Physical form and energy concentrations of broiler diets

1972 ◽  
Vol 12 (59) ◽  
pp. 604 ◽  
Author(s):  
WJ Yule

Commercial broilers were reared in controlled environment houses to nine weeks of age at 464 cm2 of floor space per bird. The treatments over the starter and finisher phases were two metabolizable energy concentrations of 11.5 and 13.2 MJ kg-1 each in either mash or pelleted form with a commercial pellet treatment as a control. Dietary energy content was negatively correlated with food conversion ratio but did not significantly influence liveweight. Pelleting significantly increased liveweight and improved food efficiency. There was no evidence of an interaction between dietary energy content and physical form of the diet. The increased cost of the higher energy diet counterbalanced the decreased food consumption per unit of body weight.

1974 ◽  
Vol 14 (67) ◽  
pp. 141 ◽  
Author(s):  
WJ Yule

Commercial broilers, kept in small, fixed-size pens, were allowed 310, 370, or 460 cm2 of floor space per bird started at one day of age, in a windowless controlled environment house. At each stocking density birds were offered diets with 12.5, 12.9, or 13.4 MJ kg-1 of metabolizable energy from 41 to 64 days of age. Male and female broilers grew more slowly (P < 0.05) when offered the lowest energy diet. They were heavier (P < 0.05) when allowed 460cm2 of floor space per bird. Total output on the basis of liveweight produced per unit of floor space over 64 days of age was largest in the most densely stocked pens. Optimal dietary metabolizable energy concentration was approximately 12.9 MJ kg-1; however, reasons for varying this recommendation are discussed.


1961 ◽  
Vol 3 (1) ◽  
pp. 1-7 ◽  
Author(s):  
J. D. Fraser

1. Twenty spring-born Friesian calves, housed indoors, were divided into two groups each of 10 calves. During their first three weeks all calves were fed alike on whole milk containing 3·5% butterfat. At three weeks of age calves in one group were changed to a diet consisting of reconstituted buttermilk powder which was made up to the same energy content as the milk. Up to the 30th day intake was gradually increased to 20% of body weight; thereafter till slaughter of the calves at approximately 200 1b. live-weight both groups were fed to appetite twice daily.2. Calves in both groups grew well and differences between groups in growth rate, and age at slaughter, food consumption and food conversion, were all statistically non-significant.


2019 ◽  
Vol 3 (3) ◽  
pp. 1011-1017
Author(s):  
James W Oltjen

Abstract Lofgreen and Garrett introduced a new system for predicting growing and finishing beef cattle energy requirements and feed values using net energy concepts. Based on data from comparative slaughter experiments they mathematically derived the California Net Energy System. Scaling values to body weight to the ¾ power, they summarized metabolizable energy intake (ME), energy retained (energy balance [EB]), and heat production (HP) data. They regressed the logarithm of HP on ME and extended the line to zero intake, and estimated fasting HP at 0.077 Mcal/kg0.75, similar to previous estimates. They found no significant difference in fasting HP between steers and heifers. Above maintenance, however, a logarithmic fit of EB on ME does not allow for increased EB once ME is greater than 340 kcal/kg0.75, or about three times maintenance intake. So based on their previous work, they used a linear fit so that partial efficiency of gain above maintenance was constant for a given feed. They show that with increasing roughage level efficiency of gain (slope) decreases, consistent with increasing efficiency of gain and maintenance with greater metabolizable energy of the feed. Making the system useful required that gain in body weight be related to EB. They settled on a parabolic equation, with significant differences between steers and heifers. Lofgreen and Garrett also used data from a number of experiments to relate ME and EB to estimate the ME required for maintenance (ME = HP) and then related the amount of feed that provided that amount of ME to the metabolizable energy content of the feed (MEc), resulting in a logarithmic equation. Then they related that amount of feed to the net energy for gain calculated as the slope of the EB line when regressed against feed intake. Combining the two equations, they estimate the net energy for maintenance and gain per unit feed (Mcal/kg dry matter) as a function of MEc: 0.4258 × 1.663MEc and 2.544–5.670 × 0.6012MEc, respectively. Finally, they show how to calculate net energy for maintenance and gain from experiments where two levels of a ration are fed and EB measured, where one level is fed and a metabolism trial is conducted, or when just a metabolism trial is conducted—but results are not consistent between designs.


1975 ◽  
Vol 20 (2) ◽  
pp. 199-205 ◽  
Author(s):  
D. Levy ◽  
Z. Holzer ◽  
Y. Folman

SummaryThe effects of roughage level (15 and 35% of the ration) and of slaughter weight (400,450 and 500 kg) were studied in an experiment of 2 x 3 factorial design. Daily live-weight gains and carcass gains were significantly higher on the lower roughage levels, but there was no difference in degree of fatness of the carcass. Dry-matter intake expressed as a percentage of body weight was 2·91 on 35% roughage compared with 2·53 and 15% roughage, i.e. 15% higher on the highroughage diet. This compensated the animals on the high-roughage diet for the lower energy content of their feed. Rate of gain increased with an increase in slaughter weight. The percentage of fat trim and of saleable meat increased, while that of bone decreased significantly with an increase in slaughter weight. The animals on the lowroughage diet were approximately 11% more efficient than the others in converting metabolizable energy into live weight.


1983 ◽  
Vol 101 (1) ◽  
pp. 113-118 ◽  
Author(s):  
S. S. Zombade ◽  
J. S. Chawla ◽  
J. S. Ichhponani

SUMMARYThree varieties of triticale (TL-238, TL-257 and TL-319) bred by the Plant Breeding Department of Punjab Agricultural University were studied for nutrient composition and metabolizable energy (ME) content for egg-type chicks. A feeding trial was also conducted to study the suitability of triticale as a replacement for maize in conventional high- and low-cereal diets for different classes of egg-type chickens.The crude protein contents of TL-238, TL-257 and TL-319 were respectively 13·4,14·4 and 2·1%. Corresponding values for starch content were 51·5, 49·2 and 54·3%, respectively. ME in triticale varieties closely followed the trend of starch content. Accordingly TL-319 was higher in ME (13·58 MJ/kg D.M.) than TL-238 and TL-257 (12·91 and 12·49 MJ/kg D.M. respectively). There were no significant differences in body-weight gain or in food conversion of chicks fed diets containing different varieties of triticale. The substitution of triticale for maize in a conventional high-cereal diet improved growth and food conversion of starter chicks. In a low-cereal diet, however, triticale had an adverse effect on the growth rate and food conversion of starter chicks. At the end of 18 weeks of age, the differences in body-weight gain, food conversion and efficiency of protein utilization by chicks on all the treatments were not significantly different (P > 0·05). Results of the production phase showed that egg production, egg mass, food conversion and energetic efficiency were significantly (P < 0·05) improved by feeding triticale.


2017 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Otong Zenal Arifin ◽  
Jojo Subagja ◽  
Vitas Atmadi Prakoso ◽  
Endang Haris Suhud

Barb (Barbonymus balleroides) considerably has economic potential as aquaculture commodity. However, there was still lack of development on aquaculture for this species. This study was conducted to observe the effect of different stocking density on growth of barb. The fish (body weight: 14.89 ± 0.13 g) were stocked in nine floating nets (dimension: 2 m x 2 m x 1 m) inside the concrete ponds with three stocking density treatments (10, 15, and 20 fish/m3). Each treatment consisted of three replications. Fish were fed on commercial pellet (30% of crude protein) as much as 3% of the biomass per day with twice a day of feeding frequency. Data of growth performances (body weight, specific growth rate, average daily growth, biomass, food conversion ratio, and survival rate) were collected every 30 days during 90 days of rearing period. Water quality variables (temperature, pH, and dissolved oxygen) were observed during experiment. The results showed that the optimal stocking density for the growth of barb was 10 fish/m3. Best value of food conversion ratio was found 10 fish/m3 compared with 15 and 20 fish/m3 (P<0.05). Meanwhile, there were no significant differences on survival rate between treatments. These results also showed the potential of rearing barb on culture ponds with appropriate stocking density.


1989 ◽  
Vol 49 (2) ◽  
pp. 183-191 ◽  
Author(s):  
G. P. Jones ◽  
P. C. Garnsworthy

ABSTRACTFour groups of six cows were fed from 12 weeks before calving to achieve condition scores at calving of 3·23 (F) and 1·98 (T). For the first 20 weeks of lactation all cows were given 10 kg/day of isonitrogenous (180 g crude protein per kg dry matter (DM)) compounds containing either a high (13·0 MJ/kg DM; HE) or a low (9·8 MJ/kg DM; LE) concentration of metabolizable energy, together with 3 kg/day molassed sugar-beet pulp and hay offered ad libitum.The mean milk yield of cows receiving compound HE (27·7 kg/day) was higher (P > 0·05) than that of cows receiving compound LE (25·6 kg/day). Cows in group FHE yielded 27·0 kg/day, compared with 25·5 kg/day for FLE (P > 0·05); cows in group THE yielded 28·4 kg/day compared with 25·17 kg/day for TLE (P <0·05). After peak lactation, milk yields were maintained better in group THE but declined at a faster rate in group TLE than in groups FHE and FLE. Neither dietary energy concentration nor condition score at calving significantly affected milk composition (butterfat 43·5, protein 29·1, lactose 50·2 g/kg). Cows receiving compound HE consumed significantly (P < 0·001) more energy (208 MJ/day) than cows receiving compound LE (188 MJ/day). Over the first 10 weeks of lactation, changes in condition were –0·83, –0·88 +0·08 and –0·25 (s.e.d. 0·22, P < 0·05) condition score units for cows in groups FHE, FLE, THE and TLE respectively.It is concluded that with diets of high energy concentration intake is mainly limited by physiological mechanisms so that thin cows eat more than fat cows and produce similar amounts of milk. With diets of lower energy concentration, intake is limited by rumen capacity and thin cows eat the same as fat cows. This results in increased fat mobilization and a slight decrease in milk yield by cows which are fat at calving but the limited fat reserves of cows which are thin at calving are insufficient to compensate for reduced energy intake so large reductions in milk yield are observed.


1976 ◽  
Vol 86 (2) ◽  
pp. 411-423 ◽  
Author(s):  
E. R. Ørskov ◽  
I. McDonald ◽  
D. A. Grubb ◽  
K. Pennie

SummaryAbout sixty male lambs were fed ad libitum from 6 weeks of age on low- or highprotein diets based on barley or barley and fishmeal and containing respectively 120 and 200 g crude protein/kg dry matter. Some lambs were changed from one diet to the other when they reached 28 kg live weight. All were slaughtered as they attained a predetermined series of live weights ranging from 20 to 75 kg.Throughout the experiment, rates of live-weight gain were substantially higher with the high-protein (HP) than with the low-protein (LP) diet, but were highest after a change from low to high protein (LHP). The feed consumption of the LHP lambs did not exceed that of the HP lambs, but the former showed a substantial superiority in feed conversion ratio at the same live weight.At similar empty body weights, the LP lambs contained more fat and less water in the empty body than the HP lambs. Although the percentage differences decreased at higher weights, differences were still apparent at 70 kg live weight.The LHP lambs showed dramatic and rapid changes in body composition, particularly in water and fat content. By 40 kg live weight, their composition approached that of the HP lambs.The ratio of water to protein was consistently lower for the LP lambs. The ratio of protein to ash also differed between LP and HP lambs. It was initially highest for the HP lambs, at about 40 kg live weight it was the same, and at 70 kg live weight it was highest for the LP lambs.The ash content of the LHP lambs remained virtually constant during the period of rapid growth and rapid deposition of water, protein and fat which took place immediately after the change of diet, and only showed compensatory increases after 35 kg live weight. This finding was supported by the pattern of changes in weight and specific gravity of the femur and tibia + fibula.Use was made of separate relationships between live weight and body composition for the LP, HP and LHP lambs to estimate rates of accretion of crude protein, fat and water in the empty body. There was a particularly striking increase in the rate of accretion of water immediately following the change of diet. There was an increase in the water content of empty-body gain and a reduction in the ratio of gain in fat to gain in protein.Derived estimates of the ratio of metabolizable energy intake above maintenance to the energy content of empty-body gain gave some suggestion of an improvement in efficiency of utilization of metabolizable energy for gain following the change from low to high protein. It is concluded however that the improvement in food conversion ratio following the change is attributable mostly to difference in the composition of gain.


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