Effects of live weight and condition score on food intake of ewe lambs

2003 ◽  
Vol 2003 ◽  
pp. 8-8
Author(s):  
Bert J. Tolkamp ◽  
Gerry C. Emmans ◽  
Ilias Kyriazakis

Food intake (FI) can be predicted on the basis of variables that describe food quality, the environment and the animal. Live weight (LW), in some form or other, is usually the only variable used to describe the animal. Animal fatness, estimated by condition score (CS), can affect intake at a given LW. A simple model to account for that is FI= a.LW.(1-b.CS) with FI in g/day, LW in kg and CS in units of a scale up to 5. It is evident that food quality will affect parameter a. Here we test the hypothesis that the parameter b in this model is significant but not affected by food quality. To that end, we measured LW, CS and intake of three different foods with ewe lambs that showed a large variation in LW and CS as a result of different nutritional histories.

2005 ◽  
Vol 2005 ◽  
pp. 16-16
Author(s):  
B. J. Tolkamp ◽  
J. M. Yearsley ◽  
I. Kyriazakis

Food intake (FI) can be predicted on the basis of variables that describe food quality and the animal. Live weight (LW) is usually the only variable that is used to describe the animal. Animal fatness, as estimated by condition score (CS), can affect FI at a given LW. Body lipid produces signals (leptin) that affect energy intake and energy expenditure. If fatness acts on intake via its effect on energy expenditure, the effects of body lipid content on food intake can be incorporated into an existing intake model. Our objectives were to construct and test models that predict effects of fatness on intake and performance, using data obtained with ewe lambs to parameterise and test the models.


1999 ◽  
Vol 24 ◽  
pp. 63-73 ◽  
Author(s):  
R. F. Veerkamp ◽  
E. P. C. Koenen

AbstractThe objectives of this study were to investigate genetic variation for traits that are part of the food utilization complex and to investigate the scope for future genetic improvement of traits possibly linked to metabolic stress: live weight (change), condition score (change) and energy balance. Many aspects of the food utilization complex appear to be heritable and are affected by genetic selection for yield. In general, genetic selection for yield increases intake and body tissue mobilization and energy balance is expected to decrease. However, unfavourable effects of genetic selection can be compensated for by measuring additional traits to be included in breeding programmes. Food intake, live weight (change) and condition score (change) are all potential options. Which traits should be measured, at what lactation stages and in which (nutritional) environment will merely depend on the coheritability with health and fertility, the genetic correlation with milk yield and the cost of measuring the trait effectively in a breeding programme.


1997 ◽  
Vol 64 (3) ◽  
pp. 385-392 ◽  
Author(s):  
R. F. Veerkamp ◽  
S. Brotherstone

AbstractVariance components were estimated from an animal model using a restricted maximum likelihood procedure which allowed for unequal design matrices and missing observations (VCE). Data sets containing: (i) 15 275 records of linear type classifications on heifers, (ii) 3399 live weight and condition scores measured at calving and (iii) 1157 records of yield, dry-matter intake, average live weight and condition score during the first 26 weeks of lactation; were analysed jointly.Heritability estimates for dry-matter intake, live weight and condition score in the largest data set were 0·44, 0·44 and 0·35 respectively and the genetic correlation between condition score and the yield traits ranged from −0·29 to −0·46. The genetic correlation between milk yield and average live weight was negative (−0·09) but after adjusting for the genetic variation in condition score this correlation was positive (0·29). Genetic correlations between live weight and stature, chest width, body depth and rump width were consistently high (0·52 to 0·64; 0·75 to 0·86; 0·59 to 0·81; 0·56 to 0·74, respectively). Chest width and body depth were little to moderately correlated with dry-matter intake (0·25 to 0·28 and 0·20 to 0·34 respectively), and angularity (−0·47 to −0·77) and chest width (0·32 to 0·73) appeared to be good predictors of condition score. These correlations showed that (i) the relative value of live weight compared with food intake capacity determines the optimum direction of selection for stature, chest width, body depth and angularity, and consequently the optimum size of the dairy cow, and that (ii) live weight, condition score and food intake can be predicted from the type traits with little loss in accuracy. A restricted index which maintains condition score at its current level was predicted to reduce overall (economic) genetic gain by 5%.


1986 ◽  
Vol 42 (1) ◽  
pp. 65-72 ◽  
Author(s):  
B. W. Butler-Hogg ◽  
I. D. Johnsson

ABSTRACTForty Hampshire Down × Mule (Blue-faced Leicester cf × Swaledale 2) ewe lambs, obtained within a week of birth, were reared on milk replacer and from 6 weeks of age on a complete pelleted diet. Food intake of individual lambs was controlled to produce periods of high (H: ca. 210 g/day) and low (L: ca. 110 g/day) rates of live-weight gain from 4 to 20 and 20 to 36 weeks of age. Groups of eight lambs were slaughtered and dissected at 20 weeks having followed either growth paths H or L, and at 36 weeks having followed growth paths LL, HL or LH.Growth path had little effect on the lean or bone content of the carcass, but had a significant effect on carcass fat content and distribution. At the same carcass weight, the ratio of intermuscular to subcutaneous fat was higher in leaner carcasses. When compared at the same weight (ca. 35 kg) but different ages (H, 20 weeks; LL 36 weeks), the slower growing LL lambs contained 1·22 kg more fat than the H lambs, primarily in the intermuscular and subcutaneous depots but also in the internal omental depot. At the same age and weight (ca. 36 weeks and 48 kg), lambs which had followed the growth path LH contained 2·5 kg more fat than lambs which had followed the HL path. These differences in fatness are thought to have come about through changes in the effective protein:energy ratio of the diet, induced by the manipulation of food intake.Carcasses of HL lambs would be of more value to the meat trade compared with LH, since they would require less fat trimming before retail sale.


2001 ◽  
Vol 73 (1) ◽  
pp. 29-40 ◽  
Author(s):  
M. P. Coffey ◽  
G. C. Emmans ◽  
S. Brotherstone

AbstractCurrent selection objectives for dairy cattle breeding may be favouring cows that are genetically predisposed to mobilize body tissue. This may have consequences for fertility since cows may resume reproductive activity only once the nadir of negative energy balance (NEB) has passed. In this study, we repeatedly measured food intake, live weight, milk yield and condition score of Holstein cattle in their first lactation. They were given either a high concentrate or low concentrate diet and were either selected or control animals for genetic merit for kg milk fat plus milk protein. Orthogonal polynomials were used to model each trait over time and random regression techniques allowed curves to vary between animals at both the genetic and the permanent environmental levels. Breeding values for bulls were calculated for each trait for each day of lactation. Estimates of genetic merit for energy balance were calculated from combined breeding values for either (1) food intake and milk yield output, or (2) live weight and condition-score changes.When estimated from daily fluxes of energy calculated from food intake and milk output, the average genetic merit of bulls for energy balance was approximately -15 MJ/day in early lactation. It became positive at about day 40 and rose to +18 MJ/day at approximately day 150. When estimated from body energy state changes the NEB in early lactation was also -15 MJ/day. It became positive at about day 80 and then rose to a peak of +10 MJ/day. The difference between the two methods may arise either because of the contribution of food wastage to intake measures or through inadequate predictions of body lipid from equations using live weight and condition score or a combination of both. Body energy mobilized in early lactation was not fully recovered until day 200 of lactation. The results suggest that energy balance may be estimated from changes in body energy state that can be calculated from body weight and condition score. Since body weight can be predicted from linear type measures, it may be possible to calculate breeding values for energy balance from national evaluations for production and type. Energy balance may be more suitable as a breeding objective than persistency.


1982 ◽  
Vol 35 (1) ◽  
pp. 121-125 ◽  
Author(s):  
P. C. Garnsworthy ◽  
J. H. Topps

ABSTRACTIn each of two trials, three groups of eight cows, with condition scores of 1-5 to 2, 2-5 to 3 and 3-5 to 4 at calving, were given a complete diet for the first 16 weeks of lactation. Food intake, milk yield, live weight and condition score were measured, and related to levels of plasma glucose and free fatty acids, serum insulin, prolactin and progesterone in weekly blood samples, in an attempt to explain differences in food intake.In both trials, levels of plasma free fatty acids were high after calving for all cows and declined rapidly until week 8, after which they were fairly constant. Glucose and insulin levels increased after calving, producing curves similar to that for dry-matter intake in the first 8 weeks of lactation. Prolactin levels fluctuated too markedly to provide useful information. Progesterone levels increased until week 7 and then fluctuated at 3-week intervals coincident with oestrus. Dry-matter intake was negatively correlated with free fatty acid levels and positively correlated with insulin in trial 1, and with glucose and progesterone in both trials.


2004 ◽  
Vol 78 (3) ◽  
pp. 355-367 ◽  
Author(s):  
R. M. Lewis ◽  
J. M. Macfarlane ◽  
G. Simm ◽  
G. C. Emmans

AbstractThe effects of food quality, breed type and sex (ram and ewe) on lamb growth and carcass composition, and their changes throughout growth, were measured. The three breed types were Scottish Blackface (B; no. = 24), Suffolk (S; no. = 28) and their reciprocal crosses (X; no. 33). The lambs had free access to a nutritionally non-limiting food, H, or a bulky food, L. Each lamb was scanned using X-ray computed tomography to measure the weights of fat, lean and bone in the carcass at three degrees of maturity (0.30,0.45 and 0.65) in live weight. Live weight and food intake data were recorded weekly. Average daily gains in live weight (ADG) and carcass tissues, intake (ADI) and efficiency (EFF = ADG/ADI) were calculated for each lamb between degrees of maturity. Gompertz and Spillman functions were used to investigate relationships between weight and both time and cumulative food intake.There was a breed by food interaction for fat and lean proportions (P < 0.05). Only on H was there a breed difference (P < 0.05) with S having less fat and more lean than either B or X, which did not differ from each other (P > 0.1). On food L there were no breed effects (P > 0.1). Across breeds, sexes and stages of maturity, food L caused lambs to have 0.810 as much fat and 1.063 as much lean compared with H (P < 0.001). There were breed by food interactions for ADG (P < 0.05) and EFF (P < 0.01). ADG on L was 0.72 of that on H for S, as compared with 0.79 for B and X. EFF on L was 0.463 of that on H for S, as compared with 0.586 for B and X. These were such that S was more sensitive to food effects on growth. The Gompertz and Spillman functions described growth well.


1987 ◽  
Vol 45 (1) ◽  
pp. 81-85 ◽  
Author(s):  
S. M. Rhind ◽  
B. A. Morris ◽  
Jill Clayton ◽  
G. Gittus

AbstractIn a 2 × 2 × 2 experiment, 296 Scottish Blackface ewes were fed to achieve one of two levels of body condition (high: condition scores ^2·75; low: condition scores ^2·50) by 2 weeks before joining with rams. Half of the ewes of each condition score were fed dried grass pellets ad libitum and 300 g hay per head daily, between 2 weeks before and 8 days after joining, while the remaining ewes were offered a live-weight maintenance ration comprising 750 g pellets and 400 g hay per head daily. From 8 days after joining the intake of all ewes was gradually changed, over a 2-week period, to 1250 g pellets and 400 g hay per head daily. Two days before joining, half of the ewes of each condition/intake group were passively immunized against testosterone. A total of 99 ewes were slaughtered 18 days after joining and their ovulation rate at the first mating determined. Ovulation rates were significantly affected by immunization (immunized: 2·31, control: 1·86, pooled s.e. = 0·055; P < 0·01) and food intake (ad libitum: 2·24, maintenance: I 92, pooled s.e. = 0·055; P < 0·05) but not by body condition at mating (high: 2·15, low: 2·02, pooled s.e. = 0·059; P > 0·05). Lambing rates were dependent on treatment (immunized: 1·82 control: 1·62, pooled s.e. = 0·044; P < 0·01), food intake (ad libitum: 1·85, maintenance: 1·59, pooled s.e. = 0·043; P < 0·01) and body condition (high: 1·82, low: 1·62, pooled s.e. = 0·044; P < 001). In ewes in a high body condition at mating, the effects of intake and immunization were additive but in ewes in low condition, immunization induced little improvement in performance in ewes fed ad libitum. Circulating antibody titres were lower in ewes fed ad libitum than in ewes offered a maintenance ration (1: 416 v. 1: 534, pooled s.e. = 14; P < 0·001), but ovulation rates and litter sizes were not related to titres.


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