The efficiency of food utilization for egg production by pullets

1958 ◽  
Vol 50 (1) ◽  
pp. 97-101 ◽  
Author(s):  
W. Bolton

1. The efficiency of food utilization for egg production by pullets has been determined for two diets, one high in energy and the other low.2. Both groups laid at the same rate (245 eggs/bird) throughout the year.3. Birds fed the low-energy diet ate more food, but the intakes of digestible protein, non-protein digestible energy and metabolizable energy were the same for both groups.4. The cost of food perton was higher for the high-energy diet; per bird per year it was the same for both groups.

1959 ◽  
Vol 52 (3) ◽  
pp. 364-368 ◽  
Author(s):  
W. Bolton

1. The efficiency of food conversion by pullets and yearlings fed on high- and low-energy diets has been determined.2. Egg production was slightly higher by birds fed the low-energy diet for both pullets and yearling hens; pullets laid more eggs than yearling hens.3. For each age, the gross food intake was greater for birds fed the low-energy diet; the consumptions of digestible protein, non-protein digestible energy and metabolizable energy were the same for both diets and both ages of bird.4. The food cost per dozen eggs was slightly greater in the yearling year when the cost of rearing the pullets was ignored, and about the same when it was included.5. The efficiency of utilization of digestible energy and protein showed only a slight decrease from the pullet to the yearling year.6. The variation in the composition and digestibility of eighteen consecutive mixes of the highenergy diet and twenty-five of the low-energy diet was: crude protein 2%, non-protein digestible energy 5% and metabolizable energy 0·4 kg. cal./g. The digestibility of the crude protein and oil was 87%, for both diets; carbohydrates were 81% digestible in the high-energy diet and 59% in the low-energy diet.


1986 ◽  
Vol 42 (3) ◽  
pp. 305-313 ◽  
Author(s):  
D. A. Poole

ABSTRACTIn each of 2 years, 20 Friesian cows were given either a low-energy or a high-energy complete diet to appetite during weeks 3 to 20 of lactation. The diets for trial 1 contained concentrates, lucerne silage and chopped grass hay in the proportions 33:47:20 or 58:29:13. In trial 2, concentrates and lucerne silage were mixed in the proportions 38:62 or 75:25. These mixtures had energy concentrations of 10·2 or 11·2 and 10·3 or 11·9 MJ metabolizable energy per kg dry matter (DM) and crude protein concentrations of 144 or 160 and 140 or 157 g/kg DM in the low- and high-energy diets of trials 1 and 2 respectively.Cows offered the low-energy diet consumed less DM daily (14·5 v. 17·4 (P < 0·001) and 15·2 v. 18·2 (P < 0·001) kg DM per day in trials 1 and 2). Daily milk yields were lower with low-energy diets (19·2 v. 22·3 (P < 0·001) and 18·7 v. 24·2 (P < 0·001) kg/day in trials 1 and 2), and there were significant differences between treatments in milk composition and live-weight changes.The correlation between food intake and milk yield during weeks 3 to 20 was moderately strong (r2 = 0·58). Variation in food utilization efficiency between diets and parity groups was small in comparison to variation within parity groups.During weeks 21 to 44 of lactation the cows were at grass. In trial 2, but not in trial 1, cows previously given the low-energy diet gave less milk (1999 v. 2644 (P < 0·001) kg) but gained more live weight. There were also differences in the composition of milk produced in this period.


Animals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 109 ◽  
Author(s):  
Xiaokang Lv ◽  
Kai Cui ◽  
Minli Qi ◽  
Shiqin Wang ◽  
Qiyu Diao ◽  
...  

Supplying sufficient nutrients, such as dietary energy and protein, has a great effect on the growth and rumen development of ruminants. This study was conducted to evaluate the effects of dietary energy and protein levels on growth performance, microbial diversity, and structural and physiological properties of the rumen in weaned lambs. A total of 64 two-month-old Hu lambs were randomly allotted to 2 × 2 factorial arrangements with four replicates and with four lambs (half male and half female) in each replicate. The first factor was two levels of dietary metabolizable energy (ME) density (ME = 10.9 MJ/Kg or 8.6 MJ/Kg), and the second factor was two levels of dietary crude protein (CP) content (CP = 15.7% or 11.8%). The trial lasted for 60 days. A low dietary energy level restrained the growth performance of lambs (p < 0.05). The ruminal concentration of acetate and the ratio of acetate to propionate increased but the propionate concentration decreased significantly with the low energy diet. However, the rumen morphology was not affected by the diet energy and protein levels. Moreover, a low energy diet increased ruminal bacterial diversity but reduced the abundance of the phylum Proteobacteria (p < 0.05) and genus Succinivibrionaceae_uncultured (p < 0.05), which was associated with the change in ruminal fermentation phenotypes. By indicator species analysis, we found three indicator OTUs in the high energy group (Succinivibrionaceae_uncultured, Veillonellaceae_unclassified and Veillonellaceae_uncultured (p < 0.01)) and two indicator OTUs in the low energy group (Bacteroidales_norank and Lachnospiraceae_uncultured (p < 0.01)). In conclusion, these findings added new dimensions to our understanding of the diet effect on rumen microbial community and fermentation response, and are of great significance for establishing the optimal nutrient supply strategy for lambs.


1968 ◽  
Vol 10 (4) ◽  
pp. 345-357 ◽  
Author(s):  
D. J. A. Cole ◽  
J. E. Duckworth ◽  
W. Holmes ◽  
A. Cuthbertson

1. Over the weight range 23–50 kg live weight, pigs were fed either ad libitum or to a restricted scale. From 59 to 91 kg live weight, eight pairs of barrows and eight pairs of gilts were fed on each of two diets varying in nutrient density. The effects of feed restriction, nutrient density of the diet and sex on voluntary feed intake, performance and carcass characteristics were studied.2. Pigs which had been restricted grew more slowly and contained less fat and more lean at 50 kg live weight.3. When restricted pigs were offered feed ad libitum from 59 to 91 kg live weight they ate more and had higher daily intakes of digestible energy than pigs liberally fed in early life.4. There was evidence of compensatory growth in pigs which had received the restricted diet, but there was no significant difference in feed utilization between restricted and ad libitum pigs. It was concluded that the compensatory growth was largely the result of increased appetite.5. Pigs finally fed on a low energy diet, in comparison with those on a high energy diet, ate more feed but less digestible energy indicating that appetite was physically limited. Efficiency of conversion of digestible energy to live weight was similar on both treatments. A higher proportion of acetic acid was produced in the caecum of pigs fed the low energy diet. Pigs receiving the low energy diet had lower killing-out percentages not entirely caused by differences in the weight of the gut and its contents. The carcasses of pigs on the low energy diet were leaner than those on the high energy diet.6. Barrows consumed more digestible energy per day than gilts, required more feed and digestible energy per unit live-weight gain, had lower killing-out percentages, shorter carcasses, larger backfat measurements and smaller eye-muscle areas as estimated by A × B measurements. Barrow carcasses contained less dissected lean and more fat than gilts' carcasses.7. The results are discussed in relation to other work and it is concluded that voluntary feed intake is influenced by the nutrient density of the diet and the level of energy requirement of the pig, which may be affected by previous nutritional history.


1974 ◽  
Vol 14 (67) ◽  
pp. 133 ◽  
Author(s):  
JF Dillon

The voluntary nutrient intake and productivity of White Leghorn x Australorp crossbred layers given diets ranging in metabolizable energy (M.E.) from 11.30 to 13.81 MJ kg-1 were examined to determine their ability to adjust daily energy intake. Pullets housed on deep litter and in cages had a characteristic M.E. intake of 1.35 and 1.30 MJ per bird day respectively. Pullets in deep-litter pens regulated their energy intake until the M.E. content of the diet reached 12.97 MJ kg-1 but 'overconsumed' by 7.7 per cent when the dietary energy was raised to 13.81 MJ M.E. kg-1. Caged pullets were less able to regulate energy intake and 'overconsumed' by 8.0 and 14.8 per cent when the diet contained 12.97 and 13.81 MJ M.E. kg-1 respectively. During the period of production studied it would appear to be economic to use diets of up to 12.1 3 MJ M.E. kg-1 though the optimum may be less, depending on the production situation. Productivity was not significantly altered when the protein of the diets was either reduced according to predicted 'overconsumption', or lowered to as little as 14.2 per cent when the highest energy diet was given. Savings in the cost of high energy diets may, therefore, be achieved by adjusting the protein content for 'overconsumption'. Birds offered a diet containing 13.81 MJ M.E. kg-1 for five hours per day had a productivity and efficiency of energy utilization similar to that of birds on lower energy diets ad libitum. The greater cost per unit energy of such a diet, however, militates against restricted feeding of high energy diets under field conditions. An unexpected peak in egg production and efficiency of energy utilization was observed when access to the diet with an M.E. content of 13.81 MJ kg-1 was allowed between 11.00 a.m. and 4.00 p.m. each day. The possible significance of this observation is discussed.


2002 ◽  
Vol 82 (2) ◽  
pp. 193-199 ◽  
Author(s):  
N. Mathlouthi ◽  
M. Larbier ◽  
M. A. Mohamed ◽  
M. Lessire

Two experiments were conducted to study the response of laying hens to a commercial enzyme preparation (Safizyme XP20) containing 70 000 IU g-1 xylanase. In the first experiment, 270 laying hens (ISA Brown), aged 28 wk, were fed basal diets of wheat (W), wheat-barley (WB) or wheat-barley and wheat bran (WBB) without xylanase, or supplemented with 1400 IU xylanase kg-1 in 3 × 2 factorial arrangement. In the second experiment, 180 ISA Brown laying hens, aged 28 wk, were assigned to 2 × 2 factorial arrangement and fed wheat-based diets containing 2753 or 2653 kcal metabolizable energy (ME) kg-1 without xylanase, or supplemented with 1400 IU xylanase kg-1. Egg production (% hen-day), egg weight, egg mass, feed conversion ratio and changes in body weight were recorded for 12 wk. The effects of xylanase on true metabolizable energy (TME) values of wheat, barley and wheat bran were determined using roosters. Layers fed W-, WB- or WBB-based diets had similar egg mass. The feed conversion ratio of layers fed the WBB-based diet was better (P ≤ 0.05) than that of the other groups. Xylanase improved (P ≤ 0.05) egg mass of layers fed W- or WB-based diets, but it did not affect the performance of hens fed the WBB-based diet. Low dietary ME significantly (P ≤ 0.05) reduced the performance of laying hens. Xylanase supplementation improved (P ≤ 0.05) egg production, egg mass and feed conversion ratio of layers fed the low energy diet. It did improve the feed conversion ratio of layers fed the high-energy diet. Addition of 1400 IU xylanase kg-1 to the low-energy diet was equivalent to an increase of at least 100 kcal ME kg-1. Xylanase increased (P ≤ 0.05) the TME values by 5.2 and 2.44% for wheat and barley, respectively, and did not affect the TME value of wheat bran. Key words: Xylanase, hens, laying, wheat, barley, wheat bran, metabolizable energy.


Author(s):  
G. Srinivasan ◽  
N. Arulnathan ◽  
V. Thanaseelaan ◽  
Sunil Chauhan

Background: High performance hybrid broilers require a high energy diet to exploit their full genetic potential. Therefore, high energy sources are being used in broiler diet which creates interest in the use of emulsifiers along with fat source. Hence, this study was conducted to evolve emulsifier supplementation strategy in low energy diet containing tallow as fat source in commercial broiler chickens. Methods: Total of 150 day old broiler chicks randomly distributed into three treatments with 5 replicates of ten chicks each. Treatment groups were fed basal diet which contains tallow as energy source (T1), basal diet supplemented with emulsifier at 250g per tonne of feed (T2) and 80 kcal Metabolizable energy reduced from basal diet supplemented with emulsifier at the rate of 250g per ton of feed (T3). Result: At 6th week of age significantly highest body weight was noticed in T2 group, lowest feed intake was recorded in T2 group but feed conversion ratio was comparable between T3 (1.72) and T2 (1.74) groups. No significant difference in carcass parameters and serum biochemical parameters were noticed. Emulsifier supplementation with reduced metabolizable energy can be used as a feeding strategy in broiler chickens to improve the production performance. 


2020 ◽  
Vol 50 (4) ◽  
pp. 492-500 ◽  
Author(s):  
T.S. Brand ◽  
D.A. Van Der Merwe ◽  
E. Raffrenato ◽  
L.C. Hoffman

This research sought to develop a mathematical model to predict the growth and feed intake of Boer goat kids destined for slaughter. Data were collected from castrated kids that were housed in individual pens and fed diets that varied in energy content (11.3, 12.0, and 12.7 MJ metabolizable energy (ME)/kg feed). Growth and feed intake were monitored weekly for 20 weeks, from the time that the kids weighed 22.2 ± 3.5 kg until they were slaughtered at 48.3 ± 0.8 kg. The linear equation (bodyweight = 0.202 age – 5.241 (R2 = 0.84)) was found to predict the growth of kids between 126 and 266 days old. Correlations between expressions of intake and bodyweight were evaluated, cumulative feed intake and bodyweight being most highly correlated (r = 0.93). Linear models were developed to predict cumulative feed intake from bodyweight for goats fed each diet. Regression coefficients were compared between diets, with the slope of the equation for goats on the low energy diet (6.74 ± 0.25) being greater than that of the medium (5.80 ± 0.23) and high energy diets (5.82 ± 0.23). This indicates that goats on the medium and high energy diets gained weight more efficiently than those on the low energy diet. The results from this study can be used by goat producers to predict the growth and intake of goats and determine the ideal feedlot finishing period for optimal productivity.______________________________________________________________________________________Keywords: cumulative intake, dietary energy, modelling


2020 ◽  
Author(s):  
Saeid Zare ◽  
Omid Askari

Abstract High velocity flows, as in aerospace applications require special techniques to stabilize and ignite diffusion flames. Some techniques focus on changing parameters like geometry, conditions of the flow, or fuel composition, but these techniques are usually too expensive or impossible due to major changes in the system. On the other hand, some techniques focus on generating a region of charged/excited species and active radicals upstream of the flame. That can substantially enhance the flame stability even under high strain rate or at lean-limit-flammability conditions. Repetitive nanosecond pulsed (RNP) discharge plasma is a nonthermal plasma technique with some remarkable potential to improve stability and ignitability of high velocity diffusion flames. This technique was used in previous papers in a plasma assisted coaxial inverse diffusion burner and showed some promising results by reducing the lift-off height and delaying detachment and blowout conditions. This burner is prepared to employ the discharges at the burner nozzle and simulate a single element of a multi-element methane burner. However, effectiveness of high-voltage high-frequency RNP plasma was limited by the mode of the discharge. During the tests, three different modes were observed at different combinations of plasma and flow conditions. These three modes are low energy corona, uniformly distributed plasma, and high-energy point-to-point discharge. Among these three, only well-distributed plasma significantly improved the flame. In other cases, plasma deployment was either ineffective or in some cases adversely affected the flame by producing undesirable turbulence advancing blow out. As a result, a comprehensive study of these modes is required. In this work, the transition between these three modes in a jet flame was discussed. It has been expressed as a function of plasma conditions, i.e. peak discharge voltage and discharge frequency. It was shown that increasing flow speed delays increases the voltage and frequency at which transition occurs from low-energy corona discharge to well distributed plasma discharge. Subsequently, the effective plasma conditions are thinned. On the other hand, by increasing the frequency of nanosecond discharges, the chance of unstable point-to-point discharges is decreased. In contrast, the discharge peak voltage causes two different consequences. If it is too low, the pulse intensity is too week that the system will experience no visible plasma discharges or the discharges will not pass the low-energy corona, no matter how high the frequency is. If too high, it will enhance the chance of point-to-point discharges and limits the stabilization outcome of the system. Therefore, an optimal region is found for peak discharge voltage.


2020 ◽  
Vol 100 (4) ◽  
pp. 631-639
Author(s):  
S. Serpunja ◽  
I.H. Kim

A total of 90 finishing pigs [(Yorkshire × Landrace) × Duroc] with an average body weight (BW) of 50.02 ± 1.78 kg were used in a 10 wk experiment. The pigs were distributed into three dietary treatments replicated six times with five pigs (two barrows and three gilts) per pen. The treatment diets were a positive control (PC; high-energy diet), a negative control (NC; low-energy diet), and an NC + 0.05% ferritin diet (TRT1). The supplementation of ferritin in a low-energy diet tended (P = 0.06) to increase the BW at week 5 compared with pigs fed low-energy diets without ferritin. At week 5 and overall period, the gain-to-feed ratio of pigs fed high-energy diets was higher (P < 0.05) compared with pigs fed low-energy diets. The pigs receiving a ferritin-supplemented diet had a comparable growth performance to pigs fed high-energy diets. At week 10, fecal Lactobacilli counts of pigs fed high-energy diets were higher (P < 0.05) compared with pigs fed low-energy diets. The supplementation of low-energy diets with ferritin resulted in comparable growth performance to pigs fed high-energy diets and had no adverse effect on digestibility and fecal gas emissions. Thus, it seems beneficial to include ferritin in low-energy diets of finishing pigs.


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