Proportion Of Live Weight Research Articles

Increased yearling weight as a proportion of 21-month weight was associated with increased milk production in dairy heifers

ABSTRACT Aims: To examine the relationship between liveweight (LWT) at 12 months as a proportion of LWT at 21 months of age (LWT(12/21)%) and first lactation and cumulative 3-year milk production in dairy heifers in New Zealand. Methods: Liveweight and milk production records were obtained for dairy heifers born from June to December (spring-calving season) between 2006–2007 and 2013–2014 dairy seasons; production records included first lactation (n = 140,113) and cumulative 3-year (n = 67,833) milksolids and energy-corrected milk (ECM) yields. Heifers were classified into five breed groups; Holstein-Friesian, Holstein-Friesian crossbred, Jersey, Jersey crossbred and Holstein-Friesian-Jersey crossbred. Within each breed group heifers were categorised into quintiles based on 21-month LWT. The LWT(12/21)% was calculated for each animal. Relationships between LWT(12/21)% and milk production within each breed group and LWT category were estimated using linear mixed effects models including the linear and quadratic effects of LWT(12/21)%. Results: The relationship between LWT(12/21)% and milk production was predominantly curvilinear, with lower milk production at lesser LWT(12/21)% compared with greater LWT(12/21)%. For all breed groups and most LWT categories, heifers that were 55 or 65% LWT(12/21)% produced greater ECM and milksolids yields compared with heifers that were 45% LWT(12/21)%. Holstein-Friesian, Holstein-Friesian crossbred and Holstein-Friesian-Jersey crossbred heifers that were 65% LWT(12/21)% produced greater cumulative 3-year ECM and milksolids yields compared with heifers of the same breed group that were 45% LWT(12/21)% Conclusions and clinical relevance: Heifers that were a greater proportion of their 21-month LWT at 12 months of age produced more first lactation and cumulative 3-year milk yields than heifers that were a lesser proportion of their 21-month LWT at 12 months of age. These results indicate that increased growth in early life of New Zealand dairy heifers is beneficial to future milk production.

Comparative effect of self–formulated and four commercial diets on the growth performance, carcass and haematological parameters of broiler finishers in the tropics

This study was conducted to evaluate growth performance, carcass characteristics, haematological parameters and cost effectiveness in broilers fed self-formulated and four commercial diets as coded T1 (Control diet), T2, T3, T4 and T5. A total of 220 Anak 2000 broiler chicks were allotted to five dietary treatments with 44 birds per diet and 11 birds per replicate in a completely randomized design. Feed and water were supplied ad libitum and the experiment lasted for 49 days. The daily feed intake (53.00 – 75.55 g), daily weight gain (26.73 – 43.36 g), feed conversion ratio (1.69 – 2.29) and mortality (4 - 14) were significantly affected by the dietary treatments (P < 0.001). Many of the carcass parameters measured were not significantly affected (P > 0.05) by the treatments. However, significant (P < 0.05) variations were observed in plucked weight (1.22-1.69 kg), eviscerated weight (1.13-1.59 kg), carcass weight (1.12-1.48 kg) and relative weight of pancreas (0.15-0.31%) as a proportion of live weight. The relative weight of head, spleen, and abdominal fat also differ (P<0.05) among the diets. Most of the haematological parameters studied were within the normal range and were similar except white blood cell (2.18-3.28%) which was significantly affected (P < 0.01) by the dietary treatment. The feed cost per kilogram gained ranged between N124.67 – N190.29 ($0.86 – 1.31) with the lowest value obtained for the self-formulated diet which proved to be most economical.Keywords: Carcass yield, Economy, Gut weight, Performance, Poultry feeds

Effects of Cellulase Supplementation on Nutrient Digestibility, Energy Utilization and Methane Emission by Boer Crossbred Goats.

This study examined the effect of supplementing exogenous cellulase on nutrient and energy utilization. Twelve desexed Boer crossbred goats were used in a replicated 3×3 Latin square design with 23-d periods. Dietary treatments were basal diet (control, no cellulase), basal diet plus 2 g unitary cellulase/kg of total mixed ration dry matter (DM), and basal diet plus 2 g compound cellulase/kg of total mixed ration DM. Three stages of feeding trials were used corresponding to the three treatments, each comprised 23 d, with the first 14 d as the preliminary period and the following 9 d as formal trial period for metabolism trial. Total collection of feces and urine were conducted from the 4th d of the formal trial, and gas exchange measures were determined in indirect respiratory chambers in the last 3 d of the formal trial. Results showed that cellulase addition had no effect (p>0.05) on nutrient digestibility. Dietary supplementation of cellulase did not affect (p>0.05) N intake and retention in goats. Gross energy (GE) intake, fecal energy and urinary energy excretion, heat production were not affected (p>0.05) by the cellulase supplementation. Total methane emission (g/d), CH4 emission as a proportion of live weight or feed intake (DM, organic matter [OM], digestible DM or digestible OM), or CH4 energy output (CH4-E) as a proportion of energy intake (GE, digestible energy, or metabolizable energy), were similar (p>0.05) among treatments. There was a significant (p<0.001) relationship between CH4 and live weight (y = 0.645x+0.2, R2 = 0.54), CH4 and DM intake (y = 16.7x+1.4, R2 = 0.51), CH4 and OM intake (y = 18.8x+1.3, R2 = 0.51) and CH4-E and GE intake. Results from this study revealed that dietary supplementation of cellulase may have no effect on nutrient digestibility, nitrogen retention, energy metabolism, and methane emission in goat.

Effect of Improving Lamphun Cattle with Black Angus on Carcass and Meat Quality

The objective of this study was to assess carcass and meat quality of Black Angus × White Lamphun (A×W) in comparison to Black Angus × Holstein Friesian (A×H) crossbred cattle. In this experiment, sixteen Angus crossbred cattle, eight from each crossbred type, were randomly selected at an average age 20-24 month for slaughter under standard condition. Slaughter weight, carcass quality and proportions of commercial prime retail cuts were determined. The Longissimus dorsi muscle (LD) was selected to evaluate meat quality. Carcass yield (proportion of live weight) was higher ( P <0.01) with the A×H than the A×W crossbred. No significant differences were observed between A×H and A×W for hot and chilled carcass weight, carcass length, back fat thickness and loin eye area. The A×W crossbred was superior ( P <0.05) compared with A×H in chuck, shot rib and sir loin percentage. The lightness (L*) of the LD of A×W was higher ( P <0.01) and redness (a*) as well as protein content was lower ( P <0.05) than in A×H. Drip loss, yellowness (b*), fat, and moisture content were not significantly different between the two crossbred types. Thiobarbitiric acid reactive substance (TBARS) levels were increased with storage period in every group, but this at a lower level with the A×W. In conclusion, A×W was superior to A×H incarcass and meat quality, with similar carcass weights at lower dressing percentage. So, promoting of A×W, is a promising first step in creating improved genotypes suitable to cover the demands of the livestock industry of Thailand at concomitantly lower production costs for the farmers.

Development of prediction models for quantification of total methane emission from enteric fermentation of young Holstein cattle at various ages

Methane (CH4) emissions from ruminant animals contribute significantly to the global greenhouse gas budget. The accurate quantification of this source of emissions requires detailed animal and feed information, however there is little information available on systematic measurement of CH4 emissions from young cattle at various ages. The present study was designed to address this gap of knowledge. Data used were derived from a study with 20 Autumn-calved Holstein cattle (10 steers and 10 heifers) with CH4 emissions measured at age of 6, 12, 18 and 22 months, respectively. The cattle were offered a typical diet used on UK commercial farms containing a single grass silage mixed with concentrates. In each period, the cattle were housed as a single group in cubicle accommodation for the first 20 days, individually in metabolism units for the next 3 days, and then in indirect open-circuit respiration calorimeter chambers for the final 5 days with feed intake, feces and urine outputs and gaseous exchange measured during the final 4 days. Within each period, gender had no effect (P>0.05) on nutrient digestibility and any CH4 emission variable in terms of total CH4 emission, CH4 emission as a proportion of live weight or feed intake, or CH4 energy output as a proportion of energy intake. The data from the two groups were therefore pooled to develop prediction equations for daily CH4 emissions (gday−1). A range of prediction equations have been developed using BW (body weight), feed intake and energy intake. The present data were also used to calculate accumulated CH4 emissions for the two genders. Although gender had no effect (P>0.05) on the results, the accumulated CH4 emissions increased with the growth of cattle (mean 36.2 and 64.3kgyear−1 for both genders in years 1 and 2, respectively). A number of prediction equations were developed for total CH4 emission factors (kgyear−1) for heifers and steers during the first and second year of the rearing. These factors were very strongly related to (r2=0.75–0.95) to BW recorded at the beginning, middle and the end of 1 or 2 year of age. These data can add novel information to the scientific literature and can be used to improve national inventories of CH4 emissions and to develop appropriate mitigation strategies for young Holstein cattle of high genetic merit herds.

Faecal index to estimate intake and digestibility in grazing sheep

SUMMARYThe current research was carried out to evaluate the use of crude protein and fibre components in faeces for estimating intake and digestibility in sheep fed with pearl millet (Pennisetum americanum (L.) Leeke). The equations were developed from four trials in metabolism cages with 16 sheep in each trial. Each animal received a different quantity of millet leaves in the diet: 0·015, 0·020 and 0·025 dry matter (DM) as a proportion of live weight (LW) and ad libitum with at least 0·2 of daily feed refusals. Organic matter intake (OMI, g/day) was measured, through the difference between offer and refusals; total faeces were collected for 5 days, which was used to determine faecal crude protein (CPf, g/day and g/kg of organic matter (OM)), faecal neutral detergent fibre (NDFf, g/day and g/kg OM), faecal acid detergent fibre (ADFf, g/day and g/kg OM) and OM digestibility (OMD). Linear regression equations were calculated to determine the relationship between OMI and CPf (P&lt;0·001, R2=0·90, relative prediction error (RPE=14·02%). A multiple linear equation was generated for OMI including CPf and NDFf (P&lt;0·001, R2=0·94; RPE=9·25%). Hyperbolic (single and multiple) and exponential models were tested to estimate OMD, where the hyperbolic multiple model including CPf and NDFf showed lower RPE (3·90%). These equations for estimating OMI and OMD were evaluated on sheep grazing P. americanum fertilized with increasing levels of nitrogen (N) (50, 100, 200 and 400 kg N/ha), comparing measured and estimated OMI. The intake estimated by multiple regression (CP and NDFf) showed a higher R2 (0·98) and lower RPE (5·25%) than the simple (CPf only) linear equation (R2=0·94; RPE=20·45%). The results demonstrated the feasibility of using the faecal index generated in metabolism cages for estimating intake and digestibility in sheep grazing P. americanum.

Effect of compensatory growth on performance, carcass composition and plasma IGF-1 in grower finisher pigs

A total of 48 female pigs (Large White × Landrace × Duroc cross) were used to determine whether a compensatory feed regime influenced performance, carcass composition and the level of plasma IGF-1. Pigs of initial age 73 days were fed a commercial diet at 0.70 of ad libitum (R) for 40 days followed by a return to ad libitum feeding for a further 42 days. The control group was fed ad libitum (A) throughout. Groups of animals on R and A feed regimes were slaughtered at the end of restriction period (SL1), 2 days after refeeding ad libitum (SL2) to establish the more immediate effects of refeeding on IGF levels, and after 42 days refeeding (SL3; n = 8 for each group). As expected, during the restriction period, average daily live weight gain in all the slaughter groups of R pigs was significantly lower than A pigs (P < 0.01); there was no significant difference in feed conversion ratios. In the re-alimentation period of SL3, R pigs grew 12.9% faster (P = 0.033), indicating compensatory growth. At SL1, there was a trend for carcass weight (P = 0.108) of A pigs to be higher than R pigs, but at SL2 live weight and carcass weight of A pigs were significantly heavier than R pigs (P < 0.05), but not at SL3. For killing-out percentage, there was no difference in SL1. After refeeding for 2 days (SL2) and 42 days (SL3), R pigs had significantly lower killing-out percentage than A pigs (P < 0.05). As a proportion of live weight, R pigs had smaller heart, kidney and liver (P < 0.05) than A pigs at SL1. At SL2, only the kidney was smaller in the restricted group (P < 0.05) and there were no significant differences in SL3. As a proportion of carcass weight, Longissimus dorsi was heavier in the R pigs at SL1 (P = 0.108) and SL2 (P < 0.05), but not at SL3. At SL1, there was a trend for intramuscular fat of A pigs to be higher than R pigs. The plasma IGF-1 level was lower in R pigs than A pigs (P = 0.010) at SL1, and slightly lower at SL2 (P = 0.110), with no significant differences at SL3. Dietary restriction period influenced plasma IGF-1 levels, which returned to the ad libitum group levels when animals were refed, as did live weight and carcass weight. It appears that the internal organs and possibly fat, but not muscles, underwent a compensatory response when animals were refed.

Estimation of Carcass Composition of Sheep, Goats and Cattle by the Urea Dilution Technique

The study involved 30 local Iraqi sheep and goats (15 each) and 10 Friesian x local dry cows. Urea Space Volume (USV) was calculated from 2 collection periods of blood samples following infusion of urea at 12 (US 12 kg) and 30 (US 30 kg) min after infusion and then as a proportion of live weight (BW) or Empty Body Weight (EBW). All animals were slaughtered within 2 d of the USV trials. Sheep recorded the highest percentage (80.57%) of carcass soft tissue followed by goat (79.10%) and cattle (77.77%). Cattle bone/meat ratio was significantly lower than that of sheep or goats. Water content of cattle soft tissue was higher (74.78%) than that of sheep (64.86%) and goats (69.76%); however, fat% showed reverse percentages (15.39% for sheep and 9.025% for cattle). The pooled regression between either BW or EBW and carcass soft tissue composition was similar. Water content indicated positive slope; whereas protein and fat showed negative slope with either BW or EBW. BW or EBW effectively predicted the amount of fat and protein in the carcass soft tissue rather than their percentages when pooled data were used. Initial Plasma Urea Concentration (PUC) mean did not differ significantly among the three studied species. All correlation coefficients between urea concentration at zero time and soft tissue composition were negative and significant except that of protein% and fat%. However, positive and significant correlation coefficients between US12 and kg of water, protein, fat and ash in carcass soft tissue (ranged 0.921-0.948) were found. US expressed as kg or % to either BW or EBW after 12 min of infusion showed higher correlation and regression coefficients than that of urea concentration at zero time with reverse direction. Correlation coefficients within each species between soft tissue compositions with urea concentration at zero time were non-significant except for protein amount of goats and ash% of cattle (p<0.05). For sheep and goats, correlation coefficients using water, fat and protein of sheep only (expressed in kilograms) and US at 12 min (kg) or as percentages to BW and EBW were highly significant (p<0.01). Cattle resulted in significant correlation values (p<0.05 and p<0.01) for water% with US at 12 min as percentages to body weight or empty body weight.

English

This study was conducted to investigate the effect of four commercial multi-enzymes on the performance, meat yield, water intake, litter moisture and jejunal digesta viscosity of chicks fed wheat/barley based diet. A total of 195 1-d-old male broiler chicks (Ross 308) were allocated to 5 treatment groups, with 3 replicates per treatment group and 13 birds per replicate pen and all data were analyzed in a randomized complete block design. During the starter period, feed conversion ratio (FCR) was significantly (P &lt; 0.05) decreased by only enzymes A, B and D. Moreover, FCR was significantly (P &lt; 0.05) decreased by all enzymes in grower and entire periods. The relative weight of the breast as proportion of live weight was significantly (P &lt; 0.05) decreased by only enzyme A. The relative weight of the abdominal fat as proportion of live weight was also significantly (P &lt; 0.05) increased by enzyme D. Enzyme supplementation decreased viscosity of jejunal contents of chicks at day 28, but only enzymes A and D reduced significantly (P &lt; 0.05) the viscosity of jejunum compared to control diet. In conclusion, there were similar improvements on FCR of birds fed diets with enzyme supplementation and choice preference of enzyme supplementation has to be base on its economic value. &nbsp; Key words:&nbsp;b-glucanase, xylanase, broilers, performance, meat yield, water intake, litter moisture, viscosity.

Associations between nematode larval challenge and gastrointestinal tract size that affect carcass productivity in sheep

Effects of gastrointestinal parasitism on sheep productivity are usually described using live weight change, however carcass productivity is more accurately described using dressing percentage (carcass weight as a proportion of live weight). This experiment had a 2 × 2 × 2 factorial design whereby 10-month-old Merino wethers were fed lucerne ( Medicago sativa) diets (fresh lucerne or lucerne chaff) with 2 levels of carboxymethycellulose (CMC) inclusion (0% or 8% CMC) and nematode larval challenge (no larval challenge or 10,000 Teladorsagia circumcincta and 10,000 Trichostrongylus colubriformis per week). Sheep were weighed and euthanased 50 or 51 days after larval challenge and CMC supplementation commenced. Weight of the carcass (hot standard carcass weight) and gastrointestinal organs (full and empty) were recorded and expressed as a proportion of live weight. Larval challenged sheep had a worm egg count (mean ± standard error) of 173 ± 38 eggs per gram of faeces and total worm count of 30,237 ± 2013 at slaughter. Larval challenged sheep had 1.3% lower dressing percentage ( p = 0.048), and 2% heavier full ( p = 0.007) and 1.2% heavier empty gastrointestinal tracts ( p = 0.012) compared to unchallenged sheep. There was no effect of CMC inclusion or lucerne type (fresh or chaff) on gastrointestinal tract weight or dressing percentage. Larval challenged sheep had 1.1% heavier full ( p < 0.001) and 0.6% heavier empty ( p < 0.001) small intestines, and 0.6% heavier full ( p = 0.005) and 0.3% heavier empty ( p = 0.026) large intestines compared to unchallenged sheep. Use of live weight change or other measures based on live weight (e.g. feed conversion efficiency) to assess the impact of nematode challenge in sheep may underestimate carcass productivity losses associated with larval challenge in sheep even at moderate levels of larval intake and without overt clinical signs of parasitism. Measurement of carcass weight and/or lean meat yield may better reflect the true economic effects of parasitism in sheep.

Kangaroos and greenhouse gases: Response to Russell

We used 50 kg as the average weight for kangaroos and not 19 kg as in table 2. This is an error in the table but not in our calculations. Published kangaroo weights range widely, perhaps because there is marked sexual and species dimorphism and because kangaroos, especially males, grow throughout most of their lives (Dawson 1995). In settling on a 50 kg average we referred to the following weight ranges for the larger, harvested species of kangaroos; for males 90–60 kg (Dawson 1995) and 78–28 kg (Wilson & Read 2003); and for females 40–23 kg (Dawson 1995), 27–16 kg (Wilson & Read 2003), and 23–19 kg (Kempton et al. 1976). Even if a 50-kg weight is high, overestimating it does not affect the conclusions. This is because the model manages the population during the transition to 2020 to take a high proportion of males, which will increase the average weight of harvested kangaroos and allow a greater proportion to be harvested. There is also scope for discussion about the size of sheep and cattle carcasses from the rangelands, the amount of meat they produce and its value. All are subject to environmental and market variation. Regardless, we stand by the estimate of an average 33 kg carcass from a 50-kg live kangaroo and the comparisons between cattle and kangaroos carcass weights as a proportion of live weight. We had decided that the personal communication of 19 kg average weight reported by Grigg (2002) was too low. Russell (1999) himself refers to kangaroo weights of 65 (male) and 25 (female) kg, giving an average of 45 kg. In concluding that 120 kangaroo carcasses equal one beef carcass, Russell (2008) asserts that the carcass yield of useable meat is higher for cattle than kangaroos. Our article does not discuss the relative boning-out percentages; however, studies on carcass composition and kangaroo anatomy reveal the opposite. Hopwood (1976) found that kangaroo carcasses yield approximately 79% muscle, which is higher than the 60–70% for beef quoted by Russell (2008). Hopwood et al. (1976) compared kangaroos and sheep and concluded that the “body composition of a kangaroo is a highly desirable one for a meat animal. Carcass fat is negligible and muscle mass is concentrated in the region of the loin, rump, and thigh increasing the percentage of high value muscle in the carcass.” Further, Russell (2008) refers to Kelly's (2005)“1.5 kg each of prime cuts;” this means that Russell discards all but the premium cuts from kangaroos; however, he does not do the same for cattle. He classifies all other kangaroo meat as “processed meat” whereas for cattle he uses the phrase “cuts or mince” to combine prime and processed meat from cattle. Russell (2008) notes that sheep numbers declined since 1990 but kangaroo numbers did not increase. However, he omits to refer to the rise in cattle. From 1990 to 2006, cattle have increased from 23.1 to 28.8 million (ABS 1992; 2008), while Australian sheep and lamb populations declined over that period from 170.3 to 92.7 million (ABS 1992; 2008). Using the same dry sheep equivalents (DSE) that were used in Wilson & Edwards (2008), the reduction of sheep creates 78 million DSE. The rise in cattle takes up 88% of this DSE and so accounts for much of the pasture made available from the decline in sheep. The decline in sheep numbers was a result of a reduction in the profitability of the wool industry. Many wool farmers adjusted by expanding other sectors such as cattle and cropping. So the decline in sheep numbers does not mean that pastures were made available to kangaroos. The expansion of other sectors may even have reduced kangaroo's access to pasture. Editor : Dr. Corey Bradshaw

Relationships Between Urea Dilution Measurements and Body Weight and Composition of Lactating Dairy Cows

The objective of the present study was to investigate the potential of the urea dilution technique, coupled with live animal measures to predict the body components of dairy cattle. The study involved 104 lactating Holstein-Friesian cows offered grass silage-based diets. Urea space volume (USV) was calculated from 2 collection periods of blood samples following infusion of urea at 12 (USV12, kg) and 30 (USV30, kg) min after infusion, and then as a proportion of live weight (LW) or empty body weight (EBW). All cows were slaughtered within 2 d of the USV trials. Large ranges existed in EBW and empty body concentrations of water, crude protein (CP), lipid, ash, and gross energy (GE). The USV12 and USV30 were both positively related to LW, EBW, and empty body component weights. The r2 values for USV12 were greater than USV30. The r2 values in the relationships of EBW and empty body composition with USV, however, were smaller than those with LW. Nevertheless, the relationships were improved when both USV and LW were used as predictors, rather than using either alone. Adding milk yield and body condition score as supporting predictors to prediction equations using USV and LW data for EBW, lipid, and GE contents further improved the relationships (r2=0.93, 0.66, and 0.77, respectively). Internal evaluation of one-third of the present data using equations developed from two-thirds of the present data indicated that using USV, live weight, and other live animal variables as predictors, rather than using USV alone, considerably improved the prediction accuracy. It was concluded that USV can be used to predict body composition, but the relationships with USV were poorer than those with LW. The USV can only be used as a supporting variable to live weight for prediction of body components in lactating dairy cows.

Effects of breed and family on rate of copper accretion in the liver of purebred Charollais, Suffolk and Texel lambs

AbstractThe feeding of housed lambs on conserved forages and pelleted rations is accompanied by a high risk of chronic copper (Cu) poisoning (CCP) which might be reduced by selecting sires for low liver Cu status. Livers were therefore retrieved from Suffolk, Texel and Charollais lambs, slaughtered during the course of a performance trial, to ascertain sire and possibly breed effects on the rate of Cu accretion in the liver. In total, 160 livers were obtained, 100 from Suffolk, 40 from Texel and 20 from Charollais lambs, the progeny of 14, eight and eight sires, respectively. Lambs came from three separately managed flocks but were brought together at 8 weeks of age, weaned onto a common complete diet containing 6·1 mg Cu per kg dry matter (DM) and offered ad libitum. One-fifth of each breed group was slaughtered at 14, 18 or 22 weeks and the remaining 40% at 26 weeks of age. Mean (s.e. ) liver Cu concentrations at those ages were 3220 (450), 4639 (464), 6426 (468), and 6513 (370) µmol/kg DM for Suffolk, and 5843 (811), 6579 (857), 8017 (811) and 10406 (589) µmol/kg DM for Texel, respectively. The pattern of liver Cu accretion differed, the Suffolk starting at a low value yet reaching a plateau at about 22 weeks of age (significant quadratic regression coefficient), the Texel, continually increasing from a high initial value at an average rate of 53·7 (s.e.10·6) µmol/kg DM per day. There was a significant effect of sire on liver Cu in the Suffolk (P 0·05) with a heritability of 0·85 (s.e. 0·44); in the Suffolk and Texel combined, the heritability was 0·60 (s.e. 0·33). The data available on the Charollais were too limited to test for sire effects but at 26 weeks of age, where most information was available, the mean liver Cu concentration was 7285 (s.e.826) µmol/kg DM. At a given age, food intake, liver weight and live weight were each lowest in the Texel but when expressed as a proportion of live weight (LW), both food intake (43 g/kg LW) and liver weight (5·15 g DM per kg LW) were similar among breeds (P 0·05). Thus, differences in liver Cu accretion are unlikely to reflect differences in Cu intake per unit liver weight. There was a tendency for liver size per kg LW to decrease as liver Cu rose in the Texel but not in the Suffolk. Continued hepatic Cu accretion in the Texel may reflect a breed-specific inability to cope with Cu overload. Increases in liver Cu to marginally toxic levels in some Suffolk, some Charollais and most Texel lambs, and to a level commonly associated with toxicity in one Texel lamb, on a ration of moderate Cu concentration highlights the difficulty of controlling risk of CCP by manipulating dietary composition. The current EC limit for Cu in ovine diets, 17 mg Cu per kg DM, is clearly too high for the breeds and dietary conditions used in this study. However a safe limit would be hard to achieve and hence the need to exploit sire variation in propensity to accumulate liver Cu to reduce disease risk.

Slaughter traits of adult coypus grown in captivity

The objective of the current study was to undertake a preliminary characterization of liveweight components in adult coypus at slaughter. Greenland (14 females, 7 males) and Silver (78 females, 36 males) breeds were grown on a farm south-east of Buenos Aires, Argentina. The animals were slaughtered aged 419±22 days. Liveweight at slaughter was measured and the weights of hot carcass, fur, head, liver, lungs plus heart, digestive tract (with contents) plus reproductive organs and fur length were recorded. The weights of these body components were also expressed as proportion of liveweight, except for the fur length. Data were analysed and the effects of sex, variety, reproductive state within sex and rearing management within sex were included in the model. The age of the animals at the time of slaughter was used as covariate. Breeds differed only in liver weight (P&lt;0·05), where Greenland was 15·9% heavier than Silver; however when comparisons were made as proportion of liveweight, no differences between breeds were found in the variables analysed. Sexual dimorphism was evident in almost all of the characteristics analysed, values for males being higher than for females. Males were 29% heavier at slaughter than females and their carcasses 31·7% heavier. When body components were expressed as proportion of liveweight, male heads were heavier but fur was lighter compared to females. In conclusion, there were differences in body components due to sex but not due to breed. However, most body components when expressed as proportion of liveweight showed no significant differences.

The donkey as a draught power resource in smallholder farming in semi-arid western Zimbabwe: 2. Performance compared with that of cattle when ploughing on different soil types using two plough types

AbstractThe work performance of two teams of four donkeys (heavy, 680 kg and light, 460 kg) and one pair of Jersey crossbred oxen (646 kg) was compared when they ploughed 4 hi day on four types of soil (clay, redsoil, sandy soil and sandy clay) using two types of plough, a conventional ox plough (40 kg) and a lighter prototype, the ‘Walco’ plough (32 kg) on an experimental farm. Work parameters were also measured with farmers’ cattle and donkey teams ploughing on f arms in Matobo and Nkayi districts. Working speed, power and effective field capacity (ETC) were higher for the ox-team (1·03 m/s, 920 W and 14·5 h/ha for the conventional plough and 0·99 m/s, 745 W and 13·9 h/hafor the Walco plough) and the heavier donkey team (0·87 m/s, 689 W and 14·2 h/hafor the conventional plough and 0·87 m/s, 787 W and 17·3 h/hafor the Walco plough) than for the lighter donkey team (0·59 m/s, 461 W and 22·1 h/hafor the conventional plough and 0·64 m/s, 445 W and 23·4 h/hafor the Walco plough). Expressed as a proportion of live weight or metabolic live weight there were no significant differences in draught forces exerted between teams but power output per unit live weight was greater in the ox-team than in the light donkey team but similar to that in the heavy donkey team. The Walco plough required a lower force (742 N) to operate than the conventional plough (816 N) but apart from this did not have any marked advantages over the conventional plough. On-farm, team sizes of donkeys varied from three to seven animals (team weight 340 kg to 1007 kg) and cattle team sizes from two to four animals (team weights 558 to 1709 kg). Regardless of team number, the heavier teams tended to out-perform the lighter teams (speed range 0·63 to 1·08 m/s, power 395 to 1136 W, EFC 9·1 to 25 h/ha)) with one exception, a well trained team of two oxen (team weight 879 kg, speed 1·02 m/s, power 775 W, EFC 9·1 h/ha). Donkeys tended to plough at a slower pace than oxen, with a lower power output, although when weight differences between teams were equalized (four heavy donkeys compared with two oxen), then there was little to chose between the species. Results suggested that teams of three or more donkeys can effectively be used for ploughing on the soils tested. The results highlighted the importance that team live weight and training/experience have in determining work performance.

Effect of soaking, germination, and enzyme treatment of whole barley on nutritional value and digestive tract parameters of broiler chickens

1. An experiment was carried out to determine the effect of soaking at 0°C, soaking at room temperature, germination, or enzyme treatment of whole barley on feeding value and digestive tract parameters of 2‐ to 4‐week old broiler chickens given diets with 700g/kg whole barley. 2. Soaking or germination decreased the soluble and total β‐glucan content (P<0.05) and, except for soaking at 0°C, the acid extract viscosity of the grain also decreased (P< 0.05). Germination and soaking in the presence of enzymes produced the lowest β‐glucan content and viscosity. 3. Except for soaking in cold water, the soaking, germination and enzyme treatments increased weight gain and decreased food: gain ratio (P< 0.05). Correspondingly, the digestibility of protein, fat, and ash, and the digestible energy content, increased (P< 0.05) after enzyme treatment or germination. 4. Chickens fed on enzyme‐treated or germinated barley diets had intestinal contents with a greater proportion of dry matter and lower viscosity than chickens fed on untreated barley (P< 0.05). Consequently, the cages and chickens were cleaner (P< 0.05) and the weight of digestive organs as proportion of live weight was lower. 5. Particle size analysis of excreta revealed that whole barley was efficiently ground by the gizzards of 16‐d‐old chickens, and very few whole kernels were found.

Mung beans ( Phaseolus aureus) for finishing pigs

Digestible energy (DE) content of raw mung beans ( Phaseolus aureus ( Roxb.) var Berkin) was 16.09 MJ kg −1 of dry matter (DM), measured by total faecal collection for five days in a switch-over trial with six 53 kg live weight (LW) Landrace-Large White entire males fed at 34 g kg −1 of LW, by substitution of 300 g kg −1 of ground mung beans in a wheat-based diet. Mung beans contained 1.45 mg g −1 of DM trypsin inhibitor (TI), 0.32 mg g −1 of DM chymotrypsin inhibitor (CTI), 9 g kg −1 of tannins and 51.2 haemagglutination units per gram of lectins. Finishing diets with 0, 100, 150, 200, 250 and 300 g kg −1 of mung beans substituted for soybean meal were formulated to contain 14.5 MJ of DE per kg, with a minimum of 0.65 g lysine per MJ of DE. Crude protein (CP) ranged from 247 to 207 g kg −1, neutral detergent fibre (NDF) from 180 to 209 g kg −1 and ether extract (EE) from 69.6 to 53.3 g kg −1 for diets with 0–300 g kg −1 mung beans respectively. Diets were fed to 61 kg entire males at 40 g kg −1 of LW for 30–35 days until slaughter at approximately 90 kg LW. Digestibility of organic matter (OM) (84.64 ± 0.19%) and EE (69.77 ± 0.32%) did not vary between diets, while digestibility of CP declined from 79.51% to 77.05% ( P < 0.05) and digestibility of NDF increased from 70.32 to 76.60% ( P < 0.01) with increasing inclusion of mung beans. Growth rate, 0.96 ± 0.02 kg per day, feed conversion, 2. 60 ± 0.05 kg of feed kg −1 gain and backfat thickness, 15.9 ± 0.27 mm at the P2 site, did not differ between diets. Internal organs appeared normal; weights as a proportion of LW did not differ between diets (pancreas 1.5 ± 0.14 g kg −1 LW; stomach 6.1 ± 0.10 g kg −1 LW; small intestine 19.6 ± 0.34 g kg −1 LW; large intestine 14.1 ± 0.30 g kg −1 LW; liver 20.7 ± 0.35 g kg −1 LW and kidney 3.8 ± 0.11 g kg −1 LW. Thus, diets did not differ in productive performance, or in the apparent effect of TI and CTI on pancreas or of lectins and tannins on the gut, liver and kidney. A safe inclusion level of 300 g kg −1 in this experiment is double the value reported for other varieties and batches of mung beans.

Somatotropin Transgenic Mice Have Reduced Jejunal Active Glucose Transport Rates

Small intestinal glucose absorption and gastrointestinal morphology were compared in adult bovine somatotropin transgenic (MT-bGH) and control mice. The MT-bGH mice were 57% heavier than controls, although both groups consumed comparable amounts of food during the 5 d before transport measurements were made. Stomach, cecum and colon were 98, 53, and 81% heavier (P < 0.001), and small intestinal tract 52% heavier and 27% longer in MT-bGH than in control mice (P < 0.001). As a proportion of live weight, MT-bGH mice tended to have a shorter small intestine than controls (P < 0.07), whereas there was no difference for either small or large bowel relative weights. Villus dimensions, crypt depth and thickness of external muscle layers in the jejunum were not significantly different in control and MT-bGH mice. Active glucose transport rate per milligram of jejunum was 24% less than in control mice (P < 0.05). Jejunal active glucose transport rate per gram of live weight in MT-bGH mice was approximately half that of control mice. The larger small intestinal mass of MT-bGH mice compensated for the reduced rate of glucose transport per unit weight of intestine such that there was no significant difference in total small intestinal tract glucose transport between control and MT-bGH mice. These results suggest that there are substantial differences in nutrient absorptive efficiency between intestinal tract from MT-bGH and control mice.

Earthworm biomass: Influence of gut content and formaldehyde preservation on live-to-dry weight ratios of three common species of pasture lumbricidae

Allolobophora caliginosa (Savigny), A. trapezoides (Duges) and Lumbricus rubellus Hoffmeister were reared on enriched sandy soil. Live and dry weights, and weights after preservation in 5% formaldehyde were determined for worms with and without gut contents. Quadratic regressions of the log transformed weights gave a significantly better fit than linear regressions for the relationships between live weight including gut contents, and either dry weight with an empty gut or dry weight with gut contents. Intermediate size worms had the highest proportion of gut contents. The dry weight of gut contents as a proportion of live weight could be more easily and accurately calculated from the difference between dry weights with and without gut contents averaged over size classes defined by the log of the weights of live worms. Dry weight minus gut contents, the best standard for biomass can be determined from field samples perserved in formaldehyde by combining linear regressions predicting live weight from formaldehyde weight which are independent of gut contents, with linear regressions predicting dry weight minus gut contents from live weight with gut contents. Because the density of the gut contents affects the latter regression it should be determined from a subsample of worms of each species on each sampling occasion.

Genetic Variation in Body Size, Composition, Temperature, and Feed Intake in Mature Chickens

Genetic variation for more than 40 traits was assessed in 26 stocks of mature chickens reared together and fed ad libitum from hatching to slaughter at 507 days of age. There was greater genetic variation among males than among females. The intraclass correlation, t, was high (>.75) for measures of size and weight and moderate (.20 to .60) for most other traits (P<.05) including a measure of lean distribution (.37). Three main categories of stocks were studied, viz. outbred Leghorns, medium-sized stocks, and contemporary heavy meat chickens. Differences in lean distribution were not associated with category, but differences of 40 to 50 g/kg lean in the breast of some stocks may be caused by a single gene. Lean:bone ratios were similar in medium and heavy stocks but were greater (P<,05) in heavy meat-types compared with outbred Leghorns. Bone density was higher (P<.01) in females compared with males and in outbred Leghorns compared with heavier stocks (P<.01). Heavy meat-type males were leaner (P<.01) and had proportionately less fat in the abdominal cavity than outbred Leghorns. Carcass fatness was similar among stocks of females, but abdominal fat was lower in Leghorns selected for high egg production compared with unselected Leghorns (P<.05) and heavy stocks (P<.001).One resistant and two Marek's disease-susceptible stocks were replicated in a specific pathogenfree (SPF) environment. Spleen weight was larger (P<.001) in the conventional environment. Females were relatively smaller (P<.05) than males in the conventional than in the SPF environment. Resistant strain females had larger (P<.05) viscera in the conventional environment.Body temperature (t = .25, P<.05) and feed intake were assessed in males. Heavy meat birds had a lower (P<.01) body temperature than outbred Leghorns and medium-sized stocks. Differences among stocks for feed intake (t = .77) were significant (P<.05); however, they were greatly reduced when feed intake was expressed as g/kg liveweight (LW) (t = .49) or g/kg LW.75 (t = .25). Outbred Leghorns ate less in absolute terms but significantly more (P<.01) as a proportion of LW or LW.75 than the medium and heavy lines.