Consumers’ demand of leaner meat products is a challenge. Although betaine and conjugated linoleic acid (CLA) have the potential to decrease porcine adipose tissue, their mode of action is poorly understood. The aim of the study was to determine the lipolytic effect of betaine and CLA in the adipose tissue of Iberian pigs. Adipose tissue explants from five pigs (38 kg BW) were prepared from dorsal subcutaneous adipose tissue samples and cultivated for 2 h (acute experiments) or 72 h (chronic experiments). Treatments included 100 µM linoleic acid (control), 100 µM trans-10, cis-12 CLA, 100 µM linoleic acid + 1 mM betaine and 100 µM trans-10, cis-12 CLA + 1 mM betaine (CLABET). To examine the ability of betaine or CLA to inhibit insulin’s suppression of isoproterenol-stimulated lipolysis, test medium was amended with 1 µM isoproterenol ±10 nM insulin. Media glycerol was measured at the end of the incubations. Acute lipolysis (2 h) was increased by CLA and CLABET (85% to 121%; P < 0.05) under basal conditions. When lipolysis was stimulated with isoproterenol (1090%), acute exposure to betaine tended to increase (13%; P = 0.071), while CLA and CLABET increased (14% to 18%; P < 0.05) isoproterenol-stimulated lipolysis compared with control. When insulin was added to isoproterenol-stimulated explants, lipolytic rate was decreased by 50% (P < 0.001). However, supplementation of betaine to the insulin + isoproterenol-containing medium tended to increase (P = 0.07), while CLABET increased (45%; P < 0.05) lipolysis, partly counteracting insulin inhibition. When culture was extended for 72 h, CLA decreased lipolysis under basal conditions (18%; P < 0.05) with no effect of betaine and CLABET (P > 0.10). When lipolysis was stimulated by isoproterenol (125% increase in rate compared with basal), CLA and CLABET decreased glycerol release (27%; P < 0.001) compared with control (isoproterenol alone). When insulin was added to isoproterenol-stimulated explants, isoproterenol stimulation of lipolysis was completely blunted and neither betaine nor CLA altered the inhibitory effect of insulin on lipolysis. Isoproterenol, and especially isoproterenol + insulin, stimulated leptin secretion compared with basal conditions (68% and 464%, respectively; P < 0.001), with no effect of CLA or betaine (P > 0.10). CLA decreased leptin release (25%; P < 0.001) when insulin was present in the media, partially inhibiting insulin stimulation of leptin release. In conclusion, betaine and CLA produced a biphasic response regarding lipolysis so that glycerol release was increased in acute conditions, while CLA decreased glycerol release and betaine had no effect in chronic conditions. Furthermore, CLA and CLABET indirectly increased lipolysis by reducing insulin-mediated inhibition of lipolysis during acute conditions.

One of the more promising techniques for the improvement of sow productivity has been the use of partial weaning or the separation of the sow and litter for periods of between 3 to 12 h/day towards the end of lactation. The purpose of the present study was to examine changes in steroid hormone concentrations, oestrus and fertility responses in lactating sows subjected to altered sucking, boar exposure and gonadotropins in mid lactation and at weaning. Thirty-two crossbred sows were allocated at random to one of four experimental treatments. Treatment 1 sows (no. = 8) were separated from their respective litters for 3 h/day from 12 days post partum through until weaning which was carried out at 21 days post partum. Treatment 1 sows were also given in-pen boar exposure for 1 h/day between day 12 post partum and weaning. Treatment 2 sows (no. = 8) were given the same protocol of litter separation (LS) and boar exposure (BE) as in treatment 1 and they were also given a combination of gonadotropins (Gn) on day 17 of lactation. Treatment 3 sows (no. = 8) were given LS + BE as above and the sows were injected with Gn on the day of weaning. Treatment 4 sows were controls given no LS, BE or Gn (no. = 8). During lactation, treatment 1 sows exhibited significantly (P < 0·05) reduced progesterone concentrations compared with treatment 2 sows. There were no other significant effects of treatment for any of the periods considered. The separation of sows from their piglets with or without gonadotropic treatment did not result in lactational oestrus in any treated sows. No significant treatment differences were found in the subsequent litter size (piglets born alive or total number of piglets). In conclusion, the present results have demonstrated no significant effects of LS, BE and Gn treatment during lactation on sow and litter performance. This was associated with low levels of peripheral plasma progesterone in all lactating sows.

Expression of estrus (EST) near the time of fixed-time artificial insemination (FTAI) increases pregnancy success in beef females. This outcome has been associated with improved pregnancy establishment and maintenance, although research is still warranted to validate this theory. Hence, this experiment compared ovarian, uterine and conceptus factors associated with pregnancy establishment in Bos indicus beef cows according to estrous expression during a FTAI protocol. One hundred lactating multiparous Nelore cows received a 2 mg injection of estradiol benzoate and an intravaginal progesterone (P4) releasing device on day −11, a 12.5 mg injection of prostaglandin F2α on day −4, P4 device removal in addition to 0.6 mg injection of estradiol cypionate and 300 IU injection of equine chorionic gonadotropin on day −2, and FTAI on day 0. An estrous detection patch was attached to the tailhead of each cow on day −2, and estrous expression was defined as removal of >50% of the rub-off coating from the patch at FTAI. Overall, 39 cows expressed EST, 55 did not express EST (NOEST), and six cows lost their patch and were discarded from the experiment. Ovarian ultrasonography was performed at FTAI, and on days 7 and 15 of the experiment. Blood samples were also collected on days 7 and 15. Only cows without a corpus luteum (CL) on day 0, and with a CL on days 7 and 15 remained in the experiment (EST, n=36; NOEST, n=48). On day 15, cows were randomly selected within each group (EST, n=29; NOEST, n=30) for conceptus collection via transcervical flushing, followed by endometrial biopsy in the uterine horn ipsilateral to the CL. Within cows not assigned to conceptus collection, blood samples were collected for whole blood RNA extraction (day 20) and pregnancy status was verified by transrectal ultrasonography (day 30). Diameter of dominant follicle on day 0 and plasma P4 concentrations on day 7 were greater (P⩽0.02) in EST v. NOEST cows. Conceptus length and messenger RNA (mRNA) expression of prostaglandin E synthase and interferon-tau were greater (P⩽0.04) in EST v. NOEST cows. Moreover, EST cows diagnosed as pregnant on day 30 had greater (P<0.01) blood mRNA expression of myxovirus resistance 2 on day 20 compared with NOEST. In summary, estrous expression near the time of FTAI enhanced pregnancy establishment factors in B. indicus cows, including conceptus development and mRNA expression of interferon-tau.

An experiment was carried out to compare silage-based and dried forage-based diets for finishing beef cattle and to examine the effects of protein supplementation and formaldehyde treatment of silage on performance and carcass composition. The four diets used consisted, on a dry matter basis, of (1) 700 g/kg formic acid-treated grass silage and 300 g/kg low protein cereal-based concentrate (LPC), (2) 720 g/kg formic acid-treated silage and 280 g/kg high protein cereal/fish meal concentrate, (3) 600 g/kg formaldehyde-treated silage and 400 g/kg LPC, and (4) 480 g/kg artificially dried grass and grass hay and 520 g/kg LPC. The silages were well preserved with 33 to 40 g ammonia N per kg total nitrogen. The diets were offered to 40 British Friesian castrated male cattle which were initially 387 (s.e. 2·9) kg live weight. For diets 1 to 4 respectively metabolizable energy intakes were 91·8, 94·7, 94·9 and 91·8 MJ/day; total nitrogen intakes 192, 234, 189 and 191 g/day; live-weight gains 0/89, 0/93, 0/86 and 0/82 (s.e. 0/045) kg/day; carcass gains 0·51, 0·52, 0·52, 0·52 and 0·50 (s.e. 0·33) kg/day; mean subcutaneous fat depths 5·6, 5·4, 5·3 and 6·0 (s.e. 0·41) mm; marbling scores 3·0, 3·3, 3·2 and 2·6 (s.e. 0·19) and areas of m. longissimus dorsi 65·7, 66·4, 64·7 and 64·3 (s.e. 1·66) cm2. It is concluded that performance, efficiency of energy utilization and carcass fatness were similar for a diet containing 700 g/kg well preserved grass silage and a dried forage-based diet with a similar intake of energy and protein. Protein supplementation of a diet based on formic acid-treated silage or formaldehyde treatment of silage did not affect performance or carcass fatness.

The food intake, growth and development of Ross broiler cockerels were recorded from 1 day old to maturity. At regular intervals, the body composition of these birds was determined and the eviscerated carcasses were chemically analysed. Allometric relationships of component weights and live weight were examined. Historical comparisons with fowl reared during the last 60 years did not reveal any significant changes in the pattern of development, despite faster absolute growth rates and heavier mature weights.

The elements of prolificacy have been analysed for the D'man sheep, a prolific Moroccan breed, by laparotomy on 38 animals. The average ovulation rate was 2·50 (s.e.0·45); a slight difference was observed between nulliparous and multiparous ewes due to high simultaneous activity by both ovaries in the latter group. Embryonic survival (42% overall) was 94% (87 to 100%) for multiparous and 44% (36 to 52%) for the nulliparous ewes at one ovulation, decreasing with increasing numbers of corpora lutea. The average litter size showed an optimum at four ovulations.

In most studies on beef cattle longevity, only the cows reaching a given number of calvings by a specific age are considered in the analyses. With the aim of evaluating all cows with productive life in herds, taking into consideration the different forms of management on each farm, it was proposed to measure cow longevity from age at last calving (ALC), that is, the most recent calving registered in the files. The objective was to characterize this trait in order to study the longevity of Nellore cattle, using the Kaplan–Meier estimators and the Cox model. The covariables and class effects considered in the models were age at first calving (AFC), year and season of birth of the cow and farm. The variable studied (ALC) was classified as presenting complete information (uncensored = 1) or incomplete information (censored = 0), using the criterion of the difference between the date of each cow's last calving and the date of the latest calving at each farm. If this difference was >36 months, the cow was considered to have failed. If not, this cow was censored, thus indicating that future calving remained possible for this cow. The records of 11 791 animals from 22 farms within the Nellore Breed Genetic Improvement Program (‘Nellore Brazil’) were used. In the estimation process using the Kaplan–Meier model, the variable of AFC was classified into three age groups. In individual analyses, the log-rank test and the Wilcoxon test in the Kaplan–Meier model showed that all covariables and class effects had significant effects (P < 0.05) on ALC. In the analysis considering all covariables and class effects, using the Wald test in the Cox model, only the season of birth of the cow was not significant for ALC (P > 0.05). This analysis indicated that each month added to AFC diminished the risk of the cow's failure in the herd by 2%. Nonetheless, this does not imply that animals with younger AFC had less profitability. Cows with greater numbers of calvings were more precocious than those with fewer calvings.

The benefits of using white clover in pastures have been widely recognised for many years. However, clover is perceived as being unreliable because of its typically low content, which is spatially and temporally variable, in mixed pastures. One proposed solution to increase the proportion of clover in the diet of grazing animals and composition in the pasture is to spatially separate clover from grass within the same field. In a field experiment ryegrass and white clover were grown in fine mixtures, and in pure alternating strips of ryegrass and clover of 1.5 m, 3 m or 18 m width within a field. Pastures were grazed for two grazing periods of 9 and 12 weeks, and measurements of sward surface height (SSH), herbage mass and composition and clover morphology were taken. Grazing behaviour was also observed. Results showed that spatial separation in the long term, when compared with a fine mixture, increased clover availability (18% to 30% v. 9%, based on standing dry matter) and was not grazed to extinction. Ewes maintained their preference for clover throughout the experiment (selection coefficient 2 to 5), which resulted in a reduction in the SSH of clover in monocultures to <3 cm and significant changes to the morphology of clover (smaller leaves, shorter petioles and thicker stolon), at the expense of maximising their intake. Spatial separation in the short term may therefore allow grazing animals to select their preferred diet; however, in the long term in continuously grazed pasture, their preference for clover depletes its availability.

Little information is available regarding the calcium (Ca) dynamics and how its concentration is influenced following the Ca treatment (injection or bolus) after calving in dairy cows. To evaluate the short- and long-term effects of different sources of Ca supplement to animals fed anionic diets during the pre-partum period, 36 multiparous Holstein cows were randomly assigned to 1 of 3 treatments: (1) control group without Ca supplement (CON); (2) subcutaneous injection of 500 ml of 40% w/v Ca borogluconate immediately post-calving (SUB) and (3) oral supplement of Ca bolus containing 45 g Ca immediately and 24 h post-calving (BOL). Serum concentrations of Ca, P and Mg were measured. Serum concentration of Ca was affected by treatments at 48 h of post-calving (P < 0.01). The mean Ca at 6 h was greater in SUB compared to CON group (2.34 v. 2.01 mmol/l; P < 0.002). The lowest Ca concentration at 12 h was related to CON cows compared with BOL and SUB cows (1.90, 2.16 and 2.14 mmol/l, respectively; P < 0.02); a similar trend was observed 24 h post-calving (P < 0.02). Serum concentrations of P and Mg were not influenced by treatments. Yield of milk, milk protein and fat-corrected milk were lowest (P < 0.05) in SUB cows within 3 weeks of lactation in comparison with CON and BOL cows. However, milk yield and milk composition did not show any difference among treatments throughout the first 3 months post-calving. In general, under conditions of this experiment, Ca supplements to fresh cows as an oral bolus are recommended in comparison with subcutaneous injection.

Extreme weather conditions such as cold stress influence the productivity and survivability of beef cattle raised on pasture. The objective of this study was to identify and evaluate the extent of the impact of genotype by environment interaction due to cold stress on birth weight (BW) and weaning weight (WW) in a composite beef cattle population. The effect of cold stress was modelled as the accumulation of total cold load (TCL) calculated using the Comprehensive Climate Index units, considering three TCL classes defined based on temperature: less than −5°C (TCL5), −15°C (TCL15) and −25°C (TCL25). A total of 4221 and 4217 records for BW and WW, respectively, were used from a composite beef cattle population (50% Red Angus, 25% Charolais and 25% Tarentaise) between 2002 and 2015. For both BW and WW, a univariate model (ignoring cold stress) and a reaction norm model were implemented. As cold load increased, the direct heritability slightly increased in both BW and WW for TCL5 class; however, this heritability remained consistent across the cold load of TCL25 class. In contrast, the maternal heritability of BW was constant with cold load increase in all TCL classes, although a slight increase of maternal heritability was observed for TCL5 and TCL15. The direct and maternal genetic correlation for BW and maternal genetic correlation for WW across different cold loads between all TCL classes were high (r > 0.99), whereas the lowest direct genetic correlations observed for WW were 0.88 for TCL5 and 0.85 for TCL15. The Spearman rank correlation between the estimated breeding value of top bulls (n = 79) using univariate and reaction norm models across TCL classes showed some re-ranking in direct and maternal effects for both BW and WW particularly for TCL5 and TCL15. In general, cold stress did not have a big impact on direct and maternal genetic effects of BW and WW.

Experiments were carried out to establish the suitability of full fat neem seed meal (FFNSM) in broiler and growing rabbit diets. In the broiler experiment, 200-day-old (Babcock) broiler chicks were used in a 10-week trial, with the FFNSM fixed at 0 (control), 25, 50, 75 and 100 g/kg diet. In the rabbit experiment 24 rabbits of three different breeds were used in an 8-week trial, with the FFNSM fixed at 0 (control), 100, 200 and 300 g/kg diet. The criteria of response were food intake, weight gain, food conversion and protein efficiency ratio and mortality. There was a significant (P < 0·05) negative correlation between the dietary inclusion of FFNSM, weight gain and food conversion efficiency of the birds in the starter phase. In the finisher phase from 5 to 10 weeks, food intake, weight gain, food conversion and protein efficiency ratio did not differ significantly (P > 0·05) between the birds on the control diet and diets containing up to 75 g FFNSM per kg. For all the measurements, rabbits on the diet with 100 g FFNSM per kg gave better results than the control. Food intake, weight gain, food conversion efficiency and protein efficiency ratio did not differ significantly (P > 0·05) between rabbits on control diet and the diet containing 200 g FFNSM per kg. Performance on the diet with 300 g FFNSM per kg was poorest.

Ultrasound scanning traits have been adapted in selection programs in many countries to improve carcass traits for lean meat production. As the genetic parameters of the traits interested are important for breeding programs, the estimation of these parameters was aimed at the present investigation. The estimated parameters were direct and maternal heritability as well as genetic correlations between the studied traits. The traits were backfat thickness (BFT), skin+backfat thickness (SBFT), eye muscle depth (MD) and live weights at the day of scanning (LW). The breed investigated was Kivircik, which has a high quality of meat. Six different multi-trait animal models were fitted to determine the most suitable model for the data using Bayesian approach. Based on deviance information criterion, a model that includes direct additive genetic effects, maternal additive genetic effects, direct maternal genetic covariance and maternal permanent environmental effects revealed to be the most appropriate for the data, and therefore, inferences were built on the results of that model. The direct heritability estimates for BFT, SBFT, MD and LW were 0.26, 0.26, 0.23 and 0.09, whereas the maternal heritability estimates were 0.27, 0.27, 0.24 and 0.20, respectively. Negative genetic correlations were obtained between direct and maternal effects for BFT, SBFT and MD. Both direct and maternal genetic correlations between traits were favorable, whereas BFT–MD and SBFT–MD had negligible direct genetic correlation. The highest direct and maternal genetic correlations were between BFT and SBFT (0.39) and between MD and LW (0.48), respectively. Our results, in general, indicated that maternal effects should be accounted for in estimation of genetic parameters of ultrasound scanning traits in Kivircik lambs, and SBFT can be used as a selection criterion to improve BFT.

Some studies have shown that expression of peroxisome proliferator-activated receptor gamma (PPARG), a key regulator of adipogenesis, and of some adipocyte-specific genes or adipokines are expressed in hepatic steatosis, leading to the concept of ‘adipogenic hepatic steatosis’ or ‘hepatic adiposis.’ Most of these studies were conducted in genetic obese mouse models or after manipulation of gene expression. The relevance of this concept to other species and more physiological models was here addressed in ducks which are able to develop hepatic steatosis after overfeeding. The expression of PPARG and other adipocyte-specific genes was thus analyzed in the liver of ducks fed ad libitum or overfed and compared with those observed in adipose tissues. Pekin (Anas platyrhynchos) and Muscovy ducks (Cairina moschata) were analyzed, as metabolic responses to overfeeding differ according to these two species, Muscovy ducks having a greater ability to synthesize and store lipids in the liver than Pekin ducks. Our results indicate that adipocyte-specific genes are expressed in the liver of ducks, PPARG and fatty acid-binding protein 4 being upregulated and adiponectin and leptin receptor downregulated by overfeeding. However, these expression levels are much lower than those observed in adipose tissue suggesting that fatty liver cells are not transformed to adipocytes, although some hepato-specific functions are decreased in fatty liver when compared with normal liver.

In a cross-sectional study, data from records of cattle slaughtered over a 1-year period at a large abattoir in South West England were analysed using an ordered category response model to investigate the inter-relationships between age, sex and breed on development of the permanent anterior (PA) teeth. Using the model, transition points at which there was a 50% probability of membership of each category of paired PA teeth were identified. Data from ∼60 000 animals were initially analysed for age and sex effect. The age transition was found to be ∼23 months moving from zero to two teeth; 30 months for two to four teeth; 37 months for four to six teeth and 42 months for six to eight teeth. Males were found to develop, on average, ∼22 days earlier than females across all stages. A reduced data set of ∼23 000 animals registered as pure-bred only was used to compare breed and type interactions and to investigate sex effects within the sub-categories. Breeds were grouped into dairy and beef-type and beef breeds split into native and continental. It was found that dairy-types moved through the transition points earlier than beef-types across all stages (interval varying between ∼8 and 12 weeks) and that collectively, native beef breeds moved through the transition points by up to 3 weeks earlier than the continental beef breeds. Interestingly, in contrast to beef animals, dairy females matured before dairy males. However, the magnitude of the difference between dairy females and males diminished at the later stages of development. Differences were found between breeds. Across the first three stages, Ayrshires and Guernseys developed between 3 and 6 weeks later than Friesian/Holsteins and Simmental, Limousin and Blonde Aquitaine 6 and 8 weeks later than Aberdeen Angus. Herefords, Charolais and South Devon developed later but by a smaller interval and Red Devon and Galloway showed the largest individual effect with transition delayed by 8 to 12 weeks.

The protection of sunflower meal (SFM) proteins by treatments with solutions of malic acid (1 M) or orthophosphoric acid (0.67 M) and heat was studied in a 3 × 3 Latin-square design using three diets and three rumen and duodenum cannulated wethers. Acid solutions were applied to SFM at a rate of 400 ml/kg under continuous mixing. Subsequently, treated meals were dried in an oven at 150°C for 6 h. Diets (ingested at 75 g/kg BW0.75) were isoproteic and included 40% Italian ryegrass hay and 60% concentrate. The ratio of untreated to treated SFM in the concentrate was 100 : 0 in the control diet and around 40 : 60 in diets including acid-treated meals. The use of acid-treated meals did not alter either ruminal fermentation or composition of rumen contents and led to moderate reductions of the rumen outflow rates of untreated SFM particles, whereas it did not affect their comminution and mixing rate. In situ effective estimates of by-pass (BP) and its intestinal effective digestibility (IED) of dry matter (DM), CP and amino acids (AAs) were obtained considering both rates and correcting the particle microbial contamination in the rumen using 15N infusion techniques. Estimates of BP and IED decreased applying microbial correction, but these variations were low in agreement with the small contamination level. Protective treatments increased on average the BP of DM (48.5%) and CP (267%), mainly decreasing both the soluble fraction and the degradation rate but also increasing the undegradable fraction, which was higher using orthophosphoric acid. Protective treatments increased the IED of DM (108%) and CP, but this increase was lower using orthophosphoric acid (11.8%) than malic acid (20.7%). Concentrations of AA were similar among all meals, except for a reduction in lysine concentrations using malic acid (16.3%) or orthophosphoric acid (20.5%). Protective treatments also increased on average the BP of all AA, as well as the IED of most of them. Evidence of higher increases for those AA showing a high resistance to degradation in the untreated meal were also observed. The total supply of metabolisable AA was increased by 3.87 times for sulphur-containing AA, whereas that of lysine was increased by 2.5 times, mainly because of lysine losses with heat treatments. These treatments and especially that with malic acid would be useful to increase the protein value of these meals but their combined use with lysine-rich protein concentrates would improve the metabolisable protein profile.

Lameness is a very important disorder of periparturient dairy cows with implications on milk production and composition as well as with consequences on reproductive performance. The aetiology of lameness is not clear although there have been various hypotheses suggested over the years. The objective of this study was to metabotype the urine of dairy cows prior to, during and after the onset of lameness by evaluating at weeks −8, −4 pre-calving, the week of lameness diagnosis, and +4 and +8 weeks post-calving. We used a metabolomics approach to analyse urine samples collected from dairy cows around calving (6 cows with lameness v. 20 healthy control cows). A total of 153 metabolites were identified and quantified using an in-house MS library and classified into 6 groups including: 11 amino acids (AAs), 39 acylcarnitines (ACs), 3 biogenic amines (BAs), 84 glycerophospholipids, 15 sphingolipids and hexose. A total of 23, 36, 40, 23 and 49 metabolites were observed to be significantly different between the lame and healthy cows at −8 and −4 weeks pre-calving, week of lameness diagnosis as well as at +4 and +8 weeks post-calving, respectively. It should be noted that most of the identified metabolites were elevated; however, a few of them were also lower in lame cows. Overall, ACs and glycerophospholipids, specifically phosphatidylcholines (PCs), were the metabolite groups displaying the strongest differences in the urine of pre-lame and lame cows. Lysophosphatidylcholines (LysoPCs), although to a lesser extent than PCs, were altered at all time points. Alterations in urinary AA concentrations were also observed during the current study for four time points. During the pre-calving period, there was an observed elevation of arginine (−8 week), tyrosine (−8 week) and aspartate (−4 week), as well as a depression of urinary glutamate (−4 weeks). In the current study, it was additionally observed that concentrations of several sphingomyelins and one BA were altered in pre-lame and lame cows. Symmetric dimethylarginine was elevated at both −8 weeks pre-calving and the week of lameness diagnosis. Data showed that urinary fingerprinting might be a reliable methodology to be used in the future to differentiate lame cows from healthy ones.

The lumbar joint, which is handled to assess body condition scores, was taken from 52 adult Rasa Aragonesa ewes with body condition scores between 1·5 and 4·5 and dissected into muscle, bone, subcutaneous and intermuscular fat. The subcutaneous fat in the lumbar joint was highly correlated with total fat in the body (r=0·97), confirming the value of this region for assessing body condition in Rasa Aragonesa ewes.

In two experiments carried out on 36 crossbred growing lambs the effect of purified bovine somatotrophic hormone (STH) on wool production and some qualitative fleece characters was studied. Food intake during and after the hormonal treatment was also examined. STH, injected in a dose of 1 mg/kg of body weight in 10- or 15-day intervals to growing lambs from 2 to 100 days of age, increased fleece weight significantly. This increase was accompanied by considerably higher daily food intake both during the hormonal treatment and 15 weeks after cessation of STH injections. No significant effect of STH on qualitative fleece characters was found.

The length and diameter of the humerus, ulna, femur and tibia were studied at generations 10 and 14 in lines of mice selected for high and low body weight at 10 weeks of age.

Although some deviations from control were not significant, a general pattern of correlated responses was evident. The divergences of high and low line means for bone length and diameter were significant in the four bones, confirming the contribution of these parameters to genetically determined alterations in body weight. Maternal effects did not affect bone length and diameter and heterosis was not important in the genetic control of these parameters. Unlike bone length, bone diameter continued to diverge in response to the additional four generations of selection. There may therefore be differences in the quantitative genetic control of bone length and diameter and consequently in the control of endochondral and intramembranous ossification.

The objective of this work was to evaluate the ultrasound method as a tool for in-vivo breast and abdominal fat prediction on Campero-INTA broilers. Breast length (mm), width (mm), surface (mm2; ultrasound) and depth (mm; ultrasound), and abdominal fat depth (mm; ultrasound) were measured at 65-66 and 72-73 days of age on 96 males. At 79 days of age, the broilers were weighed and slaughtered. Breast and abdominal fat weights (g) were obtained. Multiple regression equations were fitted using live weight (g) and in-vivo measurements to predict breast and abdominal fat weights and proportions (g/g). The best model for each case was selected by the Stepwise procedure. Equations fitted were verified using another set of data. Breast weight prediction using live weight and breast length in the model was as accurate as using live weight and breast depth. The former is recommended for breeding work. Abdominal fat weight prediction using ultrasound measurements of fat was less accurate than breast weight prediction. Repeatabilities for ultrasound breast measurements were higher (0·72 to 0·73) than those for abdominal fat (0·51 to 0·52). Operator effect may be important when training levels are different.