Adaptation to the digestion of non-starch polysaccharide in growing pigs fed on cereal or semi-purified basal diets.

Pigs (25-45 kg) were fed on either cereal or semi-purified basal diets supplemented with either high or low levels of sugar-beet pulp or wood cellulose (Solka-floc). The apparent digestibility and retention of N and apparent digestibility and metabolizability of energy (GE) and the apparent digestibility of non-starch polysaccharides (NSP) and their constituent monomers were measured during weeks 2, 4 and 6 of the trial. N and GE were less well-digested, retained or metabolized from cereal basal diets than from the corresponding semi-purified diets during all three periods.

Characteristics of ruminant mammary epithelial cells grown in primary culture in serum-free medium.

Cells were obtained from the mammary glands of sheep and cows by collagenase-hyaluronidase digestion. Characterization of cells as epithelial was by reaction with a monoclonal antibody to cytokeratin. A subpopulation of spindle-shaped or stellate cells reacted with a monoclonal antibody to desmin and may be related to myoepithelial cells.

Preovulatory follicle development and luteal function in ewes immunized against a synthetic peptide sequence of the alpha subunit of bovine inhibin.

Immunization against inhibin consistently results in an increase in ovulation rate in sheep, but the effects that this treatment has on follicle development are unknown. In order to determine the influence of inhibin, parameters of follicle development were assessed in ewes that had been actively immunized against a synthetic peptide homologous to the N-terminal sequence (alpha 1-29, Tyr30) of the alpha subunit of bovine inhibin, a treatment that neutralizes the biological activity of endogenous inhibin. The final stages of preovulatory follicle development that culminate in ovulation were induced in seasonally anoestrous ewes, and follicles were recovered prior to the predicted time of ovulation.

Studies of method of conserving grass herbage and frequency of feeding in cattle. 2. Eating behaviour, rumen motility and rumen fill.

The influence of the method of conserving grass herbage and the frequency of feeding on eating behaviour, rumen motility and rumen fill was studied in growing steers. Silage and hay were offered to twelve rumen-cannulated Friesian steers (average initial live weight (LW) 128 kg) at a restricted level of intake (20 g dry matter (DM)/kg LW) either once or eight times daily. With once daily feeding, the daily intake of hay was consumed in a single large meal which lasted about 2 h, while silage was eaten in many small meals throughout the day.

Studies of method of conserving grass herbage and frequency of feeding in cattle. 1. Voluntary feed intake, digestion and rate of passage.

The effect of method of conserving grass herbage and the frequency of feeding on digestion in and passage from the rumen was studied in growing cattle. A single sward of perennial ryegrass (Lolium perenne cv. Endura) was cut on 1 d and conserved as silage or hay.

Active immunization with a synthetic peptide region of growth hormone: increased lean tissue growth.

The effects of active immunization against a specific peptide region of GH (sequence 134-154) were examined in a species relevant for animal production in vivo. Peptide-immunized lambs exhibited significant increases in carcass protein and water contents and consequently increased carcass weight. The comparatively smaller increases in carcass water and protein contents which occurred in GH-treated lambs were offset by decreased fat accretion.

Progesterone receptor in the mammary tissue of pregnant and lactating gilts and the effect of tamoxifen treatment during late gestation.

An isotope exchange assay using [3H]progesterone was used to examine progesterone receptor moieties in cytosolic extracts obtained from mammary tissue of gilts over the course of pregnancy and lactation, and during treatment of pregnant gilts with tamoxifen. Scatchard analysis was used to determine the concentrations and dissociation constants of progesterone receptors. The concentration of progesterone receptor was high at the onset of pregnancy (1394 fmol/mg DNA), fell to a nadir at 45 days (36 fmol/mg DNA), increased to a second maximum at 75 days (1232 fmol/mg DNA) and declined thereafter till parturition: the dissociation constant (Kd) of progesterone for its receptor remained stable during pregnancy with a mean Kd of 0.

Effect of oestradiol benzoate and tamoxifen on the growth of and induction of progesterone receptors in the uterus and mammary gland of immature pigs.

Intramuscular injection of oestradiol benzoate (0.1, 1 or 10 micrograms/kg per day) and tamoxifen (0.1 or 1 mg/kg per day) to 6-week-old immature pigs for 7 days induced a dose-dependent increase in the wet weight of the uterus and in the total content of uterine DNA, RNA and protein.

A unifying mathematical analysis of methods to estimate rumen volume using digesta markers and intraruminal sampling.

A theoretical exposition of methods for estimating the quantity of digesta in the rumen using digesta-flow markers and intraruminal sampling is given, with emphasis on the kinetic assumptions underlying each method. Single- and dual-marker approaches to estimating volume in steady and non-steady-state are presented.

Effects of controlling body weight on the semen production of large white turkey males.

1. The consequences of limiting body weight gain during rearing on subsequent semen production and quality of Large White turkey males were assessed in a factorial experiment comparing ad libitum or restricted feeding in two periods (6 to 18 and 19 to 54 weeks of age). 2.

The value of progesterone, oestradiol benzoate and cloprostenol in controlling the timing of oestrus and ovulation in dairy cows and allowing successful fixed-time insemination.

The relative merits of three hormone treatments of dairy cows: (1) intravaginally administered progesterone and oestradiol benzoate; (2) intravaginally administered progesterone and injected cloprostenol; and (3) injected cloprostenol; begun 35-75 days after calving and designed to synchronize oestrus and ovulation and allow successful artificial insemination (AI) at fixed times, have been assessed utilizing information from progesterone concentrations in milk. From this it was concluded that 89% of the cows had ovulated one to three times between calving and the beginning of treatment. Treatment (2) was more effective than (1) in synchronizing ovulation.

The inhibitory effects of hull polysaccharides and tannins of field beans (Vicia faba L.) on the digestion of amino acids, starch and lipid and on digestive enzyme activities in young chicks.

The effects of polysaccharides and tannins present in the hulls of field beans (Vicia faba L.) on the digestion of amino acids, starch and lipid were studied in poultry. A control diet without hulls and the same diet substituted with 400 g hulls/kg diet from three different varieties of beans were fed to 3-week-old chicks for 4 d.

Efficacy of intermittent or continuous administration of GnRH in inducing ovulation in early and late seasonal anoestrus in the Père David's deer hind (Elaphurus davidianus).

Père David's deer hinds were treated with GnRH, administered as intermittent i.v. injections (2.

The relationships between dietary crude protein, body weight, and fertility in naturally mated broiler breeder males.

1. Naturally mated male broiler breeders were fed to achieve five levels of body weight gain on a high (160 g crude protein (CP)/kg) or low (110 g CP/kg) protein diet. Males were separately fed in 9 of the experimental treatments and fed with the females in the other.

The effect of fishmeal supplementation of a straw-based diet on growth and calorimetric efficiency of growth in heifers.

Thirty-two 160 kg dairy heifers were used to measure the effects of increasing dietary protein content on growth and heat production. A basal diet containing (g/kg) 550 sodium hydroxide-treated straw, 220 barley, 220 sugarbeet pulp and 10 urea was offered with 0, 76 and 152 g fishmeal/kg dry matter of the basal diet (F0, F1 and F2 levels respectively). The three diets were each given at two levels of feeding (low, L; high, H): 57.

On the two-compartment model for estimating the rate and extent of feed degradation in the rumen.

An analysis of the compartmental scheme used to determine the rate and extent of ruminal degradation of feeds is presented. Attention is given to the kinetic representation of the degradation of the potentially degradable fraction. Changing the kinetic order of the rate, and introducing indigestible substrate inhibition and microbial activity into its representation, are investigated.

Comparison of haematological values in restricted- and ad libitum-fed domestic fowls: white blood cells and thrombocytes.

1. White blood cells and thrombocyte values were examined in normal domestic fowls of layer and broiler strains fed restricted or ad libitum diets. 2.

The effect of fishmeal on the digestion of grass silage by growing cattle.

The effect of two levels of fishmeal substitution (50 (FM1) and 150 (FM2) g/kg) of a grass silage control diet (C) on the rumen digestion of organic matter and nitrogen, and the small intestinal disappearance of amino acids was examined in young growing cattle each equipped with simple PVC cannulas in the dorsal sac of the reticulo-rumen, the proximal duodenum and the terminal ileum. The silage was a primary growth of perennial ryegrass (Lolium perenne) (+formic acid) with a total N content of 22 g/kg dry matter (DM) (diet C). Fishmeal substitution increased this to 26 (diet FM1) and 34 (diet FM2) g/kg DM.

Post-partum, ovarian function in dairy cows as revealed by concentrations of oestradiol-17 beta and progesterone in defatted milk.

Concentrations of oestradiol-17 beta and progesterone in defatted milk have been used to study the post-partum restoration of ovarian function in 52 autumn-calved dairy cattle. In 32 cows the first preovulatory peaks in oestradiol-17 beta concentration (indicative of imminent ovulation) were less than or equal to 15 days and in 49 cows less than or equal to 49 days post partum. Delay to first ovulation was mainly due, not to failure of ovarian secretion of oestradiol-17 beta at preovulatory level, but to failure of oestradiol-17 beta at this level to exert its normal preovulatory function.

Growth, body composition, hormonal and metabolic status in lambs treated long-term with growth hormone.

The effect of long-term (10 weeks) treatment with growth hormone (GH) was investigated in twin lambs, one sibling being a control and the other treated with GH (0.1 mg/kg live weight per d). The lambs were fed on a concentrate-grass cube (9:1 w/w) diet at a daily rate of 40 g fresh weight/kg live weight.

Lysine requirements and whole-body protein turnover in growing pigs.

The influence on protein accretion and whole-body protein turnover of changing dietary protein quality while maintaining constant energy intake was studied by varying the degree of lysine supplementation of a lysine-deficient barley-based diet given to growing pigs. Measurements of nitrogen metabolism and whole-body protein turnover, using both classical and 15N end-product methods following a single dose of [15N]glycine, were made in 49-kg male pigs given diets containing 109 g lysine-deficient protein/kg supplemented to make them (1) 'deficient', (2) 'adequate' and (3) 'in excess' with respect to lysine. The 15N dose and protein intake values used to calculate amino N flux from the cumulative urinary excretion of 15N in urea and ammonia were corrected respectively for apparent digestibilities of [15N]glycine and total N determined in a separate experiment in pigs fitted with simple ileal cannulas.

Immunochemical quantification of cytochrome f in leaves of a non-yellowing senescence mutant of Festuca pratensis.

A non-competitive enzyme-linked immunosorbent assay (ELISA) which enables detection of as little as 0.1 ng cytochrome f in leaf extracts has been developed. No evidence for specific or non-specific interference by proteins other than cytochrome f was found.

Changes in body-weight, composition and hepatic enzyme activities in response to dietary methionine, betaine and choline levels in growing chicks.

The experiments described here were set up (a) to investigate the effect of age and (b) to investigate the effect of giving five diets which varied in methionine and choline or betaine contents on some of the enzymes that metabolize these nutrients in chick liver. Growth and carcass composition of the chicks fed on the different diets were also examined. There was no obvious relationship between age and enzyme activity in young chicks.

Mathematical models of sow reproduction.

Nutrition affects reproduction, but the physiological mechanisms are not known. Defining those mechanisms is a high priority for animal scientists. This paper briefly describes mathematical models developed to aid in elucidating those mechanisms and which may be applied to predict animal performance.

Short-term inhibition of legume N2 fixation by nitrate : II. Nitrate effects on nodule oxygen diffusion.

A comparison was made of changes in nitrogenase (N2ase; EC 1.18.6.