Genetic and epidemiological relationships between productivity and disease resistance: gastro-intestinal parasite infection in growing lambs

1999 ◽  
Vol 69 (3) ◽  
pp. 515-524 ◽  
Author(s):  
S. C. Bishop ◽  
M. J. Stear
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Food Intake ◽  
Genetic Correlation ◽  
Live Weight ◽  
Parasite Infection ◽  
Rate Reduction ◽  
Live Weight Gain ◽  
Faecal Egg Count ◽  
Selection For

AbstractThis paper demonstrates how interactions between host genotype for resistance to an infectious disease and the epidemiology of that disease can have large influences on animal productivity and hence on breeding goals for domestic livestock. This is illustrated for the case of gastro-intestinal parasitism in lambs. A model of the parasite infection was developed to include between-animal variation (genetic, permanent and temporary environmental) for live-weight gain, food intake, larval establishment rate in the host, worm fecundity and worm mortality rate. Achieved live-weight gain was defined as the sum of potential live-weight gain under conditions of no parasite infection, a trait correlated with food intake and growth-rate reduction due to the infection. The reduction in growth-rate was calculated from cumulative larval challenge and cumulative worm mass in the lamb. Genetic parameters were then estimated for the output traits of observed live weight at 6 months of age, growth rate reduction and faecal egg count. Model parameters were chosen so that the output means and heritabilities for faecal egg count and live-weight gain mimicked field data for Scottish Blackface lambs and growth-rate reductions were proportionately 0·25 , on average. The model predicted a weak phenotypic correlation (mean = -0·10) between observed live weight and faecal egg count, the indicator of resistance but a stronger favourable (negative) genetic correlation between these traits (mean = -0·27). The severity, or epidemiology, of the disease greatly influenced the results - the genetic correlation between observed live weight and faecal egg count strengthened from -0·02 to -0·46 as the disease severity changed from mild to severe. Selection for reduced faecal egg count resulted in large correlated increases in live-weight gain, more than twice that predicted by quantitative genetic theory, due to the reductions in growth rate losses as the disease challenge to the animals decreased. Conversely, selection for increased live-weight gain resulted in reductions in faecal egg count close to expectations. This asymmetry of selection response emphasizes the epidemiological benefits obtainable from selection for resistance to infectious chronic diseases - such selection will result in improvements in both animal health and productivity not seen when selection is for improved productivity, alone. Breeding goals should be designed to take account of such effects.

A note on the growth and food consumption of crossbred lambs of five sire breeds

1983 ◽  
Vol 37 (1) ◽  
pp. 137-140 ◽  
Author(s):  
J. A. Woolliams ◽  
G. Wiener
Keyword(s):  
Growth Rate ◽  
Energy Efficiency ◽  
Weight Gain ◽  
Food Intake ◽  
Food Consumption ◽  
Fish Meal ◽  
Live Weight ◽  
Food Conversion ◽  
Live Weight Gain ◽  
Ad Libitum

ABSTRACTLambs, 8 weeks of age, the offspring of sires of the Scottish Blackface, East Friesland, Finnish Landrace, Suffolk and Texel breeds mated to Scottish Blackface females as a common maternal breed were fed ad libitum on a concentrate containing barley and fish meal for 14 weeks. Live weight and food intake were measured at intervals of 2 weeks.Live-weight gain varied between sire breeds, Suffolk crosses having the greatest growth rate and the Blackface lambs the least, but there were no significant differences in their food conversion ratios. Food intakes were compared with those predicted by two methods. When the only criteria for prediction were live weight and the metabolizability of the diet the prediction was poor, whereas very accurate agreement was found when the criteria for prediction included consideration of the changes in energy efficiency with food intake and with maturity.

Comparison of the productivity of Texel and Rouge de l’Ouest ewes and their crosses

2002 ◽  
Vol 75 (3) ◽  
pp. 459-468 ◽  
Author(s):  
L. E. R. Dawson ◽  
A. F. Carson ◽  
L. O. W. McClinton
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Live Weight ◽  
The Other ◽  
Superior Performance ◽  
Live Weight Gain ◽  
Low Levels ◽  
Lamb Growth ◽  
Average Figure

AbstractAn experiment was undertaken to compare the productivity of crossbred ewes, produced by crossing Texel sires with Rouge de l’Ouest (Rouge) dams and Rouge sires with Texel dams, relative to purebred Texel and Rouge ewes. The purebred and crossbred ewes were crossed with Rouge and Texel sires. The proportion of productive ewes was similar in the purebred and crossbred ewes with an average figure of 0·92. Irrespective of crossing sire, Rouge ewes produced 0·48 more lambs per ewe lambed than Texel ewes (P < 0·001). The two crossbred ewe types (Texel ✕ Rouge and Rouge ✕ Texel) each produced similar numbers of lambs (on average 1·92 lambs per ewe lambed). Individual heterosis values for ewe fertility and prolificacy were small and not significant (–1·67 for the proportion of productive ewes and –3·14 for the number of lambs born per ewe lambed). Maternal heterosis values were also not significant but were of larger magnitude (6·26 for ewe fertility and 3·12 for prolificacy). Lamb mortality (number of lambs born dead per ewe lambed) at birth was similar for purebred Rouge (0·44) and Texel (0·30) ewes and was significantly reduced by crossbred matings and mating the crossbred ewes (individual heterosis –30·68, P < 0·10; maternal heterosis –80·23, P < 0·001). Individual and maternal heterosis values for lamb growth rate from birth to six weeks were 8 (P < 0·05) and 4 (P > 0·05) respectively. Lamb growth rate from birth to weaning was significantly lower in lambs from Texel ewes compared with those from the other genotypes (P < 0·05). Individual and maternal heterosis values for live-weight gain from birth to weaning were 5 (P < 0·10) and 5 (P < 0·01). The results of the current study demonstrate the superior performance of purebred Rouge ewes compared with purebred Texel ewes in terms of prolificacy and lamb growth rate from birth to weaning. However, both breeds had high lamb mortality at birth. Crossbreeding led to the production of hybrid ewes which had relatively high prolificacy with low levels of dystocia and lamb mortality.

The utilization by beef cattle of a cereal supplement given in liquid suspension or in the dry form

1973 ◽  
Vol 16 (2) ◽  
pp. 173-177 ◽  
Author(s):  
A. R. Renton ◽  
T. J. Forbes
Keyword(s):  
Adverse Effect ◽  
Weight Gain ◽  
Food Intake ◽  
Beef Cattle ◽  
Live Weight ◽  
Food Conversion ◽  
Live Weight Gain ◽  
Liquid Suspension

SUMMARYAn experiment was carried out in which a cereal supplement was given to beef cattle, either in suspension in water or as a dry supplement. There were no significant differences between treatments in live-weight gain, food intake or food conversion ratios. Although there was a tendency for the digestibility coefficients of all constituents to be lower on the diet containing the liquid supplement, the differences were not statistically significant. It is concluded that giving a supplement in suspension has no adverse effect on the utilization of the overall diet and could facilitate mechanization of the feeding operation.

Tests of two theories of food intake using growing pigs 1. The effect of ambient temperature on the intake of foods of differing bulk content

2001 ◽  
Vol 72 (2) ◽  
pp. 351-360 ◽  
Author(s):  
E. C. Whittemore ◽  
I. Kyriazakis ◽  
G.C. Emmans ◽  
B.J. Tolkamp
Keyword(s):  
Weight Gain ◽  
Food Intake ◽  
Live Weight ◽  
Growing Pigs ◽  
Effect Of Temperature ◽  
Biological Efficiency ◽  
Net Energy ◽  
Live Weight Gain ◽  
Fresh Food ◽  
High Bulk

AbstractAn experiment was carried out on pigs to provide a test of two current conceptual frameworks available for the understanding and prediction of food intake. Framework 1 assumes that food intake will be that which allows potential (genetic) performance to be achieved. If this is not achieved then it is because intake is being constrained. Framework 2 sees food intake as being a consequence of a process of optimization such that biological efficiency (the ratio of net energy ingested to oxygen consumed) is maximized. Both frameworks predict that a reduction in temperature will increase the intake of a high quality food. For a food of low quality framework 2 predicts that intake will also be increased when temperature is decreased while framework 1 predicts that it will not. This difference between the predictions of the two frameworks allows them to be tested by means of an experiment in which foods of different quality were given to animals at different environmental temperatures.Forty pigs were randomly allocated to a control (C) food based on micronized wheat with 13·1 MJ digestible energy (DE) and 232 g crude protein (CP) per kg fresh food, or one of two high bulk foods. The high bulk foods contained either 650 g/kg of unmolassed sugar-beet pulp (SBP) or 650 g/kg of wheat bran (WB). Half the pigs were maintained at a thermoneutral temperature of 22ºC for 14 days followed by a cold temperature of 12ºC for 14 days. The other half were maintained at 12ºC for a period of 14 days followed by a temperature of 22ºC for 14 days. Food intake was recorded daily and live weight twice weekly.There was a highly significant food ✕ temperature interaction ( P < 0·001) for food intake. A reduction in temperature resulted in an increase in food intake on C and WB but had no effect on the intake of SBP. There was a highly significant effect of both temperature and food on intake ( P < 0·001). A reduction in temperature resulted in a significant increase in food intake, intake on WB was higher than that of either C or SBP. There was no overall effect of temperature on live-weight gain although a reduction in temperature resulted in a non-significant increase in the gain of C and reduction in the gain of WB and SBP. There was a highly significant effect of food ( P < 0·001) on live-weight gain, as gain on C was higher than that on either WB or SBP.The results of the experiment were in agreement with the predictions set forward by the first framework that growing pigs are eating to achieve maximum performance subject to constraints.

scholarly journals Study on effect of different levels of concentrate on growth performance of both male and female lamb

2016 ◽  
Vol 2 (2) ◽  
pp. 274-278
Author(s):  
Masum Billah ◽  
Md Humayun Kabir ◽  
Md Hafizur Rahman ◽  
Md Abdul Hamid
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Treatment Group ◽  
Live Weight ◽  
Experimental Period ◽  
Control Group ◽  
Male And Female ◽  
Live Weight Gain ◽  
Concentrate Supplementation ◽  
Concentrate Mixture

The present study was carried out to assess the effect of concentrate on growth performances of both male and female lamb. For this purpose twenty four (12 male and 12 female) lamb aged about 5-6 months were selected and divided into three groups (Treatment group T1, T2 and control group T0). In each group having 4 males and 4 females lamb, all lambs were supplied green roughages ad-libitum, control group T0 was allowed no concentrate and treatment group T1 & T2 were supplied 100 gm & 200 gm concentrate mixture respectively for 90 days experimental period. Animals were weighed at 15 days interval. Significant differences of live weight gain among these three groups were found. Allowing 100 gm (T1) concentrate mixture along with green grass improved growth rate in both male and female lamb. Increasing of concentrate supplementation improved live weight gain (found in T2 group). Total live weight gain (kg) and average daily live weight gain (g/d) were 4.25±0.52 kg and 47.20±5.75 g, 5.38±0.83 kg and 59.73+9.17 g and 7.00±0.54 kg and 77.78±6.00 g in male lambs and 2.25±0.21 kg and 25.00±2.34 g, 3.18±0.32 kg and 35.39±3.63 g and 3.81±0.24 kg and 42.33±2.77 g in female lambs for the To, T1 and T2 groups respectively. Live weight was significantly (P<0.05) higher in male than female lambs. The results showed that 100 g concentrate supplementation with green roughages improved growth rate in lambs (male and female) under stall feeding condition. Increase of supplementation might improve nutrients supply to promote higher live weight gain.Asian J. Med. Biol. Res. June 2016, 2(2): 274-278

Holo-analysis of the efficacy of Bio-Mos® in pig nutrition

2006 ◽  
Vol 82 (5) ◽  
pp. 683-689 ◽  
Author(s):  
G. D. Rosen
Keyword(s):  
Weight Gain ◽  
Food Intake ◽  
Live Weight ◽  
Negative Control ◽  
Outer Cell ◽  
Test Duration ◽  
Food Conversion ◽  
Protein Food ◽  
Live Weight Gain ◽  
Empirical Modelling

AbstractThis exploratory holo-analysis of the efficacy of Bio-Mos®, (BM), an outer cell wall derivative of a strain of Saccharomyces cerevisiae, is part of an empirical modelling research programme comparing the efficacies of potential replacements for veterinary prescription-free pronutrient antibiotics in pig production. The data resource was mined from 128 saccharide publications of which 31/97 on BM (1997 to 2003) provided 69 negatively controlled start-to-finish tests from 10 countries (USA 71%) using 3778 pigs(30·5 per treatment). Respective food intake, live-weight gain and food conversion responses of 0·0075 kg/day (0·99%), 0·0145 kg/day (3·58%) and −0·0526 (3·07%) have coefficients of variation of 511, 163 and 229% and beneficial gain and conversion frequencies of 73 and 68%, 54% jointly. Holo-analytical multiple regression models of BM food intake, live-weight gain and food conversion effects using conventional and less stringent probabilities contain significant independent variables for negative control performances, dosage, discontinuous dosage, test duration, year of test, non-USA test, male, grower-finisher, slatted floor, processed food, antibacterial foods, animal protein food, main vegetable protein not soya bean, added oil/fat food and factorial data, which account for 11 to 68% of variations in response. The models quantify differences in research and praxis and indicate areas for future modelling research on BM dose-response relations, effects of ration ingredient and nutrient contents, other saccharide efficacy comparisons, including lactose, and BM comparisons and interactions with other proposed antibiotic replacements.

Rearing of dairy cattle 3. A note on the use of whole milk for calves fed once daily

1972 ◽  
Vol 15 (3) ◽  
pp. 315-318 ◽  
Author(s):  
J. D. Leaver ◽  
N. H. Yarrow
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Dairy Cattle ◽  
Daily Intake ◽  
Live Weight ◽  
Once Daily ◽  
Live Weight Gain ◽  
The Third ◽  
Whole Milk ◽  
Milk Substitute

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.

The effect of Haemonchus contortus infection on haematological parameters in young Merino sheep and its significance for productivity

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
Keyword(s):  
Weight Gain ◽  
Haemonchus Contortus ◽  
Serum Iron ◽  
Live Weight ◽  
Haematological Parameters ◽  
Live Weight Gain ◽  
Wool Growth ◽  
Faecal Egg Count ◽  
Faecal Egg Counts ◽  
Iron Concentrations

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.

Effects of isolation on the behaviour, live-weight gain, adrenal capacity and immune responses of weaned red deer hind calves

1997 ◽  
Vol 64 (3) ◽  
pp. 541-546 ◽  
Author(s):  
A. J. Hanlon ◽  
S. M. Rhind ◽  
H. W. Reid ◽  
C. Burrells ◽  
A. B. Lawrence
Keyword(s):  
Weight Gain ◽  
Food Intake ◽  
Red Deer ◽  
Challenge Test ◽  
Stocking Density ◽  
Live Weight ◽  
Live Weight Gain ◽  
Significant Difference ◽  
Lymphocyte Responses

AbstractAt weaning at 3 months of age (week 1), 30 red deer hind calves were housed in six groups of five animals at a stocking density of 1·5 m2 per head and maintained in these groups for 4 weeks. At the start of week 5, all calves were immunized with ovalbumin (OVA). Fifteen calves, from three groups, selected at random, were transferred to individual pens which restricted visual and tactile contact with others (ISO) while the remaining animals were kept in their groups (GP). The behaviour, food intake, live-weight gain, antibody and lymphocyte responses in vitro to OVA and lymphocyte responses in vitro to the non-specific mitogen, concanavalin A (ConA), of all calves were assessed in each of weeks 5 to 9. Isolated calves had a lower mean live-weight gain than GP calves (P < 0·001), although there were no differences in food intake. Significantly more time was spent lying (P < 0·001) but less time feeding (P < 0·05) and self-grooming (P < 0·001) by ISO than by GP calves. There was no significant difference between ISO and GP calves in the cortisol response to an ACTH challenge test (10 i.u.) at week 11. Lymphocyte responses and antibody titres to OVA were lower in GP than in ISO calves at weeks 7 (P < 0·05) and 8 (P < 0·05), respectively. In contrast, GP calves had greater lymphocyte responses to the non-specific mitogen, ConA, in weeks 7 (P < 0·05) and 10 (P < 0·001) but not in week 9 compared with ISO calves. Differences in lymphocyte stimulation were attributed to the non-specific mitogenic nature of ConA. Factors such as agonistic interactions evident in group housing may have compromised the antibody and lymphocyte responses to OVA by GP calves but conversely the lack of social contact may have also suppressed behavioural activity in ISO calves.

scholarly journals Growth rate and meat quality of guinea fowl kept in farm conditions

2021 ◽  
Vol 22 (4) ◽  
pp. 581-588
Author(s):  
Vladimir A. Zabiyakin ◽  
Sergey A. Zamyatin
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Live Weight ◽  
Unknown Origin ◽  
Guinea Fowl ◽  
Live Weight Gain ◽  
White Breed ◽  
Feed Costs ◽  
Meat Productivity ◽  
Edible Parts

The research (2018-2019) was conducted in the conditions of a peasant farm in the Voronezh region. The paper evaluates the indicators of the growth rate and meat productivity of the preserved gene pool groups of guinea fowl. The experiment involved three groups of daily guinea fowl of 200 heads of different genetic origin: lines of the Volga white breed (the original VB-4, selected by the rate of live weight gain and reproductive characteristics; autosex VBA-1, selected by the color of down, feather and productive characteristics) and gray-speckled guinea fowl of unknown origin. Studies have shown that the live weight of guinea fowl of the VBA-1 line exceeded the live weight of poultry from other groups of guinea fowl, a significant excess was noted at 8, 12 and 13 weeks of age. The greatest coefficient of variation of the trait was observed at 8 weeks of age. The analysis of relative gain in live weight of guinea fowl showed that up to 10 weeks of age, the highest relative growth rate of guinea fowl of all experimental groups was observed (14.0-17.0 %). Starting from the age of 11 weeks, this indicator gradually decreased (4.3-13.4 %). It was found out that under the same conditions of keeping and feeding, the feed costs per 1 kg of live weight gain in guinea fowls of the VBA-1 line were less by 0.09-0.16 kg (3.11-6.33 %) compared to poultry of the VB-4 line and by 0.2-0.4 kg (5.49-12.82 %) compared to their gray-speckled peers. The results of anatomical cutting of guinea fowl carcasses showed that the experimental groups of poultry significantly (P< 0.05) differed among themselves in the degree of development of internal organs and tissues. The yield of edible parts was 60.2-61.1 %, depending on the group of poultry. The large live weight noted by us in linear poultry is the reason for their better meat productivity, which is directly related to an increase in the absolute mass of the eviscerated carcass, its edible parts, muscles and bones. Based on the data obtained, the optimal age of poultry slaughter for meat was determined at 10-12 weeks of life.

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