scholarly journals Effect of age upon utilisation of iron in chickens

2011 ◽  
Vol 49 (No. 9) ◽  
pp. 407-410
Author(s):  
E. Fajmonová ◽  
J. Zelenka ◽  
K. Holendová

The effect of age upon iron retention in cockerels of laying and meat type hybrids was examined within 46 subsequent balance periods. Chickens were fed ad libitum a diet with the content of 312 mg Fe per 1 kg. The dependence of Fe utilisation upon age from Day 3 to Day 100 was expressed by the second degree parabolas with minimum values in the tenth week of age. The dependence of Fe content in weight gains on age was highly significant (P < 0.01). The course of this dependence was expressed by parabolas with minimum values on Day 38 and Day 28 in slow and fast growing chickens, resp. The growth rate of total amount of Fe in the body was by 6 per cent lower (P < 0.01) than that of live weight of chickens.    

1972 ◽  
Vol 14 (3) ◽  
pp. 317-322 ◽  
Author(s):  
J. P. Langlands

SUMMARYEight Border Leicester castrated male lambs (wethers) were fostered on to 8 Merino ewes (MB) at birth, and 10 Merino wethers were fostered on to Border Leicester ewes (BM). Two additional groups of 10 wethers consisted of Border Leicester lambs (BB) and Merino lambs (MM) reared by their natural mothers. The lambs and ewes grazed together and growth rate, and milk and herbage consumption of the lambs were recorded.Live-weight gains to weaning at 74 days were 275, 245, 204 and 184 g/day for groups BB, MB, BM and MM respectively. Lambs reared by Border Leicester ewes received more milk and consumed less grass than lambs of similar genotype reared by Merinos, but BM lambs consumed less milk than BB lambs. Merino lambs also consumed less grass than Border Leicester lambs.It was concluded that Merinos grew more slowly than Border Leicester lambs primarily because of their lower voluntary food intake. The lower milk production of Merino ewes was considered to be of secondary significance since if herbage is available ad libitum, lambs with high voluntary intakes will compensate for the lack of milk by consuming more forage.


1976 ◽  
Vol 87 (1) ◽  
pp. 171-179 ◽  
Author(s):  
D. M. Murray ◽  
Olga Slezacek

SummaryThe effect of three different growth rates from 15 to 40 kg live weight on the body composition of lambs was studied. The treatments were: High (H) ad-libitum feed intake, Low (L) restricted feed intake and High–Maintenance–High (HMH) ad-libitum feed intake from 15 to 25 kg followed by a 50-day period during which live weight was maintained constant, which in turn was followed by ad-libitum feeding. The animals were individually penned and fed a pelleted lucerne chaff-cereal grain mixture. Two animals were killed at the start of the experiment (15 kg) and the remaining 27 animals (nine in each treatment) were killed at common live weights of 25, 30, 35 and 40 kg. Analyses of covariance were used to compare linear regression equations representing results from each treatment using the logarithmic transformation of the allometric equation, y = axb.Animals in the H and L treatments had a mean growth rate from 15 kg until slaughter of 0·23 and 0·09 kg/day, respectively. From a live weight of 15 to 25 kg, the HMH group grew at a similar rate as the H group, viz. 0·22 and 0·21 kg/day, respectively. After the 50-day period of maintenance of live weight, the HMH animals killed at 30, 35 and 40 kg showed a marked compensatory growth response to ad-libitum feeding. These HMH animals had a mean growth rate of 0·37 kg/day compared with 0·26 kg/day for H animals over identical live-weight ranges.Empty body weight (EBW) formed a similar proportion of full body weight (FBW) in all three treatments. As a proportion of FBW, hot carcass weight (HCW) was similar in the H and L treatments, while at the 35 and 40 kg slaughter weights HCW was less in the HMH than in the H treatment. HCW also formed a lower proportion of EBW at the 35 and 40 kg slaughter weights in the HMH, than in both the H and L treatments. In the L treatment, HCW formed a greater proportion of EBW than in the H treatment, indicating a greater offal component of EBW in the H animals.The results of carcass dissection studies showed that, at the same dissected side weight (DSW), the amount of muscle, bone, connective tissue and total side fat (TSF) was similar in the three treatments. Although no differences were found between treatments in TSF, there were significant treatment effects on both the subcutaneous and inter-muscular fat depots. Animals in the H treatment had more and less, respectively, subcutaneous and intermuscular fat than the L animals. The amount of intermuscular fat was also greater in the HMH than in the H treatment.


2008 ◽  
Vol 52 (No. 12) ◽  
pp. 547-551 ◽  
Author(s):  
J. Zelenka ◽  
J. Hedbavny

Retention of total mercury was examined in groups of 95 slowly-growing laying type chickens and 52 fast-growing broiler hybrids in 47 subsequent balance periods from 1 to 100 days of age. Chickens were fed <I>ad libitum</I> on a diet containing 5.41 µg of Hg per kilogram. Until Day 4 the values of coefficients of apparent retention of Hg were negative or very low. They were influenced by excretion of endogenous nutrients originating primarily from the yolk sac. When evaluating the period of 4 to 100 days of age, the dependence of Hg retention coefficients upon age was highly significant (<I>P</I> < 0.01). The course of this dependence was expressed by parabolas for laying type chickens with the maximum value at Day 61 of age and for broilers with the minimum value at Day 53. In fast growing chickens, Hg content in body gain decreased until Day 14 and then increased while in slow growing chickens it was linearly increasing for the whole experimental period. The average coefficients of Hg retention from the feed mixture were 48.18 ± 0.719 (mean ± SEM) and 47.90 ± 1.057% and Hg retained per g of live body gain were 7.494 ± 0.4682 and 6.775 ± 0.6233 ng in laying and meat type cockerels, respectively. The difference between hybrids was insignificant (<I>P</I> > 0.05). The growth rate of total amount of Hg in the body was lower (<I>P</I> < 0.01) than that of body weight of chickens, allometric coefficients were 0.706 and 0.747 for slow and fast growing chickens, respectively.


1970 ◽  
Vol 12 (1) ◽  
pp. 23-36 ◽  
Author(s):  
T. T. Treacher

SUMMARY1. Scottish Half-bred ewes carrying twin foetuses were fed individually to make live-weight gains in the last six weeks of pregnancy of (1) 20%, (2) 10% and (3) 0% of their live weight in week 14 of pregnancy. In lactation the ewes were fed ad libitum. The lambs were removed 12 to 16 hr after parturition and the ewes were machine-milked twice daily for the first six weeks of lactation.2. Total birth weights per ewe of twin lambs from the treatments were (1) 10·10 kg, (2) 9·44 kg and (3) 8·18 kg and differed significantly.3. The level and pattern of voluntary intake in lactation did not differ significantly between the treatments. Total dry-matter intakes in the six weeks of lactation were (1) 121·9 kg (2) 105·9 kg and (3) 109·5 kg.4. The pregnancy treatments affected the level of milk production and the shape of lactation curves. The total yields in the first six weeks of lactation were (1) 58·8 kg, (2) 43·5 kg and (3) 26·9 kg. Higher contents of fat and protein and the lower content of lactose in the milk from treatment-3 ewes on days 1 and 3 of lactation indicated a slower onset of lactation in these ewes. Between days 7 and 35 of lactation the contents of fat and SNF were lowest on treatment 3 but the differences were not significant.5. The live-weight changes in lactation, which were in inverse order to the gains in late pregnancy, were (1) 3·4 kg, (2) 5·5 kg and (3) 9·5 kg.


1999 ◽  
Vol 68 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Y. Le Cozier ◽  
E. Ringmar-Cederberg ◽  
S. Johansen ◽  
J. Y. Dourmad ◽  
M. Neil ◽  
...  

AbstractFrom 74 to 180 days of age, a complete diet was offered either ad libitum (AL) or at proportionately 0·8 of the observed consumption (R) to two groups of purebred Yorkshire gilts, comprising 128 and 127 animals, respectively. Half of the animals in each group was served at the first detected oestrus, and the other half at the third detected oestrus, according to a plan defined at the start of the experiment. Animals which failed to show oestrus before 240 days of age were culled.At 100 kg live weight (LW), AL gilts were younger (-20 days) and had thicker backfat (+2.3 mm) than R gilts. At the first detected oestrus, AL females were also younger (198 v. 203 days), heavier (127 v. 117 kg LW) and fatter (17·8 v. 14·7 mm backfat thickness) than R gilts. No difference between feeding treatments during rearing was observed in the percentage of females detected on heat before day 240. Seventy-three animals were culled from the start of the experiment until service, half of them (54%) failing to show oestrus. At service, LW and backfat thickness in the four treatments ranged from 117 to 148 kg LW and 14·9 to 19·7 mm, respectively. The body fatness, estimated from the ratio of backfat to LW, was higher in AL than in R gilts (0·14 and 0·12 , respectively), whereas no difference was observed between E1 and E3 gilts (0·13 on average). After the first service 15% of the gilts came back into heat but the conception rate was not affected by feeding treatment during rearing.


1975 ◽  
Vol 55 (3) ◽  
pp. 377-381
Author(s):  
A. D. L. GORRILL ◽  
J. W. G. NICHOLSON ◽  
T. M. MACINTYRE

Two growth trials were conducted to determine an optimum level of fat in milk replacer and an optimum level of protein in creep feed for artificially reared lambs. In experiment 1, milk replacers containing 31 or 36% fat (dry matter, DM, basis) were fed ad libitum to 58 lambs at 1 day of age. The protein was supplied by low-heat spray-dried skim milk powder and Na caseinate and the fat from a mixture of 10% coconut oil and 90% tallow. A finely ground unpelleted creep feed with 20% protein, on a DM basis, was fed ad libitum. The lambs consumed more of the 31% fat milk replacer and gained more live weight (288 vs. 254 g/day; P < 0.025) to weaning at 25–30 days of age than did lambs fed the 36% fat formula. Weight gains to 10 wk of age were 190 and 170 g/day, respectively (P < 0.10). In experiment 2, 84 lambs were fed a 26% fat milk replacer ad libitum, and creep feeds with 15, 20 or 25% protein (DM basis). The supplementary protein was supplied by herring meal and soybean meal. Weight gains of lambs to weaning at 24 days of age were similar on the three creep feeds. However, gains to 10 wk of age averaged 218, 235 and 244 g/day (P < 0.05) on the 15, 20 and 25% protein diets, respectively. One and 2 kg of DM were consumed/kg lamb body weight gain to weaning and to 10 wk of age, respectively. It was concluded that the milk replacer should contain 26–31% fat, and the creep feed 20% protein or more for maximal performance of artificially reared lambs.


1994 ◽  
Vol 58 (1) ◽  
pp. 41-47 ◽  
Author(s):  
D. C. Patterson ◽  
C. A. Moore ◽  
R. W. J. Steen

AbstractBulls (½ Blonde d'Aquitaine ⅜ Charolais) were used in a 2 × 3 factorial design experiment with two planes of nutrition in the finishing period and three slaughter weights. High and low planes of nutrition were based on diets with similar forage to concentrate ratio (0·40 of dry matter (DM)) offered ad libitum or at 0·78 of ad libitum DM intake at equal live weight respectively. The target slaughter live weights were 550, 625 and 700 kg. Twelve bulls were taken to each slaughter point and an additional five animals were killed as a pre-experimental slaughter group. Mean initial live weight was 412 (s.e. 5·3) kg at a mean age of 342 (s.e. 2·5) days. No significant interactions were found between the main factors. For the high and low planes, live-weight and estimated carcass gains were 1251 and 989 (s.e. 47·7), and 816 and 668 (s.e. 35·3) g/day respectively, the reduction in gains being similar to the proportional degree of nutritional restriction. Plane of nutrition had no effect on live-weight or carcass gain per unit of energy intake. The low plane of nutrition produced significant decreases in body cavity fat depots, subcutaneous fat in the sample joint and increased the proportions of both saleable beef and high-priced joints in the carcass.With increase in slaughter weight, energy intake per unit of live weight0·75 and rates of both live-weight and carcass gain tended to decline. The dressing proportions were 583,579 and 609 (s.e. 9·1) g/kg for the slaughter live weights of 550, 625 and 700 kg. Carcass conformation improved while fat depots in the body cavity and estimated concentration of separable fat in the carcass increased with increase in slaughter weight, and both estimated lean and bone concentrations decreased. Forequarter as a proportion of total side tended to increase with increase in slaughter weight. Slaughter weight had no effect on concentration of saleable meat or ultimate pH of carcass muscle. It is concluded that bulls of this genotype can be taken to high slaughter weights on diets having a relatively high proportion of forage as grass silage, with high rates of growth and acceptable carcass leanness.


1980 ◽  
Vol 30 (2) ◽  
pp. 307-310
Author(s):  
R. V. Large

ABSTRACTSoay ewes were mated to a Soay or a Dorset Down ram. Live-weight changes of the ewes, birth weights, growth rates and carcass production of the lambs were recorded, and the food consumption of the ewes and lambs was measured. The use of the Dorset Down ram resulted in significantly heavier birth weights, higher growth rates and heavier carcasses. Under conditions of good nutrition the Soay ewes proved to be capable of carrying very high foetal burdens and it was estimated, from lamb live-weight gains, that they produced a large quantity of milk, relative to their size, particularly when crossed with the Dorset Down ram.


2002 ◽  
Vol 75 (1) ◽  
pp. 75-83 ◽  
Author(s):  
S.P. Turner ◽  
M. Dahlgren ◽  
D.S. Arey ◽  
S.A. Edwards

AbstractFeeder space allowance should be sufficient to ensure adequate access to food for all group members, irrespective of competitive ability. However, the influence of social group size on minimum feeder space requirement of pigs given food ad libitum is poorly understood. Performance, aggression and feeding behaviour were assessed over a 6-week period from 29·3 (s.e. 0·19) kg live weight, using four replicates of a 2 ✕ 2 factorial design with two group sizes (20 v. 80) (small and large) and two feeder space allowances (32·5 v. 42·5 mm per pig) (low and high). Food intake was significantly lower in the low feeder space allowance treatments (1·44 v. 1·56 (s.e.d. 0·050) kg per pig per day, P < 0·05) and group mean growth rate was reduced in the later phase between 41 and 56 kg live weight. There was no main effect of group size or interactive effect between group size and feeder space allowance on performance. Mean skin lesion score and the frequency of aggression given or received at the feeders was unaffected by treatment. Heavy weight pigs showed similar feeding behaviour in each treatment, but light pigs visited the feeder more frequently in groups of 20 (23·1 v. 16·0 (s.e.d. 2·04) visits per pig per day, P < 0·05) and spent the greatest time feeding when at a low feeder space allowance (5461 v. 4397 (s.e.d. 288·8) s per pig per day, P < 0·05). To avoid a depression in growth rate, pigs >40 kg should be allocated a minimum feeder space allowance of 42·5 mm per pig. There was little indication of a need to specify differential feeder space allowances according to group size.


1997 ◽  
Vol 64 (1) ◽  
pp. 171-176 ◽  
Author(s):  
J. R. Webster ◽  
I. D. Corson ◽  
J. M. Suttie

AbstractLow winter growth is a characteristic of male red deer and is caused, in part by a combination of reduced appetite and higher energy expenditure due to cold weather. This study aimed to determine whether housing during winter would reduce energy expenditure and increase the growth rate of male red deer calves. An additional aim was to investigate whether food restriction in winter would be compensated for by increased spring growth. In each of two consecutive years, 80 calves were randomly allocated to eight groups (no. = 10) comprising two replicates of four treatments during winter. Groups were housed inside (I) or outside (O) and given food either ad libitum (AL) or restricted (R) to maintain live weight. Winter treatments (southern hemisphere) ran from 22 May to 25 August (year 1) and from 5 June to 5 September (year 2). During these periods, animals were weighed weekly and group food intake recorded daily. At the end of winter animals were moved outside onto pasture and weighed monthly until the end of spring (27 November, year 1 and 7 December, year 2). In year 2 weighing continued during summer, until 4 April. The animals were slaughtered on 28 November and 18 January (year 1) and 5 April (year 2). The effect of housing on live-weight gain (LWG) and dry-matter intake (DM1) in AL groups was not significant in either year. However in R groups, O had a higher DMI than I in both years (P < 0·05) and a higher LWG than I in year 1 (P < 0·05). LWG was loiver in R than in AL groups in winter in year 1 (P < 0·05) and year 2 (P < 0·001) and live weight was lower in R than in AL groups at the end of winter in both years. Live weight was still lower in R than in AL groups at the end of spring in both years (P < 0·01). In year 2, this live-weight difference was not significant by the end of summer. Hot carcass weight (HCW) was greater in AL animals than R animals (P < 0·05) and dressing proportion was higher in R than in AL (P < 0·05) in year 1. GR (an index of body fatness) was greater (P < 0·05) in O than I in year 1 and was greater (P < 0·05) in AL than in R animals in year 2. Differences in GR between treatments were not significant in either year, with HCW as a covariate.In conclusion, housing calves given food ad libitum during winter did not reduce DMI or increase growth rate. When normal growth rates were prevented by restricting food intake, housing lowered DMI requirement, although such a situation is unlikely to be a useful farm management practice as recovery from the growth check was slow. Annual variations in climate may determine both the food savings made by housing and the extent of compensatory growth of food-restricted animals in spring.


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