Diets for laying hens containing unusual ingredients and varying concentrations of cereals including no cereals

1. Light‐ and medium‐hybrid laying hens received one of six diets (A, B, C, D, E and F) containing decreasing amounts (758, 560, 374, 270, 185 and 0 g/kg) of cereals and increasing amounts of unusual ingredients, from 22 weeks of age.

2. The diet containing no cereal and 225 g dried poultry manure/kg (diet F) caused a severe reduction in performance and was discontinued at 27 weeks of age; the other treatments were continued until 48 weeks of age.

3. In the case of medium hybrids, rate of lay (number of eggs/100 hen d) was similar with diets A, B and C and about 2 percentage points lower with diets D and E; egg output (g per hen d) tended to decrease slightly as dietary cereal concentration decreased.

4. In the case of light hybrids, rate of lay was about 5 percentage points lower with diets B, C and D and about 13 percentage points lower with diet E than with diet A.

5. Mortality was similar on each diet.

6. The effect of diet on live‐weight gain was inconsistent and statistically not significant.     

Phosphorus requirements of poultry. IV. The effects on growing pullets of feeding diets containing no animal protein or supplementary phosphorus

Pullets reared to 18 weeks of age on diets containing no animal protein supplements and to which no source of inorganic phosphorus was added showed no clinical symptoms of rickets and no significant differences in average body weight, feed consumption, efficiency of feed conversion or livability compared with pullets reared on comparable diets supplemented with inorganic phosphorus.

The results indicate that growing pullets are able to use effectively organic sources of dietary phosphorus for growth and bone formation and can be reared satisfactorily on starter diets containing lower levels of total phosphorus than currently recommended.

Replacing protein of animal origin in pullet starter and growers' diets by soyabean meal and DL‐methionine or by extracted soyabean meal and extracted sunflower seed meal did not result in any adverse effects.     

Plasma concentrations of thyroid hormones in growing pullets and laying hens reared under two tropical climates and fed on diets with different energy concentrations

1. Blood samples were taken from growing (14-week-old) and laying (36-week-old) hens reared in either a temperate or a hot, humid climate and fed on 2 dietary energy concentrations (10.03 or 11.7 MJ ME/kg) to determine the plasma concentrations of 3,3 ,5-triiodothyronine (T3) and thyroxine (T4) by radioimmunoassay. 2. Plasma T3 concentrations were higher in birds fed on the low energy diet and higher at 14 than at 36 weeks of age, while the effects of climate were complex. 3. Plasma T4 concentrations were higher at 14 than at 36 weeks of age and interactions with the dietary and climatic factors were observed. 4. Interactions between dietary and climatic factors were observed since plasma T3 and T4 concentrations were higher at 14 weeks under the hot, humid than under the temperate climate. Furthermore, at 36 weeks plasma T3 concentrations were higher under the temperate climate and plasma T4 concentrations did not differ. 5. These findings are not easy to explain. However it may be suggested that the energy content of the diet clearly affects the plasma concentrations of thyroid hormones and that this effect is modulated by the climate to a variable degree that is linked to the age and the physiological state of the birds.     

Performance, carcass characteristics, and lipid metabolism in growing and finishing Simmental steers fed varying concentrations of copper.

An experiment was conducted to determine the effects of dietary copper (Cu) on performance, carcass characteristics, and lipid metabolism in Simmental steers. Thirty-six Simmental steers (329.3 +/-11.4 kg) were stratified by weight and randomly assigned to treatments. Treatments consisted of the following: control (no supplemental Cu) and 10 or 40 mg Cu/kg DM from Cu sulfate. Each treatment consisted of six replicate pens, with each pen containing two steers. A corn silage-soybean meal-based diet was fed for 56 d. Steers were then switched to a high concentrate diet. Performance was not affected by treatment during the growing or finishing phases. Plasma Cu concentrations were higher (P < 0.05) in steers receiving supplemental Cu by d 56 of the growing phase and remained higher (P < 0.05) at all 28-d sampling periods during the finishing phase. Liver Cu concentrations were higher (P < 0.001) in steers receiving supplemental Cu at the end of the growing phase and on d 84 and at the end of the finishing phase. Steers supplemented with 40 mg Cu had higher (P < 0.001) liver Cu concentrations than those supplemented with 10 mg Cu/kg DM. Serum and longissimus muscle cholesterol concentrations were similar between treatments. Longissimus muscle and backfat fatty acid composition was similar between treatments. These results indicate that Cu supplementation given to Simmental steers increased Cu status but had no effect on performance, carcass characteristics, or lipid or cholesterol metabolism.     

Effect of low protein diets for growing Leghorn pullets upon subsequent laying performance

An experiment was conducted with White Leghorn pullets to study the effect on laying performance of dietary protein content and amino acid supplementation during the growing period. From 0 to 6 weeks of age birds fed on diets containing either 149 g protein/kg supplemented with methionine and lysine or 182 g protein/kg grew faster than those fed on a diet containing 149 g protein/kg alone. However, only those fed on the supplemented diet utilised their food more efficiently. From 7 to 20 weeks of age neither body weight gain nor food utilisation was affected by the dietary protein content. Pullets fed the low protein diet supplemented with 2 g methionine/kg and 2.5 g lysine/kg during the period of 0 to 6 weeks of age had significantly better egg production than birds fed the low protein diet alone. The dietary protein content during 7 to 20 weeks of age did not influence subsequent egg production.     

Grain source and processing in diets containing varying concentrations of wet corn gluten feed for finishing cattle

Two experiments were conducted to evaluate combinations of wet corn gluten feed (WCGF) and barley, as well as the particle size of dry-rolled barley and corn, in finishing steer diets containing WCGF. In Exp. 1, 144 crossbred steers (initial BW = 298.9 +/- 1.4 kg) were used to evaluate barley (0.566 kg/L and 23.5% NDF for whole barley) and WCGF combinations in finishing diets containing 0, 17, 35, 52, or 69% WCGF (DM basis), replacing barley and concentrated separator byproduct. A sixth treatment consisted of corn (0.726 kg/L and 11.1% NDF for whole corn), replacing barley in the 35% WCGF treatment. In Exp. 2, 144 crossbred steers (initial BW = 315.0 +/- 1.5 kg) were used to evaluate coarse or fine, dry-rolled barley or corn (0.632 and 0.699 kg/L; 26.6 and 15.9% NDF for whole barley and corn, respectively) in finishing diets containing WCGF. A factorial treatment design was used; the factors were grain source (corn or barley) and degree of processing (coarse or fine). The diets contained 50% WCGF, 42% grain (corn or barley), 5% alfalfa hay, and 3% supplement (DM basis). In Exp. 1, DMI and ADG responded quadratically (P < or = 0.03), peaking at 35 and 52% WCGF, respectively. The efficiency of gain was not affected (P > or = 0.42) by dietary treatment. Steers fed dry-rolled corn and 35% WCGF had heavier HCW, lower DMI, greater ADG, increased G:F, increased s.c. fat thickness at the 12th rib, and greater yield grades compared with steers fed dry-rolled barley and 35% WCGF (P < or = 0.04). The apparent dietary NEg was similar among the barley and WCGF combinations (P > or = 0.51); however, the corn and 35% WCGF diet was 25% more energy dense (P < 0.001) than was the barley and 35% WCGF diet. In Exp. 2, no grain x processing interactions (P > or = 0.39) were observed. Particle size was 2.15 and 2.59 mm for fine- and coarse-rolled barley and was 1.90 and 3.23 mm for fine- and coarse-rolled corn. Steers fed a combination of corn and WCGF had increased ADG, greater G:F, heavier HCW, larger LM area, more s.c. fat thickness at the 12th rib, greater yield grades, increased marbling, and more KPH compared with steers fed a combination of barley and WCGF (P < or = 0.03). Fine-rolling of the grain increased fat thickness (P = 0.04). The addition of WCGF to the barley-based diets increased DMI and gain. Decreasing grain particle size did not greatly affect performance of the steers fed the 50% WCGF diets; however, carcasses from the steers fed the fine-rolled grain contained more fat.     

A comparison of red and white light and high and low dietary protein regimes for growing pullets

Medium‐weight hybrid pullets were used to test the effects of (a) providing red instead of white light from 3 to 18 weeks of age and (b) feeding a diet containing 15\ per cent crude protein from 6 to 12 weeks followed by one containing 12 \ per cent crude protein to 18 weeks of age instead of feeding the first‐mentioned diet from 8 to 18 weeks of age.

Results showed that these alternative rearing practices had only a small influence on performance. On balance, any immediate advantages resulting from the use of red light and/or low‐protein food were outweighed by disadvantages which arose in the subsequent laying period.     

Influence of fibre on metabolisable energy of diet and performance of growing pullets in the Tropics

1. Diets in which maize and palm kernel meals were major ingredients and whose metabolisable energy values were varied by the inclusion of graded amounts of maize cob (50 to 200 g/kg diet) were fed to growing pullets for 9 to 21 weeks of age. 2. Apparent metabolisable energy decreased from 11.82 to 9.79 MJ/kg diet as neutral detergent fibre increased from 182 to 330 g/kg. 3. Metabolisable energy intake was significantly reduced when the maize cob content was above 100 g/kg diet. 4. Protein intake was unaffected by treatment but apparent nitrogen retention was significantly depressed for pullets receiving the diet with 200 g/kg maize cob. Birds on the diet did not come into lay during the study.     

Environmental temperature and dietary protein concentrations for growing turkeys

Growing turkeys were kept at one of 4 constant temperatures (14, 17, 20 or 23 degrees C) from 10 to 15 weeks of age and given a food with one of three protein concentrations (201, 229 or 294 g/kg diet). Food intakes, food conversion ratios and breast meat yields (as a proportion of body weight) were decreased at the higher temperatures but there were no significant differences in growth. At each temperature, the turkeys given the higher dietary protein concentrations had increased body weight gains but their breast meat yields were similar. Thus the poor breast meat yields which resulted from rearing at high temperatures could not be counteracted by high dietary protein concentrations.     

Performance and blood plasma amino acid and urea concentrations in growing pigs given diets of cereals and groundnut meal and supplemented with graded amounts of L-lysine

The addition of graded amounts of L-lysine to a basal diet of cereals and groundnut meal given to growing pigs caused the expected improvements in rate of growth, N retention and carcass quality. Best responses were obtained when the diet contained 9 g lysine/kg; above that level there were no significant additional responses.Blood samples were taken from the anterior vena cava before and at intervals after a meal of each diet, and the concentration of amino acids and urea in the plasma determined. The concentrations of most amino acids in blood plasma increased after a meal, reaching maxima about 2 h after feeding.At all times of sampling the concentrations in plasma of essential amino acids other than lysine were largely unaffected by the lysine content of the diet, but the concentration of lysine increased linearly over a wide range of lysine intake.The concentration of urea in blood plasma fell as the lysine content of the diet increased. Lowest concentrations were found with diets containing 9 g or more lysine/kg.It was concluded that measurement of the concentrations of urea in blood plasma of growing pigs fed twice daily may be of more value in assessing the amino acid requirements and efficiency of protein utilization than determination of changes in concentration of blood plasma amino acids.     

The effect of varying flock size on the development and subsequent laying performance of floor‐reared pullets

Light‐weight, hybrid pullets were reared on litter in flocks of 400, 800 and 1200 birds per pen. Floor space allowance was held constant at 0–093 m² per bird and other related factors of management were standardised. The different sizes of flock had no significant effect on growth rate or mortality, but individual food consumption was significantly higher in the 400‐bird flocks than in the larger units.

At 18 weeks of age, some of the birds from each treatment were transferred to battery cages and others to deep‐litter laying quarters and records of their performance in terms of egg numbers and size, food consumption, mortality and body weight gain were taken over a period of 1 year. The only consistently significant finding was that birds reared in groups of 1200 tended to produce larger eggs (as shown by market grading) and, when housed on deep litter, to eat more food than birds reared in the smaller flocks.     

Growth, reproductive performance, and manganese status of heifers fed varying concentrations of manganese

An experiment was conducted to examine the effects of dietary Mn on growth, reproductive performance, and Mn status of beef heifers. Eighty Angus (n = 40) and Simmental (n = 40) heifers, averaging 249 kg, were stratified by BW within a breed and randomly assigned to 1 of 4 treatments providing 0 (control), 10, 30, or 50 mg of supplemental Mn/kg of DM from MnSO(4). Heifers were individually fed a diet containing cottonseed hulls, corn gluten feed, citrus pulp, and ground corn, and the control diet contained 15.8 mg of Mn/kg of DM by analysis. Average daily gain, DMI, and G:F for the 196-d period were not affected by Mn supplementation. Control heifers had reduced (P = 0.04) liver Mn when contrasted with the 3 levels of supplemental Mn. Serum cholesterol was greater (P = 0.001) in Angus compared with Simmental heifers over the course of the 196-d experiment but was not affected by treatment. Dietary Mn did not significantly affect measures of reproductive performance. Results of this study indicate that 15.8 mg of Mn/kg of diet DM should be adequate for growth, onset of estrus, and conception of beef heifers.     

Effects of varying zinc concentrations on quality of alfalfa for lambs

Zinc concentrations in alfalfa hay were varied using a N-Zn liquid fertilizer as a foliar applicant (.34 or .68 kg Zn/ha) or as a soil fertilizer (4.07 kg Zn/ha). Mean concentrations of Zn across five cuttings of alfalfa in 2 yr were 18, 27, 41 and 21 mg Zn/kg DM for control, low foliar, high foliar and soil treatments, respectively. Each treatment was fed in ad libitum amounts to eight crossbred wether lambs (20 to 35 kg) in 6-wk growth and intake trials, followed by 2-wk digestibility and balance trials with individual lambs. For one cutting, hays were also fed in an 81-d trial to four ram lambs (30 to 35 kg) and live weight gain and testicular development were measured. Average daily gain (ADG) and intake over 6 wk differed (P less than .01) with cutting but not with Zn treatment. Average daily gain and testes weight of ram lambs also were not affected by treatment. In the metabolism trials, Zn treatment did not alter (P greater than .05) intake or dry matter digestibility (DMD) of alfalfa, but did influence digestibility of neutral detergent fiber (NDF). Digestible NDF (%) was higher (P less than .05) for high foliar than for low foliar treatments. Apparent absorption and retention of Zn was significantly greater for control than for Zn-treated alfalfas and did not differ with cutting. Mean serum Zn concentrations for control, low and high foliar, and soil treatments were .79, .81, .78 and .75 micrograms Zn/ml, respectively, for all cuttings, with no differences due to treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of varying stocking density on the development and subsequent laying performance of floor‐reared pullets

Light‐weight, hybrid pullets were reared on litter at 0.070, 0.093, 0.139 and 0.186 m² of floor area per bird. Flock size was constant at 400 birds per pen and other related factors of management were standardised. Results showed that the different densities of stocking had no commercially important effect on growth rate, food consumption or viability, but feathering was poorer in the more densely populated groups.

At 18 weeks of age, some of the birds from each treatment were transferred to battery cages and others to deep‐litter laying quarters and records of their performance in terms of egg production and quality, food consumption, mortality and body weight gain were taken over a period of one year. The use of high stocking densities during the preceding rearing stage caused no impairment of the performance of layers kept in batteries, but was possibly responsible for a small decline in productivity of layers housed on deep litter.     

选择性采食方式对生长猪的日粮选择及其生产性能的影响

为研究当猪能够从3种不同成分的颗粒料中作出采食选择时其是否能采食其所需的最佳日粮,特利用单独圈养的生长猪进行了一次试验。试验选用40头杂交猪(20头阉公猪,20头小母猪),其初始体重为22.0±2.1kg,在4周试验期中分成对照日粮组(C组)和选择性采食日粮组(CF组)。C组试验猪饲喂单一的全价料颗粒料,CF组试验猪能自由地从高能量颗粒料(E)、高蛋白颗粒料(P)和预混料/其它成分颗粒料(P/R)3种不同成分的颗粒料中挑选其所需的日粮。CF组试验猪利用一个分成3个隔间可同时供应3种颗粒料(每个隔间供应一种颗粒料)的长形料槽供料。所有日粮均自由采食。在采取选择性采食的方式中,小母猪所选择的高蛋白颗粒料要多于去势公猪,两者分别为222和193g/kgDM。而C组试验猪(无论小母猪还是去势公猪)均饲喂粗蛋白含量相同的日粮(即204g/kgDM;性别间差异显著P<0.05)。本试验不存在其他处理与性别之间的相互作用。对照组猪的净能摄入量高于试验,分别为13.8和10.3Mj/d(P<0.001)。小母猪的净能摄入量往往低于去势公猪,分别为12.6Mj/d和11.4Mj/d。CF组试验猪预混料/其它成分颗粒料的摄入量非常少(15g/d;13g/kgDM)。CF组仔猪日增重明显低于C组(779g/d和541g/d;P<0.001)。结果显示,当3种颗粒化的日粮配料被分别加入长料槽3个隔间中的其中一个时,仔猪不能选择最适合其生长的一种日粮配料。至于试验仔猪不能选择一种最适合其需要的日粮配料是否是由于特殊的器官感觉(如口味、风味或颗粒的物理性状)所致还有待进一步研究。如果弄清了这一原因,人们就能利用此方法去研究日粮成分(如次级配合料)或不同饲料处理方法的重要性。