The effect of inbreeding on feed consumption and utilisation by sheep

1967 ◽  
Vol 9 (3) ◽  
pp. 359-364 ◽  
Author(s):  
J. M. Doney

Twelve inbred (coefficient of inbreeding 25%) and 12 outbred, singlereared, Scottish Blackface castrated male lambs were taken at six months of age from amongst the progeny of three rams. They were housed and fed individually on a pelleted diet in three separate phases. In the first two phases restricted amounts were offered. These were calculated to produce, firstly, a small rate of live-weight gain and, secondly, a small rate of live-weight loss. In the third phase feed was offered to maximum voluntary intake during 2 two-hour periods daily.On restricted intakes there were no significant differences between the groups. In the third phase the outbred sheep consumed 17% more feed than the inbred group and the daily rates of live-weight gain and wool growth were 33% and 27% higher, respectively. Since the inbred lambs were smaller, the voluntary intake per unit live-weight did not differ significantly between groups.The estimated requirements of feed for maintenance (20·1 ± 0·4 and 21·9±0·6 g./kg. live-weight, respectively, for the outbred and inbred groups) differed significantly. There were no apparent differences in the estimated efficiency of conversion of available surplus feed to body tissue or wool growth.

1972 ◽  
Vol 15 (1) ◽  
pp. 11-19 ◽  
Author(s):  
M. K. Curran ◽  
I. J. Lean ◽  
J. E. Duckworth ◽  
W. Holmes

SUMMARY1. The growth, feed consumption per unit weight gain, carcass characteristics and some aspects of meat quality were studied in two trials with crosses derived from Landrace (L), Pietrain (P), Hampshire (H) and Large White (LW) breeds.2. In Trial 1, 96 pigs of both pure Landrace and LW(× (L♀ × P♂)♂ origin were studied up to slaughter weights of 64 and 91 kg live weight. In Trial 2, Landrace, LW♀ × (L♀ × P♂)♂ and LW ♂x (P♀x L♂)♂, (H♀ × P♂ × L♂ and (H♀ × P♂)♀ × LW♂ pigs were compared up to 91 kg live weight using 48 pigs of each type.3. All crossbred types showed better economy of production than Landrace when assessed by live-weight gain and feed consumption per unit weight gain. Their carcasses contained greater quantities of lean meat and similar quantities of rind, bone and fat than Landrace at comparable weights, but they exhibited a variable tendency to poorer meat quality. LW × (L × P) and LW × (P × L) carcasses at 91 kg live weight were shorter than Landrace; 4% and 14% of pigs in trials 1 and 2 respectively were less than the currently acceptable length of bacon pigs (775 mm). (H × P) × LW and (H×P)×L carcasses at this weight were much shorter; 34% and 38% respectively were less than 775 mm.


1987 ◽  
Vol 108 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Margaret Gill ◽  
D. E. Beever ◽  
P. J. Buttery ◽  
P. England ◽  
M. J. Gibb ◽  
...  

SummaryThe effect of oestradiol-17β on the response to fishmeal supplementation of grass silage was studied in young growing cattle. Voluntary intake and live-weight gain were recorded over 63 days with 36 British Friesian male castrates (initial live weight (LW) 119 kg) offered silage alone (C) or with 50 (FM1), 100 (FM2), or 150 (FM3) g fishmeal/kg silage dry matter. Twelve calves were allocated to each of treatments C and FM3 and six to treatments FM1 and FM2. Half of the calves on each treatment were ear-implanted with oestradiol-17β (Compudose 365) at the start of the experiment. The calves on treatments C and FM3 were slaughtered after 75 days and chemical analysis conducted on half of each carcass. The silage had an organic-matter digestibility in vivo of 0·794 and was well-fermented, with a pH of 3·7. Intake averaged 24·2±0·42 g D.M./kg LW over all the treatments and live-weight gain was 0·77 kg/day on the silage alone. There was a significant (P < 0·05) interaction between fishmeal and oestradiol-17β, such that response to the hormone was observed only in the presence of fishmeal at 100 or 150 g/kg silage D.M. A similar interaction was apparent between fishmeal at 150 g/kg silage D.M. and oestradiol-17β in the final weights of empty body and carcass. This level of fishmeal also increased protein gain from 96 to 147 g/day and this was further increased to 179 g/day in the implanted animals receiving fishmeal. However, the overall effect of oestradiol-17β on protein gain was not significant. Gross efficiency of energy utilization was significantly (P < 0·01) increased by fishmeal supplementation suggesting an improved balance of nutrients compared with the silage alone diet.


1985 ◽  
Vol 40 (2) ◽  
pp. 259-265 ◽  
Author(s):  
P. England ◽  
Margaret Gill

ABSTRACTIn an experiment designed to investigate the effects on the growth and voluntary food intake of grass silage by calves, the silage was supplemented with varying levels of fish meal and sucrose. The grass silage had a pH of 3·6, a lactic acid content of 90·0 g/kg dry matter (DM) and total nitrogen content of 15·5 g/kg DM. Supplements of 50, 75 and 100 g fish meal per kg silage DM and 50, 75, 100 and 150 g sucrose per kg silage DM were mixed with the silage just prior to feeding. The eight diets were offered to 32, 4-month-old British Friesian steers for 12, 7-day periods. Intake was recorded daily and live weight weekly.Digestibility of organic matter (P < 0·05) and N (P < 0·001) were increased by fish-meal supplementation but the effect of level of fish meal was not significant. Sucrose supplementation significantly decreased both N (P < 0·01) and cellulose (P < 0·05) digestibility. The effect on cellulose digestibility increased with level of sucrose (P < 0·01).The intake of silage DM increased in response to increasing level of fish-meal inclusion when intake was expressed in terms of kg/day (P < 0·01) but not when expressed in g/kg live weight. Total DM intake showed a significant (P < 0·001) linear response when expressed both in terms of kg/day and g/kg live weight. The intake of silage DM declined in response to increased level of sucrose supplementation both in absolute (P < 0·05) and live-weight terms (P < 0·001) but sucrose supplementation had no significant effect on total intake.Live-weight gain was significantly increased with increasing level of fish-meal supplementation (P < 0·001), but sucrose supplementation had a significant effect on live-weight gain relative to the control treatment at only the 75 g/kg level, where live-weight gain was increased.


1972 ◽  
Vol 15 (3) ◽  
pp. 315-318 ◽  
Author(s):  
J. D. Leaver ◽  
N. H. Yarrow

SUMMARYWhole milk was given once daily to three groups each of 18 Friesian heifer calves and concentrates and hay were also available. Calves in one group received 2·4 kg milk/day and in a second 3·0 kg milk/day and in both of these groups individual calves were weaned when their daily intake of concentrates reached 400 g. In the third group the calves received 3·0 kg milk/day and were weaned after 28 days. Concentrate and hay intakes were not significantly affected by the treatments. Mean growth rate over 56 days increased with increasing quantity of whole milk offered but the differences between treatments were not significant. The performance of calves given whole milk was compared with the performance achieved in previous experiments where milk substitute was given. It was estimated that 1 kg whole milk gave the same live-weight gain as 170 g milk-substitute powder. From this estimate price/cost relationships were determined to indicate when whole milk or milk substitute should be fed to calves.


1978 ◽  
Vol 90 (2) ◽  
pp. 425-429 ◽  
Author(s):  
P. B. O'Donovan ◽  
A. Gebrewolde ◽  
B. Kebede ◽  
E. S. E. Galal

SummaryTwo group-feeding and one individual-feeding experiments were made for 112 and 182 days, respectively, with 76 cross-bred and eight Zebu bulls. Simmental, Friesian and Jersey sire breeds were mated to three Ethiopian Zebu breeds, namely Boran, Horro and Barca, while Zebu bulls were included for comparison purposes in Expt 3. The trials were conducted in confinement at Holetta Research Station, located at 2400 m elevation and having a mean maximum temperature range of 18·7–24 °C. In the group-feeding trials (Expts 1 and 2) a common diet was fed, consisting of native hay (30%) molasses (20%) and a concentrate supplement. In the third experiment, two diets containing 30 and 50% native hay were supplemented by concentrate and fed individually to eight Simmental and eight Friesian cross bulls, while eight Zebus served as a control.The average daily gains, feed intake and conversion did not differ markedly between Simmental and Friesian crosses, but lower values were generally found for Jersey crosses. Cross-breds outgained Zebus, consumed more feed and converted it more efficiently to live-weight gain. Performance differences were noted between the Zebu breeds as well as some evidence of sire × dam breed interactions. Significantly higher gains were achieved with the low than with the high roughage diet.


1990 ◽  
Vol 50 (1) ◽  
pp. 99-109 ◽  
Author(s):  
G. A. A. Albers ◽  
G. D. Gray ◽  
L. F. Le Jambre ◽  
I. A. Barger ◽  
J. S. F. Barker

ABSTRACTFaecal egg counts, haematocrits, erythrocyte potassium contents and serum iron concentrations were determined in 1005, 3- to 5-month-old Merino lambs infected with a single dose of 11 000 Haemonchus contortus larvae. Live-weight gain and wool growth also were recorded. Lambs were infected in six different groups over a 3-year period. When infections were terminated after 5 weeks, faecal egg counts in the six infected groups had reached a peak of 5170 to 20 339 eggs per g (average 12 909), haematocrits had declined to between 196 and 309 ml/1 (average 233), erythrocyte potassium contents had risen to between 16·7 and 37·5 mequiv. per 1 (average 31·5) and serum iron concentrations, in some cases following an erratic course, had dropped to between 0·512 and 1·546 mg/1 (average 0·946).Of the three haematological parameters, haematocrit correlated best with faecal egg count (r = 0·7 in four of six infected groups). However, in two groups with low faecal egg counts this correlation was much lower (r = 0·3). Erythrocyte potassium concentration and serum iron concentration significantly correlated with variability of haematocrit not accounted for by faecal egg count, suggesting that both erythropoiesis and iron availability influence the degree of anaemia.The effect of H. contortus infection on productivity of lambs was best predicted by haematocrits: for each further 0·01 proportional decrease in haematocrit, a 0·03 reduction of live-weight gain over a 9-week post-infection period, a 0·007 reduction in clean wool growth and a 0·004 reduction in fibre diameter over a 4- to 9-week period were observed. Some evidence was obtained indicating a tolerance level of anaemia at approximately 280 ml/1 packed cell volume.


1988 ◽  
Vol 47 (2) ◽  
pp. 209-214
Author(s):  
J. R. Southgate ◽  
A. R. Peters ◽  
S. N. Dixon

ABSTRACTA comparison of anabolic treatment regimes was made in 761 autumn-born Friesian steers on 14 farms. Prior to turn-out for grazing at 6 months of age and approximately 180 kg live weight, steers were weighed and divided into three equal-weight groups. Group 1 received silastic implants containing 45 mg oestradiol-17β. Group 2 received 36 mg zeranol and group 3 were untreated controls. All steers were weighed at intervals of approximately 3 months (i.e. mid summer, yarding at autumn, mid winter and pre-slaughter) and group 2 steers received a further 36 mg zeranol at the second, third and fourth weighing. At the third weighing half the cattle in each of the treatment groups 1 and 2 received 300 mg trenbolone acetate. Also at the third weighing, group 3 (controls) were subdivided into three equal-weight groups, the first of which received 45 mg oestradiol-17β and 300 mg trenbolone acetate and the second 36 mg zeranol and 300 mg trenbolone acetate. The third subgroup remained as untreated controls.From 10 farms a 25% sample close to group mean weight at mid winter were slaughtered on the same day and subjectively assessed for subcutaneous fat score and conformation on 15-point scales. The left thin flank was separated into tissues. Samples of lean fat, liver and kidney were analysed for zeranol residues. All implant treatments resulted in higher live-weight gain, heavier slaughter weights and earlier slaughter. Trenbolone increased daily gain only during the first 3 months after treatment. Implanted carcasses were heavier both in the fore- and hindquarter but trenbolone also produced heavier forequarters. Carcasses from treated steers had more subcutaneous fat, less perinephric and retroperitoneal fat and less intermuscular fat in the thin-flank joint. Zeranol residues in implanted steers were not significantly higher than controls except in the kidney, but even these were significantly below accepted tolerance levels.


1984 ◽  
Vol 38 (3) ◽  
pp. 455-461 ◽  
Author(s):  
B. R. Brinklow ◽  
R. Jones ◽  
J. M. Forbes

ABSTRACTFour experiments were carried out, with a total of 98 Suffolk-cross lambs fed at a restricted level, to study the effects of skeletal long photoperiod (7 h light: 10 h dark: 1 h light: 6 h dark) compared with short photoperiod (8 h light: 16 h dark) on growth and blood levels of hormones. The experiments started when the lambs were from 2 to 10 months of age and continued for 9 to 14 weeks.In the first experiment, the weight gains of both females and castrated males were significantly increased by skeletal long photoperiod. Plasma prolactin was increased and cortisol decreased by skeletal long photoperiod.Experiment 2 included females and castrated males; prolactin was stimulated by skeletal long photoperiod and there was a significant positive correlation between live-weight gain and prolactin.The weight gains and carcass characteristics of the female lambs used in the third experiment were not affected by photoperiod. Live-weight gain was negatively related to plasma cortisol.In experiment 4, there were 12 intact males and 12 castrated males. The intact animals grew significantly faster; skeletal long photoperiod caused a depression in testosterone levels in plasma even though it tended to increase live-weight gain.When the data from all four experiments were pooled, it was found that skeletal long photoperiod gave a significant increase in live-weight gain in animals whose pineal gland was intact (40 per photoperiod; 138 v. 113 g/day); there was no effect on gut fill at slaughter and the increase in carcass weight (0·5 kg) was not significant.


Author(s):  
A.F. Khabirov ◽  
◽  

The reaction of the organism of broiler ducklings to the introduction of the probiotic additive "Lactobifadol" into the organism when reared up to 7 weeks of age was investigated. A positive effect was achieved to increase the live weight of the experimental poultry by 5.0 % (p <0.5), the average feed consumption per 1 kg of live weight gain in the group of broiler ducklings fed with Lactobifadol feed was 4.7 % less when compared to intact poultry. The dynamics of feed consumption per 1 kg of live weight gain in the first three weeks of rearing was descending, and from 4 weeks of age until the end of rearing, fodder consumption increased significantly. For 6 weeks of growing, the average consumption of compound feed per head per day in the control group of broiler ducklings was 157.5 g, in the experimental group – 158.5 g per 1 bird/day. The inclusion of "Lactobifadol" in the diet to a certain extent stimulates the processes of erythrocytopoiesis, providing, within the physiological norm, an increase in the level of hemoglobin and the number of leukocytes.


Author(s):  
Hasan Cicek ◽  
Murat Tandogan

In this study, optimum slaughter age of the commercial broilers was estimated regarding maximum net income. Study materials were average target performance (live weight gain and feed consumption) of Cobb 500 and Ross 308 commercial hybrids, prices of feed, chicks and broiler meat. The optimum slaughter age was estimated by a mathematical function (y = f (x) = a+bx-cx2) that reflects the quadratic (parabolic) relationship. According to this function, the optimum slaughter age was calculated as 5.62 weeks (39.34 days). As a result, it can be said that genetic improvement positively affects the correlation between live weight gain and feed consumption of broilers. However, prices of feed, chicks, and broiler meat have more decisive role on slaughter age.


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