The effect of feed restriction on sexual maturity and initial reproductive performance of broiler pullets under different light treatments

1969 ◽  
Vol 9 (39) ◽  
pp. 417 ◽  
Author(s):  
RAE Pym ◽  
R Sledge
Keyword(s):  
Body Weight ◽  
Reproductive Performance ◽  
Sexual Maturity ◽  
Feed Restriction ◽  
Restricted Feeding ◽  
Egg Weight ◽  
Laying Performance ◽  
The Mean ◽  
The Difference ◽  
Lighting Systems

An experiment was conducted to examine the effect of restricted feeding under two lighting systems during the rearing period on the initial laying performance of broiler type pullets. The rearing treatments were imposed at nine weeks of age, removed at 22 weeks and the trial was discontinued at 36 weeks of age. The feeding treatments (restricted versus ad lib.) were arranged factorially with the lighting treatments (decreasing versus increasing). Birds reared on restricted feeding reached sexual maturity 16 days later than full fed birds, ate 17 per cent less feed to 22 weeks and gained seven per cent less in body weight to 24 weeks of age and ten per cent less to 36 weeks. Birds reared under the decreasing lighting regime reached sexual maturity at the same age as those reared under increasing lighting, ate five per cent more feed during the rearing and laying periods and gained five per cent more in body weight to 24 weeks. The mean weight of eggs laid between 24 and 34 weeks of age from pullets subjected concurrently to decreasing lighting and restricted feeding was approximately two grams heavier than that of the other three treatment combinations. Mean egg weight was one gram greater in the restricted than in the full fed group, although the difference was not statistically significant. Laying mortality was lower in the restricted fed group than in the full fed group.

scholarly journals Reproductive Performance of Japanese Quail Hens (Coturnixcoturnix japonica) Fed with Feed Restriction Regimes during Growth Period

2019 ◽  
Author(s):  
R T Hertamawati ◽  
Suyadi . ◽  
E Soedjarwo ◽  
O Sjofjan
Keyword(s):  
Body Weight ◽  
Reproductive Performance ◽  
Sexual Maturity ◽  
Egg Production ◽  
Reproductive Organ ◽  
The Body ◽  
Feed Restriction ◽  
Restricted Feeding ◽  
Feed Conversion ◽  
Ad Libitum

Reproductive performance of quail hens (Coturnixcoturnix japonica) at sexual maturity was evaluated following two feeding restriction programs (100%, 90% and 80% of ad libitum) and energy metabolism (EM) of ration: 2900 Kcal/kg and 2800 Kcal/kg) between 2 weeks and 5 weeks of age with five replicates of 10 chicks per replicate. Body weight and feed conversion were measured weekly during feed restriction. After experimental feeding treatment, age at first egg, BW, egg weight, development of reproductive organ on sexual maturity were evaluated of one hen’s quail per treatment. The results of the experiment indicated that the restricted feeding until 80% of ad libitum was consequently (p 0.01) delayed sexual maturity and influence the development of the reproductive organ. However, it did not show significant influence on the body weight of the first-laid egg and initial egg production. Restricted feeding at 90% of ad libitum and EM ration 2900 Kcal/kg showed the best results for quail feed management during growth.

scholarly journals Effect of Immediately-After-Birth Weaning on the Development of Goat Kids Born to Small Ruminant Lentivirus-Positive Dams

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 822 ◽  
Author(s):  
Nalbert ◽  
Czopowicz ◽  
Szaluś-Jordanow ◽  
Moroz ◽  
Mickiewicz ◽  
...  
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Linear Models ◽  
Small Ruminant ◽  
Negative Impact ◽  
Body Weight Gain ◽  
Mixed Linear Models ◽  
Daily Body Weight ◽  
The Mean ◽  
The Difference

A longitudinal study was carried out to investigate the influence of two different rearing systems of young kids on their development to sexual maturity. Kids born to small ruminant lentiviruses-infected (SRLV) female goats were split into two groups: the immediately-after-birth weaned group and the unweaned group. Kids’ body weight (BWT) was measured before the first consumption of colostrum, and then at the age of one week, and one, two, four, and seven months. The relationship between the rearing system and BWT at each age was investigated using mixed linear models adjusted for potential confounders. The mean BWT of kids of the immediately-after-birth weaned group was significantly lower at the age of one week, one month, and two months, and then the difference became insignificant. The mean daily body weight gain (DWG) was significantly lower in the immediately-after-birth weaned group during the whole first month of life, but then DWG in both groups became equal. Crude mortality rate did not differ significantly between groups. This study shows that weaning kids immediately after birth does not appear to have any negative impact on kids’ development except transient growth retardation, which is fully compensated until they reach sexual maturity.

Effect of constant photoperiods on the laying performance of broiler breeders allowed conventional or accelerated growth

2005 ◽  
Vol 143 (1) ◽  
pp. 97-108 ◽  
Author(s):  
P. D. LEWIS ◽  
D. BACKHOUSE ◽  
R. M. GOUS
Keyword(s):  
Body Weight ◽  
Sexual Development ◽  
Sexual Maturity ◽  
Egg Production ◽  
Egg Laying ◽  
Broiler Breeders ◽  
Egg Weight ◽  
Laying Performance ◽  
Body Weights ◽  
Accelerated Growth

An experiment was conducted at the University of KwaZulu–Natal to assess the effect of constant photoperiods on sexual maturity and egg-laying performance in broiler breeders given two levels of control-feeding during the rearing phase. Cobb broiler breeder females were grown to reach 2·1 kg body weight at 17 or 21 weeks, and maintained on 10, 11, 12, 13, 14 or 16-h photoperiods from 2 days to 68 weeks of age. There were no significant interactions between photoperiod and growth rate for any production parameter. The time required reaching 2·1 kg increased proportionally with photoperiod but, because of delayed sexual development, birds on longer photoperiods consumed more feed to, and were heavier at, sexual maturity than shorter daylengths. The longer-photoperiod birds also had inferior rates of lay in the first half of the cycle, but superior in the second, which, together with the photoperiodic effects on maturity, resulted in birds on 11, 13 or 14 h producing most eggs to 68 weeks, and those on 16 h fewest. It is possible that the pattern of egg production was due to some of the birds on [ges ]13-h photoperiods becoming photorefractory, having a mid-cycle pause, and then spontaneously resuming egg production in the latter half of the cycle. However, a hinge-analysis of current and other data to the more usual depletion age of 60 weeks showed that the combined effects of photoperiod on sexual maturity and egg production resulted in constant 10-h birds producing the highest number of eggs, with numbers decreasing by 3·6 eggs/h of photoperiod above the hinge and 7·8 eggs/h of photoperiod below it. Mean egg weight increased by 0·4 g/h of photoperiod, but the proportion of abnormally large and floor eggs and the incidence of mortality were unaffected by daylength. For each photoperiod, accelerated growth resulted in body weights being heavier than controls at sexual maturity, despite the mean age at maturity being 10 days earlier for the faster-growing birds. Body weights for the two growth groups were not significantly different at 68 weeks. Faster-growth birds consumed 1 kg less feed to 2·1 kg body weight, but 1·3 kg more feed to sexual maturity and 2·7 kg more to 68 weeks, and produced 6 more eggs than, but had similar patterns of egg production to, the conventionally managed controls. Mean egg weight, the proportion of floor eggs and the incidence of mortality were similar for both groups. Notwithstanding that the overall production of abnormally large eggs was low (1·1 eggs per bird); the faster-growing birds produced significantly more than the controls. Egg weight was positively influenced by age at sexual maturity, body weight at sexual maturity and photoperiod, but was unaffected by rate of growth to 2·1 kg per se.These findings show that there are differences between broiler breeders and egg-type pullets in their response to constant photoperiods. It is likely that the factors responsible for these differences, particularly in terms of sexual development, are the exhibition of photorefractoriness by, and the retardational effects of controlled feeding on, broiler breeders.

Effects of feed restriction during the laying period on the performance of two strains of mature caged commercial layers in the humid tropics

1981 ◽  
Vol 96 (1) ◽  
pp. 195-203 ◽  
Author(s):  
K. Benyi ◽  
O. Akinokun ◽  
S. H. B. Lebbie
Keyword(s):  
Body Weight ◽  
Feed Efficiency ◽  
Egg Production ◽  
Feed Consumption ◽  
Feed Restriction ◽  
Egg Weight ◽  
Laying Performance ◽  
Treatment Interaction ◽  
Ad Libitum ◽  
Dressing Percentage

SUMMARYTwo strains of commercial layers, 42 weeks old, were fed ad libitum, 85 and 70% of ad libitum for five 28-day periods to study the effects of feed restriction on body weight, carcass characteristics, laying performance and mortality. There were highly significant strain effects on all traits (P < 0·01) except dressing percentage. Period differences were also observed for egg production, egg weight and feed efficiency. In addition, in all cases the relationship between period and these traits was non-linear and was affected by strain or treatment.Feed restriction had significant effects (P < 0·01) on all traits except dressing percentage and mortality. Feed restriction to 70% of ad libitum reduced egg production, egg weight, body weight and feed consumption and improved feed efficiency. However, in most cases there was no difference between ad libitum feeding and 15% feed restriction.Strain × treatment interaction had significant effects on egg production and feed efficiency.

Seasonal variations in wool growth and heat tolerance of sheep. I. Wool growth

1960 ◽  
Vol 11 (1) ◽  
pp. 75 ◽  
Author(s):  
M Wodzicka
Keyword(s):  
Body Weight ◽  
Day Treatment ◽  
The Other ◽  
Seasonal Rhythm ◽  
Group Iii ◽  
Wool Growth ◽  
Group I ◽  
The Mean ◽  
Group Ii ◽  
The Difference

The monthly wool growth of three groups of rams was studied at Beltsville, Maryland. Group I received natural daylight (at 38° 53' N.) and was shorn monthly. Group II had a 7:17 hours of daylight to hours of darkness rhythm and was shorn every 6 months, once in winter and once in summer. Group III received natural daylight and was likewise shorn every 6 months. The rams of all groups produced more wool in summer than in winter. This difference was significant (P<0.001). The mean body weight and food intake were both greater in the winter months, which indicated that the seasonal rhythm of wool growth was not a consequence of poorer feeding in winter. The rams which were shorn monthly (group I) grew considerably more wool than the other two groups, but the difference was not statistically significant. The short-day treatment of group II did not increase the annual wool production nor decrease the seasonal rhythm of wool growth. The balance of evidence from this and other experiments indicates that temperature rather than light controls the seasonal rhythm of wool growth.

scholarly journals The efficacy of plant extracts on cecal amebiasis in rats

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Enerst C. Ohanu ◽  
Paul C. Inyang-Etoh
Keyword(s):  
Body Weight ◽  
Plant Extracts ◽  
Public Health Problem ◽  
Parasite Load ◽  
Negative Control ◽  
Major Public Health Problem ◽  
Cure Rate ◽  
Standard Drug ◽  
The Mean ◽  
The Difference

Amebiasis caused by <em>Entamoeba histolytica</em> is a major public health problem in tropical and subtropical countries. Treatment failure with specific chemotherapy has been reported suggesting the possibility of drug resistance. This study investigated the anti-amoebic effects of four plant extracts on cecal amebiasis in rats. The cecal amebiasis was induced by the injection of 3.0×105 troph/mL of <em>E. histolytica</em> parasite directly into the rat’s caecum. A total of 137 rats were used for these studies; five rats in each group for both positive and negative control, 15 rats in each group to test the four plant extracts and metronidazole. The infected rats were treated for cecal amebiasis using each of the four plant extracts at graded doses of 100 mg/kg, 200 mg/kg and 400 mg/kg and with metronidzole at a dose of 62.5 mg/kg,100 mg/kg and 125 mg/kg for five consecutive days. The efficacy of the four plant extracts were evaluated based on Neal’s, 1951 method. The plant extracts of Garlic, <em>Guava</em>, Pawpaw and Pumpkin at 400 mg/kg and 200 mg/kg body-weight gave a cure rate of 80%, 100%, 60%, 40% and 40%, 80%, 40%, 0%, respectively. The mean parasite count in the cecal contents of the treated rats at a dose 400 mg/kg were 18.5±1.6, 0.0±0.0, 33.3±1.8 and 49.5±4.0, respectively. The difference was statistically significant (P&lt;0.05). This study has revealed that Guava at a high dosing level (400 mg/kg body weight) is as good as the standard drug in reducing the both parasite load (probably with limited side effect).

The performance of laying hens fed various dietary protein levels in the growing period and first laying year

1971 ◽  
Vol 11 (49) ◽  
pp. 161 ◽  
Author(s):  
JK Connor ◽  
HW Burton
Keyword(s):  
Dietary Protein ◽  
Sexual Maturity ◽  
Egg Production ◽  
Bodyweight Gain ◽  
Protein Restriction ◽  
Protein Layer ◽  
Egg Weight ◽  
Protein Levels ◽  
Growing Period ◽  
Laying Performance

Two experiments examined the effects of protein restriction in the growing period on the production of egg type pullets. The protein levels of diets fed in the growing period were 15, 13, and 11 per cent. The treatments were incorporated in factorial designs with nutritional treatments in the laying period involving diet protein levels of 17, 15, and 13 per cent and, for one of the experiments, with housing densities of either 4 sq. ft. or 2 sq. ft. per bird. Restriction of protein during the growing period retarded growth and delayed sexual maturity, but neither of the levels of restriction examined increased subsequent laying performance. Eggs lost due to delays in the onset of production were not compensated for by increases in subsequent production and egg weight was generally depressed by protein restriction. The pattern of egg production was altered by restriction. A 13 per cent protein layer diet introduced at point of lay also reduced bodyweight gain and delayed age at sexual maturity. Interactions between nutritional and housing treatments in the growing and laying periods were apparent in egg production and egg weight.

Effect of prolonged undernutrition on the recovery and reproductive performance of maiden Merino ewes

1967 ◽  
Vol 7 (24) ◽  
pp. 7 ◽  
Author(s):  
P McInnes ◽  
TJ Grainger ◽  
MD Smith
Keyword(s):  
Body Weight ◽  
Reproductive Performance ◽  
New South ◽  
New South Wales ◽  
The Other ◽  
First Year ◽  
Treatment Groups ◽  
South Wales ◽  
Feeding Trials ◽  
The Mean

Data are presented on the recovery and reproductive performance of 2 1/2-year-old maiden Merino ewes after a prolonged period of undernutrition. The 217 sheep had been hand-fed on a submaintenance ration in pen feeding trials at Glenfield, New South Wales. During the seven months of the trials they had lost 6 kg (28 to 22 kg) body weight. They were transported to Condobolin in south-western New South Wales, divided into two treatment groups and run on good quality pastures. One group was joined immediately (May 1959) and again ten months later, and the other group was mated after six months at Condobolin (in October 1959) and again 12 months later. The ewes recovered rapidly. The mean weight of both groups had reached 30 kg within six weeks and 40 kg within six months. In the first year 73 of the 100 May-mated ewes bore lambs, but only 38 of these lambs were weaned. Ewes bearing lambs had a higher body weight at the start of joining and gained more during joining than the barren ewes. At the other three joinings (October 1959, May 1960, October 1960) lambing percentage was from 86-89 and weaning percentage from 62-69-both normal for the district. The proportion of twin lambs (3-6 per cent) was low. Wool weight in 1959 was not affected by time of mating or by pregnancy.

A COMPARISON OF VARIATIONS IN PLASMA LUTEINIZING HORMONE CONCENTRATIONS IN MALE AND FEMALE DOMESTIC CHICKENS (GALLUS DOMESTICUS) FROM HATCH TO SEXUAL MATURITY

1975 ◽  
Vol 67 (2) ◽  
pp. 211-223 ◽  
Author(s):  
P. J. SHARP
Keyword(s):  
Luteinizing Hormone ◽  
Reproductive Performance ◽  
Sexual Maturity ◽  
Gallus Domesticus ◽  
Parallel Study ◽  
Stages Of Development ◽  
Male And Female ◽  
The Mean ◽  
Lh Secretion

SUMMARY Changes in plasma LH concentrations were followed in chickens of both sexes from hatch to sexual maturity using a radioimmunoassay. Mean levels of LH were lower in the females than in the males at all stages of development. These levels rose rapidly in both sexes during the first week after hatch to maxima of 6·5 ± 1·2 (s.e.m.) ng/ml (n = 6) in the males and 4·6 ± 0·6 ng/ml (n = 6) in the females. Thereafter levels of the hormone in the circulation stabilized in the males but fell over a period of 1 or 2 weeks in the females to 2·5–3 ng/ml. Plasma LH levels started to rise steeply in both sexes when they were between 16 and 19 weeks old at the same time as there was an increase in the rate of comb growth. Afterwards in six of the males studied in detail the mean plasma LH level rose significantly (P < 0·01) over a period of 5–8 weeks from 8·1 ± 1·2 to 13·2 ± 1·9 ng/ml. In a parallel study on six females the rate of LH secretion increased for approximately 3 weeks and then decreased for about the same period forming a prepubertal LH peak. The first eggs were laid between 22 and 25 weeks of age when mean plasma LH levels had fallen to about 1·8 ng/ml. The mean plasma LH level in these hens when they were laying (1·8 ± 0·3 ng/ml) was significantly lower (P < 0·01) than when they were sexually immature (2·7 ± 0·3 ng/ml). The duration of the period of rapid comb growth in each bird was closely related in the males to the time during which prepubertal LH levels were rising rapidly, and in the females to the duration of the prepubertal LH peak. Differences in mean plasma LH concentrations in individual birds of either sex before the onset of puberty appeared to be related to subsequent reproductive performance.

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