The relative protein and energy requirements of boars, gilts and barrows

1977 ◽  
Vol 17 (87) ◽  
pp. 574 ◽  
Author(s):  
M Taverner ◽  
RG Campbell ◽  
RH King
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Dietary Protein ◽  
Protein Level ◽  
Crude Protein ◽  
Regression Equations ◽  
Food Conversion ◽  
Response Curves ◽  
Digestible Energy ◽  
Food Conversion Efficiency

Two experiments were conducted to study the response of boars, gilts and barrows to increasing levels of dietary crude protein and digestible energy. In the first experiment boars, gilts and barrows were fed diets ranging in crude protein from 14.6 to 22.7 per cent in restrictive amounts between 20 and 70 kg liveweight. Growth rate and food conversion efficiency measurements ranked the sexes in order of superiority as boars, gilts and barrows. Boars contained more lean in their hams than gilts or barrows and had lower back fat measurements than barrows. Although analysis of variance indicated there was no significant sex by protein interaction, the multiple regression equations of growth rate and the proportion of lean in the ham for the three sexes were significantly different from one another. The response curves based on the regression equations indicated that for optimum growth, boars and gilts required 19.6 per cent crude protein whereas barrows required only 18.4 per cent crude protein. The proportion of lean in the ham was maximized with 21 per cent crude protein for boars and 20 per cent crude protein for the gilts and barrows. There was a significant quadratic relationship between economic returns and dietary protein. The relationship was the same for boars and gilts and significantly different from that for barrows; returns were maximized at approximately the same protein level as growth rate for the three sexes. In the second experiment, 30 boars and 30 gilts were allocated to 30 treatment groups involving the two sexes, three levels of digestible energy (14.59, 15.51 and 16.22 MJ kg-1) and five levels of crude protein (18.2, 19.4, 20.6, 21.8 and 23.0 per cent). All diets were fed restrictively and pig performance was compared over the liveweight range 20 to 80 kg. Boars grew significantly faster, had a significantly lower food conversion ratio and produced leaner carcases than gilts. Increasing the DE level of the diet improved growth rate and food conversion efficiency but reduced carcase quality. Dietary protein level had no effect on any performance or carcase quality measurement.

The early weaning of pigs: I. The effect upon growth of variations in the protein, fat, sucrose, antibiotic, vitamin and mineral contents of diets for pigs of 8–25 lb. live weight and a comparison of wet and dry feeding

1956 ◽  
Vol 48 (2) ◽  
pp. 220-234 ◽  
Author(s):  
H. Smith ◽  
I. A. M. Lucas
Keyword(s):  
Growth Rate ◽  
Food Consumption ◽  
Conversion Efficiency ◽  
Crude Protein ◽  
Live Weight ◽  
Food Conversion ◽  
Growing Period ◽  
Ad Libitum ◽  
Antibiotic Level ◽  
Food Conversion Efficiency

1. The pigs in the three experiments reported were weaned at 10 days old and fed water and drymeal diets ad libitum until they reached 25 lb. live weight. They were housed individually in cages and records were kept of each pig's food consumption and of its live weight every third day.2. Most of the diets fed were based on roller-dried skim milk, rolled oat groats, white fishmeal, sucrose, dried yeast, cod-liver oil, minerals and antibiotic.3. Forty-eight pigs were used in Exp. 1, which was designed as a 4 × 2 factorial. Food-conversion efficiency was significantly improved by 10% when the crude protein in the diet was raised from 24 to 29%. Increasing the protein to 34 or 39% brought no further significant improvement. There were no significant differences between growth rates which were attributable to the four levels of protein.The inclusion of 10% sucrose in the diet did not result in increased food consumption, but there were significant improvements of 8% in growth rate and 10% in food conversion efficiency. There were no treatment interactions.4. Twenty-four pigs were used in Exp. 2, which was designed as a 2 × 2 factorial. Figs fed a diet containing 7% fat grew 4% faster and 6% more efficiently than others fed a diet containing 3·7% fat, but neither difference approached statistical significance. There was no advantage in feeding the meal as a slop, indeed, there was a tendency for the pigs to scour more than on dry feeding. As in Exp. 1 there was no treatment interaction.5. Forty-eight pigs were used in Exp. 3, which was designed as a 2 × 2 × 2 factorial. The basal diet contained about 30% crude protein and 10% sucrose.An increase in the antibiotic level from 18 to 112 mg./lb. diet significantly increased growth rate by 7%, but the 9% increase in efficiency of food conversion was not statistically significant.The addition of a trace mineral supplement significantly improved rate of gain by 7%, but the 6% increase in efficiency of food conversion was not statistically significant.The addition of a complex vitamin mixture had no significant effect upon either rate or efficiency of growth.6. In all three experiments the shape of the growth curve of pigs weaned at 10 days old wag divided into two periods. During the initial ‘check period’, lasting about 10 days, the pigs ate only small amounts of food, grew very slowly, and sometimes scoured. After the ‘check period’ there was a sudden change to the ‘growing period’, during which the pigs ate increasing amounts of meal and grew rapidly.The only treatment which significantly affected the length of the check period was in Exp. 3, when the addition of the vitamin supplement to a diet containing a high antibiotic level shortened the check period by 3 days but then counteracted this advantage by reducing rate of gain during the growing period.7. Between 25 lb. weight and 8 weeks of age twenty-four pigs from the experiments reported were fed ad libitum on a dry-meal diet containing 22% crude protein. The average live weight of these pigs at 8 weeks was 49 lb.

scholarly journals Growth, digestibility, and enzyme activities in the pancreas and intestines of guinea-pigs fed on raw and heated soya-bean flour

1989 ◽  
Vol 62 (3) ◽  
pp. 529-537 ◽  
Author(s):  
A. Hasdai ◽  
Zafrira Nitsan ◽  
R. Volcani ◽  
Yehudith Birk
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Dietary Protein ◽  
Guinea Pigs ◽  
Soya Bean ◽  
Apparent Digestibility ◽  
Food Conversion ◽  
Bean Flour ◽  
Nutritional Effects ◽  
Food Conversion Efficiency

The nutritional effects of giving raw (RSF) or heated (HSF) soya-bean flour to young guinea-pigs were investigated in trials 1 and 2, in which the levels of dietary protein were 120 and 190 g/kg diet respectively. The growth rate of animals fed on RSF was lower than that of those fed on HSF. Growth retardation of guinea-pigs fed on RSF was accompanied by a lower apparent digestibility of the protein (0.49–0.53) compared with HSF (0.67–0.76) and lower food conversion efficiency. In RSF-fed animals, increasing dietary protein affected growth and food conversion efficiency negatively. The pancreas of animals fed on RSF and HSF was similar in weight but secreted less trypsin, chymotrypsin and amylase, in RFS-fed animals. It was concluded that the mechanism by which raw soya-bean negatively affects the growth rate of guinea-pigs by reducing the activity of intestinal enzymes, differs from that suggested for rats and chicks, but is similar to that of pigs and calves.

High level cereal diets for the growing/finishing pig: III. A comparison with a control diet of diets containing high levels of maize, flaked maize, sorghum, wheat and barley

1968 ◽  
Vol 70 (3) ◽  
pp. 287-297 ◽  
Author(s):  
T. L. J. Lawrence
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Energy Content ◽  
Control Diet ◽  
The Other ◽  
Food Conversion ◽  
Digestible Energy ◽  
And Control ◽  
Food Conversion Efficiency ◽  
Finisher Diets

SUMMARYIn a randomized block experiment, seventy-two Large White type weaner pigs (thirty-six hogs and thirty-six gilts) were individually and restrictedly fed to 200 lb live weight six diets (as wet mashes). Five of these diets contained high levels (85 % in the starter diets and 90 % in the finisher diets) of either maize, flaked maize, sorghum, wheat or barley. The sixth diet, which acted as the control diet for the experiment, was similar to the barley diet except that 25 % of weatings replaced a similar percentage of barley. A further three groups of six litter-mate hog pigs per group were used to measure the digestibility of these diets.For the starter diets the maize diet had the highest digestible energy content, for the finisher diets the highest values were for the wheat and sorghum diets which in turn were similar to each other. The digestible energy content of the flaked maize diet was higher than the contents of the barley and control diets but lower than the contents determined for the other three diets.Three of the pigs fed the sorghum diet developed leg weaknesses and this affected growth rate and food conversion efficiency. The symptoms suggested a pantothenic acid deficiency but the results of assays carried out on all the diets indicated that the condition was not necessarily due to a deficiency of this vitamin. Growth rates in the starter period (up to 115 lb) did not differ significantly between diets but food conversion for the maize and barley diets was significantly superior to that for the wheat and sorghum diets. In the finisher period growth rate and food conversion efficiency for the maize and wheat diets was significantly superior compared with that for the other four diets. Overall, from start to slaughter, the maize diet was significantly superior to the flaked maize, sorghum and control diets in both these parameters of performance. The energetic efficiencies of growth tended to be poorer for those diets with the better food conversion ratios, the best efficiency being for the control diet.Carcass length differences were not significant but backfat thickness and eye muscle area differences followed closely the pattern found for lean and fat content of the carcass. In this context the highest percentages of lean were found first in the control and, secondly, in the barley treatment carcasses. Some differences were found in the development of anatomical regions and tissues within these regions. In particular, and relative to the five other diets, there were in the control diet carcasses (1) higher percentages formed by the leg and shoulder and (2) a higher percentage of lean in the middle.

Selection indices to improve the efficiency of lean meat production in cattle

1986 ◽  
Vol 42 (2) ◽  
pp. 183-193 ◽  
Author(s):  
G. Simm ◽  
C. Smith ◽  
J. H. D. Prescott
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Conversion Efficiency ◽  
Breeding Value ◽  
Meat Production ◽  
Food Conversion ◽  
Lean Meat ◽  
Selection Indices ◽  
Efficiency Of Selection ◽  
Food Conversion Efficiency

ABSTRACTSelection indices to improve the efficiency of lean meat production in cattle were derived with an aggregate breeding value which comprised growth rate, food conversion efficiency, killing-out proportion and carcass lean proportion. Index measurements were growth rate, food conversion efficiency and ultrasonic fat area. Relative economic values of traits in the aggregate breeding value were calculated for an 18/20-month beef system, assuming a fixed national output of lean meat. Literature estimates of phenotypic and genetic parameters were used. Two indices were derived, one with a complete restriction on genetic changes in birth weight, and the other without restriction. Correlations between the index and the aggregate breeding value were 0·53 for the restricted index, and 0·57 for the unrestricted index. The maximum proportional reduction in expected economic response, due to complete restriction of birth weight was about 0·08. Selection on either index would actually lead to a slight decrease in carcass lean proportion, but this was less than the decrease expected from selection solely on growth rate. Correlations between the indices and the aggregate breeding value (measuring the accuracy of selection) fell by only about 0·01 when ultrasonic measurements were omitted from the index, but fell by about 0·09 when food conversion efficiency was omitted. Sensitivity of the indices to changes in parameters was also examined. With proportional changes of ±0·5 in individual economic weights, or absolute changes of ±0·2 in genetic correlations or −0·2 in heritabilities, the efficiency of selection ranged from 0·93 to 1·00.

The early weaning of pigs V. The inclusion of digestive enzymes and antibiotics in diets for pigs weaned at 6–7 lb. live weight

1959 ◽  
Vol 53 (1) ◽  
pp. 130-135 ◽  
Author(s):  
A. F. C. Calder ◽  
G. A. Lodge ◽  
R. Blair
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Live Weight ◽  
Food Conversion ◽  
Or Efficiency ◽  
Rate Of Growth ◽  
Reduced Rate ◽  
Second Period ◽  
Harmful Effects ◽  
Food Conversion Efficiency

1. Dry-meal diets for pigs weaned at 6–7 lb. mean live weight and 6·9 days mean age were supplemented with antibiotic, pepsin and an α-amylase preparation according to a factorial design involving sixty-four pigs on eight treatments. Antibiotic was included in the respective diets from weaning to 40 lb. live weight and the enzymes from weaning to 25 lb. live weight.2. Antibiotic supplementation gave a 12·5% increase in rate of growth from weaning to 40 lb. P < 0·001) by reducing the incidence of scour and increasing food consumption from weaning to 25 lb. Antibiotic exerted no effect upon efficiency of food conversion.3. Pepsin supplementation increased the incidence of scour and reduced rate of growth by 3·7% whilst being fed (P < 0·1) and by 8·6% after it was omitted at 25 lb. live weight (P < 0·01). Efficiency of food conversion was reduced by 5·5% when pepsin was fed (P < 0·05) and by 4·6% after it was omitted at 25 lb. live weight (P < 0·1).4. α-Amylase appeared to exert little influence upon either growth rate or efficiency of food conversion except in the presence of pepsin. It appeared to counteract the harmful effects of pepsin on growth rate from weaning to 25 lb. and on food conversion efficiency from 25 to 40 lb. This resulted in a 5·5% increase in growth rate during the first period (P < 0·01) and 5·7% improvement in food conversion efficiency during the second period (P < 0·05).5. The overall effects of antibiotic, pepsin and α-amylase supplementation upon time taken to reach 40 lb. live weight were a reduction of 5·6 days, an increase of 3·8 days and a reduction of 3·9 days, respectively.

Oxygen Requirements for Growth of Young Coho (Oncorhynchus kisutch) and Sockeye (O. nerka) Salmon at 15 °C

1981 ◽  
Vol 38 (4) ◽  
pp. 399-404 ◽  
Author(s):  
J. R. Brett ◽  
J. M. Blackburn
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Sockeye Salmon ◽  
Critical Level ◽  
Limiting Factor ◽  
Adaptive Mechanism ◽  
Food Conversion ◽  
Lower Oxygen ◽  
Oxygen Requirements ◽  
Food Conversion Efficiency

The growth rate and food conversion efficiency of young coho and sockeye salmon on a full ration were determined in freshwater at oxygen concentrations ranging from 2 to 15 mg/L (15 °C). The data, and a reanalysis of selected published records for bass, carp, and coho, were examined critically in relation to the Limiting Factor hypothesis. It was concluded for all species that above a critical level ranging from 4.0 to 4.5 mg O2/L, growth and conversion efficiency were not limited when tested for relatively short periods (6–8 wk) under the pristine conditions of laboratory tanks. A slight but significant trend to exhibit higher hematocrits at lower oxygen levels revealed the possible presence of an adaptive mechanism for improved respiratory capacity at subcritical oxygen concentrations.Key words: limiting oxygen, growth rate, blood hematocrits, salmon tolerance

Effect on pig performance of varying the level of meat meal in cereal grain-meat meal diets

1976 ◽  
Vol 16 (81) ◽  
pp. 478
Author(s):  
VF Fagan ◽  
PR Gillis
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Optimum Level ◽  
Optimum Growth ◽  
Food Conversion ◽  
Lean Meat ◽  
Stage Of Development ◽  
Meat Meal ◽  
Cereal Grain ◽  
Food Conversion Efficiency

A pig feeding experiment was conducted in which six levels of meat meal ranging from 5 per cent to 30 per cent in increments of 5 per cent were fed throughout the experiment. Two additional treatments were included in which an initial meat meal level of 20 per cent was changed to 10 per cent in one treatment (20-10 per cent) and 0 per cent in the other (20-0 per cent) at 54.6 kg liveweight. The optimum level of meat meal was found to vary with the stage of development of the animals. At 30 kg liveweight optimum growth rate and food conversion efficiency occurred at a meat meal level of approximately 21.0 per cent. At 70 kg liveweight optimum growth rate and food conversion efficiency occurred on a diet with approximately 14.5 per cent meat meal. Reducing the level of meat meal at 54.6 kg from 20 per cent to 10 per cent had no adverse effect on any of the attributes measured. However, the reduction from 20 per cent to 0 per cent had a highly significant depressive effect on growth rate, food conversion efficiency and lean meat development. For the treatments fed at constant levels of meat meal, fat cover decreased with increasing meat meal whereas lean meat development increased with increasing meat meal up to 25 per cent but then showed a decline at 30 per cent.

The food conversion efficiency in lambs of two crosses of sheep

1967 ◽  
Vol 7 (26) ◽  
pp. 199 ◽  
Author(s):  
ME Bourke
Keyword(s):  
Growth Rate ◽  
Organic Matter ◽  
Conversion Efficiency ◽  
Animal Tissue ◽  
Food Conversion ◽  
Factors Associated ◽  
Digestible Organic Matter ◽  
High Level ◽  
Food Conversion Efficiency

The experiment investigated factors associated with differences in growth rate from birth to seven weeks, by two crossbreeds of lamb. The Dorset Horn x Border Leicester-Merino grew at 0.18 kg per day, and the Dorset Horn x Merino grew at 0.14 kg per day (P<0.001) although both crosses consumed the same digestible organic matter intake. Thus the second cross was significantly more efficient (P<0.05) than the first cross. Two levels of milk were also fed to both crosses and, although the high level improved growth rate (P <0.001), it did not effect the efficiency of conversion of food to animal tissue.

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