scholarly journals Effects of genotype on the performance and intake characteristics of sheep grazing contrasting hill vegetation communities

1999 ◽  
Vol 69 (2) ◽  
pp. 419-426 ◽  
Author(s):  
K. Osoro ◽  
M. Oliván ◽  
R. Celaya ◽  
A. Martínez
Keyword(s):  
Weight Gain ◽  
Small Body ◽  
Live Weight ◽  
Calluna Vulgaris ◽  
Diet Selection ◽  
Grass Species ◽  
Environment Interaction ◽  
Vegetation Communities ◽  
Live Weight Gain ◽  
Grazing Season

AbstractThe live-weight responses, voluntary herbage intakes and diet compositions of two breeds of sheep of different mature live weights, grazing two contrasting hill vegetation communities, were studied over three consecutive grazing seasons. A total of 228 Latxa and 255 Gallega non-lactating ewes, with mature live weights of 42.4 and 33.1 kg respectively, grazed two replicates, each of two 5-ha plots comprising by area either 0⋅3 Calluna vulgaris and 0.7 grass species (Agrostis capillaris, Festuca rubra and Nardus stricta) (treatment C3) or 0.7 C. vulgaris and 0⋅3 of the above grass species (treatment C7).The Latxa ewes achieved higher rates of live-weight gain than the Gallega ewes under conditions of high availability (sward surface height >3⋅0 cm) of the preferred grass species (A. capillaris and F. rubra) but had lower rates of live-weight gain in the later part of the grazing season when the availability of the preferred grass species was low. In general, the Latxa ewes had higher voluntary herbage intakes per unit live weight and selected a diet of higher digestibility than the Gallega ewes (P < 0⋅001). The composition of the diet was significantly affected by treatment (P < 0⋅001) and was of a higher digestibility in the earlier part of the grazing season (P < 0⋅001).The results indicate the existence of a significant (P < 0⋅001) genotype × environment interaction affecting diet selection and animal performance. Between-breed differences in diet selection are likely to be important in determining grazing behaviour and thus the suitability of different genotypes for particular environments. Breeds with a small body size are likely to be better suited to the poorer land resources where the availability of preferred species is low.

The effects of method of processing on the intake and digestibility by lambs of dried perennial rye-grass and tall fescue

1974 ◽  
Vol 19 (2) ◽  
pp. 193-200 ◽  
Author(s):  
R. M. Tetlow ◽  
R. J. Wilkins
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Weight Gain ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Live Weight ◽  
Grass Species ◽  
Live Weight Gain

SUMMARYCobs and pellets which differed in particle size (modulus of fineness, MF) were prepared from dried perennial ryegrass and tall fescue and given to sheep. The MF values of the feeds were 2·45,1·09,0·81 and 0·74 for perennial ryegrass and 2·28,0·84,0·67 and 0·57 for tall fescue. Organic matter digestibility was similar for the two grass species when measured in vivo, but when measured in vitro values for perennial ryegrass were about 3 units higher than those for tall fescue. Voluntary intake and live-weight gain were higher for sheep given tall fescue, the difference in live-weight gain being just significant at P < 0·05. The response to change in particle size was similar for the two grass species. Intake was lowest and digestibility highest for the feeds with the highest MF, but differences between the three finely-ground forms of each species were not significant. There was a tendency for the intake of digestible organic matter to be lower for the feeds with lowest MF than for those with intermediate values for MF. The rate of passage of undigested particles was slower for cobs with the highest MF than for the other feeds, which did not differ significantly one from another.

Individual performance and production per unit area of grazing steers of different potential growth rates

1997 ◽  
Vol 65 (3) ◽  
pp. 373-381 ◽  
Author(s):  
H. A. Molinuevo
Keyword(s):  
Weight Gain ◽  
Mixed Model ◽  
Unit Area ◽  
Live Weight ◽  
Individual Performance ◽  
Environment Interaction ◽  
Initial Weight ◽  
Potential Growth ◽  
Live Weight Gain ◽  
The Relationship

AbstractThe purpose of this work was to investigate the relationship between individual animal performance and production per unit area of land of steers of different potential growth rate under different grazing stocking rates (SR). The analysis involved 160 steers divided equally between two breeds, over 2 years at four SRfor each breed and two replicates for each SR. Thus there werefive steers per replicate. The breeds were purebred Aberdeen Angus (Angus) and 4 Limousin (Limousin). After weaning steers were grazed for 251 days on a pasture dominated by Festuca arundinacea. Given that equal SR does not equate to equal treament for breeds characterized to be of different size and rate of growth at a given age, the analysis was undertaken on the basis of three categories of metabolic body size per ha (S). The variables analysed were individual live-weight gain (final minus initial weight, kg), relative individual live-weight gain (logefinal weight - loge initial weight) and production (kg/ha). A mixed model was used to examine effects of breed, S, year and the interactions between these variables. In general significant (P < 0·05) differences were found for all factors of classification and interactions. Independent linear regressions were calculated for each breed between absolute live-weight gain, relative live-weight gain, and production on S. It was concluded that there was a genotype × environment interaction, with the Angus breed tending to show a higher production per unit area than the Limousin, especially at high levels of S when scarcity of forage was apparent. Nevertheless Limousin steers had higher absolute individual performance than the Angus. The higher production of the smaller breed may be explained by a higher SR at a given S level and also by its higher relative individual live-weight gain in relation to that of the larger breed. The data were coded to use Mott's model to study the relationship between absolute performance (kg) and production (kg/ha). However this model ignores the existing interaction involving breeds.

Feed intake of grazing cattle. V. A further study of the influence of pasture restriction combined with supplementary feeding on production per animal and per acre

1967 ◽  
Vol 9 (3) ◽  
pp. 313-324 ◽  
Author(s):  
W. Holmes ◽  
M. K. Curran
Keyword(s):  
Weight Gain ◽  
Milk Yield ◽  
Feed Intake ◽  
Previous Experiment ◽  
Live Weight ◽  
Stocking Rate ◽  
Live Weight Gain ◽  
Grazing Season ◽  
Grazing Cattle ◽  
Electric Fence

This paper reports the second of two experiments which examined the possibility of improving pasture utilisation by restricting grazing and giving cows a supplement of concentrates. Two treatments (A and B) were continuously imposed, each on a group of 10 adult Ayrshire cows, for about 4 months. Cows received either pasture alone allocated daily by electric fence (B), or half this area of pasture plus 3 Ib. cubed concentrates per 10 lb. milk (A).Herbage intakes were estimated by grass cutting techniques and also by faecal index methods, and animal performance was recorded. Over the whole experiment the two treatments gave similar levels of production per animal. Significant differences in milk yield and live-weight gain were detected only in periods 1 and 4, respectively, when the intended restriction was not completely achieved. While production per acre of grass was doubled by treatment a about 4,000 lb. grain was considered necessary to replace one acre of grazing.The results are discussed in relation to the previous experiment. They suggest that the method of replacing half the normal grazing with barley or other concentrated feeds could be usefully employed to alleviate pasture shortage in parts of the grazing season and might therefore facilitate the maintenance of a high stocking rate.

scholarly journals The effect of supplemental concentrate feed on live weight gain of yearling heifers over grazing season in subirrigated rangelands of East Anatolia

2014 ◽  
Vol 38 ◽  
pp. 278-284 ◽  
Author(s):  
Ali KOÇ ◽  
Adem KAYA ◽  
Mehmet Kerim GÜLLAP ◽  
Halil İbrahim ERKOVAN ◽  
Muhlis MACİT ◽  
...  
Keyword(s):  
Weight Gain ◽  
Live Weight ◽  
Live Weight Gain ◽  
Grazing Season ◽  
East Anatolia

Diet selection of sheep: effects of adding urea to foods with different protein contents

2001 ◽  
Vol 73 (1) ◽  
pp. 183-195 ◽  
Author(s):  
S. M. James ◽  
I. Kyriazakis ◽  
G. C. Emmans
Keyword(s):  
Weight Gain ◽  
Live Weight ◽  
Diet Selection ◽  
Fresh Matter ◽  
Live Weight Gain ◽  
Beneficial Effects ◽  
Urea Content ◽  
General Preference ◽  
D 12 ◽  
Selection Of

AbstractTwo experiments were conducted in which growing sheep were given choices between foods differing in their contents of urea. The crude protein (CP) contents of both of the foods of the pair were also varied. The hypothesis tested was that the diets selected would be those that met the effective rumen degradable protein (eRDP) requirements of the animals and would avoid excess consumption of eRDP. Three basal foods, differing in CP were formulated. D was designed to be deficient in CP with 80 g CP and 58 g eRDP per kg DM; H was calculated to be adequate with 159 g CP and 114 g eRDP per kg DM; P had excess with 210 g CP and 148 g eRDP per kg DM. Other foods were made by adding 12·5 or 25 g urea per kg fresh matter to each of the three basal foods to make a further six foods. In both experiments Texel✕Greyface female sheep were used. In experiment 1, 34 sheep weighing 37·2 (s.d. 1·85) kg were randomly allocated to one of six groups and each group was offered a choice between a pair of foods. Groups 1 to 3 were offered pairs in the D series (Dv. D + 12·5 g urea per kg (no. = 6), Dv. D + 25 g urea per kg (no. = 6) and D + 12·5 g urea per kg v. D + 25 g urea per kg (no. = 5)). Groups 4 to 6 were offered the same pairs of foods but with H instead of D. In experiment 2, 96 sheep weighing 29·8 (s.d. 3·37) kg were randomly allocated to one of 12 groups. Groups 1 to 6 (no. = 6) were allocated a single food (D, D + 25 g, H, H + 25 g, P or P + 25 g urea per kg) throughout the experiment. Groups 7 to 12 were given a choice (no. = 10) between two foods. One food of the pair was the basal D, H or P. The other food was the same basal food supplemented with either 12·5 or 25 g urea per kg. On the single foods adding urea to D resulted in an increase in food intake and live-weight gain suggesting that D was deficient in eRDP. Adding urea to either H or P had no beneficial effects on intake or live-weight gain. This suggests that both contained sufficient eRDP in relation to energy. Across all choice treatments in both experiments there was a highly significant preference (P< 0·01) for the food with the higher urea content. In experiment 1 0·62 (s.e. 0·04) of the diet selected was the food with the higher urea content. In experiment 2 the figure was 0·64 (s.e.0·03). The general preference for the food with the higher urea content was unaffected by the CP contents of the foods used. The results do not support the hypothesis that sheep will avoid excess eRDP when given a choice and suggest that eRDP may not be a relevant dimension in diet selection in the conditions of these experiments.

Effects of grazing system on production and parasitism of dairy breed heifers and steers grazing wet marginal grasslands

2006 ◽  
Vol 82 (2) ◽  
pp. 201-211 ◽  
Author(s):  
T. Kristensen ◽  
S. M. Thamsborg ◽  
H. R. Andersen ◽  
K. Søegaard ◽  
A. L. Nielsen
Keyword(s):  
Organic Matter ◽  
Weight Gain ◽  
Live Weight ◽  
Live Weight Gain ◽  
Grazing Season ◽  
Pasture Quality ◽  
Marginal Areas ◽  
Grazing System ◽  
Parasite Infections ◽  
Daily Gain

AbstractProduction and endoparasitism of first grazing season Holstein heifers and steers were investigated over two grazing seasons. Studies were conducted on low-lying peaty soil. In year 2000, 40 animals were included in a 2×2 factorial, replicated experiment with two sexes (steers v. heifers) and two stocking rates (SR): normal v. low (840 v. 420 kg live weight per ha at turn-out) in a set stocking grazing system. Mean grass heights over the entire season were 6·3±4·8 cm (mean±s.d.) at normal SR and 9·8±6·1 cm at low SR. Mean daily live-weight gain during grazing was significantly (P<0·001) lower at normal SR (256±147 g) compared with low (468±142 g) but sex did not significantly affect the daily gain. Serum pepsinogen levels, indicating uptake of gastric nematodes, were higher at normal SR and consistently higher in steers compared with heifers, although not significantly. In 2001 the experiment included 80 animals in a 2×2 factorial experiment with two sexes (steers v. heifers), two grazing systems (set stocking and two-paddock rotation) and four replicates. Pasture quality was low, 570 g digestible organic matter per kg organic matter and 139 g crude protein per kg dry matter on average, independent of grazing system. Mean daily live-weight gain was not significantly affected by grazing system. A tendency (P=0·07) to lower daily gain for the heifers than for steers was observed (427±161 g v. 474±138 g). Lower levels of pasture contamination with parasites were observed in the paddocks without grazing up to mid July but otherwise rotation did not prevent parasite infections. It is concluded that first grazing season steers and heifers have the same potential for growth when grazing marginal areas with low pasture quality. Set stocking or the two-paddock rotation scheme did not affect productivity or level of parasite infection at the end of season. Parasite infections became a problem at high SR. SR is an important factor for both daily live-weight gain per animal and total production per ha. However, due to the very heterogeneous structure of marginal areas there is a need for other indicators than kg live weight per ha at turn-out in order to define a clear relationship between stocking rate and production.

scholarly journals Reduction of body-weight gain enhances in vitro embryo production in overfed superovulated dairy heifers

Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 783-794 ◽  
Author(s):  
S Freret ◽  
B Grimard ◽  
A A Ponter ◽  
C Joly ◽  
C Ponsart ◽  
...  
Keyword(s):  
Weight Gain ◽  
Dietary Intake ◽  
Live Weight ◽  
Reproductive Hormones ◽  
Embryo Production ◽  
Live Weight Gain ◽  
Dairy Heifers ◽  
Period 2 ◽  
Significant Difference

The aim of our study was to test whether a reduction in dietary intake could improve in vitro embryo production in superovulated overfed dairy heifers. Cumulus–oocyte complexes of 16 Prim’ Holstein heifers (14 ± 1 months old) were collected by ovum pick-up (OPU), every 2 weeks following superovulation treatment with 250 μg FSH, before being matured and fertilized in vitro. Embryos were cultured in Synthetic Oviduct Fluid medium for 7 days. Heifers were fed with hay, soybean meal, barley, minerals and vitamins. From OPU 1 to 4 (period 1), all heifers received individually for 8 weeks a diet formulated for a 1000 g/day live-weight gain. From OPU 5 to 8 (period 2), the heifers were allocated to one of two diets (1000 or 600 g/day) for 8 weeks. Heifers’ growth rates were monitored and plasma concentrations of metabolites, metabolic and reproductive hormones were measured each week. Mean live-weight gain observed during period 1 was 950 ± 80 g/day (n = 16). In period 2 it was 730 ± 70 (n = 8) and 1300 ± 70 g/day (n = 8) for restricted and overfed groups respectively. When comparing period 1 and period 2 within groups, significant differences were found. In the restricted group, a higher blastocyst rate, greater proportions of grade 1–3 and grade 1 embryos, associated with higher estradiol at OPU and lower glucose and β-hydroxybutyrate, were observed in period 2 compared with period 1. Moreover, after 6 weeks of dietary restriction (OPU 7), numbers of day 7 total embryos, blastocysts and grade 1–3 embryos had significantly increased. On the contrary, in the overfed group, we observed more <8 mm follicles 2 days before superovulation treatment, higher insulin and IGF-I and lower nonesterified fatty acids in period 2 compared with period 1 (no significant difference between periods for embryo production). After 6 weeks of 1300 g/day live-weight gain (OPU 7), embryo production began to decrease. Whatever the group, oocyte collection did not differ between period 1 and 2. These data suggest that following a period of overfeeding, a short-term dietary intake restriction (6 weeks in our study) may improve blastocyst production and embryo quality when they are low. However, nutritional recommendations aiming to optimize both follicular growth and embryonic development may be different.

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