Thirty wether lambs (52.5 +/- 1.5 kg) were used in a replicated 3 x 5 factorial treatment arrangement and four periods to determine dietary intake and digestibility of three ground forages with increasing levels of supplemental ground corn. Forages were a mature, low-protein grass hay (LQH; 5.2% CP), an immature, ...

Effects of S fertilization, 0 or 138 kg of S/ha, as (NH4)2SO4 on chemical composition, ensiling characteristics, and utilization of sorghum (Sorghum bicolor L.) silage by wether lambs was investigated. Pioneer 947' sorghum forage was ensiled at the soft dough growth stage. Sulfur fertilization increased (P < .01) concentrations of ...

Eighty Targhee ewes with single or twin lambs were used to investigate the effects of chelated zinc methionine and level of dietary CP on milk and wool production, DMI, and ewe and lamb BW change. Treatments were arranged as a 2 x 2 x 2 factorial. Dietary treatments started 30 ...

Two groups of 45 Awassi ewes, were fed a control diet (group C) or a diet containing 0.30 poultry litter from laying birds (group PL). The experiment began when the rams were put with the ewes and continued through pregnancy and lactation. Mean weight changes of ewes of both groups ...

The influence of dietary protein supplementation on resistance to haemonchosis was examined in Hampshire down lambs fed either a basal diet or a diet supplemented with soyabean. At seven months of age the lambs were challenged with an initial loading dose of Haemonchus contortus, followed by a trickle infection three ...

Seasonality of breeding was evaluated in 165 purebred St. Croix ewes over a period of 3 yr at a latitude of 35 degrees 6' N. Ewes were divided into six groups for breeding starting in August of 1989 and a group was exposed to rams every 2 mo throughout the ...

The purpose of this study was to develop a sheep model to investigate reproduction, transmission, and shedding of Escherichia coli O157:H7 in ruminants. In addition, we investigated the effect of diet change on these parameters. Six groups of twin lambs given oral inoculations of 10(5) or 10(9) CFU of E. ...

Liver and kidney copper (Cu) and selenium (Se) concentrations were studied over a 7-month period after parenteral supplementation using Cu heptonate and barium (Ba) selenate in 44 8-month-old South African (SA) Mutton Merino wethers. Responses in plasma Cu and blood Se concentrations, as well as fecundity were also measured in ...

Thirty wether lambs were randomly assigned to three treatments consisting of a control (C) and two vitamin E-supplemented treatments (VE), one fed 500 IU of vitamin E.lamb-1.d-1 (E500) and the other fed 1,000 IU of vitamin E.lamb-1.d-1 (E1000). After a 56-d feeding period, lambs were slaughtered and carcass traits were ...

The productivity of Merino ewes treated with ivermectin and a controlled-release capsule containing albendazole was compared with untreated ewes grazing the same pastures on each of 3 farms. Treated breeding ewes had significantly increased greasy fleece weights (GFW, 6.5% and 7.1%) compared with untreated breeding ewes, on 2 of 3 ...

Superovulatory response to conventional treatment with eCG (1200 IU) and progestagen sponges (MAP, n = 9; FGA, n = 9; or controls without sponge, n = 6) was studied in Corriedale anestrous ewes. The follicular population just before the administration of eCG and the total ovarian response (large anovulatory follicles ...

Observations were carried out of actual acidity, volatile fatty acid (VFA) concentrations, enzyme activity in the rumen, total protein, urea, total lipid and glucose in the serum of conventional (CL) and gnotobiotic lambs (GL) in the period of milk nutrition. The inoculum of gnotobiotic lambs contained Streptococcus bovis, Prevoxella ruminicola, ...

The purpose of this experiment was to determine whether differences in retention time (RT) of digesta in the rumen are associated with individual differences in wool growth rate between Merino rams. Fifty-eight rams were offered a pelleted diet at ad libitum and restricted levels. Digesta RT in the rumen was ...

Rasa Aragonesa lambs were used to evaluate the repartitioning effects of a beta-adrenergic agonist and its withdrawal on nutrient metabolism. One group of animals (T-I) was fed salbutamol at a dose of 2 mg x kg-1 diet x day-1 for 38 days, while in another group (T-II) the beta-adrenergic agonist ...

Twenty-three male lambs were intoxicated with 2.5 ppm aflatoxins in their feed for a period of 3 weeks. Thirteen lambs were maintained as a control group (0 ppm aflatoxins in their feed). The coagulation profiles were determined from blood samples that were obtained at 0, 7, 14 and 21 d ...

Seven lambs were fed a mixture of bog plants containing 15 g (wet matter) Narthecium ossifragum per kg live weight for 10 consecutive days. Their serum creatinine concentration increased from day 1 to 4 but then fell to normal by day 6 after feeding started. In the same animals, the ...

Four-paddock rotational grazing of orchardgrass, ryegrass, or alfalfa was compared to an all-concentrate diet fed in drylot using 202 weaned lambs. Comparisons of animal performance ended in each of the 3 yr (1983, 1984, 1985) for all animals when drylot lambs reached a subjective body condition score of 12 (range ...

The effects of finishing system on growth performance and carcass composition were determined in an experiment using 40 crossbred, early-weaned lambs (28 kg BW). Finishing systems were 1) grazed alfalfa, 2) 100% concentrate diet fed in drylot, and 3) grazed ryegrass for 42 d followed by a 100% concentrate diet ...

To test the hypothesis that subclinical gastrointestinal parasitism, associated with an impairment in N digestion and metabolism and a reduction in the voluntary feed intake (VFI), could affect the diet selection of sheep given a choice between two feeds that differed in their crude protein (CP) content, twenty-four Texel x ...

Studies of olfactory deprivation have most frequently used unilateral naris occlusion to effect deprivation. Recent psychophysical evidence suggests that adult rodents with either acute or chronic naris occlusion show little decrement in olfactory ability. In this study the effect of naris occlusion coupled with ipsilateral or contralateral olfactory bulb deafferentation ...

Formulated zinc methionyl bST (sometribove, 50, 100, or 150 mg) was administered as a single treatment once every 2 wk or as two equal treatments once/week to evaluate the efficacy of prolonged release delivery of bovine somatotropin (bST) in finishing lambs. Feed conversion during the 6-wk treatment period was improved ...

Efforts to increase livestock utilization of tarbush are being coupled with studies to examine tarbush toxicity. Thirty-eight (19/treatment) ewe lambs were assigned at birth to receive either tarbush or alfalfa (15%, dry matter basis) in a sorghum-based growing ration. Lambs were pen-fed this diet 60 d pre-weaning and 60 d ...

In situ experiments and two lamb digestion trials were conducted to evaluate the effects of chemically treating recycled newsprint (NP). Treatment of NP with 2% HCl (percentage of NP DM) followed by autoclaving for 4 h was most efficacious and was used in an in vivo digestion trial with 25 ...

Organotins are used worldwide in agricultural practice as fungicides and herbicides. In this study morphological and ultrastructural investigations related with the subacute administration of the fungicide triphenyltin acetate (TPTA) were carried out in rabbits and lambs. Twenty-eight New Zealand White male rabbits were fed diets containing 0, 15, 75 or ...

Four years of grazing trials were conducted with Brassica forages to evaluate their chemical composition and effect on ADG of fattening lambs and breeding ewes in late fall. Brassicas tested included kales (Brassica oleracea L. var. acephala DC), turnips (B. rapa L.), and a chinese cabbage hybrid (B. rapa L. ...

Sixty Romanov x Dorset (RVDP) and sixty Romanov x Suffolk (RVSU) male lambs were used in a 2 x 5 factorial arrangement of treatments including two breed crosses and five diets to determine the effect of breed crosses on performance and to compare growth and carcass characteristics of lambs. Diets ...

Weight and growth data on 5,136 lambs, from 104 sires and 1,552 dams were collected during 5 yr (13 lambing seasons) of selection for high weaning weight in a single flock under range conditions. Ewes were culled based on fertility and replaced by ewe lambs selected for high weaning weight. ...

This study determined 1) how experience early in life with cured weeping lovegrass (Eragrostis curvula) (low-quality roughage) or fresh oats (Avena sativa) (high-quality roughage) affected consumption of low- or high-quality roughage by lambs later in life and 2) whether this early dietary experience affected passage of undigested residues through the ...

Thirty-two crossbred (Suffolk x Rambouillet) wether lambs were used to examine the effectiveness of protein source (soybean meal [SBM] or fish meal [FM]) in alleviating decreased performance associated with dietary aflatoxin (AF) in growing lambs. After a 21-d adaptation period to concentrate diets, lambs were assigned to the following dietary ...

The effects of nutrition on the hypothalamo-pituitary-gonadal axis were studied in three groups of six mature Merino rams that were fed for 56 days with a ration that maintained their initial live mass (intermediate diet: 675 g chaff plus 175 g lupins), the same ration with a lupin supplement (high ...

Wether lambs from four breeds, Rambouillet (n = 38), Targhee (46), Columbia (38), and Polypay (38), were used to estimate an optimal slaughter weight for lean lamb production. Wethers, weaned at an average of 105 d of age and 38.5 kg, had ad libitum access to a finishing diet of ...

Four experiments were carried out to determine the effect of the presence of ewes and rams on the reproductive state of ewes. In Expt 1, the breeding season of ewes kept with a vasectomized ram ended later (April 18 +/- 8 days; mean +/- SEM) than that of ewes isolated ...

Growing lambs were fed diets either low or adequate in phosphorus and their effects on Ca and P retention, bone formation and resorption and on ruminal microbial protein synthesis were measured. Plasma osteocalcin was used as an indicator of bone formation rate. Levels in plasma were lower in lambs fed ...

Circadian oscillations of penicillin productivity with a period of 22 +/- 2 h have been observed in carbon-limited batch fermentations of Penicillium chrysogenum. The specific penicillin production rate oscillated with an amplitude of 20 to 100% of its mean value, depending on the growth rate of the active (respiring and ...

The objectives of this study were to examine the interaction between added palm oil in high-forage diets and initial concentration of plasma cholesterol on performance, plasma lipids, and carcass characteristics of growing ram lambs. Thirty-two Hampshire-Suffolk ram lambs (initial BW = 34.4 kg) were assigned to a 2 x 2 ...

Forty-two crossbred lambs (33.4 kg initial body weight; twenty-four wethers and eighteen ewes) were used in a 42 d experiment with a 2 x 3 factorial treatment arrangement to determine effects of forage level and source on splanchnic tissue mass. Diets were 250 and 750 g/kg of chopped lucerne (Medicago ...

Growth retardation induced by dietary restriction in the lamb results in a decrease in LH pulse frequency and therefore in delayed puberty. Increased circulating cortisol levels have been associated with nutritional restriction in a variety of species. The current study tested the hypothesis that hyperactivity of the adrenal axis sustains ...

If an animal experiences gastrointestinal malaise after eating a novel feed, it develops a dislike for the feed called a conditioned flavor aversion (CFA). Understanding flavor aversions is important for diet-training procedures, understanding animal responses to poisonous plants, and preparing animals for new foraging environments. Our research objectives were to ...

The effects of fetuses or placentas (with fetuses) removal on progesterone receptors (PR) in deciduomal tissues were investigated in unilateral pregnant (ULP) hamsters. Deciduomal reactions in response to artificial stimuli were induced on the tube-ligated uterine horns of ULP hamsters. Fetuses or placentas (with fetuses) were removed on day 8 ...

Vitamin B12 was measured in samples of normal ovine colostrum and milk and in sera of lambs and ewes taken at various stages of lactation, from lambing up to 16 d. Colostrum obtained within 24 h of lambing contained high concentrations of vitamin B12, but within a few days the ...

Aspergillus niger was grown in a 7-L chemostat at biomass levels of 7 to 9 gL(-1); dilution rates of 0.03, 0.05, 0.075, and 0.009 h(-1); and dissolved oxygen tensions of 7%, 12%, and 40% of air saturation. Broth rheological measurements were made on-line, while off-line image analysis was used to ...

Five Suffolk ewes underwent daily laparoscopy for 18 days at the onset, middle and end of the breeding season (August, November and February, respectively) and during anoestrus (May) to examine their ovaries. Ovarian follicles > or = 2 mm were measured and their relative locations reported on an ovarian map ...

The purpose of the study was to determine the effect of trenbolone acetate (TBA) on performance, plasma lipid metabolites, and carcass characteristics of growing ram and ewe lambs in two separate experiments. Treatments consisted of 1) a control, no implants, and 2) a TBA implant (60 mg of Finaplix; Hoechst-Roussel ...

Icelandic ewes, living under natural photoperiod conditions, were treated with daily melatonin (2.5 and 10 mg day-1) for 75 days from the autumn equinox. Ewes were also exposed to a ram from the autumn equinox until the end of June, for 30 days from the end of the anoestrous period ...

Two trials were conducted to examine the influence of N enrichment of dried citrus pulp (DCP) through ammoniation vs urea supplementation on digestion and feeding value of a DCP-based diet for sheep. Treatments were 1) ammoniation of DCP with urea (CP-U), 2) ammoniation with ammonium hydroxide (CP-A), 3) supplementation with ...

Data on 4,754 lambs born from Pelibuey (PB) and Barbados Blackbelly (BB) ewes collected over 9 years at the Mococha Experimental Centre in Yucatan, Mexico, were used to determine environmental, dam-breed and sire-breed effects on birth weight (BW), weaning weight (WW) and average daily gain (ADG). Effects of year and ...

The thyroid gland is necessary for the transition from the breeding season to anestrus in the ewe, but the importance of seasonal changes in thyroxine in this process is not known. The objective of this experiment was to determine the effects of exogenous thyroxine during the breeding season on the ...

Forty-eight crossbred lambs (22.5 +/- 2.6 kg average BW) of equal numbers from both sexes were used to observe the effect of protein supplement (none, canola meal, or fish meal) and temperature (21 +/- 1.8 degrees C or 4.7 +/- 1.7 degrees C) on growth and energetic efficiency in a ...

Every 10 years snowshoe hare populations across the boreal forest of North America go through a population cycle, culminating in a decline lasting 4 or more years. We tested the hypothesis that snowshoe hares during the decline are in poor condition and less able to respond to challenges in their ...

Relationships between pentose cycle oxidative activity and differential fat growth were evaluated. Rambouillet wether lambs (n = 60) were slaughtered serially at 0, 40, 80, and 120 d on feed (15 lambs/group). Rack dissection and kidney fat weights were collected, and longissimus muscle i.m. fat content was determined. Postmortem longissimus ...