Effects of photostimulatory lighting and feed allocation in female broiler breeders 1. Reproductive development

1998 ◽  
Vol 78 (4) ◽  
pp. 603-613 ◽  
Author(s):  
F. E. Robinson ◽  
R. A. Renema ◽  
L. Bouvier ◽  
J. J. R. Feddes ◽  
J. L. Wilson ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Egg Production ◽  
Carcass Composition ◽  
Feed Restriction ◽  
Broiler Breeders ◽  
Feeding Programs ◽  
Feeding Program ◽  
Group A ◽  
Feeding Regimen ◽  
Group B

Changes in carcass traits during sexual maturation were studied with female Shaver Starbro breeders in a 2 × 2 factorial design with two lighting programs and two feeding programs. Pullets were individually caged in a light tight facility at 20 wk of age. The light period of fast photoperiod (FP) hens was changed from 8L:16D to 15L:9D at 20 wk of age. Slow photoperiod (SP) hens were switched from a 8L:16D photoperiod at 20 wk to 11L:13D, with increases to 12L:12D, 13L:11D, 14L:10D, and 15L:9D weekly to 24 wk of age. Slow feed (SF) hens were given small (5 g or less) weekly increases in feed allocation from 20 to 25 wk. Fast feed (FF) hens received larger feed allocations than the SF birds from 20 to 25 wk (maximum difference of 25 g more feed than SF hens received). Birds were processed at weekly intervals between 20 and 26 wk of age (Group A) or at sexual maturity (Group B), which was considered to be the day of the first oviposition.Age at sexual maturity did not differ due to photostimulation or feeding treatment. Whereas feeding program had no effect on carcass composition parameters at sexual maturity, the SP hens had a higher relative carcass lipid content at the expense of protein and ash content compared to FP hens. The weight of the large yellow ovarian follicles (LYF) at sexual maturity was affected by feeding regimen (FF, 50.2 g; SF, 43.6 g) and photoperiod (FP, 43.2 g; SP, 50.6 g). While hens on the SP photostimulation program had 8.9 LYF compared to 8.0 in FP hens at sexual maturity, the FF feeding regimen hens had 9.0 LYF compared to 7.9 in SF hens. The gradual feeding program of the SF treatment may be a potential means of limiting follicle recruitment and thereby potentially increasing settable egg production compared with feeding programs using more rapidly increasing feed allocations. Key words: Broiler breeders, photostimulation program, feed restriction, ovary morphology

scholarly journals Ultrasonographic Examination and Measurements of Testes, Epididymis and Accessory Glands at Different Growth Stages of Chios Rams

2021 ◽  
Author(s):  
Ahmed Ali ◽  
Abdel-Razek Kh. Abdel-razek ◽  
Salem Fahmy
Keyword(s):  
Sexual Maturity ◽  
Tunica Albuginea ◽  
Growth Stages ◽  
Ultrasonographic Examination ◽  
Maximum Thickness ◽  
Accessory Glands ◽  
Scrotal Circumference ◽  
Group A ◽  
Group B ◽  
Different Growth Stages

Background: Testes, epididymis and accessory glands measurements should be mandatory as an imminent for male selection. This study aimed at defining the ultrasonographic characteristics and measurements of testes, epididymis and accessory glands at different growth stages in Chios rams.Methods: Sixteen rams were assigned by age class into: group A (pre-pubertal, n=3), group B (pubertal, n=5) and group C (mature, n=8). Scrotal circumference (SC) was measured using a tape. Scrotal contents were examined using a B-mode ultrasound. Testicular breadth (TB), thicknesses of tunica albuginea (TA) and mediastinum (MS) and the largest dimension of epididymal tail (EpT) were estimated. Trans-rectal ultrasound was carried out to estimate the echogenicity and diameter of bulbourethral gland (BUG), height of pars dessiminata of prostate (PDP) and maximum breadth of seminal gland (SG).Result: SC increased curvilinear with age. Testicular echogenicity increased with age. Thickness of TA did not differ with age. MS could not detect in pre-pubertal rams, reached maximum thickness with puberty and became relatively thinner by maturity. EpT evidently enlarged with puberty. BUG, PDP and SG exhibited moderate echogenicity. They reached their greatest size with sexual maturity. SC estimated by tape and TB estimated by US correlated with most of the ultrasonographic measurements of the epididymis and accessory glands.

scholarly journals Effect of Fresh Forage Canola on Production Performance and Egg Quality of Laying Hens

2021 ◽  
Vol 25 (05) ◽  
pp. 995-1001
Author(s):  
Yixiao Ma
Keyword(s):  
Egg Production ◽  
Laying Hens ◽  
Egg Quality ◽  
Initial Period ◽  
Practical Interest ◽  
Production Performance ◽  
Feed Consumption ◽  
Group A ◽  
Group B ◽  
Group D

Feed shortage had become a major factor constraining the development of animal husbandry. Forage canola has been found to be a potential feed crop due to its high yield and good quality. Therefore, this study mixed different proportions of forage canola to the diet of laying hens and all eggs were collected for analysis. Laying hens were divided into four groups according to the feeding amount of canola: 0 kg, 3 kg, 6 kg, 9 kg, with 30 laying hens in each group. In the feeding trial, there was no negative effect on hen body weight, egg production, or overall egg quality. The results showed that Group B, C and D complete feed consumption is less than Group A. From the spectrum analysis, the trend of the Group A was different from that of the other three groups. After 35 days of rearing, the laying rate of the Group B and the Group C increased about 30% compared to 1 to 7 day. The weight of the Group B and Group C increased about 5% compared with the initial period, while the Group A increased 0.6% and the Group D increased by 3%. The eggshell strength of the Group B and Group C also increased significantly. The contents of phosphorus and potassium in the Group B and C were higher than those in the Group A and Group D. The effects of canola to poultry diets is therefore of practical interest. This study will provide us a potential forage substance in laying hens production performance. © 2021 Friends Science Publishers

Developmental growth and body weight loss of cattle. IV. Chemical components of the commercially dressed and jointed carcass

1969 ◽  
Vol 20 (1) ◽  
pp. 199 ◽  
Author(s):  
RM Seebeck ◽  
NM Tulloh
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Body Weight Loss ◽  
Carcass Composition ◽  
Chemical Component ◽  
Carcass Weight ◽  
Chemical Components ◽  
Single Chemical ◽  
Group A ◽  
Group B

This paper describes a study of chemical components of the carcasses from Angus steers. The left side of each carcass was jointed commercially and each joint was analysed for protein (N x 6.25), water, ash, and fat (ether extract). Two groups of steers were used, viz. group A which grew continuously and group B which grew like group A and were then subjected to a period of weight loss before slaughter. Corresponding animals in both groups were killed at the same body weight. Statistical analysis was by analyses of covariance of the weights of components converted to logarithms. As carcass weight increased, the proportions in the carcass of protein, water, and ash decreased while the proportion of chemical fat increased. When carcass composition was calculated on a fat-free basis, there were significant changes in the proportions of protein, water, and ash as the weight of the fat-free carcass increased during the age range of 12 to 24 months. These are contrary indications to the theory of chemical maturity put forward by Moulton (1923). As carcass weight increased, the weight of each chemical component increased but changes occurred in the distribution throughout the carcass of protein, ash, and chemical fat. The effect of the weight loss treatment on the proportion of each chemical component was independent of carcass weight. When group A and group B animals were compared at the same carcass weight, weight loss led to a significant increase in the proportion of ash and a significant decrease in that of protein. The weight of ash in group B carcasses was estimated to be slightly less than that expected in these animals at their peak of body weight, i.e. before weight loss commenced. There were significant differences between groups A and B in the distribution of the chemical components (particularly protein and fat); these treatment differences in distribution indicate a limitation to the use of chemical analyses of a single joint for predicting whole carcass composition. When relationships between chemical and dissected components were studied, each single chemical component was well related to its corresponding dissected component. For each dissected component except muscle, however, there were significant differences between groups A and B in the equation of best fit, either in slope or in the intercept (difference between adjusted means). Differences of this type limit the use of chemical analysis for estimating dissected components where differences between groups are being studied.

THE PERFORMANCE OF LAYING HENS REARED ON RESTRICTED AND FULL FEEDING PROGRAMS

1959 ◽  
Vol 39 (2) ◽  
pp. 217-225 ◽  
Author(s):  
T. M. MacIntyre ◽  
J. R. Aitken
Keyword(s):  
Body Weight ◽  
Specific Gravity ◽  
Egg Production ◽  
Egg Size ◽  
Laying Hens ◽  
Feed Restriction ◽  
Feeding Programs ◽  
The Mean ◽  
Late Start ◽  
Held Back

Experiments were conducted in 3 successive years to measure the effect on the performance of laying hens of restricting feed during the rearing period on range. About 1100 birds were reared and carried through a laying year in each experiment. Feed restriction was 72, 76 and 63 per cent of full feed for the test groups in Experiments 1, 2, and 3 respectively. All birds were full-fed in the laying house.Feed restriction changed the pattern of egg production, in that the restricted birds came into production later but subsequently laid at a higher rate than their full-fed counterparts. After 318 and 322 days in production the restricted birds in Experiments 1 and 2 respectively had overcome the disadvantage of a late start (7 and 14 days) and produced as many eggs as the full-fed birds. In Experiment 3, the restricted birds were held back 20 days, and after 315 days in production were still significantly behind in number of eggs produced.The restricted birds in the three experiments consumed an average of 0.17 pounds less feed per dozen eggs over the combined rearing and laying periods This amounts to a saving of 3 pounds of feed per bird, since the mean egg production of the restricted groups was 18 dozen eggs per bird.Early egg size was markedly increased by feed restriction and egg weights taken later in the year (after 3 months in production) remained slightly higher for the restricted groups. Albumin score for eggs from the restricted birds was better in all tests, but not significantly so in any given experiment. Specific gravity of the eggs was not influenced by feed restriction.Mortality on range and in the laying house was not affected by feed restriction on range. Body weight at housing time was much lower for the restricted birds but was not significantly lower at the end of the laying year.

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 age at photostimulation on reproductive efficiency and carcass characteristics. 2. Egg-type hens

1996 ◽  
Vol 76 (3) ◽  
pp. 283-288 ◽  
Author(s):  
F. E. Robinson ◽  
T. A. Wautier ◽  
R. T. Hardin ◽  
J. L. Wilson ◽  
M. Newcombe ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Egg Production ◽  
Reproductive Organ ◽  
Carcass Composition ◽  
Day Length ◽  
Feed Consumption ◽  
Whole Body ◽  
Sequence Length ◽  
Treatment Groups ◽  
Time Required

Increasing day length is the primary cue for the timing of sexual maturation in poultry. Typically, Single Comb White Leghorn (SCWL) pullets are reared under conditions of short days (8L:16D) until 18 wk of age. In this study, the effects of varying the age at photostimulation from 16, 18 or 20 wk of age were studied in terms of carcass composition at photostimulation and at sexual maturity, as well as reproductive performance.A flock of 1600 SCWL pullets (Shaver 288 strain) were housed in floor pens in light-tight facilities (8L:16D). All birds were provided with ad-libitum access to both feed and water. At 16 wk, 18 wk and 20 wk, 50 birds per treatment were moved to laying cages and provided to a photoperiod of 14L: 10D. An additional 288 birds per treatment were housed two birds per cage, and group egg production and feed consumption data were collected to 64 wk of age. At photostimulation (n = 20 birds per treatment) and on the day following the first oviposition, (n = 20 birds per treatment) birds were killed by cervical dislocation. All surviving hens were killed at 64 wk of age. All carcasses were studied in terms of selected organ weights and reproductive organ morphology. Birds killed at photostimulation and at sexual maturity were further studied for whole body carcass composition.Significant differences were found in dry matter, water, lipid and ash content among treatment groups at the age of photostimulation. As age at photostimulation increased, absolute weight of carcass fat, protein and ash increased. The percent carcass lipid content increased for all groups between photostimulation and sexual maturity with the 16 wk treatment group showing the largest increase. The time required to reach sexual maturity from the age of photostimulation decreased as the age at photostimulation increased. No significant differences were found in total egg production. The 16 wk group laid significantly smaller eggs. Delaying sexual maturity until 20 wk of age resulted in an increased prime sequence length and fewer pause days to produce approximately the same number of eggs as birds that were photostimulated at 16 wk of age. Key words: Chicken, egg-type hens, sexual maturity, egg production, carcass composition

scholarly journals Properties and composition of carcass of domestic spotted young cattle of two preslaughter weights

2011 ◽  
Vol 27 (4) ◽  
pp. 1443-1450 ◽  
Author(s):  
M. Petricevic ◽  
N. Stanisic ◽  
Lj. Sretenovic ◽  
M.M. Petrovic ◽  
S. Stajic ◽  
...  
Keyword(s):  
Muscle Tissue ◽  
Carcass Composition ◽  
Fat Tissue ◽  
Significant Difference ◽  
Kidney Fat ◽  
Group A ◽  
Young Cattle ◽  
Group B ◽  
Almost All ◽  
A Share

Objective of this research was to determine the slaughter properties and carcass composition of carcass sides derived from young cattle of Domestic Spotted breed, of pre-slaughter weights of 500 (group A) and 600 kg (group B). Heavier cattle had higher share of kidney fat in carcass, whereas the share of offals showed no significant differences. Statistically significant difference was registered only in share of toungue (P<0.05), that was higher in cattle of group A. Share of extra/premium (tenderloin), I category (round) and II category (loin, back, shoulder) showed no significant differences between groups of cattle. Statistically significant difference (P<0.05) was established in the share of III category carcass parts. Share of forearm and chest was significantly higher in lighter cattle (3.55% and 7.95%) compared to heavier animals (2.89% and 6.33%), whereas the share of subshoulder was considerably lower in group A (6.89%) compared to cattle of group B (9.73%). Data obtained by dissection of main carcass side parts differed significantly in regard to the share of muscle tissue in round and belly, that was significantly higher in cattle of group A (P<0.05). Share of fat tissue (subcutaneous and intermuscular) was higher in cattle of group B in almost all carcass side parts, however, statistically significant difference between groups was determined only in round, back, neck and subshoulder. Also, share of bones in chest differed statistically significantly (P<0.05) and it was higher in group A (20.09%) compared to cattle of group B (15.52%).

Light program and feed restriction during the rearing of out-of-season medium-sized pullets: body weight, bone development, and sexual maturity.

1969 ◽  
Vol 88 (3-4) ◽  
pp. 135-144
Author(s):  
Héctor L. Santiago-Anadón ◽  
José R. Latorre-Acevedo
Keyword(s):  
Sexual Maturity ◽  
Bone Growth ◽  
Bone Development ◽  
Control Diet ◽  
Growth Patterns ◽  
Feed Restriction ◽  
Feeding Level ◽  
Feeding Programs ◽  
The Tropics ◽  
Bird Weight

An experiment was conducted to determine the most appropriate light program and feeding level for the rearing of out-of-season pullets in the tropics and the effects on growth and sexual maturity. Data were obtained during an 18-wk rearing period from 880 Isa Brown medium-sized pullets. The pullets were randomly distributed between two groups subjected to either a constant light program (CLP) or a decreasing light program (DLP) in open houses. In each case, pullets were subdivided into five groups, which received the following feeding programs: control diet (T-1) with a feeding level suggested by the breeding company; 10% (T-2), and 20% (T-3) over the control diet; and 10% (T-4), and 20% (T-5) under the control diet. The variables studied were mean bird weight (MBW), tarsus-metatarsus length (TML), and age at sexual maturity. Under CLP and DLP, respectively, there were no significant differences in MBW among T-1 (1.46 and 1.5 kg), T-2 (1.51 and 1.49 kg), and T-3 (1.47 and 1.56 kg). However, T-4 (1.35 and 1.41 kg) and T-5 (1.26 and 1.29 kg) showed lower MBW (P<0.05). Until 10 wk of age, there were no differences in TML between the two light programs. Under DLP, bone growth at 18 wk was similar for all feed levels: 103,103,104,103, and 101 mm for T-1 through T-5, respectively. However, under CLP, TML of T-5 (101 mm) was less than that of T-1, T-2, and, T-3 (104 mm). Irrespective of light program, overfed pullets demonstrated growth patterns similar to those of the control at 18 wk of age, whereas restriction of feed resulted in less weight than that of control pullets, although bone growth was similar. Feed restriction of 10% (T-4) and 20% (T-5), under both light programs, delayed sexual maturity from three to 14 days compared to that of other treatments. 

Sign in / Sign up

Export Citation Format

Share Document