Two new single-nucleotide polymorphisms (SNPs) (C1166T and G1190A) were discovered in the follicle-stimulating hormone receptor (FSHR) gene and two (G261A and T302C) in the zona pellucida glycoprotein (ZP3) gene. These SNPs were genotyped in three Chinese domestic purebred sow lines (42 Small Meishan, 46 Qingping and 41 Jinhua sows) and three European purebred sow lines (225 Duroc, 195 Large White and 65 Landrace sows) by using SNP chips. Phenotypic data including the functional teat number (i.e. milk-producing teats, TN) and number of piglets born alive per litter (NBA). These traits were tested for association with the genotypes of four SNPs. The association analysis revealed genotype of G261A in the ZP3 gene was significantly (P < 0.01) associated with overall NBA and NBA at later parities (NBA2+) but not with NBA at first parity (NBA1). There was a significant (P < 0.05) difference between sows with genotype GG (14.83 ± 0.18) and AA (14.26 ± 0.09) in TN at position 261 in the ZP3 gene. No significant associations were observed for the SNPs in the FSHR gene with NBA or TN in our populations. The results showed that the new SNPs in the ZP3 gene may be an effective potential marker to be used in conjunction with traditional selection methods.

The effects of calcium hydroxide (Ca(OH)2 )treatment of malt distillers' grains (MDG) on apparent digestibility in vivo, food intake and lamb performance were measured in three experiments. Experiment 1 measured effects on intake and apparent digestibility of wet MDG either untreated (C), mineralized with a high-calcium mineral (M), Ca(OH)2 treated at ambient temperature (L) or at 70°C for 72 h (LH) and offered ad libitum to mature wether sheep (approx. 75 kg live weight). Dry matter (DM) intakes for MDG were 1251,1585,1838 and 1889 (s.e. 93) g/day for C, M, L and LH respectively when given with 780 g DM per day of a standard complete diet (diet A). Corresponding values for whole diet organic matter (OM) apparent digestibility when MDG was given at a fixed rate (1250 g DM per day) with a standard diet (660 g DM per day diet A) were 049, 049, 0·58 and 0·60 (s.e. 0·008) respectively. Experiment 2 compared mineralized wet MDG (M) with a prototype dried food made from Ca(OH)2-treatedensiled MDG (neutralized with NaOH before treatment) held at 60°C for 18 h before drying (NID) and a proprietary lamb finishing compound (PC). The supplements were offered at an increasing rate (350 g DM per day to 1200 g DM per day) to 30 Blackface lambs of approximately 31 kg initial live weight, penned in pairs, and given ad libitum access to hay and water. Mean DM intakes (g DM per day) to day 60 for supplements were 925, 750 and 934 (s.e. 19) and for hay were 258, 200 and 311 (s.e. 17) for NID, M and PC respectively. Corresponding values for live-weight gain (g/day) were 136, 123 and 130 (s.e. 11); for condition score (day 59) were 3·9, 3·6 and 4·0 (s.e. 0·06) and for number of lambs finished at day 60 were 8, 2 and 10. Experiment 3 evaluated the apparent digestibility and effects on rumen function of NID, M and PC fed at a fixed rate with chopped hay (804 g DM per day supplement + 396 g DM per day hay) to rumen fistulated wethers (approx. live weight 70 kg). Apparent digestibility values for OM were 0·63, 0·53 and 0·65 (s.e. 0·015) and for neutral-detergent fibre were 0·69, 0·55 and 0·57 (s.e. 0·037) for NID, M and PC respectively. Rumen pH, volatile fatty acid concentrations or hay digestibility in sacco were not significantly affected by supplement. Ca(OH)2 treatment greatly improved the nutritional characteristics of MDG giving substantial improvements in apparent digestibility, intake and performance.

The appetite and growth of individually-fed, weaned Hampshire and Saddleback piglets and of Hampshire and Large White × Landrace piglets were compared in three experiments from 14 to 49, 28 to 55 and 21 to 45 days of age. There was a reduced rate of growth in the Hampshire piglets, which was not found to be related to any need of Hampshire piglets for a higher quality diet. Neither was there any reduction in the efficiency with which Hampshire piglets used ingested nutrients, nor a differential rate of deposition of any body component. Hampshire piglets ate less food than Saddleback or Large White × Landrace piglets and this reduced appetite was largely accounted for by the lower body size.

Diets of cooked maize meal and dried skim milk were fed to newly weaned mice for 2 weeks, and to lactating females for 3 weeks. The diets ranged from 16% to 100% maize, with complementary amounts of from 84% to 0% milk and a 5% supplement of yeast.

Live-weight gains from 3 to 5 weeks of age were greatest when an intermediate diet containing 76% maize was fed. Average gains on 16%, 76% and 100% maize were 8·0 g, 17·7 g and 5·5 g respectively. The full sib phenotypic correlation was 0·45 but gains were independent of weaning weight. No carry-over effect was detected from maize-milk diets that had been fed to the dams; the dams' own gains at the same age had little influence on their offspring.

Weight of food consumed per mouse varied little between diets despite marked differences in gain. Food and energy intakes relative to gain showed no trend between 16% and 88% maize but doubled between 88% and 100% maize. Protein was used most economically for gains on 88% maize.

There were health problems. When high milk diets were first used many mice suffered from diarrhoea. A few mice on 95% maize, whose dams had been given the same diet during lactation, died without prior symptoms. Mice on 100% maize were thirsty, but not glycosuric.

Females nursing litters on high milk or high maize diets drew on reserves in the carcass, liver, pancreas, spleen and fat. In addition, high milk diets caused hypertrophy of kidneys and caecum, and diarrhoea.

In a series of feeding trials, measurements were made of silage drymatter (DM) content and pH, animal live weight and intake of DM other than silage. Silage intake has been related to these measurements by multiple regression. Subsequently, within the recorded ranges of the variables used, good predictions have been made of silage intake by large groups of cattle.

1. Analyses are presented of 1628 calvings from 397 pedigree Hereford cows kept in three herds whose records were made available by their owners. In addition a further 541 calvings were examined from a sample of 100 cows taken at random from the herdbook entries.

2. Mean age at first paternity for 71 homebred bulls was 25·6 mo. Mean age at first calving varied between the three herds from 29·5to 32·8 mo, with 39·7 mo for the random cows.

3. Random herdbook cows produced an average of 3·3 calves per cow compared with 4·2 from those in the three herds; these latter cows had an average calving interval of 13·1 mo.

4. The pattern of cow and calf disposal varied partly according to the differences in herd age and culling policy. While one herd retained more than 80% of heifers and subsequently sold half of them after two or three calvings for breeding, another retained only one-third but kept these for their full working life. Similarly the percentage of bull calves sold for breeding varied between 43 and 83%.

5. The net reproductive rate, or number of calves weaned per 100 cow-herd-years was 74, 88 and 67 for the three herds, and 66 for the random herdbook cows. The mean generation intervals were 4·1 yr for sires and 5·8 yr for dams whose breeding life in the herds had been completed.

6. The biases in reproductive statistics estimated from herdbook entries were examined, and it was concluded that such data can be of use where better herd records are unavailable.

To estimate the effect of supplementation on hay: grain substitution rates, 18 experimental rations were evaluated in digestibility trials, each using four steers (300 kg live weight) housed in metabolism stalls. Four hays (digestible dry matter = 40 to 62 %) were given to appetite, supplemented with maize grain plus urea at several different levels, up to 2·5% of animal live weight, and substitution rates were estimated as the slope of the linear regression of hay intake on grain intake. General substitution rates were independent of hay quality, and the pooled rate was 830 g (Sb = 0·036) per kg of grain dry matter. Nevertheless, the analysis of the observed partial substitution rates and those in the literature, suggests a possible interaction between the effects of hay digestibility and grain level on substitution rates.

Data from a large field trial comparing the performance of contemporary crossbred ewes from traditional and experimental prolific rams were used to study two factors, (1) the influence of lambing at 1 yr of age on subsequent ewe performance and (2) the effect of level of farm performance on the difference between the traditional and the prolific types. Neither effect was found to be important.

The dry-matter (DM) intake and growth rate in male lambs were predicted from rumen degradability characteristics, rumen DM losses at different times, neutral- or acid-detergent fibre (NDF or ADF) contents and DM apparent digestibility of roughages. Four different straws consisting of wheat, barley, oat and rice were each offered ad libitum to 24 Merino male lambs with 200 glday concentrate for 4 weeks to determine DM intake and growth rate. Apparent digestibilities of the straws were measured with three Merino male sheep. Measurements were made during the last 10 days of each 20-day period. The degradation characteristics of the straws were measured by incubating samples in nylon bags for 8, 16, 24, 48, 72 and 96 h in the rumens of three Merino male sheep fitted with rumen cannulae. The exponential model p = a + b(l - er^) was fitted to the data. Potential degradabilities of DM (defined as a + b) and apparent digestibilities of DM ranged from 530 to 679 and 440 to 560 g/kg, respectively. The mean DM intake of the straws varied from 543 to 745 glday, the digestible DM intake from 236 to 417 glday and growth rate from 17 to 95 glday. Using the degradation characteristics A, B and c in a multiple regression analysis, the correlation coefficients with DM intake and growth rate were 0·79 and 0·70, respectively. NDF and ADF were related to DM intake (i = 0·65; r = 0·64) and growth rate (r = 0·55; r = 0·56). The correlation coefficient between DM apparent digestibility and DM intake was 0·76. It is concluded that the rumen degradation characteristics have potential for predicting intake of straws and growth rate in sheep.

The aim of this study was to analyse the effects of species (Muscovy and Pekin ducks) and age at the beginning of the overfeeding period on fatty liver production, carcass composition and lipid and moisture content of the liver and breast muscle. We reared four groups of 40 ducks per species for the study, starting at 2-week intervals in order to have four different ages together at the beginning of the overfeeding period (10, 12, 14 and 16 weeks). At the end of the overfeeding period, all ducks were slaughtered. Our results confirmed the high levels of difference in carcass composition and lipid content in the plasma, liver and breast muscle between Muscovy and Pekin ducks at all ages. Pekin ducks were not able to develop a high degree of hepatic steatosis, but had increased lipid storage in peripheral adipose and muscle tissues than Muscovy ducks. However, the fatty liver weight of Pekin ducks increased with age, with lipid deposition in the liver and peripheral tissues. The ability of Muscovy ducks to produce fatty livers remained unchanged with age in line, with lipid deposition in the liver and peripheral tissues. The sites of lipid deposition thus depend on species and not on the physiological maturity of ducks.

1. Four growth trials were carried out with 297 group-fed steers given diets based on barley, minerals and vitamins, unsupplemented or supplemented with either soya bean meal or various sources of non-protein nitrogen.

2. Steers given unsupplemented barley (11% crude protein in dry matter) had inferior growth rates up to 300 kg live weight but thereafter were equal to those given barley supplemented with urea in the drinking water or soya bean meal.

3. There were no significant differences in the growth rates of steers given barley supplemented with soya bean meal and those given barley supplemented with ammonium and mineral salts of formic acid or a mixture of acids (predominantly acetic).

4. In two out of three trials, tenth-rib joints from steers given barley supplemented with ammonium salts of mixed acids contained less fat and more protein and water than those from steers given barley supplemented with soya bean meal or proprietary protein supplements.

5. A number of possible explanations for the apparent carcass differences is discussed.

Evaluation of lifetime productivity of individual animals in response to various interventions allows assessment of long-term investment opportunities for farmers. In order to gain a better understanding of promising feed interventions for improvement of small ruminant production in Southwestern Nigeria, a dynamic modelling approach was used to explore the effect of different feeding strategies on the lifetime productivity of West African Dwarf (WAD) goats. Modifications were made to the current version of Livestock Simulator developed for cattle production to simulate goat production systems particularly for WAD goats. Effects of changes in input parameters (quality of feed and potential adult weight) confirmed the sensitivity of the modelled weight development and reproductive performance. The values of simulated model outputs corresponded well with observed values for most of the variables, except for the pre-weaning mortality rate in the cut-and-carry system where a wide discrepancy between simulated (2.1%) and observed (23%) data was found. The scenario analysis showed that simulated goats in the free grazing system attained sexual maturity and kidded much later than those in the grazing with supplementation and the cut-and-carry systems. The simulated results suggested that goats require supplementation with protein and energy sources, in order to promote lifetime productivity, early sexual maturity and higher birth weight. In terms of economic returns based on feed cost alone, the moderately intense system produced the most profit. We therefore conclude that grazing with adequate supplementation using farm-generated feed resources offers an opportunity for improving smallholder goat production systems in West Africa.

The paper sets out to stress that although marketing is often put forward as one of agriculture's weaknesses (or even failures) it is wrong to assume that good marketing is a panacea. It can in fact be argued that the emphasis on the importance and relevance of marketing in agriculture today is in the circumstances merely a natural development. The way ahead in milk marketing as much as agricultural marketing is for this development to continue gradually. Dramatic results should not be expected in the short terra but in time may be expected to contribute significantly to the survival of the dairy and agricultural industry in the UK.

It is very well known that milk records show a considerable downward trend in yield from the East to the West of England and Wales. The Bureau of Records of the Milk Marketing Board have produced some admirable maps, shaded by counties according to the average yield, and these bring out the trend very clearly ; roughly the yield declines from 730 to 630 gallons, a drop of 15 per cent. This trend in yield is not a new phenomenon. Twenty-five years ago Dr. Hammond and I found the same thing with 26 counties which by 1923 had had milk recording societies functioning for five years ; the decline was approximately from 700 to 600 gallons. We selected two societies which were at that time about at the extremes and extracted lactation figures from the milk record books of the members in an effort to probe a little deeper into the difference. I hope to refer to these two again and will only say now that Norfolk milk recorded cows gave 22.8 per cent, more milk than those of Penrith, and of this difference, 6 per cent, was due to higher yield at the start of the lactation and the rest to greater persistence of yield and to longer continued milk flow.

In the previous paper, Sutton et al. (1985) examined the effect of concentrate type on the performance of lactating dairy cows and reported significant effects with respect to silage intake and milk protein concentration. In this experiment, conducted in parallel with that reported by Sutton et al. (1988), the effect of concentrate type on nutrient digestion in the rumen and protein supply to the tissues of lactating cows was examined, although the comparison was restricted to examination of the high protein diets only.

Energy and nitrogen balance partitioning was studied in sheep given whole cottonseed (WCS), vetch hay and commercial concentrates. Sheep were offered diets containing 0 (CON) and 250 g/kg WCS at maintenance (LF) and twice maintenance (HF) levels. Digested energy, metabolizable energy (ME) and heat production (HP) were measured in a balance trial combined with indirect calorimetry. Dietary ingredients were also incubated in sacco in sheep rumens. Feeding WCS resulted in decreased energy digestibility at HF (0·718 v. 0·751) but not at LF. Loss of energy as methane expressed as a proportion of gross energy intake for CON and WCS respectively was 0·078 and 0·057 at LF and 0·061 and 0·051 at HF. In both diets, HP was similar at LF. In contrast HP amounted to 0·657 of the ME for CON and only 0·61 for WCS at HF.

Apparent nitrogen digestibility was not affected by WCS consumption. Urinary nitrogen was similar for both diets at LF, but at HF it was higher in the WCS diet. Thus at HF, retained nitrogen was 045 and 0·12 of apparently digested nitrogen for CON and WCS respectively.

Ruminal degradation of organic matter was proportionately 0·87 and 0·77 of apparent digested organic matter in the total tract for the CON diet, at LF and HF respectively and 0·80 and 0·73 for the WCS diet, at LF and HF respectively. In the four groups ruminal nitrogen degradation was equal to apparent whole-tract nitrogen digestion. It was concluded that feeding WCS may decrease metabolic HP in ruminants. Utilization of WCS could be improved by taking measures to decrease urinary nitrogen losses.

Carcasses of Piétrain-cross pigs slaughtered at 64 kg live weight and purchased by retail butchers were accompanied by questionnaires aimed at obtaining an appraisal of them relative to the butchers' normal purchase. Consumer reaction to loin chops from Pietrain crosses and contemporaries sired by the Large White was determined by panel—, household- and shop-testing respectively. Retail butchers showed a strong preference for Pietrain-cross carcasses on lean content but not shape and few considered that the muscle tissue had defects. In panel— and household tests participants showed a strong preference for Pietrain-cross chops on their appearance but broad equality for the two types of chops on organoleptic properties. In shop tests a preference was shown for Piétrain-cross chops over Large Whitecross chops and those normally stocked by the shop.

Adipogenesis, myogenesis and fibrogenesis are related processes that can contribute to meat quality. Therefore, extending the knowledge of these processes would facilitate the identification of molecular markers that predict intramuscular fat accretion. The main purpose of this work, based on previous results, was to further study the expression of key genes related to adipogenic, myogenic, fibrogenic processes and some cytokines in Longissimus thoracis (LT) and Masseter (MS) muscles of Pirenaica and Holstein young bulls. Longissimus thoracis and MS muscles from Pirenaica (n = 4) and Spanish Holstein (n = 4) were sampled for proximate analysis, determination of adipocyte size distribution and expression of key candidate genes. Fat percentage was lower in LT than in MS muscle in Pirenaica young bulls (P = 0.023) and was higher in LT muscle in Holstein than in Pirenaica young bulls (P = 0.007). Gene expression analysis revealed that the mRNA level of myogenic differentiation 1 (MYOD) was higher in LT than in MS muscles in both groups of animals (P < 0.001) and that myostatin (MSTN) expression was also higher in LT than in MS muscle in Holstein bulls (P = 0.001). On the other hand, MSTN and PPARG showed higher expression in LT and MS in Pirenaica young bulls (P = 0.026), while the expression of fatty acid-binding protein 4 (FABP4) was higher in Holstein young bulls, also in both muscles (P < 0.001). The results suggested that the development of intramuscular adipose depot was directly related to the expression of adipogenic genes, such as FABP4, but inversely related to the expression of the cytokine MSTN and the myogenic gene MYOD, genes which showed a muscle-specific expression.

Experiments were carried out to determine the effects of giving 1·36 kg of ‘RuffTabs’, polythene particles of dimension 1·27 × 0·63 × 0·95 cm3 (RT) to castrated male cattle (steers) given an all-concentrate diet, on the outflow of fluid from the rumen, on rumination and on the molar proportions of volatile fatty acids produced in the rumen.

RT reduced the flow of fluid from the rumen of steers, given a restricted amount of an all-concentrate diet, from 4·65 to 2·75% rumen volume/hr. RT had no effect on the total time spent daily in ruminating and eating. The molar proportions of volatile fatty acids were unaffected by RT in steers which were given the diet ad libitum but when RT was given to steers offered a restricted allowance of feed there was a highly significant (P < 0·001) reduction in acetic and an increase in butyric, valeric and caproic acids.

The feed intake of the steers was unaffected by RT.

The effect on the morphology of the reproductive organs of ewe lambs of exposure to phyto-oestrogens for long periods of time were studied in 10 ewe lambs reared on lucerne compared with 10 controls on Italian ryegrass.

Anatomical studies of the reproductive organs showed that the ewe lambs reared on lucerne had significantly bigger reproductive tracts than the controls, the thyroids and the mammary glands were heavier and the latter showed secretory activity. The ovaries of the ewes fed on lucerne were smaller and lighter than those of the controls but no difference in ovarian activity was detected.

Microscopic examination showed specific features affecting the uterus, cervix and vagina. The prevalence of neutral mucopolysaccharides in the composition of the cervical mucus found in ewe lambs fed on lucerne indicated a decrease in viscosity of the mucus.