased again in the clumped treatment. The effects of varying the spatial heterogeneity of high quality foods on the trade-off between costs of searching and intake benefits for saprophages are discussed in relation to predictions from optimal foraging theory for circumstances when intake rate maximisation is affected by the constraint of limited nutrients.

Effect of leucaena supplementation level, and provision of urea, on utilisation by sheep of Rhodes grass hay

2001 ◽  
Vol 41 (2) ◽  
pp. 155 ◽  
Author(s):  
I. W. Karda ◽  
G. McL. Dryden
Keyword(s):  
Organic Matter ◽  
Rumen Fluid ◽  
Latin Square ◽  
Rhodes Grass ◽  
Microbial Nitrogen ◽  
Grass Hay ◽  
Digestible Organic Matter ◽  
Ruminal Degradation ◽  
Chloris Gayana ◽  
Dietary Treatments

Tarramba leucaena (Leucaena leucocephala cv. Tarramba) foliage had per kilogram dry matter, 169 g protein and 29.8 g condensed tannins. Its value as a supplement, given either with or without urea, to sheep given a low-quality Callide Rhodes grass (Chloris gayana cv. Callide) hay was studied. Six rumen fistulated sheep (mean s.d. liveweight, 34 1.4 kg) were used to compare 6 dietary treatments in an incomplete latin square design. Rhodes grass hay was given ad libitum either alone, or with urea 7 g/day (U), or with leucaena 150 g/day (L150), or leucaena with urea (L150U), or leucaena 300 g/day (L300), or leucaena with urea (L300U). Digestible organic matter intake was increased significantly by leucaena supplementation although digestibility of the whole diet did not alter. Rumen fluid ammonia-N was not altered by leucaena supplementation, but was increased by urea. This suggests that Tarramba foliage protein has some resistance to ruminal degradation. Liquid and solids passage rates were not affected by the treatments. Microbial nitrogen supply to the intestine (g/day), and the efficiency of microbial nitrogen synthesis (g/kg organic matter apparently digested in the rumen), were increased by leucaena supplementation (P<0.01). Microbial protein synthesis was the only response in which 300 g/day air-dry Tarramba foliage gave improved results over 150 g/day.

Effect of altering the non-structural: structural carbohydrate ratio in a pasture diet on milk production and ruminal metabolites in cows in early and late lactation

1997 ◽  
Vol 64 (3) ◽  
pp. 393-402 ◽  
Author(s):  
V. R. Carruthers ◽  
P. G. Neil ◽  
D. E. Dalley
Keyword(s):  
Protein Synthesis ◽  
Milk Production ◽  
Milk Yield ◽  
Latin Square ◽  
Carbohydrate Intake ◽  
Microbial Protein ◽  
P Efficiency ◽  
Total Carbohydrate ◽  
Microbial Protein Synthesis ◽  
Digestible Organic Matter

AbstractThe effect on digestibility, ruminal metabolites, microbial protein synthesis and milk production of manipulating the non-structural (NSC): structural (SO carbohydrate ratio in a predominantly pasture diet was investigated in cows in early (trial 1) and late (trial 2) lactation. Twenty-four cows in trial 1 and 15 cows in trial 2 were offered pasture only (P), 0·85 P plus 0·15 NSC/protein mixture (PR), and P plus an additional 0·1 (trial 1) or 0·15 (trial 2) NSC (PE) in a Latin-square arrangement. All diets were isonitrogenous and P and PR were isoenergetic. PE but not PR increased microbial protein synthesis and decreased ruminal ammonia and milk urea levels, compared with P. Efficiency of microbial synthesis (g N per kg digestible organic matter intake) was not altered by treatment. Treatments had minor effects on ruminal pH and no effect on volatile fatty acid concentrations. PE and PR did not affect milk yield or protein yield and decreased fat yield compared with P in trial 1. Milk yield was increased on PE and PR compared with P and was greater on PE than PR, in trial 2. Yields of fat and protein were higher on PE than on P and yield of protein was higher on PR than on P. The results suggest that increasing the ratio of NSC: protein by increasing total carbohydrate intake was more effective in improving nitrogen utilization in the rumen than was increasing the NSC: SC ratio without increasing carbohydrate intake.

scholarly journals The effect of protein degradation products in grass silages on feed intake and intake behaviour in sheep

1995 ◽  
Vol 73 (1) ◽  
pp. 51-64 ◽  
Author(s):  
M. Van Os ◽  
J.P. Dulphy ◽  
R. Baumont
Keyword(s):  
Treatment Effects ◽  
Degradation Products ◽  
Latin Square ◽  
Dietary Treatment ◽  
Intake Rate ◽  
Once Daily ◽  
Rumen Ph ◽  
Chewing Efficiency ◽  
Amine Addition ◽  
Intake Regulation

The effects of NH3 and amines on grass-silage intake, intake behaviour and rumen characteristics were studied in sheep. From a single sward, two direct-cut grass silages were prepared, either untreated (WAS) or with 4·51 formic acid/tonne (FAS). Four experimental diets: WAS, FAS, FAS with addition of 2·9 g NH3/kg DM (FAS + N) and FAS with 2·8 g amines/kg DM (FAS + A), were offered ad lib. once daily to four rumen-cannulated wethers in a 4 × 4 Latin square design. Daily DM intake (DMI) tended to be influenced by dietary treatment (P = 0·09). Compared with FAS, DMI was lower for WAS. Addition of NH3 did not alter DMI, whereas amine addition slightly lowered daily DMI. Reduced DMI resulted from lower intake rates during both the principal meal and the subsequent small meals. Lower initial intake rate during the principal meal suggested reduced palatability of WAS and FAS + A. Amines and NH3, however, did not influence chewing efficiency. No treatment effects were observed on total rumen pool size, DM and neutral-detergent fibre content. Furthermore, NH3, and amines did not alter rumen pH, NH3, and volatile fatty acid concentrations to the extent that they could act on chemostatic intake regulation. Amine addition, however, lowered osmolality of the rumen liquid. No treatment effects on rumen motility were observed. In conclusion, daily DMI was not reduced by the addition of NH3, suggesting that NH3per se is not the causal factor in the negative correlations between silage NH3 content and intake observed by other authors. Amines, however, tended to reduce DMI only by their effect at the oro-pharyngeal level of intake control.

Intake Rate Maximization and the Foraging Behaviour of Crossbills

1989 ◽  
Vol 20 (1) ◽  
pp. 65 ◽  
Author(s):  
Craig W. Benkman
Keyword(s):  
Foraging Behaviour ◽  
Intake Rate ◽  
Rate Maximization

scholarly journals Effects of cutting time and maceration on preference and nitrogen balance in beef steers fed mixed birdsfoot trefoil–timothy grass hay cut at sunrise or sundown

2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Luiz H P Silva ◽  
André F Brito ◽  
Carole Lafrenière ◽  
Robert Berthiaume
Keyword(s):  
Latin Square ◽  
Moisture Loss ◽  
Birdsfoot Trefoil ◽  
Intake Rate ◽  
Beef Steers ◽  
N Retention ◽  
Timothy Grass ◽  
Period 2 ◽  
N Utilization ◽  
Speed Up

Abstract Forages cut at sundown usually contain a greater concentration of nonstructural carbohydrates (NSC) than those cut at sunrise. Maceration can speed up the rate of moisture loss of cut forage during field drying and reduce NSC utilization by plant cells. We aimed to evaluate the effects of cutting time and forage maceration on feed preference, apparent total tract digestibility of nutrients, and N balance in growing steers. A mixed sward of birdsfoot trefoil and timothy grass was divided into two halves, with the first half cut at sundown (1800 h) after a sunny day and the second half at sunrise (0600 h) the next day. Approximately 50% of the sundown- and sunrise-cut herbage were macerated. Forages were harvested as hay resulting in four treatments: 1) sunrise-cut hay (AM); 2) AM plus maceration (AM-M); 3) sundown-cut hay (PM); and 4) PM plus maceration (PM-M). Hays were offered as the sole feed source to four crossbred steers (296.1 ± 7.25 kg) according to a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Each period lasted 21 d with 14 d for diet adaptation and 7 d for collection. Hays cut at sundown had 15% greater NSC than those cut at sunrise. A cutting time by maceration interaction was found (P &lt; 0.05) for intake and apparent digestibility of crude protein (CP), indicating that these two variables decreased more when maceration was applied to sundown- versus sunrise-cut hays. Similarly, interaction effects were observed (P &lt; 0.05) for total digestible nutrients and digestible energy, showing that maceration decreased the energetic value of sundown-cut hays but did not change that of sunrise-cut hays. Steers fed hays cut at sundown had decreased urinary N excretion and improved retained N (P &lt; 0.05), whereas N retention was reduced by maceration (P &lt; 0.05). In addition, six crossbred steers were used to assess feed preference, 2 wk before (period 1) and 1 wk after (period 2) the digestibility trial. Animals were randomly assigned to receive a sequence of the four hays combined in pairs. The intake rate was greater for sundown- than sunrise-cut hays, and it was decreased by maceration. Steers showed the greatest preference for PM hay, while AM-M was the most rejected. In conclusion, shifting forage cutting from sunrise to sundown increased hay NSC concentration, which resulted in improved N utilization and preference. Forage maceration during field drying decreased CP concentration and N retention in beef steers under the conditions of our study.

Effect of amount of rumen degradable protein on the utilization of wheat straw by Dohne Merino wethers

2003 ◽  
Vol 76 (2) ◽  
pp. 319-326
Author(s):  
J. van E. Nolte ◽  
A.V. Ferreirat ◽  
H.H. Köster
Keyword(s):  
Organic Matter ◽  
Wheat Straw ◽  
Volatile Fatty Acids ◽  
Latin Square ◽  
Ammonia Nitrogen ◽  
Microbial Nitrogen ◽  
Digestible Organic Matter ◽  
Microbial Efficiency ◽  
Forage Intake ◽  
Degradable Protein

AbstractA 5 ✕ 5 Latin square was conducted with ruminally and duodenally cannulated Dohne Merino wethers consuming wheat straw to determine the effect of different rumen degradable protein (RDP) levels on forage intake, fermentation characteristics, nutrient flow and digestion. The wethers had ad libitum access to water and wheat straw (32 g crude protein (CP) per kg dry matter (DM); 742 g neutral-detergent fibre (NDF) per kg DM) that was offered twice daily, immediately after intraruminal infusion of the supplements at 07:00 and 19:00 h. The supplemental RDP (calcium caseinate; 900 g CP per kg DM) levels were: 0, 40, 80, 120 and 160 g/day. Each period consisted of 14 days of adaptation and 6 days of sampling. Forage and total organic matter (OM) intakes increased in a linear manner (P < 0•01) with increasing supplemental RDP levels. Digestible organic matter intake (DOMI) displayed a quadratic increase with elevated amounts of RDP (P < 0•01). The effects of treatments on rumen and total tract digestion, as well as fluid dilution rate were minimal. Microbial nitrogen (MN) flow to the duodenum and microbial efficiency increased quadratically (P < 0•04) with increased RDP supplementation. Rumen ammonia nitrogen (NH3-N) concentrations increased linearly (P < 0•01) and total volatile fatty acids (VFA) tended to increase linearly (P = 0•07). In conclusion, RDP supplementation to Dohne Merino wethers consuming wheat straw generally enhanced rumen fermentation and forage intake. A total RDP intake (sources: calcium caseinate and wheat straw) of 3•30 g/kg M0•75 or 0•12 of DOM maximized DOMI.

Milk production from grass silage diets: effects of silage characteristics and the amount of supplementary concentrate

1994 ◽  
Vol 59 (1) ◽  
pp. 31-41 ◽  
Author(s):  
K. Aston ◽  
C. Thomas ◽  
S. R. Daley ◽  
J. D. Sutton ◽  
M. S. Dhanoa
Keyword(s):  
Formic Acid ◽  
Milk Yield ◽  
Dry Matter ◽  
Protein Concentration ◽  
Latin Square ◽  
Grass Silage ◽  
Digestible Organic Matter ◽  
Concentrate Level ◽  
Design Experiments

AbstractHigh digestibility ryegrass was ensiled using either good methods including formic acid application (HDG) or poor methods without formic acid (HDP). Low digestibility ryegrass (LDG) and lucerne (LUC) were ensiled using similar methods to HDG. Digestible organic matter in the dry matter (DM) in vivo (DOMD) for HDG, HDP, LDG and LUC were 0·756, 0·774, 0·645 and 0·562 respectively. Silages were offered ad libitum to 40 HolsteinFriesian cows in two Latin-square design experiments during weeks 8 to 22 of lactation either alone (experiment 1) or with 3, 6, 9 or 12 kg concentrate DM per day (experiment 2). Relative intakes of silage given alone were respectively 1·00, 0·44, 0·98 and 0·79. Low intake of HDP could not be predicted from silage analysis. In experiment 2, DM intake increased by 0·11 kg and milk yield by 0·24 kg for each 0·010 change in grass silage DOMD. Intake of HDG, LDG and LUC declined linearly with increasing concentrate, on HDP the effect was non-linear and intake increased up to the 6 kg level.In experiment 1, milk and protein yields were greatest on HDG, protein yield was higher on LDG than LUC and fat concentration higher on HDP and LUC. With supplementation milk yield was greatest on HDG up to the 6 kg level, at higher levels differences between silages were not significant. Fat concentration was highest on LDG and protein highest on HDG and lowest on LUC. On all silages giving the highest concentrate level reduced the concentration and yield of fat. Protein concentration increased up to the 9 kg level. Fat plus protein yields reached a maximum on HDG with 6 kg concentrate DM per day and with 9 kg on the remaining silages.

Differential effects of predation risk and competition over vigilance variables and feeding success in Eurasian siskins (Carduelis spinus)

Behaviour ◽  
2013 ◽  
Vol 150 (14) ◽  
pp. 1665-1687 ◽  
Author(s):  
Jordi Pascual ◽  
Juan Carlos Senar
Keyword(s):  
Food Intake ◽  
Predation Risk ◽  
Foraging Behaviour ◽  
Interference Competition ◽  
Ecological Factors ◽  
Intake Rate ◽  
Similar Length ◽  
Feeding Success ◽  
High Predation ◽  
Food Intake Rate

Many investigations have studied the effects of predation risk and competition over vigilance and feeding success, but they have proven to be difficult to discriminate. Moreover, none of the studies that have avoided the confusion has considered all the vigilance variables, food intake rate and time spent in the foraging patch. In this study, we designed an experiment with Eurasian siskinsCarduelis spinusforaging on three bird table feeders: one with low predation risk and competition, one with low predation risk and high competition and one with high predation risk and intermediate competition. Birds responded to increasing interference competition by increasing mean scan durations (probably due to the birds having to be vigilant for both other flock members and predators) and maintaining the length of mean inter-scan durations, while they responded to increasing predation risk by reducing mean inter-scan durations (probably in order to detect the predator sooner) while maintaining similar length of mean scan durations. Birds were often ejected from the feeder or departed because of disturbances, so time spent on feeders was reduced both because of competition and predation risk. Pecking rates were affected by competition but not by predation risk. Our results clearly show that birds vigilance strategy while foraging might be very different when they are mainly concerned with scanning for predators or when they primarily monitor competing flock companions. In addition, they stress the importance of recording all the vigilance and feeding variables when studying the effect of ecological factors over the foraging behaviour of birds.

A comparison of tall fescue and orchardgrass silages for lactating cows

1993 ◽  
Vol 73 (4) ◽  
pp. 907-914 ◽  
Author(s):  
L. J. Fisher ◽  
S. Bittman ◽  
D. E. Hunt ◽  
J.A. Shelford ◽  
B. D. Mason
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Latin Square ◽  
Plasma Urea ◽  
Lactating Cows ◽  
Boot Stage ◽  
Molar Percent ◽  
Preference Trial

The feeding value of tall fescue silage (Festuca arundinacea schreb.) harvested at the boot stage of maturity with a crude protein (CP) content of 15.4% was compared to that of orchardgrass silage (Dactylis glomerata) harvested at the same stage of maturity with a CP content of 12.5%. Two feeding trials with lactating cows were used in this comparison. The first trial employed 10 cows in a 2 × 2 Latin- square, with treatment period 35 d in length. In the second experiment five cows were used in a preference trial where individual feed intakes, duration of feeding, and rate of forage consumption were monitored electronically for a period of 9 d.In the first trial, the cows consumed more tall fescue than orchardgrass silage (P < 0.05) (14.08 vs. 12.90 kg d−1 dry matter (DM)) but there were no differences between cows fed the two silages in milk yield (30.4 vs. 29.8 kg d−1) or milk compositon. Source of silage did not influence rumen fluid pH, molar percent of volatile fatty acids or plasma glucose; however, plasma urea-N levels were significantly higher (P < 0.05) (17.00 vs. 15.14 mg dL−1) when cows were fed tall fescue silage compared with when they were fed orchardgrass silage. In the preference trial employing electronically monitored forage feeding gates, all five cows demonstrated a preference for the tall fescue silage consuming a daily average of 9.83 kg DM for tall fescue compared with 3.73 kg for orchardgrass silage. Cows spent more time (P < 0.05) (68.3 vs. 14.1 min−1) and ate faster (69.6 vs. 54.0 g DM min−1) from the gates offering tall fescue silage compared with the gates offering orchardgrass silage. From the results of these two trials it was concluded that tall fescue silage was comparable to orchardgrass in supporting milk production and superior to orchardgrass in terms of palatability. Key words: Tall fescue, silage preference, lactating cows

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