bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of microbial protein flow from the rumen of sheep using microbial nucleic acid and urinary excretion of purine derivatives
Authors: Puchala R. , Kulasek G. W.
Published: March 2010

Two methods for estimating the flow of microbial protein synthesized in the rumen to the duodenum were compared: one uses microbial nucleic acids entering the duodenum, and the other uses allantoin excreted in the urine. Ten ewes were fitted with rumen and duodenum cannulae, as well as Foley catheters for collection of urine. The experiment was carried out using two series of treatments with two replications each. The ewes were randomly divided into five groups, which were assigned to one of five diets. (In the second series sheep were excluded from diets received in the first series.) The diets, differing in protein and energy content, were as follows: (1) low protein, low energy (LPLE); high protein, low energy (HPLE); (3) maintenance for protein and energy (MPME); (4) low protein, high energy (LPHE); and (5) high protein, high energy (HPHE). The rates of rumen microbial protein synthesis were 3.34, 7.00, 9.44, 4.47 and 13.44 g microbial nitrogen (N) d−1 for diets 1–5, respectively. Results indicated a high correlation between allantoin and total purine derivatives (allantoin, uric acid, xanthine and hypoxanthine) excreted in the urine and the amount of microbial nucleic acids entering the duodenum. A regression equation y = exp (0.830 + 2.089x), using allantoin N (g d−1) excreted in the urine, was proposed for estimating microbial N synthesis (g d−1) in the rumen. The ratio of allantoin N to creatinine N in the urine samples collected at 6-h intervals varied markedly. Key words: Sheep, rumen, microbial protein, allantoin, purine derivatives
Protein supplementation of high protein alfalfa silage fed to lactating dairy cows
Authors: Robinson P. H. , McQueen R. E. , Charmley E.
Published: March 2010

Eight multiparous cows in late lactation were fed alfalfa silage ad libitum twice daily and one of four supplements seven times daily. Supplements differed in level of barley (1.65 kg DM d−1) for the control diet and 2.40 kg DM d−1 for supplemented diets) and source of supplemental protein (control diet: none; blood meal diet: 100% blood meal; blood meal–casein diet: 50% blood meal and 50% casein; casein diet: 100% casein). Silage contributed approximately 90% of dietary dry matter (DM) in the control diet and about 85% in supplemented diets. Intake of DM and crude protein (CP) was lower for control than for supplemented diets. Intake of DM, organic matter, neutral detergent fibre and CP all increased linearly as casein replaced blood meal. Rumen concentrations of volatile fatty acids and pH suggested that fermentation was stimulated as casein replaced blood meal. Production of milk, protein and lactose was higher for supplemented cows. Control cows lost 0.66 kg d−1 of body weight, and this differed from the body weight change for supplemented cows. The overall performance of animals on supplemented diets was judged superior to that of animals on the control diet, and overall performance was also judged to have improved within supplemented diets as casein replaced blood meal. Data collected did not conclusively identify the mechanism for improved performance with casein; however, it seems likely that increased rumen microbial growth and passage to the lower digestive tract improved both energy and protein status. Key words: Dairy cows, protein, rumen, casein, blood meal
The effect of supplemental protein source on ammonia levels in rumen fluid and blood and intake of alfalfa silage by beef cattle
Authors: Nicholson J. W. G. , Charmley E. , Bush R. S.
Published: March 2010

Growing beef cattle fed legume silage were supplemented with urea, soybean meal, fishmeal or a barley-based control in two experiments. In the first experiment, the concentrates were fed before the silage and in the second the silage and concentrates were mixed at feeding. In exp. 1 there were no significant (P > 0.05) effects of CP supplement on feed intake, weight gains or feed efficiency, although animals fed fishmeal gained the most and those fed urea the least. Rumen fluid ammonia N (RFNH3-N) increased more after feeding urea and soybean meal than the control or fishmeal supplements. Blood urea N (BUN) levels changed in parallel with RFNH3-N levels but the magnitude of change was reduced to about half. Blood ammonia N (BNH3-N) levels showed statistically significant changes only with the urea supplement. Cattle fed urea took longer to consume their supplement than those fed the other supplements. In exp. 2 there was no effect of supplement on gains or feed conversion. Animals fed the control supplement consumed more dry matter than those fed fishmeal (P < 0.05). Cattle fed the control supplement had lower RFNH3-N and BUN than those fed the other supplements (P < 0.01) but differences among the sources of CP were small. The urea supplement resulted in a higher BNH3-N than the control or fishmeal supplements (P < 0.05). There was no apparent effect of treatment on blood glucose level in either experiment. It was concluded that cattle adjust their daily eating pattern to maintain BNH3-N levels within physiological limits; that intake of silage dry matter is limited by level of non-protein N and rumen degradable protein; and that provision of bypass protein can improve efficiency of feed conversion of high-silage diets even when depressing feed intake. Key words: Alfalfa, silage, protein supplement, nitrogen, intake
Effects of Isotricha, Eudiplodinium, Epidinium + Entodinium and a mixed population of rumen protozoa on the in vitro degradation of fish meal, soybean meal and casein
Authors: Jouany J. P. , Papon Y. , Lassalas B. , Ivan M.
Published: March 2010

An in vitro rumen simulation system was used to study effects of different types of rumen protozoa (Isotricha, Eudiplodinium, Epidinium + Entodinium, total mixed fauna) on the degradation of three feed proteins (fish meal, soybean meal, casein). A comparison of the fermentations containing different feed proteins was made with the control fermentations containing no added feed protein. Rumen contents used in the fermentations originated from defaunated sheep, or from sheep containing a single genus of protozoa (Isotricha spp. or Eudiplodinium spp.), a mixture of genera Entodinium spp. and Epidinium spp., or a total mixed fauna. In the presence of the total mixed fauna the degradabilities were 82.0, 51.1 and 26.5% for casein, soybean meal and fish meal, respectively. The absence of protozoa resulted in decreased (P < 0.05) degradation of fish meal and soybean meal but had no effect (P > 0.05) on casein. The single genus Isotricha spp. decreased (P < 0.05) the degradation of all three protein sources compared with the defaunated fermentations or those containing the total mixed fauna. Eudiplodinium did not affect (P > 0.05) fish meal or soybean meal, but it decreased (P < 0.05) the degradation of casein compared with the defaunated fermentations. However, when this organism was compared with the total mixed fauna the degradability of fish meal was not affected (P > 0.05), but that of soybean meal or casein was decreased (P < 0.05). The combination of Epidinium + Entodinium decreased (P < 0.05) the degradation of all three protein sources when compared with the total mixed fauna. When compared with the defaunated fermentations, the protozoal combination had no effect on fish meal (P > 0.05), but the degradation of soybean meal and casein was decreased (P < 0.05). Total volatile fatty acid (VFA) production was systematically reduced (P < 0.05) by the sole presence of Isotricha. The presence of other genera or the total mixed fauna had variable effects on the production of VFA or gases for different sources of protein. It was concluded that the mode of action of a single species or genus of protozoa on nitrogen metabolism in the rumen is different from that of total mixed fauna. The protozoal effect on protein degradation varies according to the type of protozoa present and the nature of the protein. Key words: Protozoa, in vitro degradation, fish meal, soybean meal, casein, rumen
The economics of hog production in Saskatchewan
Authors: Taylor J. S. , Brown W. J. , Kulshreshtha S. N.
Published: March 2010

A survey was conducted of Saskatchewan hog producers, and the data were classified by type and size of operation and degree of specialization. The objectives were to determine the physical and economic characteristics of hog farms, the costs of production, and whether costs decrease as size increases. Several trends were evident from a comparison of the various categories. The land base of hog producers with the highest level of specialization was significantly smaller than that of the less specialized farms. Hog producers have higher debt/asset ratios than the average of all farmers in Saskatchewan. In general, the total costs, both cash and non-cash, of hog production in 1988 were consistently greater than gross value of hog production and declined as herd size increased for both the farrow-to-finish and feeder-to-finish operations. Total cash costs also declined consistently as size increased for both the farrow-to-finish and feeder-to-finish operations, resulting in the larger size categories being able to cover cash costs with total value of hog production. Key words: Hog production, economics, Saskatchewan
Nutrient composition of four cuts of British Columbia grainfed veal
Authors: Nasvadi G. E. , Law C. , Mackey J. D. , Logue K. P.
Published: March 2010

The objective of this study was to determine the nutrient content of four cuts of BC grainfed veal. Rib chops, loin chops, rolled shoulder roasts and shanks were evaluated for proximate composition, cholesterol, eight minerals, thiamin, niacin and riboflavin. Both raw and cooked samples were examined as lean meat only and as total edible portion (lean plus fat). Nine samples were purchased for each treatment, homogenized, combined, and analyzed in triplicate. Results of nutrient analysis showed significant differences from US Department of Agriculture data. Raw and cooked lean-only and total edible samples were found to be lower in fat, sodium and niacin but higher in iron, potassium and copper. Phosphorus levels were lower in some but not all cuts, as were calcium levels. Thiamin levels were higher in some cuts. Values for moisture, ash, protein, cholesterol, zinc, magnesium and riboflavin were comparable to the U.S. data. Key words: Veal, Canadian veal, grainfed veal, nutrient composition
Serum growth hormone in and semen characteristics of proven AI dairy sires after administration of growth hormone-releasing factor
Authors: Kazmer G. W. , Zinn S. A. , Rycroft H. , Campbell R. M.
Published: March 2010

A growth hormone-releasing factor (GRF) analog was administered at 11, 22 and 33 μg 100 kg−1 to proven dairy sires of varying genetic merit for production traits. Administration of GRF increased mean GH concentrations, but the area under the response curve was not different among the three dosages, nor were there differences between genetic groups overall. However, the maximum GH concentration following the administration of 11 μg 100 kg−1 was greater among superior sires. None of semen motility, sperm concentration or total sperm were affected through an entire spermatogonic cycle. Key words: GRF, growth hormone, semen, dairy bulls
The role of growth hormones, ß-adrenergic agents and intact males in pork production: A review
Authors: Squires E. J. , Young L. G. , Hacker R. R. , Adeola O.
Published: March 2010

In this review, the physiological actions and efficacy of porcine somatotropin (PST) and β-adrenergic agonists as repartitioning agents and the use of intact males to improve the production efficiency of pork are discussed. The strengths and weaknesses of these methods are highlighted to provide insight into the potential benefits and problems from their commercial applications. The repartitioning agents alter nutrient metabolism in pigs, producing dramatic increases in lean- and decreases in adipose-tissue growth. The PST-induced decrease in adipose-tissue growth results from the reduction in rates of lipogenesis, glucose oxidation and insulin-stimulated glucose metabolism. In general, β-adrenergic agonists reduce the rate of lipogenesis through a reduction in the number of insulin receptors and in the binding of insulin to adipocytes. β-adrenergic agonists also stimulate synthesis of myofibrillar protein while depressing its degradation. The natural anabolic androgens produced in the testes account for the increased lean and decreased adipose tissue of intact males compared with castrates. The effects of androgens are mediated by their interaction with specific receptors in the target tissues. The main limitation to the use of intact male pigs is the occasional presence of objectionable boar taint in the meat. The causes of and methods for measuring boar taint are discussed in this review. The implementation of effective measures for measuring and controlling taint in pork will allow the pork industry to take advantage of the biological effects of the naturally produced androgens in intact males. Key words: Pigs, production efficiency, somatotropin, β-adrenergic agonists, intact males, review
The effect of cold adaptation on kinetics of insulin and growth hormone in heifers
Authors: Scott S. L. , Christopherson R. J.
Published: March 2010

Ten Holstein heifers 1 yr of age were housed in groups of five in temperature-controlled environmental chambers maintained at either 20 °C (warm environment) or − 17 °C (cold environment). Each heifer received an injection of insulin or growth hormone followed by frequent blood sampling. Plasma samples were analyzed for insulin, insulin-like growth factor I (IGF-1), growth hormone, glucagon, triiodothyronine, thyroxine and glucose. Basal plasma concentrations of all hormones except growth hormone and IGF-1 were elevated (P < 0.05) in the cold environment. Kinetic parameters for growth hormone and insulin were calculated using a two-pool model. Both the zero-time intercept and the rate constant for the slow component of growth hormone were lower (P < 0.05) in cold-adapted animals. The total turnover rate of growth hormone in both pools also tended to be reduced by cold adaptation (P < 0.07). The reduction in growth-hormone turnover may be related to the reduced average daily gains that were observed in the cold (P < 0.05). Plasma glucose concentration following both the insulin and growth-hormone injections was higher in the cold-adapted heifers (P < 0.001 and P < 0.05, respectively). The response of glucagon to insulin injection was greater in the cold (P < 0.05), as was the response of IGF-I to growth-hormone injection (P < 0.10). These cold-induced alterations in the endocrine system appear to be directed toward providing substrates, including glucose, for use in thermogenesis rather than growth. Key words: Cold adaptation, growth hormone, insulin, metabolic clearance rate, hormone kinetics, cattle
Chelated chromium for stressed feeder calves
Authors: Mowat D. N. , Chang X. , Yang W. Z.
Published: March 2010

Using crossbred calves obtained at feeder sales in Ontario, we evaluated two different sources of organically complexed chromium (Cr) for supplementing corn silage. A preliminary trial was conducted with 12 unstressed steers with or without 1 mg kg−1 chelated Cr during a 56-d growing period. Chelated Cr markedly decreased (P < 0.05) serum cortisol and glucose levels. In the main trial, 72 calves, weighing 233 kg, were randomly allotted to four treatments: control, high-Cr yeast, chelated Cr, and chelated Cr plus chelated Zn, Cu and Mn for the initial 7 d. Morbidity was determined by visual detection followed by rectal temperature checks. One third of morbidity occurred by day 12; two thirds, by day 16. High-Cr yeast tended to reduce morbidity; however, chelated Cr was more effective, resulting in 16.5% morbidity, or less (P < 0.05) than one third of the control. Daily gain was 41% higher (P < 0.05) with chelated Cr during the first 21 d after arrival, mainly due to the marked reduction in number of sick calves. During days 21–35, compensatory gain occurred with the morbid or antibiotic-treated calves. These data indicate that early (relative to peak morbidity) supplementation of stressed feeder calves with chelated Cr markedly reduces morbidity. Key words: Chromium, stress, calves, morbidity, cortisol, steers
Performance of growing steers fed either hay or silage supplemented with canola or fish meal
Authors: Seoane J. R. , Christen A-M. , Amyot A. , Petit H. V.
Published: March 2010

One hundred and eighty-six crossbred steers (194.4 ± 1.5 kg) were used to determine the effect of protein supplementation of medium-quality grass hay or silage on performance during wintering and compensatory growth during the grazing period. All steers received the hay or the silage ad libitum during the 182-d wintering period. They were also fed fixed quantities of one of three supplements: C, a control with no supplemental protein; CM, a canola meal; and FM, a fish meal containing supplements. Daily amounts of supplementation were fixed to supply to each steer the same amount of barley (85 g 100 kg−1 BW), of dry molasses (15 g 100 kg−1 BW) and of minerals, vitamins and Bovatec (10 g 100 kg−1 BW). The protein supplements CM and FM supplied the equivalent of 95 g of crude protein daily 100 kg−1 BW compared with 15 g 100 kg−1 BW for the control. Expressed as g kg−0.75, forage DM intake was 13.3% higher when fed as hay than as silage (P < 0.0001). Protein supplementation increased forage DM intake when fed as hay (P < 0.02) but not when fed as silage. Average daily gains (ADG) tended to be 5.8% higher for steers fed hay than for those fed silage (P = 0.06). Protein supplementation markedly improved ADG (P < 0.0001). When hay was fed, no differences were found in ADG between CM and FM supplementation; however, FM supplementation produced higher ADG than CM when silage was fed (P < 0.001). Feed efficiency was not affected by the type of forage fed, but it was higher for steers receiving protein supplementation (P < 0.001), the effect being more evident when the forage was fed as silage (P < 0.001) than when fed as hay (P = 0.07). Compensatory gains were obtained when the steers were taken out to pasture in early spring; steers fed silage, which obtained smaller ADG during wintering, showed higher ADG in pasture (P < 0.01). After 62 d grazing, the effect of protein supplementation during winter on body weight had almost disappeared. Key words: Protein supplementation, forages, cattle, growth
Growth of and digestibility by sheep fed diets comprising mixtures of grass and legume hay compared with those fed high-grain diets
Authors: Mir P. S. , Mir Z.
Published: March 2010

A digestibility trial with 24 mature wethers and a growth trial with 54 weaned lambs were conducted to evaluate the utilization of ground diets containing varying proportions of grass and legume hay relative to a 90% grain diet. The forage and grain diets were (1) 100% crested wheatgrass hay (CWG); (2) 75% CWGand25% alfalfa hay (AA); (3) 50% CWGand50% AA; (4) 25% CWGand75% AA; (5) 100% AA; and (6) 90% barley and 10% barley straw. Even though apparent digestibility of dry matter (DM) and fiber fractions of AA-containing diets was lower than that of the grain diet and the 100% CWG diet, weight gain was similar for all diets. Consumption of the grain and 100% CWG diet was lower (P < 0.05) than that of the 100% AA diet. Conversion of feed DM to liveweight gain for lambs fed the grain diet was only 4.9 and was lower (P < 0.05) than that of the forage diets, which ranged between 6.1 and 7.0. Dressing percentages of lambs at slaughter for the animals fed the grain and 100% AA diet were 45.0 and 43.2%, respectively, which were higher (P < 0.05) than that of animals fed the CWG-containing diets. These data suggest that inclusion of AA in CWG diets did not result in the expected positive associative effect on growth and feed efficiency in sheep. Key words: Sheep, crested wheatgrass, alfalfa, digestibility, growth
Effects of route and level of administration of procaine penicillin on the performance of broiler chickens
Authors: Proudfoot F. G. , Hamilton R. M. G. , Jackson E. D. , Hulan H. W. , Salisbury C. D. C.
Published: March 2010

Three experiments were done to determine the effects of administering procaine penicillin G to broiler chickens. In exps. 1 and 2, groups of 100 male, day-old chicks received one of the following treatments: (1) control, no penicillin; (2) 27.5 mg penicillin kg−1 added to the diet; (3) an amount of penicillin added to the drinking water equivalent to the amount consumed the previous day by the birds in group 2; and (4) same route of administration as group 3, except the dose was one half of the daily intake by group 3. In exp. 3, both female and male (1200 each) broiler chickens were given diets that contained either 0, 1.1, 2.2 or 4.4 mg kg−1 of penicillin. Each experiment was terminated when the birds were 42 d of age. Route or level of penicillin administration had no effect (P > 0.05) on mortality or feed conversion in any of the experiments. When the penicillin was added to the diets of the birds in exps. 1 and 2, their body weights at 21 and 42 d were 3.5 and 2.9%, respectively, less than those of the control group, but when it was administered via the drinking water the weights were 1–3% higher at these ages than those of the control group. Lower monetary returns (> 0.05) were obtained for the chickens in the penicillin groups than in the control group; these differences (6.6–15.6%) were due mainly to the cost of the antibiotic. In exp. 3, higher body weights (P < 0.05) at 21 d (3.6–5.4%) but not (P > 0.05) at 42 d were obtained for the birds given penicillin-supplemented diets than for those fed the control diets. No measurable levels of residue (limit of detection 100 μg kg−1) were found in samples of kidney, liver and muscle (breast and thigh) from birds in exp. 2, which had received 27.5 mg penicillin kg−1 for the 42-d experimental period. Key words: Broiler chickens, growth promoter, procaine penicillin, route of administration, residue levels
Beneficial effects of dietary ascorbic acid supplement on hens subjected to ochratoxin A toxicosis under normal and high ambient temperatures
Authors: Haazele F. M. , Guenter W. , Marquardt R. R. , Frohlich A. A.
Published: March 2010

Three experiments were conducted to study ochratoxin A (OA) toxicity and the effect of supplemental ascorbic acid (AA) in laying hens housed under two environmental temperatures. In exp. 1, 18 hens were divided into three groups of six hens and fed diets containing either 0, 1.7, or 3.1 ppm OA for 14 d. In exps. 2 and 3, 24 hens were randomly assigned to four dietary treatments in six replications. Treatments consisted of a control and three diets containing either 300 ppm AA, 3 ppm OA, or 300 ppm AA plus 3 ppm OA. Treatment diets were fed for 14 d following the feeding of the basal diet for 14 d. The test-period temperature was 25 °C in exp. 1 and 2 and 33 °C in exp. 3. In exp. 1, feeding OA at 1.7 ppm significantly (P ≤ 0.05) decreased feed intake and increased liver weights and eggshell elasticity. At 3 ppm, OA significantly (P ≤ 0.05) reduced feed intake, body-weight change and egg production, and increased shell elasticity. Similar trends were also observed in exps. 2 and 3 when laying hens were fed 3 ppm OA compared with those fed the control diet. An analysis of plasma constituents showed that OA also increased Cl− concentration and aspartate transaminase activity and decreased plasma Ca++ concentrations. Exposing hens to 33 °C (compared with 25 °C) appeared to aggravate the negative effects of OA. All the negative effects of OA, apart from body-weight changes, reductions in feed intake, and increases in eggshell elasticity at 33 °C, were either moderated or significantly (P ≤ 0.05) reversed by dietary AA supplementation. The results suggest that some of the detrimental effects of OA in the diet of the laying hen can be counteracted by dietary supplementation of AA. Key words: Ochratoxin A, toxicity, ascorbic acid, hen, temperature
Short-term consequences of a sudden increase in feed allowance in broiler breeder hens
Authors: Robinson F. E. , Yu M. W. , Lupicki M. E. , Hardin R. T.
Published: March 2010

The immediate effects of a sudden increase in feed allowance on selected morphological and reproductive traits were investigated in broiler breeder hens at 44 wk of age. Fifty Indian River hens were individually caged at 40 wk of age. Prior to 40 wk of age the birds had been feed restricted in accordance with the breeder's recommended feeding program. Five treatment groups (T1, T2, T3, T4 and T5) of 10 birds each were formed based on level of feeding and duration of exposure to such feeding. T1, T2 and T3 birds were feed restricted (128 g of daily feed bird−1) from 40 to 44, 40 to 45 and 40 to 46 wk of age, respectively. T4 and T5 birds were also feed restricted at the same level as the other groups to 44 wk of age and then were full fed from 44 to 45 and 44 to 46 wk of age, respectively. To facilitate study of follicular recruitment and yolk deposition, hens were fed 10 g of oil-soluble red and black dyes, daily, on alternate days, beginning at 42 wk of age. Birds were killed on day 0 (44 wk; T1), day 7 (45 wk; T2, T4), or day 14 (46 wk; T3, T5). Full-fed hens consumed approximately 100 g more feed per day than did feed-restricted hens, with marked increases in feed intake on the first day of full feeding. After 7 d of ad libitum feeding, significant increases were seen in body weight, liver weight, percent liver fat, plasma lipid concentration, ovary weight, and the incidence of a double hierarchy (simultaneous development) of large follicles. After 14 d of ad libitum feeding, significant increases were also observed in absolute fat-pad weight, individual weights of the four largest preovulatory follicles and number of large preovulatory follicles. The increased number of large follicles in the ovary was not associated with any change in egg production. It is apparent that the morphological disruptions associated with overfeeding broiler breeder hens can be identified within 7 d of full feeding, while any effects on egg production are not seen within the first 14 d of ad libitum feeding. Key words: Broiler breeder, feed intake, yolk deposition, ovarian morphology, egg production
Nutrient composition and sensory characteristics of Canadian grain-fed veal cutlets
Authors: Nasvadi G. E. , Law C. , Mackey J. D. , Logue K. P.
Published: March 2010

Nutrient analysis indicated grain-fed veal is significantly higher in polyunsaturates, iron and copper and lower in total lipids, sodium, potassium and niacin than given by U.S. data. Sensory evaluation by trained panelists revealed panfried samples were significantly more tender and more juicy and had a more intense, meaty flavor than braised samples. Key words: Veal, Canadian veal, grain-fed veal, Canadian grain-fed veal, nutrient composition, sensory evaluation
Rate of metabolic heat production and rectal temperature of steers exposed to simulated mud and rain conditions
Authors: Degen A. Allan , Young Bruce A.
Published: March 2010

Rate of metabolic heat production and rectal temperature were measured in steers (n = 4) standing in 0 (control), 10, 25 and 50 cm of water and in steers standing in 50 cm of water that were also showered. The measurements were done at air temperatures of 0 and 15 °C. There was no significant difference in the rate of metabolic heat production of the steers due to the two air temperatures. However, there was an increase in the rate of metabolic heat production of steers that stood in 50 cm water and were showered; by 39–56% over control steers. Rectal temperature was not affected by either air temperature or treatment. Key words: Steers, mud, rain, heat production, rectal temperature
Within-herd evaluation of sow reproductive traits
Authors: Schaeffer L. R. , Kennedy B. W. , Kemp R. A.
Published: March 2010

A procedure for computing within-herd genetic evaluations of sows and boars for the reproductive trait of total number of pigs born that incorporates national genetic evaluations of males and females is described. National genetic evaluations and solutions for litter effects associated with a particular herd are weighted according to the amount of national information on each into a set of mixed model equations for that herd. Computer programs were written to run on a microcomputer and to handle a herd with up to 2000 sows. The concept is to provide interim genetic evaluations for total number born, as is currently done for growth rate and backfat thickness, in a timely manner for herd owners, and such that the evaluations make use of and can be compared with national evaluations. The programs were field-tested in five Ontario herds and evaluations of 1271 animals were examined. Correlations were 0.91 or greater between the interim evaluations and subsequent national evaluations and were 0.93 or greater between the interim evaluations and the previous national evaluations. Key words: Swine, reproductive traits, genetic evaluation, animal models
Hematological and biochemical changes following an acute stress in control and somatostatin-immunized pigs
Authors: Dubreuil Pascal , Couture Yvon , Farmer Chantal , Petitclerc Denis
Published: March 2010

Sixteen Yorkshire pigs (49 ± 2 kg BW) were used. Half (4M, 4F) were immunized against somatostatin (SRIF-IMM) and the other half against its conjugated protein (BSA-IMM) at 10, 12 and 14 wk of age. At the age of 19 wk, half the animals were subjected to 5 min of snare restraint, followed 2 d later by the other half; on both days the unstressed animals were used as controls. On both sampling days, jugular blood samples were collected from all pigs via catheters. Antibody titers against SRIF at 1:150 serum dilution were 0.5 ± 0.1% and 54.5 ± 4.9% in BSA-IMM and SRIF-IMM pigs, respectively. Gender, day of sampling and SRIF immunization had no influence (P > 0.05) on any of the measured variables, but a significant interaction (P < 0.01) between stress and the time of sampling was observed. At 2 min, increases (P < 0.05) in hematocrit (26%), haemoglobin (18%) and total protein (10%) were observed in stressed animals. Values returned to prestressed levels within 30 min after cessation of stress. The total leukocyte count increased (P < 0.05) by 10–20% in all samples following stress, while the lymphocyte count decreased by 15% and the neutrophil count increased by 36% over time. Maximal increases in serum concentrations of Na (3%), K (23%), Ca (11%), P (12%) and cholesterol (8%) were seen as soon as 2 min post-stress while FFA values decreased (25%) 20 min following the induction of stress. An 80% increase in glucose concentration was seen at 10 min post-stress but values returned to baseline levels after 4 h.In conclusion, the acute stress of snare restraint produced numerous changes in blood variables as early as 2 min post-stress, regardless of gender and SRIF immunization status. Therefore, special attention should be given to the methodology of blood sampling and to the level of stress imposed on the animals during the blood sampling before drawing any conclusion based on hematological or biochemical values. Key words: Pigs, stress, immunization, somatostatin, hematology, biochemistry
The influence of growth hormone injections either pre- or post-breeding on the reproductive performance of sows and gilts
Authors: Kirkwood R. N. , Peacock A. J. , Thacker P. A.
Published: March 2010

Two experiments were conducted to examine the effect of porcine growth hormone (pGH) injections on reproductive performance of swine. In exp. 1, 62 mixed-parity Yorkshire × Land-race sows received 6 mg of pGH either daily (n = 20) or on alternate days (n = 20) from 2 d preweaning until 4 d postweaning, with remaining sows (n = 22) serving as controls. A single blood sample was obtained from each sow prior to the first injection, at weaning and at 4 d postweaning and samples were assayed for insulin, IGF-I and triiodothyronine (T3). Serum insulin tended (P = 0.1) to be higher at 4 d postweaning in sows injected daily but was unaffected by injections on alternate days. However, T3 and IGF-I were higher (P < 0.05 and P < 0.01, respectively) in both pGH groups compared with controls. No significant effects of either pGH treatment were apparent for the mean remating interval or subsequent litter size but the rebreeding interval was less variable (P < 0.01) for sows injected on alternate days. In experiment two, 40 Yorkshire × Landrace gilts received either 6 mg of pGH or vehicle on alternate days from days 5 to 21 of pregnancy. Single blood samples were obtained on days 5, 10, 15 and 20 of pregnancy and were assayed for insulin, IGF-I, T3 and progesterone. The injection of pGH had no effect on serum insulin or progesterone, caused a mild increase (P = 0.15) in serum T3 and increased (P < 0.01) serum IGF-I. There was no effect of treatment on pregnancy rate, ovulation rate, number of embryos or on embryo weight or crown-rump length. From the data of both experiments, we conclude that the injection of pGH either pre- or post-breeding will not improve the reproductive performance of swine. Key words: Growth hormone, IGF-I, reproduction, swine
Growth and growth hormone kinetics in Holstein steer calves
Authors: Mears G. J. , Schaalje G. B.
Published: March 2010

Average daily gain (ADG), basal plasma growth hormone (GH) concentration, and plasma GH kinetics following a bolus injection of GH were determined at birth and at 75, 150, 250, 350 and 450 kg body weight in 19 Holstein steer calves. From 100 kg body weight, calves were fed one of three diets: 85% grass hay and 15% concentrate; 85% grass hay and 15% concentrate with rumen undegradable protein (formaldehyde-treated canola meal); and, 85% concentrate and 15% grass hay. Addition of rumen undegradable protein to the hay-based diet did not (P > 0.05) increase ADG. However, ADG were higher (P < 0.001) for calves on the 85% concentrate diet. Calf basal plasma GH concentrations, plasma GH clearance rates, and GH secretion rates were not affected by either diet or ADG adjusted for the effect of diet. In contrast, body weight had a large effect on basal plasma GH concentration and plasma GH kinetics. As body weight increased, basal plasma GH concentration and GH half-life decreased. Growth hormone steady state volume of distribution, metabolic clearance rate and secretion rate per kg of body weight all decreased as calves became heavier. Key words: Steer growth, growth hormone, GH, basal GH, clearance, secretion
The effect of deworming naturally infected heifers on liveweight gain, reproductive performance and fecal egg counts
Authors: Boyles S. L. , Johnson L. J. , Slanger W. D. , Kreft B. J. , Kirsch J. D.
Published: March 2010

Twenty-six of 52 heifers with an average liveweight of 318 kg were dewormed by intraruminal injection of oxfendazole and placed in drylot on 31 January. The other 26 animals served as controls. All heifers were pastured starting on 14 June and the treatment heifers were dewormed in the same manner as at the start of the experiment (31 January) on 1 July and 31 July. The groups started out with similar total worm eggs per gram of fecal sample, but the dewormed heifers had fewer counts each month thereafter. The drylot average daily gain of the treated heifers was higher (P = 0.01) and less variable (P = 0.12) and by 29 May these animals were heavier by 11.7 kg (P = 0.10). The treated animals did not gain as fast on pasture (P = 0.20), but the gain continued to be less variable (P = 0.09). Age at puberty was not different. Number of open heifers in the treated group was 4 vs. 15% for the control group (P = 0.18). Deworming by intraruminal injection resulted in faster feedlot gains, more uniform gains during both drylot and pasture, reduced parasites and no abscess at injection sites. Key words: Anthelmintics, oxfendazole, cattle, heifers
Antibody responses of growing beef cattle fed silage diets with and without selenium supplementation
Authors: Nicholson J. W. G. , Bush R. S. , Allen J. G.
Published: March 2010

The relationships between blood Se levels and glutathione peroxidase (GSH-Px) activities and the ability of cattle to produce antibodies in response to antigen challenges with sheep red blood cells (SRBC) and ovalbumin (OA) were examined in a two-phase experiment with yearling beef cattle. There were no treatment effects on weight gains, feed intake or efficiency of feed conversion in either phase. In phase 1, cattle fed the unsupplemented control diet had lower (P ≤ 0.05) blood Se levels and GSH-Px activities by week 8 than cattle fed Se-fertilized forage, but neither was different (P > 0.05) from those of cattle fed Se-enriched yeast or inorganic Se. Antibody titers resulting from injection of SRBC at week 4 of the experiment peaked about 3 wk after injection, then declined. Differences due to Se treatment were small. The same animals were used in phase 2, where half of the animals on each of the four treatments of phase 1 were fed a supplement with Se-enriched yeast and the other half were fed an unsupplemented control. Differences in blood Se levels and GSH-Px activities due to phase-1 treatments persisted throughout phase 2. Differences due to phase-2 treatments were apparent after 9 wk. The cattle were challenged with OA at week 12 and at week 17 with both OA and SRBC. Differences in antibody titer due to Se treatment were small but tended to be higher (P > 0.05) in the Se-supplemented cattle. These results support the suggestion that blood Se levels over 100 μg L−1 are needed to maintain optimum immunocompetence. Key words: Selenium, glutathione peroxidase, immunocompetence, cattle, antibody
The effect of immaturity and harvesting method on the yield and properties of barley straw
Authors: Kernan J. A. , Spurr D. T. , Crowle W. L. , Sumner A. K.
Published: March 2010

The effects of immaturity and harvesting method of barley grain on residue yields and nutritive properties were investigated at Saskatoon, Saskatchewan in 1983, 1984, and 1985. Three barley (Hordeum vulgare L.) cultivars (Betzes, Harrington, and Scout), were harvested at kernel moisture contents (KMC) ranging from 56% to 12% using the traditional swathing/air drying/threshing method and the direct combining/artificial drying method. Residue nutritive changes that resulted from varying swathing height and from ammonia treatment were also studied. Harvesting immature barley increased the yield and nutritive value of the residue but reduced grain yield and quality. In 1984, direct combining at 35% KMC yielded 40% more residue but only 5% less grain than swathing. Nutritive value of the residue, determined by equivalent crude protein (ECP) and in vitro organic matter digestibility (IVOMD), increased with higher KMC at harvest and was usually greater for direct combined than for swathed residue. Harvesting at a higher stubble height in 1985 increased residue nutritive value. Ammonia treatment of residue from all KMC's and harvesting methods increased ECP by an average of 77% in 1983 and 144% in 1984, and the IVOMD by 19% both years. KMC at harvest had little effect on improved nutritive value resulting from ammoniation. Key words: Barley, harvesting method, yield, immaturity, nutritive value, kernel moisture content, residue, straw, protein, digestibility
Harvest alternatives to reduce the alkaloid content of reed canarygrass forage
Authors: Tosi H.R. , Wittenberg K.M.
Published: March 2010

Growing conditions favorable to the accumulation of alkaloids in reed canarygrass (RCG) can result in gramine concentrations exceeding tolerable levels for grazing animals. Alternative harvest techniques for this forage material include silage and hay production. A replicated trial with 22-L mini-silo units showed that gramine and hordenine concentrations in RCG herbage do not decrease as a result of ensiling. Reed canarygrass regrowth cut and field-wilted to 74.9% dry matter (DM) had reduced (P < 0.05) gramine and hordenine concentrations. A second trial using RCG regrowth, dried under laboratory controlled conditions also showed decreases (P < 0.05) in forage gramine and hordenine concentrations. Hay baled at 73.1% DM and stored for 32 d had a further reduction (P < 0.05) in hordenine concentrations. No change in gramine concentration was observed during storage of forage as hay, but this may be due to low initial levels in the baled hay. An intake and digestibility study with growing ram lambs showed DM and neutral detergent fiber digestibilities for the β-carboline and tryptamine free cultivars, Rival and Venture, to be comparable to timothy, cultivar Champ, when regrowth was cut at the same stage of maturity. This study suggests that RCG forage considered to be too high in gramine for grazing animals could be harvested as hay to reduce forage alkaloid concentrations. Key words: Reed canarygrass, gramine, hordenine, silage, hay
Variation in the mineral content of cereal grains grown at selected locations throughout Manitoba
Authors: Boila R. J. , Campbell L. D. , Stothers S. C. , Crow G. H. , Ibrahim E. A.
Published: March 2010

Cultivars of wheat, barley, oats and rye were grown at 12 locations throughout Manitoba over 2 consecutive years. The concentrations of macrominerals Ca, P, Mg, K and S, and of microminerals Cu, Zn, Mn and Fe in the grains were determined and found to differ (P < 0.05) among cultivars of each grain. These differences among cultivars were considered to be minor, however, when comparisons between mineral concentrations and dietary requirements of economically important livestock were made. Location and year of growth (environmental variance) were factors affecting the concentrations of Cu, Zn and Mn, accounting for 72–96% of the total variance in these mineral concentrations (total variance = environmental variance plus cultivar × environmental variance). The concentrations of macrominerals in cultivars of wheat or barley differed among locations and year of growth, with cultivar × environment effects accounting for 25–50% of the total variance observed, except for S where these effects accounted for 86–87% of the total variance; this percentage was lower for oats and rye where a lower number of cultivars or locations was evaluated. Variation in mineral concentrations in the four Manitoba-grown grains was often considerable with coefficients of variation ranging from 8.5 to 40.1%. With all cereal grains, supplemental Ca, P, K, S, Cu, Zn, and Mn would be required to insure adequate dietary intakes for ruminants in general and Mg for lactating dairy cows, with Ca, P, Zn and Fe required for swine and poultry, Mn required for poultry and K required for some classes of poultry. Supplemental Cu would be required with wheat-based diets fed to swine and poultry. Key words: Minerals, wheat, barley, oats, rye, Manitoba
Effects of growth hormone on FSH, insulin and triiodothyronine-mediated estradiol production by granulosa cells from prepubertal gilts in vitro
Authors: Rajkumar K. , Kirkwood R. N. , Thacker P. A.
Published: March 2010

Three experiments were performed using porcine granulosa cells from medium-sized follicles (2–4 mm) cultured in serum-free medium at a density of 2 × 106 viable cells per well. Cells were cultured in the presence of combinations of FSH, insulin, growth hormone (GH) and triiodothyronine (T3), and subsequent estradiol (E2) production was monitored. In the presence of insulin, a dose-dependent E2 production response to FSH was observed (exp. 1). However, in all experiments, E2 production was reduced (P < 0.05) by the inclusion of GH in the media. The inclusion of T3 augmented the E2 response to insulin, an effect attenuated by GH. We conclude that GH, at the dose employed, is inhibitory to E2 production in granulosa cells of medium-sized ovarian follicles. Key words: Granulosa cells, growth hormone, estradiol
Effects of mammary-derived growth inhibitor on proliferation of bovine myoepithelial cells in vitro
Authors: Zavizion B. , Politis I. , Gorewit R. C.
Published: March 2010

The effects of mammary-derived growth inhibitor (MDGI) on proliferation of bovine mammary myoepithelial cells was examined. MDGI (10 ng L−1) inhibited myoepithelial proliferation. The specificity of the MDGI effect was tested with anti-MDGI rabbit serum which was shown to neutralize MDGI and abolish the effect of MDGI on myoepithelial cell proliferation. Key words: Bovine, MDGI, myoepithelial cells
Evaluation of the growth performance and carcass characteristics of commercial pigs produced in Quebec
Authors: Hammell K. L. , Laforest J. P. , Dufour J. J.
Published: March 2010

Data for a total of approximately 2900 commercial pigs tested in 12 trials from 1987 to 1990 at the Beaumont test station in Quebec were used to determine the effect of sex, sire breed, cross type and parity number of the dam on growth performance and carcass characteristics. Pigs were housed four to a pen and were fed commercial diets. Feed intake and growth rate were measured during the test, and carcass measurements were taken at slaughter and at 24 or 72 h following slaughter. Castrated males ate more per day, had a better gain and reached slaughter weight (96.4 ± 5.6 kg) at a younger age than gilts. Gilts had a better carcass yield and were leaner than castrated males. Commercial pigs sired from Duroc or Duroc–Hampshire boars had a growth performance superior to that of pigs sired by Landrace, Yorkshire or Hampshire boars. Progeny from Duroc or Duroc–Hampshire boars also produced carcasses with less loin fat, a thicker loin muscle, a higher estimated lean yield and a better classification index. Pigs from three-way crosses had a higher average daily gain and a better feed conversion than pigs from other types of crosses (single, backcross, four-way, synthetic and purebred), and they reached market weight at a younger age. Most carcass characteristics were also affected by the type of cross, but no specific type of cross was clearly superior to the others for the various variables studied. An increase in parity number of the dam caused a gradual decrease in growth performance, except for pigs from parity six, which presented the best results. There was also a linear decrease in loin muscle thickness, estimated lean yield and classification index and a linear increase in loin fat thickness with increase in parity number of the dam. Key words: Pig, growth performance, carcass composition
Growth and serum thyroid hormone and insulin-like growth factor I (IGF-I) responses to natural passive immunization against somatostatin in the lamb
Authors: Kessel A. G. Van , Korchinski R. S. , Laarveld B.
Published: March 2010

The colostral transfer of maternal humoral immunity against somatostatin (SRIF) was examined as a mechanism of improving growth performance of the lamb. Lambs were the offspring of 15 ewes actively immunized against an SRIF-ovalbumin conjugate (SI; 14 male, 7 female) and of 13 ewes actively immunized against ovalbumin (C; 10 male, 5 female). At 5 d of age, lambs were removed from the ewes and received a 50:50 mixture of whole cow's milk and milk replacer ad libitum. At 46 d of age lambs were weaned and provided with an 18% crude protein pelleted grower ration ad libitum. Lamb weight was recorded and blood samples were obtained at regular intervals from 5 to 46 d of age and at 102 d of age. From 5 to 46 d of age, immunization increased growth rate of male (P < 0.001) but not female lambs. Serum thyroxine (T4) was lower (P < 0.001) in male than in female lambs. Serum triiodothyronine (T3) was higher (P < 0.05) in SI male than in C male lambs. SI female lambs initially demonstrated higher serum T3 levels than C female lambs, but this effect reversed after 19 d of age. Serum insulin-like growth factor I (IGF-I) levels were higher (P = 0.08) in SI than in C lambs without significant influence of sex. From 46 to 102 d of age, somatostatin immunization increased growth rate of male (P = 0.08) but not female lambs. Serum levels of T4, T3 and IGF-I at 102 d of age were not affected by immunization. Passive immunization against SRIF through colostral transfer of immunity may improve growth rate of the lamb via an influence on thyroid hormone metabolism. Key words: Sheep, somatostatin, immunoneutralization. growth, thyroid, IGF-I