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B J Kerr

Publications and source records attributed to B J Kerr.

45 records · Page 3Linked to original sources
PubMed1995

Effect of feeding reduced protein, amino acid-supplemented diets on nitrogen and energy balance in grower pigs.

Two experiments were conducted to determine the effect of feeding reduced CP, amino acid (AA)-supplemented diets on the nitrogen (N) and energy (E) balance of grower pigs. In Exp. 1, 24 barrows (22.2 kg BW) were fed corn-soybean meal (C-SBM) diets containing either 16% CP, 12% CP, or 12% CP supplemented with lysine (LYS), tryptophan (TRP), and threonine (THR). After 6 d of adaptation to the diets and feeding frequency, a 5-d N and E balance trial was conducted. Supplementation of the 12% CP diet with LYS, TRP, and THR improved N retention ( P < .01) but failed to improve N retention to the level attained by pigs fed the 16% CP diet (P < .01). Efficiency of N retention was similar between pigs fed the AA-supplemented 12% CP diet and pigs fed the 16% CP diet (P > .10). Energy retention was increased by AA-supplementation of the 12% CP diet ( P < .10) to a level higher than that of pigs fed the 16% CP diet (P < .01). In Exp. 2, 60 barrows (21.7 kg BW) were fed one of the following diets: 16% CP; 12% CP diet supplemented with indispensable AA (IDAA) to simulate the 16% CP diet; 12% CP supplemented with LYS, TRP, THR, and dispensable AA N (DAAN); 12% CP supplemented with LYS, TRP, and THR; or a 12% CP negative control diet. After 6 d of adaptation to the diets and feeding frequency, a 5-d N and E balance trial was conducted. Nitrogen retention was improved (P < .01) by supplementing the 12% CP diet with LYS, TRP, and THR but remained inferior (P < .01) to that obtained when pigs were fed the other three diets. Pigs fed the 12% CP diet with LYS, TRP, THR, and DAAN supplementation retained less N (P < .07) than pigs fed the 16% CP but retained an amount similar (P > .10) to pigs fed the 12% CP diet with IDAA and DAAN supplementation. Pigs fed the 12% CP diet with LYS, TRP, and THR supplementation exhibited the highest efficiency of N retention (P < .01). Pigs fed the 12% CP diet supplemented with LYS, TRP, THR, and DAAN retained more (P < .01) E than pigs fed the 12% CP diet supplemented with IDAA and DAAN and more (P < .07) E than pigs fed either the 12% CP diet supplemented with LYS, TRP, and THR or the unsupplemented 12% CP diet. Pigs fed the 16% CP diet retained more (P < .06) E than pigs fed the 12% CP diet with IDAA and DAAN supplementation. Although the data show that the efficiency of N retention is greatest when LYS, TRP, and THR are supplemented to the 12% CP diet, maximal N retention is achieved only when the 12% CP diets are supplemented with both the deficient AA and a source of N for dispensable AA synthesis.

Amino Acids↗
PubMed1995

The effect of dietary lysine on growth, carcass composition, and lipid metabolism in high-lean growth gilts fed from 72 to 136 kilograms.

One hundred fourteen high-lean growth gilts (72.5 kg BW) were used to determine the apparent digestible lysine requirement for maximum growth performance and carcass protein deposition rate from 72.5 to 136 kg BW. The experiment was a randomized complete block design with initial BW used to establish blocks. Six dietary treatments were included, ranging from .44 to .94% (.10% increments) apparent digestible lysine (.62 to 1.13% total lysine) with six replicate pens per treatment and three pigs per pen. Pig weights and feed consumption were collected weekly to determine ADG, ADFI, and gain: feed ratio (G/F). Six gilts were slaughtered at 72.5 kg BW to determine initial carcass composition. When the mean weight of pigs in a pen reached 104 or 136 kg, one pig per pen was selected (closest to 104 or 136 kg, respectively) and slaughtered for determination of carcass measurements and composition. From 72.5 to 104 kg and from 104 to 136 kg, ADG and G/F increased (linear, P < .05; quadratic, P < .10, respectively) as apparent digestible lysine increased. From 72.5 to 136 kg, G/F increased (quadratic, P < .10) as apparent digestible lysine increased. Average backfat thickness and longissimus muscle area at 104 kg were not influenced (P > .10) by apparent digestible lysine. However, average backfat thickness increased (quadratic, P < .05) with increasing digestible lysine for gilts slaughtered at 136 kg. Carcass CP accretion was not influenced (P > .10) from 72.5 to 104 kg but tended to increase (linear, P < .10) from 72.5 to 136 kg as digestible lysine increased. Plasma and longissimus muscle cholesterol concentrations were unaffected (P > .10) by increasing digestible lysine. These results suggest that high-lean growth gilts require greater dietary lysine than current NRC (1988) estimates to maximize ADG, G/F, and carcass CP accretion from 72.5 to 104 and from 104 to 136 kg.

Animals↗
PubMed1995

Effect on performance and carcass characteristics of nursery to finisher pigs fed reduced crude protein, amino acid-supplemented diets.

An experiment was conducted to evaluate the effect of feeding reduced CP, amino acid (AA)-supplemented diets to pigs from weaning to slaughter weight on growth performance and carcass characteristics. Pigs were fed a 19%-16%-14% CP starter-grower-finisher high-CP sequence of diets, respectively, or a sequence of diets reduced in CP by 4 percentage units (3 percentage units in the finisher period) with or without lysine (LYS), tryptophan (TRP), and threonine (THR) supplementation. Pigs fed the low-CP diets without AA supplementation grew more slowly, were less efficient in feed conversion, and developed carcasses that contained a smaller longissimus muscle, greater, average backfat depths, and a lower percentage of muscle compared with pigs fed the high-CP sequence of diets (P < .01). The reduction in growth performance, feed efficiency, longissimus muscle area, and percentage of muscle in pigs fed the low-CP diets was alleviated by LYS, TRP, and THR supplementation (P > .10). Although pigs fed the low-CP diets supplemented with AA had reduced average and 10th rib backfat depths compared with pigs fed the unsupplemented, low-CP diets (P < .01), these fat depth measures remained greater (P < .05) than those of pigs fed the high-CP diets. Feeding reduced dietary CP, regardless of AA supplementation, resulted in reduced heart (P < .10) and liver weights (P < .01) compared with feeding the high-CP diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1994

Influence of dietary lysine on growth and carcass composition of high-lean-growth gilts fed from 34 to 72 kilograms.

One hundred eight high-lean-growth gilts (34.4 kg BW) were used to determine the dietary lysine requirement to maximize growth, carcass characteristics, and protein accretion from 34 to 72.5 kg BW. The experiment was a randomized complete block design; initial BW served as the blocking factor. Six dietary treatments were included, ranging from .54 to 1.04% (.10% increments) digestible lysine (.69 to 1.25% total lysine). Pigs were housed in pens of three, with six replicate pens per treatment. Pig weights and feed consumption were collected weekly to calculate ADG, ADFI, and gain:feed (G/F). Initially, five pigs were slaughtered to determine baseline carcass composition. When the mean weight for pigs in a pen reached 55 and 72.5 kg, one pig per pen was randomly selected and slaughtered for carcass measurements. The right side of each carcass was ground twice and sampled to determine carcass composition and tissue accretion rates. Average daily gain was increased by dietary lysine from 34 to 55 kg (linear, P < .01), from 55 to 72.5 kg (linear, P < .10), and from 34 to 72.5 kg (linear, P < .01). Although ADFI from 34 to 55 and from 55 to 72.5 kg was not influenced by dietary lysine, ADFI for the entire experiment tended to decrease (quadratic, P < .10) as digestible lysine increased. Increased dietary lysine resulted in improved G/F from 34 to 55 kg (linear, P < .01) and from 55 to 72.5 and 34 to 72.5 kg (quadratic, P < .01). Average backfat thickness was not influenced by dietary lysine at 55 kg but decreased (linear, P < .05) as dietary lysine increased at 72.5 kg. At 55 kg, longissimus muscle area was larger (linear, P < .05) for gilts fed increased digestible lysine. However, longissimus muscle area was similar for all treatments at 72.5 kg. Gilts fed increased digestible lysine had greater CP accretion from 34 to 55 kg (linear, P < .01), 55 to 72.5 kg (linear, P < .05; quadratic, P < .10), and from 34 to 72.5 kg (quadratic, P < .05). Based on the feed intake observed in this study, the high-lean-growth gilt requires at least 22 g/d total lysine intake from 34 to 72.5 kg to maximize CP accretion.

Adipose Tissue↗
PubMed1994

Influence of amino acid supplementation of low-protein diets and metabolizable energy feeding sequence on performance and carcass composition of toms.

An experiment was conducted to determine the influence of essential amino acid (EAA) supplementation of low-protein diets and of MEn feeding sequence on performance and selected carcass characteristics of turkey toms. Feeding diets containing 93 or 100% of the protein and 100% of the EAA concentrations recommended by NRC (1984) or a diet containing 93 and 107% of the recommended protein and EAA concentrations, respectively, had no effect on BW or feed efficiency of toms at 104 or 117 d of age. Dietary protein-EAA concentrations also had no effect on carcass and breast meat yields or proximate composition of carcasses at 105, 112, or 118 d of age, irrespective of MEn feeding sequence. Feeding diets supplying 108% of the MEn concentrations (MH) listed by NRC from 41 to 104 d improved BW (P < .02) and feed efficiency (P < .01) as compared with feeding 102% (M) of the MEn listed by NRC, but only the improvement in feed efficiency was evident at 117 d. Feeding diets supplying 108% MEn from 41 to 104 d, followed by the 102% MEn diet from 104 to 117 d (MHM), resulted in the same 117-d BW and feed efficiency as feeding the MH MEn sequence from 41 to 117 d. Metabolizable energy feeding sequence had no consistent effect on carcass or breast meat yields. Feeding the MHM sequence decreased (P < .05) fat pad and carcass fat of toms processed at 105, 112, and 118 d, compared with the MH feeding sequence. However, fat pad and carcass fat of toms fed the MHM MEn sequence generally exceeded those of toms fed M MEn diets from 1 d to time of processing.

Amino Acids, Essential↗
PubMed1987

Squamous cell carcinoma of the esophagus in association with long-term immunosuppressive therapy.

An increased risk of skin and lymphoreticular malignancies is well documented in renal transplant patients receiving long-term immunosuppressive therapy, but squamous cell carcinoma of the esophagus is rare. We have reported the first case in the English literature in which there is a strong association between long-term immunosuppressive therapy and squamous cell carcinoma of the esophagus. It occurred in a 28-year-old white man ten years after cadaveric kidney transplantation.

Adult↗
PubMed1987

Limiting amino acids in an 11% crude protein corn-soybean meal diet for growing pigs.

Three experiments were conducted to test the hypothesis that methionine, isoleucine, valine or nitrogen either singly or in combination are limiting in an 11% crude protein, lysine-tryptophan-threonine-supplemented, corn-soybean meal diet for growing pigs. A 16% crude protein diet was used as a positive control in each experiment and all amino acid additions were made, at a minimum, to equal requirements. Average initial weights were 21.3 kg, 23.0 kg and 19.1 kg in Exp. 1, 2 and 3, respectively. The experiments averaged 4 wk in duration. In Exp. 1 and 2, neither the addition of glutamic acid as a source of nitrogen, nor methionine to the 11% diet resulted in any improvement (P greater than .20) in rate or efficiency of growth. Addition of the combination of isoleucine and valine to the 11% diet resulted in an increase (P less than .05) in both growth rate and feed efficiency to a level not different (P greater than .20) from that of the pigs consuming the positive control diet. The addition of valine to the 11% crude protein diet with supplemental lysine, tryptophan and threonine (Exp. 3) caused an improvement in daily gain (P less than .05) but not feed efficiency (P greater than .10). Isoleucine addition tended to reduce pig performance. The results of these experiments suggest that an 11% crude protein, corn-soybean meal diet fortified with lysine, tryptophan and threonine is not limiting in sulfur amino acids or nitrogen. Valine may be the only limiting amino acid.

Amino Acids↗
PubMed1985

The efficacy of salinomycin as a growth promotant for swine from 9 to 97 kg.

Six trials involving 586 pigs initially averaging 9 kg were conducted at three locations (two trials/location) to evaluate the effects of the dietary addition of 0, 27.5, 55, 82.5 and 110 ppm of a monocarboxylic polyether antibiotic, salinomycin, on feed intake, growth rate and feed efficiency of swine fed corn-soybean meal-based diets. Over the total trial (9 to 97 kg), quadratic improvements in gain (P less than .01) and feed:gain (P less than .04) occurred with increasing level of salinomycin, but feed intake was not affected (P greater than .25). Mean improvements for all drug levels over control values for the total trial were 4.3% for daily gain (P less than .01) and 3.4% for feed:gain (P less than .01). For the total trial, rate and efficiency of gain were optimized in pigs fed the 82.5-ppm level of salinomycin with an improvement of 5.2% in daily gain and 4.8% in feed:gain over pigs fed the control diet. The absence of any significant trial X treatment interaction suggests that the nature of the response was not dependent on differences in environment, management or other factors that existed among trial locations.

Animal Feed↗