The nutrition of the early weaned lamb:II. The effect of dietary protein concentration, feeding level and sex on body composition at two live weights
01 Aug 1970-The Journal of Agricultural Science (Cambridge University Press)-Vol. 75, Iss: 01, pp 19-26
TL;DR: In an experiment with ninetynine lambs the effects on the body composition of male and female lambs were examined when five diets containing different concentrations of crude protein (in the range 10-20%) were given at three levels of feeding as mentioned in this paper.
Abstract: 1. In an experiment with ninety-nine lambs the effects on the body composition of male and female lambs were examined when five diets containing different concentrations of crude protein (in the range 10–20%) were given at three levels of feeding and lambs were slaughtered at two live weights (27·5 and 40 kg).2. With lambs slaughtered at 27·5 kg there were significant increases in the rate of both nitrogen and fat retention with increases in levels of feeding. There were also linear increases in the rate of protein deposition and decreases in fat deposition with increases in the concentration of crude protein. This effect was particularly marked at the high level of feeding.3. With lambs slaughtered at 40 kg live weight there were also linear increases in fat and in nitrogen deposition with increasing feeding level but the effect of increasing the protein concentration on increases in nitrogen retention departed from linearity.4. While at 27·5 kg there were no significant effects of feeding level on nitrogen and ether-extract content of the bodies at slaughter, with animals slaughtered at 40 kg there was a significant linear decrease in ether-extract content with increasing feeding level and a corresponding linear increase in nitrogen content with increased level of feeding.5. Male lambs deposited more nitrogen and less fat than females. This was true of both rate of deposition and of carcass composition at 40 kg live weight.
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TL;DR: The influence of sheep production systems on the environment of the Mediterranean area and the different productive systems of lamb in Spain are described, highlighting the importance of productive and pre-slaughter factors on carcass quality and post-sl Slaughter factors on meat quality.
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01 Jan 2013
TL;DR: Nutrient requirements of all livestock are based on the size of the animal, how active the animal is, the body growth rate, and/or the animal’s level of milk production and fat content in milk produced.
Abstract: Nutrient requirements of all livestock are based on the size of the animal, how active the animal is, the body growth rate, and/or the animal’s level of milk production and fat content in milk produced. Maintenance requirements are for low levels of activity as when being fed in a dry lot situation. When animals are on pasture activity increases and these the requirements may be as much as 25% higher due to this increased activity.
218 citations
TL;DR: Mature females depleted reserves of dissectiblefat and muscle considerably during both winters of the study, particularly the second, when nearly all dissectible fat and 32% of estimated fall muscle mass were lost.
Abstract: Twelve collections of mature female caribou and calves (Rangifer tarandus groenlandicus) were conducted between June 1982 and June 1984 on Coats Island, Northwest Territories, Canada, to study seasonal changes in body composition in this winter mortality limited population. Mature females depleted reserves of dissectible fat and muscle considerably during both winters of the study, particularly the second, when nearly all dissectible fat and 32% of estimated fall muscle mass were lost. Recovery of fat and muscle was rapid during the two summers, because of good quality forage and little environmental disturbance. Lactation appeared to slow fattening in early summer 1983, but by October females achieved fatness similar to that in 1982, when a majority of females in summer and fall were nonlactating. Low rumen fill and consistently high fat and muscle levels in fall 1982 and 1983 suggested that mature females then approached "set points" in body fat and muscle content. Calves grew rapidly in summer; most of...
132 citations
TL;DR: It is suggested that barley diets for early-weaned lambs can with advantage be supplemented with non-protein N to increase the crude protein in the dry matter up to about 12%.
Abstract: 1. The effects of adding increasing supplements of urea to mainly barley diets for early-weaned lambs were investigated in two experiments. In the first experiment the passage of nutrients along the alimentary tract was studied by taking samples of abomasal, ileal and rectal contents and using a marker technique. In the second experiment, feed consumption and rate of gain were recorded over the growth period up to 40 kg live weight, and nitrogen balances were carried out. In the second experiment a barley-fish meal diet was also included.2. The fermentation of organic matter in the rumen increased with the amount of urea in the diet and levelled off when the diet contained about 12% crude protein.3. Urea supplementation had significant effects in increasing N retention and rate of live-weight gain and in decreasing feed conversion ratio, but supplementation beyond about 12% crude protein in dry matter had no further effect on these measurements. In each instance results with the barley–fish meal diet were better than the results with any of the barley-urea diets.4. From the concentrations of diaminopimelic acid (DAPA) in abomasal fluid it was estimated that microbial protein was produced in the rumen at a rate of 15.6% g/100 g organic matter fermented. This ratio did not appear to alter significantly with urea supplementation, but the comparison depends on the assumption that the concentration of DAPA in the bacterial protein did not itself change with urea supplementation.5. Using results from both experiments, it was calculated that the retained N on the urea-supplemented barley diets was approximately 47% of the amount of protein N absorbed in the small intestine.6. It is suggested that barley diets for early-weaned lambs can with advantage be supplemented with non-protein N to increase the crude protein in the dry matter up to about 12%. When barley diets are given with a protein supplement the addition of non-protein N is unlikely to be beneficial unless the protein supplement is given in such a way that it is not subject to degradation to yield ammonia in the rumen.
124 citations
TL;DR: Although in general, sensorial quality was not significantly affected by slaughter weight or sex, meat from lighter lambs had greater general acceptability than meat from heavier lambs (29kg).
118 citations
Cites background from "The nutrition of the early weaned l..."
...Andrews and Ørskov (1970) suggested that differences in fatness are, within the same breed or crossbreed, more noticeable at some stages of growth than others, or can vary depending on the growth rate or nutrition regime....
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References
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254 citations
186 citations
TL;DR: There appeared to be a linear relationship between the concentrations of starch in abornasal and ilcal dry matter, indicating a limited capacity for starch digestion in the small intestine, and the possible relationships between the extent of fermentation in the rumen and energy and nitrogen metabolism are discussed.
Abstract: 1. Lambs fitted with cannulas in the abomasum, terminal ileum and caecum were used to study the digestion of starch and dry matter when rations with high starch content were given. Polyethylene glycol was used as an indigestible reference substance.2. In Expt I reduction in level of feeding from an estimated ad lib. intake to 70% of this level reduced the amount of dietary starch escaping fermentation in the rumen from 6.8 to 4.4% of intake on a barley diet and from 12.8 to 7.7% on a diet consisting of 40% dried grass and 60 yo barley. Inclusion of 40% chopped dried grass in the diet increased the amount of dietary starch escaping fermentation in the rumen. There appeared to be a linear relationship between the concentrations of starch in abornasal and ilcal dry matter, indicating a limited capacity for starch digestion in the small intestine.3. In Expt 2 a barley diet was compared with diets based on flaked maize, ground maize or cracked maize. With these diets the percentage of dietary starch escaping fermentation in the rumen was respectively 6.2, 5.4, 12.1 and 142, showing that more starch escapes fermentation with uncooked maize diets than with barley diets.4. The molar proportions of volatile fatty acids produced by fermentation in the caecum were apparently influenced by the amount of starch passing to the intestines. The highest proportion of acetic acid (78%) was associated with 4.5% of starch in abomasal dry matter, and the lowest proportion (57%)was associated with 20.1% of starch in abomasal dry matter.5. The possible relationships between the extent of fermentation in the rumen and energy and nitrogen metabolism are discussed.
139 citations
TL;DR: Huxley's allometry equation was found appropriate for standardising the measurements, and the exponent was taken as a numerical expression of the relative maturity of each tissue or part.
Abstract: 1. From a review of the literature it has been shown that there are two opposing views regarding the best method of interpreting growth data, which arise from conflicting opinions as to the role of fat deposition in the growth of the animal.2. Data of McMeekan and Palsson and Verges have been re-analysed and their own results are compared with results obtained when the effects of variation in fat content are eliminated.3. No evidence has been found of any effect of plane of nutrition on the total weights of bone and muscle relative to the weight of bone plus muscle together.4. The weight of bone plus muscle in the head and neck was increased relative to the total weight of bone plus muscle during periods of restricted nutrition. Apart from this there was no clear evidence of a relationship between the order of maturity of the joints and their relative retardation of development.5. Huxley's allometry equation was found appropriate for standardising the measurements, and the exponent was taken as a numerical expression of the relative maturity of each tissue or part.
106 citations
TL;DR: The results agree reasonably well with estimates of protein requirements for lambs given by the Agricultural Research Council (1965) and the overall optimum dietary crude protein concentration for growth between 16 and 40 kg body weight was about 17·0, 15·0 and 11·0% when the mean digestible energy intake was 3·0.
Abstract: The live-weight gains of male and female lambs were measured during growth from 16 to 40 kg live weight when five cereal-based diets varying in dietary crude protein concentration (from 10 to 20%) were given at three levels in a 5×3×2 factorial design.Males grew faster than females by about 15% (P < 0·001); this difference increased with age and with the amount of feed given (P < 0·05). Growth rate responded linearly to increase in feeding level (P < 0·001) and curvilinearly to increase in dietary protein concentration (P < 0·01). A significant interaction (P < 0·01) occurred whereby growth increased with higher protein concentrations as feeding level increased.At the highest feeding level (near ad libitum) the results suggest that the optimum dietary crude protein concentration for growth was about 17·5, 15·0, 12·5 and 12·5% at body weights of 20, 25, 30 and 35 kg respectively. The overall optimum dietary crude protein concentration for growth between 16 and 40 kg body weight was about 17·0, 15·0 and 11·0% when the mean digestible energy intake was 3·0, 2·6 and 2·1 Mcal/day.The results agree reasonably well with estimates of protein requirements for lambs given by the Agricultural Research Council (1965).
80 citations