bluuebunny/crossref_metadata_2025 huggingface dataset:
Fertility in a tropical beef herd divergently selected for pregnancy rate
Authors: Hetzel D. J. S. , Mackinnon M. J. , Dixon R. , Entwistle K. W.
Published: September 2010

Selection on the basis of estimated breeding value for cow fertility was successful in establishing two distinct lines of high (H) and low (L) fertility in a herd of Droughtmaster (Brahman × Shorthorn) cattle. The average difference in pregnancy rates over 3 years between the H and L line was 12% (P < 0·01) in the selected cows. In lactating cows this difference was 17% indicating that lactational anoestrus was an important component of the line difference in fertility. The total calf losses between confirmed pregnancy and weaning were 17%, but there were no line differences. Cow mortalities were 5% higher (P < 0·01) in pregnant cows than in empty cows but were similar in the H and L 'lines.

H cows were proportionately 0·06 lighter in body weight (P < 0·01) at mating and 0·075 lighter (P < 0·01) at weaning than L cows. Much of this difference was due to the greater number of calves carried and weaned by H cows during their lifetime. Smaller lactation effects on weight gains and weight losses in H cows indicated that these cows were less sensitive in terms of weight gain to seasonal fluctuations in nutrition. H cows conceived earlier than L cows in 2 out of the 3 years and reared calves which were proportionately 0·04 lighter at weaning (P < 0·01). It is suggested that lower milk production in H cows leading to shorter periods of lactational anoestrous, combined with lower sensitivity to nutritional stress, was responsible for their higher fertility.
Effect of live weight and body composition of gilts at 24 weeks of age on subsequent reproductive efficiency
Authors: King R. H.
Published: September 2010

A total of 96 gilts were used in two experiments to determine the effect of live weight and body composition at about 170 days of age on age of attainment of puberty, ovulation rate and subsequent reproductive efficiency.

In the first experiment 48 crossbred (Large White ♂ × Landrace ♀) gilts were randomly allocated at 21 days of age to each of six treatment groups which gave six different intakes of a protein-adequate diet. The food intakes were designed to achieve six live weights ranging from 59·6 to 118·0 kg at boar introduction at 170 days of age. Age at puberty declined linearly from 202 to 173 days with increasing live weight at boar introduction (P < 0·01). Ovulation rate at puberty was also positively affected by live weight at 170 days (P < 0·05).

In the second experiment, four littermates from each of 12 litters were randomly allocated at 28 days of age to four treatment groups. The groups were offered diets of varying protein adequacy at different feeding levels up to boar introduction at 165 days of age. The treatment groups comprised a factorial design with the factors being live weight (light, L or heavy, H) and fat level (lean, 1 or fat, f relative fat content). At boar introduction, mean live weights were 70·6, 71·5, 101·3 and 100·0 kg, and mean backfat depths were 11·3, 20·9, 21·7 and 27·0 mm for the LI, Lf, HI and Hf groups, respectively. Heavier gilts at boar introduction were younger (183 v. 199 days, P < 0·01) at puberty. Ovulation rate at puberty was also greater (11·0 v. 9·5, P < 0·05) in the heavier gilts. Gilts which were leaner at boar introduction also tended to attain puberty earlier (186 v. 195 days, P < 0·10) than fatter gilts.

In both experiments neither the subsequent reproductive efficiency of gilts after parturition nor the performance of their piglets was significantly affected by body weight or body composition at boar introduction.
A note on the crossbreeding of Zebu cattle in vom
Authors: Mbap S. T. , Ngere L. O.
Published: September 2010

A study was carried out on data collected between 1970 and 1979 on the crossbreeding of cattle in Vom using British Friesian, Brown Swiss and Jersey bulls. Only crossbreeding involving Friesian bulls was successful. There were progressive increases in lactation yield, yield per day of lactation length, lactation length, daily fat yield, birth weight and calving interval in the grades with increases in the Friesian contribution. The daily fat concentration however decreased with the increase in Friesian proportion. Most of the genotypes namely, pure White Fulani, 0·5 Friesian: 0·5 White Fulani; 0·75 Friesian: 0·25 White Fulani, 0·875 Friesian: 0·125 White Fulani and pure Friesian calved regularly each year. Phenotype correlations between lactation length and yield for most of the genotypes were high, positive and significant.
A note on the characteristics of oestrus and ovulation in Awassi ewes
Authors: Kassem R. , Owen J. B. , Fadel I.
Published: September 2010

The length of the oestrous cycle observed in 20 ewe lambs and 424 ewes of the Awassi breed gave mean values of 16·4 (s.d. 1·31) days for ewe lambs and 17·4 (s.d. 1·84) days for ewes. Plane of nutrition did not affect cycle length in ewe lambs and age of ewe (from 2 to 5 years) did not affect oestrous cycle length in ewes (P > 0·05). Of 40 ewes treated with progesterone intravaginal sponges 33 (83%) showed oestrus and 28 (70%) ovulated at the first (synchronized) and 31 (78%) and 30 (75%) at the repeat oestrus. Mean duration of oestrus was 40·0 (s.d. 16·37) h (range 8 to 72) for the first and 34·7 (s.d. 11·19) h (range 16 to 54) for the repeat oestrus. Ovulation rate, measured in the same ewes, gave mean values of 1·18 (s.d. 0·460) for the first and 1·223 (s.d. 0·440) for the repeat oestrus.
Carcass composition of serially slaughtered Friesian, Hereford × Friesian and Charolais × Friesian steers finished on two dietary energy levels
Authors: Keane M. G. , More O'Ferrall G. J. , Connolly J. , Allen P.
Published: September 2010

The carcass composition of Hereford × Friesian (HE), Friesian (FR) and Charolais × Friesian (CH) steers finished on diets of high (H) and medium (M) dietary metabolizable energy (ME) concentrations and slaughtered at low (L), normal (N) and heavy (W) carcass weights was examined in a 3 × 2 × 3 (no. = 9 per individual treatment) factorial experiment. A pre-finishing slaughter group of nine animals of each breed type was also included, giving a total 189 animals in 21 experimental groups. ME concentrations of the H and M diets which were offered ad libitum were 12·6 and 10·4 MJ/kg dry matter. Target carcass weights for L, N and W were 260, 300 and 340 kg for HE and FR and 260, 320 and 380 kg for CH.

Carcass side weights (before tissue separation) of the HE, FR and CH pre-finishing slaughter groups were 90·8, 970 and 101·0 (s.e.d. 3·9) kg. Corresponding tissue proportions were 188, 199 and 200 (s.e.d. 4·3) g/kg bone, 663, 686 and 690 (s.e.d. 5·3) g/kg muscle and 135, 99 and 96 (s.e.d. 5·7) g/kg fat. Main effect side weights of the finished groups were 152·3, 151·4 and 162·2 (s.e.d. 1·4) kg for HE, FR and CH. 158·5 and 152·2 (s.e.d. 1·1) kg for H and M and 131·2, 155·2 and 179·6 (s.e.d. 1·4) kg for L, N and W, respectively. Tissue proportions in the same order were 146, 160 and 157 (s.e.d. 2·0), 149 and 159 (s.e.d. 1·6) and 163, 154 and 146 (s.e.d. 2·0) g/kg bone, 579, 601 and 635 (s.e.d. 5·5), 600 and 610 (s.e.d. 4·5) and 637, 599 and 574 (s.e.d. 5·5) g/kg muscle and 264, 228 and 195 (s.e.d. 6·4), 240 and 219 (s.e.d. 5·2) and 188, 235 and 264 (s.e.d. 6·4) g/kg fat. CH had more (P < 0·001) of their muscle in the pelvic limb and less (P < 0001) in the thorax than HE and FR. HE had more (P < 0·001) of their carcass fat in the subcutaneous depot and less (P < 0·001) in the intermuscular depot than FR and CH. The allometric regression coefficients for the main joint and tissue weights on side weight were <1·0 for both limbs, loin, bone and muscle. Coefficients were >1·0 for the thorax, ribs, flank and fat. The regression coefficients for the main muscles of the pelvic limb and loin and total thoracic limb muscle on total side muscle were 1·0. Similarly the regression coefficients for the bones of the two limbs on total side bone were <10, while the coefficients for the loin, ribs and thorax bones were >10. It was calculated (for the H diet) that at a carcass weight of 300 kg, HE, FR and CH would have carcass tissue proportions of 576, 600 and 642 g/kg muscle and 261, 227 and 180 g/kg fat. The three breed types would have similar carcass fat contents at carcass weights of 264, 300 and 376 kg for HE, FR and CH, respectively.
Carcass composition in lambs of Greek dairy breeds of sheep
Authors: Zygoyiannis D. , Stamataris K. , Kouimtzis S. , Doney J. M.
Published: September 2010

Nine male and nine female lambs each from the Karagouniko (K), Chios (C) and East Friesland (F) breeds were weaned at a mean age of 50 days and were killed over a commercial range of live weight from 16 to 44 kg (carcass weights 6 to 22 kg).

Carcass weight was linearly related to fasted live weight prior to slaughter (r = 0·994). There were significant but small differences between breeds in mean weight of lungs, pelt and internal fat. The carcass components of bone, muscle and fat tissues were related to carcass weight by linear or quadratic regression. Adjusted to mean carcass weight, the mean weight of bone did not differ between breeds (2·82 kg, s.e. = 0·056 at 12·8 kg carcass). The K and C lambs had significantly less muscle than the F lambs (6·77, 6·63 and 8·20 kg, respectively, s.e.d. = 0·094) and more fat (2·87, 2·95 and 1·29 kg, respectively, s.e.d. = 0·017) when compared at mean carcass weight. The breed differences were significant over the whole range whether compared at equal weight or at an equal proportion of estimated mature weight. At the same proportion of carcass fat, corresponding to the United Kingdom market average (250 g/kg) the calculated carcass weights were 16, 17 and 30 kg, respectively, for K, C and F lambs.

It is concluded that the Friesland breed differs from many others in the proportions of muscle or fat at corresponding carcass weights but this difference is not a general characteristic of dairy sheep. Comparison of breeds at defined proportions of carcass components, as determined by market standards, can be effectively achieved by serial slaughter over a suitable weight range.
Carcass and eating quality of ram, castrated ram and ewe lambs
Authors: Dransfield E. , Nute G. R. , Hogg B. W. , Walters B. R.
Published: September 2010

Carcass and meat composition and eating quality of m. longissimus lumborum (LI) and leg joints were compared in entire male (ram), castrated male (wether) and female (ewe) Dorset Down-cross and Suffolk-cross lambs at about 20 weeks old. Rams grew faster than wethers and ewes particularly in the earlier maturing Suffolk crosses. Carcass weights ranged from 13 to 24 kg and at the mean carcass weight of 17·7 kg ram carcasses yielded larger shoulder joints. Ram carcasses were assessed visually leaner than those from the other sexes with similar conformation scores. Dorset Down carcasses tended to be fatter than Suffolk carcasses and the leanest carcasses were from Suffolk rams. Intramuscular fatness in LI was similar in all sexes. Intramuscular collagen contents were higher in ram LI than in other sexes. There were no differences in protein content, pH or colour of raw or roast LI. In assessments of eating quality of LI by triangle tests, male and female assessors differentiated twin rams and wethers equally. Category scaling showed LI from ewes to be slightly tougher than those from rams and wethers. Consumer evaluation of leg joints did not detect any differences in odour due to sex and ram meat was assessed better than that from wethers or ewes.
Effects of monosodium l glutamate on diet palatability and piglet performance during the suckling and weaning periods
Authors: Gatel F. , Guion P.
Published: September 2010

The effect of monosodium L glutamate (MSG) on diet palatability and piglet performance during the suckling and weaning periods was studied in the course of five successive experiments involving a total of 230 litters during the suckling period and 120 pens of seven piglets during the post-weaning period. During the suckling period, the addition of 5 g MSG per kg diet led to a significant 0·36 proportional increase of creep food intake from the 18th day post farrowing. However, no increase in weaning weight was observed subsequent to the intake of the diet with added MSG. Moreover, in an experiment where MSG was added with an associated commercial flavour, no flavour enhancing effect of MSG was detectable. Few health problems were encountered at weaning and the number of scouring piglets was not related to one particular diet. During the first 13 days after weaning the addition of MSG to the diet increased daily food intake by proportionately 0·1 (P < 0·01) as well as growth rate by proportionately 0·07 (P < 0·01). Moreover, the addition of MSG to the diet was more effective with piglets of low weaning weight and thus contradicted the classical relationship between post-weaning performance and weaning weight. Finally, in an experiment where weaning occurred at lower ambient temperature, no improvement of post-weaning performance was observed following the addition of MSG.
Biological and economic impact of trypanosome infections on milk production in N'Dama cattle managed under village conditions in The Gambia
Authors: Agyemang K. , Dwinger R. H. , Jeannin P. , Leperre P. , Grieve A. S. , Bah M. L. , Little D. A.
Published: September 2010

Over a 3-year period, productivity characteristics and criteria of trypanosomiasis incidence and severity have been monitored by monthly examination of individual N'Dama cattle in villages in The Gambia. From this database, 60 lactating cows in which Trypanosoma congolense or T. vivax had been detected on blood examination (group 1) were compared with 50 cows which had not been found infected with trypanosomes during the monitoring period (group 2). The latter were selected on the basis of comparability of age and stage of lactation to those of group 1 for examining the effect of trypanosome infections on the quantity of milk extracted for human consumption, and on the growth of their sucking calves. Data from a 6- to 7-month period were examined in the analysis.

The quantity of daily milk extracted during the 1st month ot intection (group 1) decreased by proportionately 0·25 in comparison to the amount extracted during the preceding month when parasites were not detected. The corresponding figure in the uninfected controls (group 2) was 0·02. The mean daily milk extracted for human consumption from uninfected cows during a 6-month period was proportionately 0·26 higher than the mean for the infected cows. Growth rates of calves sucking infected and uninfected dams were similar.

These observations indicate that infection with pathogenic trypanosomes of lactating N'Dama cattle causes a reduction in milk production.

In economic terms, it was estimated that the decline in milk extracted for human consumption due to trypanosome infections amounted to an average of £1 per month per cow.
Some factors influencing behaviour of cattle in a slaughterhouse lairage
Authors: Cockram M. S.
Published: September 2010

One hundred and twenty-seven groups of cattle were studied in a slaughterhouse lairage to determine the factors affecting their ability to rest. The cattle were studied by direct observation over one 30-min period during their first 3·5 h in the lairage. An ethogram/time budget analysis of one focal Hereford × Friesian steer or heifer per group was undertaken and the lying behaviour of the whole group was recorded. Linear regression analysis was used to examine the effect of length of time in the lairage on behaviour. The effects of source, sex, group size, space allowance and bedding were examined by a comparison of regression lines. In cattle from markets, standing and moving behaviour, and the number of aggressive interactions decreased and lying behaviour increased with time in the lairage. This was not the case in cattle coming direct from farms. In cattle from markets, steers settled down at a faster rate than heifers, and cattle kept in group sizes >5 settled down at a faster rate than those kept in group sizes ≤5. The presence of straw bedding was associated with greater lying behaviour in market heifers and in market cattle kept in group sizes ≤5 than in similar cattle without straw bedding. Cattle from markets but not those from farms started to settle down within 3·5 h of arrival in the lairage and their behaviour was affected by the social and physical environment.
The effect of supplementary nickel on urea metabolism in sheep given a low protein diet
Authors: Milne J. S. , Whitelaw F. G. , Price J. , Shand W. J.
Published: September 2010

Work in the United States of America has shown that dietary supplements of nickel (Ni) can result in an increase in rumen urease activity and can increase growth rate and food conversion efficiency in lambs and steers given low protein diets. It has been suggested that Ni enhances urea recycling through its effect on urease activity. To examine this hypothesis, four sheep were given a high-energy, lowprotein diet with or without a supplement of 5 mg/day Ni, given as NiCl2.6H2O by continuous infusion into the rumen. Urea irreversible loss rate (ILR) and pool size were measured by means of a single intravenous injection of 14C-urea. The addition of Ni resulted in a significant increase in rumen urease activity (P< 0·05) but there was no significant effect on urea ILR, urea pool size, urinary urea excretion or on the quantity of urea recycled to the gastro-intestinal tract. Ni also had no effect on plasma urea or rumen ammonia concentrations, on diet digestibility or on nitrogen retention. It is concluded that the enhancement of urease activity by supplementary Ni conferred no nutritional advantage to the sheep.
The effect of energy concentration in complete diets on the performance of heifers and mature cows
Authors: Crosse S. , Murphy J.
Published: September 2010

Two experiments were carried out in the springs of 1986 and 1987 to investigate the effect of energy concentration in complete diets on the performance of heifers and mature cows. In 1986, all animals were on trial for an 8-week indoor period. In 1987, 14 heifers were on trial for 8 weeks, four heifers were on trial for 7 weeks and six heifers were on trial for 4 weeks. Carry-over effects were compared while animals were on pasture. Two diets offered ad libitum were compared. Diet H contained 0·7 concentrates and 0·3 grass silage. Diet L contained 0·5 concentrates and 0·5 grass silage. In 1986, the concentrate portion of diet H had a higher metabolizable energy (ME) content than diet L whereas in 1987 the same concentrate mixture was used in both diets.

Increasing the energy concentration of the diet from 10·66 MJ ME per kg dry matter (DM) to 11·21 MJ ME per kg DM resulted in a significant proportional increase of 0·36 in DM intake for heifers and mature cows in 1986. The proportional increase in DM intake in 1987 for heifers was 0·17. DM intake (kg DM per day) for heifers and mature cows in 1986 and for heifers in 1987 for diets H and L was 11·8, 8·7, 15·0, 11·0, 14·9, 12·7 respectively. The energy concentration of the complete diet did have a significant effect on average milk yield during the treatment period in the 1986 trial for mature cows but not for heifers in either year. Milk yields were 19·1, 17·5, 26·3, 240, 19·8, 18·9 kg/day respectively for heifers and mature cows in 1986 and for heifers only in 1987. In vivo digestibility coefficients in 1986 for energy, DM, organic matter, modified acid-detergent fibre and protein for diet H (0·708, 0·702, 0·724, 0·678, 0·671) were significantly higher than those for diet L (0·677, 0·666, 0·694, 0·653, 0·625).

The total lactation yield for the heifers and mature cows was not significantly influenced by the energy concentration of the diet given in early lactation.
Selection for rate and efficiency of lean gain in Hereford cattle. 2. Evaluation of correlated responses
Authors: Mrode R. A. , Smith C. , Thompson R.
Published: September 2010

Correlated responses in two lines of Hereford cattle selected for lean growth rate (LGR) from birth to 400 days of age and lean food conversion ratio (LFCR) from 200 to 400 days of age for a period of 8 years were evaluated. Correlated changes were estimated by two methods: deviation of selected lines from a control line and restricted maximum likelihood. Generally, estimates from the two methods were similar but tended to be more precise for the latter. Statistically significant correlated responses occurred in growth rate in the LGR line and in lean proportion and food conversion ratio in both selected lines. Selection for LGR was accompanied by increases in body weight at various ages in both male and female progeny. In the LFCR line there were little or no changes in body weight for male calves but some increases at certain ages for female progeny. There were no adverse correlated responses detected in reproductive traits such as calving difficulty and calving and pre-weaning mortality.
Protein requirements of boars of high genetic potential for lean growth
Authors: Rao D. S. , McCracken K. J.
Published: September 2010

Six replicates (five Landrace and one Duroc) of four littermate entire male pigs were used to evaluate the effect of protein level in diets of constant amino acid composition on live-weight gain, efficiency of gain, nitrogen balance and carcass characteristics. The diet contents ranged from 151 to 282 g crude protein (CP) and 8·5 to 16·4 g lysine per kg dry matter (DM) and were studied over two live-weight ranges, 33 to 55 kg and 55 to 88 kg. All the diets had similar metabolizable energy (ME) values (15·0 MJ/kg DM). Pigs were given food twice daily to appetite. Sixteen pigs (four replicates) were used for metabolism trials at 35 to 43, 58 to 65 and 78 to 88 kg live weight and after attaining a live weight of 88 kg they were slaughtered to assess carcass characteristics. Between 33 and 55 kg live weight significantly linear improvements (P < 0·01) in the daily live-weight gain and in the ratio ME: live-weight gain were observed for daily intakes in excess of 300 g ideal protein and 21 g lysine (212 g CP and 12·5 g lysine per kg DM). Between 55 and 88 kg live weight, linear improvements in the same two variables were observed for daily intakes of 395 g ideal protein and 28 g lysine (212 g CP and 12·5 g lysine per kg DM). For the 33 to 88 kg live-weight period the average ME intake was 30 MJ/day and the predicted intakes for maximum growth and food conversion efficiency were in excess of 370 g ideal protein and 26 g lysine. Nitrogen retention improved significantly with increasing dietary crude protein content in all three balance periods. Fat thickness measurements decreased linearly (P < 0·05) and the proportions of lean and fat in rumpback increased and decreased respectively (P < 0·01) as the dietary protein level increased.
A note on the flow of endogenous protein to the omasum and abomasum of steers
Authors: Hart F. J. , Leibholz Jane
Published: September 2010

Three steers cannulated in the rumen and abomasum were given a diet of wheat straw, chopped and soaked in sodium hydroxide and then washed to pH less than 8. The straw was sprayed with sucrose, urea and minerals. The diet was free of digestible protein and given at 1·7 to 4·1 kg/day. Microbial protein flowing to the omasum was measured by 15N. By difference, the flow of endogenous protein nitrogen to the omasum was found to be 2·2 g/kg dry-matter intake. The flow of endogenous protein nitrogen to the abomasum was 3·3 to 9·4 g/kg dry-matter intake, and it decreased with increasing food intake.
Factors affecting food efficiency and body composition of growing ruminants offered straw-based diets: supplementation with lipids with and without protein meal
Authors: van Houtert M. F. J. , Perdok H. B. , Leng R. A.
Published: September 2010

Growing heifers (experiment 1) and wether lambs (experiments 2 and 3) were offered ammoniated cereal straw with or without a protein meal. The effects of supplementation with long-chain fatty acids (LCFA; as calcium salts of LCFA (CaLCFA) or fat prills) on nutrient utilization were studied.

Intake of the basal diet (g/kg live weight) was unaffected by the protein meal, but was often reduced by supplementation with LCFA, especially fat prills. Live-weight gain was increased both by supplementation with protein meal and CaLCFA. Fat prills only increased live-weight gain in the presence of protein meal and depressed live-weight gain in the absence of protein meal. There were small differences between the two sources of LCFA in their apparent effects on rumen fermentation.

Supplementation with protein meal increased relative protein content (P < 0·05) and tended to increase water content (P > 0·05) in the wethers in experiment 3 (corrected to equal empty-body weight at slaughter). Of the LCFA, only CaLCFA tended to increase relative body fat content (by proportionately 0·23; (P > 0·05) but decreased relative protein and water content by 0·05 and 0·06 (P < 0·05).

Supplementation of straw-based diets with as little as 20 g CaLCFA per kg food dry matter improved live-weight gain and efficiency of nutrient utilization of ruminants, particularly when offered in combination with a protein meal. There appeared to be marked differences in the effects of CaLCFA and fat prills on food intake, productivity and to some extent body composition.
A note on the effect of monensin sodium administered by intraruminal controlled-release devices on productivity of dairy cows at pasture
Authors: Lynch G. A. , Hunt M. E. , McCutcheon S. N.
Published: September 2010

The effects of monensin sodium, administered by intraruminal controlled-release devices at a rate of 320 mglday, on milk and milk solids production and bloat score were examined in a trial with 90 lactating dairy cows given only mixed ryegrasslwhite clover pasture. Monensintreated cows had significantly greater yields of milk and milk protein than control cows (1397·2 (s.e. 22·9) v. 1296·9 (s.e. 16·3) kg milk, 49·6 (s.e. 0·9) v. 46·5 (s.e. 0·6) kg protein) over the 14-week period of treatment (P < 0·01). Yield of fat was similar in monensin-treated and control cows (62·9 (s.e. 1·5) v. 63·4 (s.e. 1·1) kg). Live weight, condition score and bloat score were not influenced by treatment but pasture conditions were not conducive to severe bloat challenge.
Energy and protein supplements to straw-based diets for yearling cattle: effects on straw intake and digestibility
Authors: Al-Saghier O. A. S. , Campling R. C.
Published: September 2010

A series of change-over experiments examined the intake and digestibility of straw-based diets in yearling dairy heifers. Voluntary intakes of straws given as the sole food to yearling dairy heifers were 1·28, 1·20 and 0·90 kg dry matter (DM) per 100 kg live weight for barley, wheat and oat straws respectively, and the corresponding digestibility of organic matter was 0·47, 0·53 and 0·48. When supplemented with 2 kg rolled barley the intakes of straw did not alter, nor were they affected by replacing part of the rolled barley with an equal amount of soya-bean meal and thus increasing the dietary concentration of protein from about 50 to 110 g/kg DM. The use of molassed sugar-beet pulp in place of rolled barley reduced the intake of straw. Flaked maize promoted slightly higher intakes of straw than an equal amount of coarsely milled maize. Replacing rolled barley by lucerne hay reduced straw intake. It is estimated that, to provide sufficient energy and protein for a daily gain of 0·5 kg, heifer straw-based diets would require a supplement of 1·2 kg rolled barley and 0·8 kg soya-bean meal.
Genetic and phenotypic parameters for litter traits of D'Man ewes
Authors: Boujenane I. , Kerfal M. , Khallouk M.
Published: September 2010

A total of 1754 records for litter traits of 458 D'man ewes sired by more than 45 rams were analysed to estimate repeatability, heritability and genetic and phenotypic correlations. Repeatability estimated by the intraclass correlation method was 0·11, 0·11, 0·12 and 0·15 for litter sizes at birth and at weaning and litter weights at birth and at weaning, respectively. Paternal half-sib estimates of heritability were 0·09 (s.e. 0·06), 0·04 (s.e. 0·05), 0·15 (s.e. 0·07) and 0·08 (s.e. 0·05), respectively. Genetic correlations among the traits were all positive and varied from 0·17 to 0·72, whereas phenotypic correlations ranged from 0·68 to 0·86.
Growth rate, total body water volume, dry-matter intake and water consumption of domesticated ostriches (Struthio camelus)
Authors: Degen A. A. , Kam M. , Rosenstrauch A. , Plavnik I.
Published: September 2010

Growth rate, total body water volume (TBW), dry-matter intake (DMI) and water consumption were determined in ostriches from hatching to 350 days at which time they weighed approximately 100 kg. A Gompertz equation was used to describe the sigmoidal growth curve; mature body mass (Mmb) wascalculated as 104·1 kg from this equation. Highest average daily gain (ADG) was 455 g/day which occurred between 70 days and 98 days. Time to reach 0·5 Mmb and to grow from 0·25 to 0·75 Mmb per Mmb025 were 46·8 days and 39·7 days, respectively. Maintenance energy requirements were 1·07 MJ/kg063per day and energy requirements for kg mb increase were 0·260 MJ/kg109: thes e values were derived from a non-linear regression model. TBW as a fraction of mb declined from 0·84 in 35-day-old chicks to 0·57 in 322-day-old birds, indicating a concomitant increase in the fraction of body lipid content. Mass specific DMI decreased from 0·061 g/g mb in chicks to 0·020 g/g mb in 322 to 350 day old birds, while mass specific water influx decreased from 0·21 ml/g mb to 0·046 ml/g mb during this time. The ratio of DMI to ADG increased steadily from 1·07 to 17·1; the ratio of water consumption to DMI remained relatively constant at approximately 2·3.
Genetic and clonal responses in closed dairy cattle nucleus schemes
Authors: de Boer I. J. M. , van Arendonk J. A. M.
Published: September 2010

The additive genetic response per generation and the genetic superiority of female genotype(s) selected for commercial cloning (clonal response) were maximized for a closed adult nucleus scheme, with 256 or 1024 test places, by varying the mating design (number of clones, full-sibs and half-sibs). Responses were corrected for effects of finite sample size and correlated index values on the selection intensity, and variance reduction due to selection. Additive genetic responses, which varied from 0·153 to 0·514 phenotypic standard deviations per generation, were 0·68 to 0·89 of corresponding uncorrected predictions. Reductions were largest when the intensity and accuracy of male selection were high. Clonal responses varied from 0·460 to 2·506 phenotypic standard deviations, increasing with the intra-clone correlation, the intensity of clonal selection and the test capacity. Reductions in clonal responses, which varied from proportionally 0·04 to 0·27, were smallest when dominance variance was high. Increasing the test capacity resulted in a proportionally 0·21 to 1·55 increase in genetic responses, while proportional increases in clonal responses varied from 0·09 to 0·36. With selection of only one male per full-sib family, designs which maximized genetic and clonal responses were different in all cases. Differences were largest when the heritability and the intra-clone correlation were low and the intensity of clonal selection was high. Without the restriction on male selection, optimal mating designs were different, unless dominance variance and intensity of clonal selection were both low.
Body dimensions of Nigerian cattle, sheep and goats
Authors: Hall S. J. G.
Published: September 2010

One hundred and thirty-six multiparous cows, 63 goats and 71 sheep were measured in breeding flocks and herds in Nigeria. The humped cattle breeds, and the large-bodied, humpless Kuri, are narrow-bodied and tall in relation to their length when compared with British breeds. Pelvic dimensions are small. The sheep and goats native to the coastal and middle belts (the West African Dwarf breeds) are miniature versions of those found in the north. Neither appears to be achondroplasic but dwarfing seems to have proceeded differently in the two species in that the adult West African Dwarf goat is similar in its relative body proportions to the adult northern goat, implying a proportional miniaturization. The West African Dwarf sheep appears to be a neotenous form with body proportions similar to those of an immature sheep.
Evaluation of intrauterine insemination of sheep with frozen semen: effects of time of insemination and semen dose on conception rates
Authors: Findlater R. C. F. , Haresign W. , Curnock R. M. , Beck N. F. G.
Published: September 2010

The field application of a laparoscopic technique to permit intra-uterine insemination of ewes with frozen-thawed semen was examined in two trials, conducted over successive years, to (i) determine the optimum time of insemination relative to sponge removal/pregnant mares's serum gonadotropin (PMSG) injection and (ii) establish the relationship between semen dose and conception rate. Pooled semen was used in both trials, and each involved > 900 ewes in a number of commercial flocks.

Maximum conception rates were achieved when insemination was conducted between 54 h and 60 h after sponge removal/ PMSG injection. However, there was no significant difference in conception rate when motile sperm numbers were reduced from 52·2 × 106to 13·0 × 106 motile sperm per uterine horn.

The overall conception rates (pooled over flocks and treatment groups) were 56% and 58% for the two trials, with a wide degree of variation between flocks in both cases (45% to 79% for trial 1 and 45% to 69% for trial 2). However, there was evidence for consistent differences in conception rates between the six flocks involved in both years of the trials.
The effects of involuntary coprophagy on the production of skatole in growing pigs
Authors: Hawe S. M. , Walker N.
Published: September 2010

Six boars weighing about 65 kg were penned individually in preliminary observations to investigate their response to increasing levels of faeces in a concentrate diet fed as a gruel. During an introductory 5-day period pigs were restricted to 1·5 kg concentrates plus 100 g fresh faeces daily. The daily concentrate allowance was then increased to 2·2 kg and faeces increased by 50 g/day providing the ration was consumed completely. Two animals showed diarrhoea at intakes of 1 kg faeces per day while the remaining four animals showed no signs of ill health at the maximum allowance of 1·4 kg faeces per day.

In the main experiment littermate pairs of the same sex (16 boars plus 16 gilts in total) were allocated to control (concentrates only) or treated (concentrates plus fresh faeces) groups. Animals were housed in metabolism crates from about 55 kg live weight and the diet allowances were increased gradually up to 2·5 kg concentrates with or without 500 g fresh faeces per day. This was achieved on day 17 and continued to slaughter some 40 days later when pigs weighed around 85 kg live weight. Levels of skatole and indole were significantly higher in the caecal contents of treated pigs at slaughter but similar in faeces compared with controls. There was no effect of dietary treatment on skatole or indole levels in subcutaneous fat.

It seems unlikely that natural coprophagy would contribute significantly to skatole and indole levels in carcass tissues.
A note on the nutritional evaluation of worm meal (Eisenia fetida) in diets for rainbow trout
Authors: Velasquez L. , Ibañez I. , Herrera C. , Oyarzun M.
Published: September 2010

Worm meal obtained from worms (Eisenia fetida) raised on waste materials was evaluated for Rainbow trout as a replacement for fish meal at dietary concentrations of 250, 500 and 1 000 g replaced per kg. During the study period none of the diets was detrimental to fish health. The dietary concentrations of 250 and 500 g/kg replacement gave higher growth rates than that of the control group (0 g/kg replacement), the former having consumed less food. The biological parameters of food conversion efficiency and protein efficiency ratio, for these replacement levels, also showed values better than the control diet. Liver somatic index and the chemical composition of fish fillets showed no significant differences between diets, except for a significant decrease in lipid content with increasing worm meal inclusion.
Optimum linear indices for non-linear profit functions
Authors: Pasternak H. , Weller J. I.
Published: September 2010

An iterative method is presented, based on the method of Moav and Hill (1966) to derive the optimum linear selection index for any number of traits with linear or non-linear profit functions. For non-linear profit functions the index weights will be functions of the trait means prior to selection and the selection intensity. Using the equations developed, the optimum selection index for three dairy cattle milk production traits was computed. Convergence was obtained after three to four iterations, and was robust to the starting values used for iteration. The ratio of expected genetic gains were only marginally different for selection intensities of 1 and 4 standard deviation units. Differences were greater for the index coefficients. All alternative indices tested gave lower gains in profit than the optimum index. For linear profit functions this index reduces to the standard linear index, and for two uncorrelated traits this index reduces to the index of Moav and Hill (1966).
Evidence of genotype by environment interaction for reproductive and maternal traits in beef cattle
Authors: Morris C. A. , Baker R. L. , Hickey S. M. , Johnson D. L. , Cullen N. G. , Wilson J. A.
Published: September 2010

A total of 161 bulls from 11 breeds were used to generate crossbred calves from Angus cows in 1973 to 1977 at each of three diverse New Zealand locations, and from Hereford cows at one of the locations in the same years. The bulls comprised four local breeds, Angus, Friesian, Hereford, and Jersey, and seven recently imported breeds, Blonde d'Aquitaine, Charolais, Chianina, Limousin, Maine Anjou, Simmental and South Devon. This paper reports the reproductive and maternal performance of the straightbred and first-cross cows over the first four calvings, with first mating as yearlings at 14 to 16 months of age. A total of 7575 mating records from 2109 cows were analysed. Location differences were greater for reproduction than for growth traits and resulted in genotype × environment interactions for some components of cow performance and particularly the composite traits, weight of calf weaned per cow joined (productivity) and cow ‘efficiency’ (the ratio of productivity to cow weight). At all locations the Friesian-cross cows weaned the greatest weight of calf per head but were matched or surpassed by the lighter Jersey crosses in terms of efficiency of calf production. Most of the European crosses performed relatively much better in the most favourable environment than in the harsh environment and this was particularly marked for the productivity of Simmental crosses. Heterosis as a proportion of the purebred mean was important for cow performance and particularly pregnancy rate (0·12), productivity (0·21) and the efficiency ratio (0·16). Heritabilities for weight and age at puberty were both 0·34 (s.e. 0·08). Repeatabilities and heritabilities for cow reproductive traits were low (0·0 to 0·10) but higher for calf weights up to weaning as a trait of the cow (0·09 to 0·38). In general, the large European breeds which excelled in growth and carcass production produced female progeny which reached puberty at greater ages, had lower reproductive performance (especially in less favourable environments) and larger mature size. Some breed utilization strategies to achieve trade-offs between these genetic antagonisms are discussed.
Rice polishings as an alternative to sugar cane molasses as a supplement with urea to low-quality forage diets for ruminants
Authors: Garcia D. Cardenas , Newbold C. J. , Galbraith H. , Topps J. H. , Chen X. B. , Rooke J. A.
Published: September 2010

The effect of including 14 g urea with either 75 g dry matter (DM) from sugar cane molasses (UM) or Colombian rice polishings (RP) at three levels, 68 (RP1), 137 (RP2) or 203 (RP3) g DM on grass hay DM intake and on rumen fermentation was investigated. An incomplete Latin-square design was used and each experimental period was divided into 12 days for adaptation to each diet followed by 9 days in metabolism cages when all measurements were made using five adult sheep.

Pooled mean values for rumen metabolites (five samples per day) were calculated. Rumen pH was not affected by the nature of the supplements. Concentrations of volatile fatty acids (VFA) (UM 92·8, RP1 84·2, RP2 86·4, and RP3 84·0 (s.e.d. 3·4) mmol/l) and lactate (UM 2·0, RP1 1/6, RP2 1/7, RP3 1/8 (s.e.d. 0·014) mmol/l) (UM v. RP, P < 0·05 and P < 0·10 respectively) were lower when RP were given, while concentration of branched and longer chain VFA (26·5, 34·0, 31·1 and 33·5 (s.e.d. 1·6) mmol/mol total VFA, UM v. RP, P < 0·01) and ammonia (98, 131, 141, 137 (s.e.d. 16·1) mg/l, UM v. RP, P < 0·05) were increased. Numbers of rumen protozoa (1·6, 3·2, 2·7, 3·3 (s.e.d. 0·75) × 105 per ml, UM v. RP, P < 0·20) tended to be higher 2 h after feeding when RP rather than UM were given. However, hay DM intake (1050, 960, 960, 880 (s.e.d. 45·3) g/day, UM v. RP, P < 0·05), and microbial protein supply (11·7, 9·3,11·1,10·8 (s.e.d. 0·59) g N per day, UM v. RP, P < 0·05), estimated from urinary purine excretion were reduced by feeding RP instead of UM.

At the levels of inclusion tested RP did not increase the efficiency of rumen fermentation and were not as effective a supplement with urea as was molasses for a low-quality forage diet.
Influence of quality of dietary protein supplement and anabolic steroids on muscular and skeletal growth of foals
Authors: Saastamoinen M. T. , Koskinen E.
Published: September 2010

Twenty-two weanling foals, about 7 months (215 days) old, were allotted to two groups. One group received high-quality protein (HP; milk powder) and the other received poor-quality protein (PP; barley protein). In addition, six foals in each group were injected intramuscularly (1 mg/kg body weight) with an anabolic steroid (Nandrolon lauras, Laurabolin vet®) at intervals of 3 weeks from weaning to 12 months (362 days) of age. Skeletal and muscular measurements from foals were also made at intervals of 3 weeks. Closure of the right distal growth plate was assessed radiographically in 13 colts in their 2nd and 3rd years of life. Blood samples were taken to investigate the blood chemistry. The HP-group foals gained weight faster from weaning to 12 months of age and were heavier at the age of 12 months than the PP-group foals. The growth of longissimus dorsi muscle and cannon bone circumference were also significantly greater in the HP-group foals. The high-quality dietary protein supplement also increased serum amino acid concentrations and haemoglobin and packed cell volume values. The foals treated with the anabolic steroid increased in body length more slowly from weaning to 12 months of age than the untreated foals. Growth plates closed about 1·5 months later in the horses treated with anabolic steroid than in the untreated horses. Weanling foals seem to require a protein supplement rich in lysine for their optimal growth. More than 31 g/day (0·46 g/MJ metabolizable energy) lysine can be recommended up to 10 months of age.
A note on the diets selected by boars given a choice between two foods of different protein concentrations from 44 to 103 kg live weight
Authors: Kyriazakis I. , Emmans G. C. , Taylor A. J.
Published: September 2010

Ten Large White × Landrace boars at an initial live weight of 43 kg were given free access to two isoenergetic foods with 119 (L) and 222 (H) g crude protein (CP) per kg food as a choice, for 54 days. Six more similar boars were given access to food H only. The diet selected by the choice-fed pigs (measured as the proportion of food H per kg total food intake) changed systematically with time; the CP content of the selected diet fell from 193 in the first 7 days to 146 g CP per kg food in the last 7 days. The performance of the choicefed pigs, over the 54-day period, was as good as that of those given food H only: live-weight gain was 1101v.1069 g/day and food conversion efficiency 0·380v.0·374 g gain per g food respectively. However, the choice-feeding system allowed boars to reduce the protein content of their diet as they grew. It is suggested that it might be possible to give pigs a choice between two appropriate foods during the whole growing-fattening period instead of frequently changing the composition for their single food in order to try to meet their requirements.
Growth hormone release in calves selected for milk fat yield
Authors: Løvendahl P. , Sejrsen K.
Published: September 2010

In two experiments Red Danish dairy calves of both sexes, and of two lines selected for high (H) and low (L) milk fat production (proportional difference 0·22), were tested at 4 months and again at 10 months of age for their growth hormone (GH) release following intravenous administration of either thyrotropin releasing hormone (TRH, experiment 1: 0·15 μig/kg live weight, no. = 16 H + 10 L) or arginine hydrochloride (ARG, experiment 2: 0·10 g/kg live weight, no. = 19 H + 10 L). The GH response was measured in serial blood samples for 0·5 h prior to and for 2 h following intravenous injections. The response peak, measured as the geometric mean of the 5-, 10- and 15-min samples following TRH was greater in the line selected for high yield, at 10 months (H, 42·4 μg/l; L, 20·6 μig/l; P < 0.01) but not at 4 months of age (H, 25·4 μg/l; L, 18·6 μg/l; P > 0·05). The response peak following arginine measured in the 20-, 30- and 45-min samples was smaller than the peak following TRH and did not differ between selection lines, although there was a tendency for H calves to have a larger release at 10 months of age. After puberty (10 months) male calves responded more to both secretagogues than females, while there was no difference before puberty (4 months). These results suggest that GH release may be useful as a juvenile predictor of dairy merit, but results need to be confirmed in further and larger studies.