• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.12
• /
• pp.1785-1793
• /
• 2008

Fifty-four PIC barrows were used to evaluate the effects of lower dietary lysine content and energy level on carcass characteristics and meat quality in slaughter pigs. Pigs were allotted to one of three treatments by body weight with six replicate pens in each treatment. The dietary treatments for body weights of 20-50 kg, 50-80 kg and 80-90 kg were as follows, respectively: control diet (digestible energy 14.22 MJ/kg, lysine/DE 0.67 g/MJ, 0.53 g/MJ and 0.42 g/MJ); a low lysine group (digestible energy 14.22 MJ/kg, lysine/DE 0.49, 0.38 and 0.30 g/MJ); and a low lysine-low energy group or low nutrient group (digestible energy 13.11 MJ/kg, lysine/DE 0.49, 0.38 and 0.30 g/MJ). The daily weight gain, daily feed intake and feed efficiency were calculated in the overall growth period (nearly 12 weeks). Meanwhile, carcass characteristics and meat quality were evaluated at 60 and 90 kg body weight respectively. During the overall growth trial, lowering dietary lysine and nutrient level both decreased weight gain (p<0.05) and feed efficiency (p<0.01). At 60 kg body weight, decreasing dietary lysine and nutrient level noticeably decreased dressing percentage (p<0.01) and back fat depth at last rib of PIC pigs (p<0.01), but enhanced marbling scores (p<0.10), intramuscular fat content (p<0.10) and water loss rate (p<0.01) of the longissimus dorsi muscle. At 90 kg body weight, lean percentage (p<0.01) was evidently reduced by both lowering lysine content and nutrient level in the diet. However, the shoulder back fat depth (p<0.05) and marbling scores of the loin eye muscle (p<0.05) were increased; Lowering dietary nutrient level could improve back fat depth of 10th rib (p<0.01) and last rib (p<0.01), intramuscular fat content (p<0.10), redness (p<0.01) and water loss rate of the loin eye muscle (p<0.05), but decrease loin area (p<0.05). Finally, when comparing the 60 kg and 90 kg slaughter weights, it was found that the shoulder back fat depth (p<0.01, p<0.10), 6th-7th rib (p<0.01, p<0.01), 10th-rib (p<0.01, p<0.01) and last rib back fat depth (p<0.01, p<0.01) of the low lysine and low nutrient group were all obviously increased comparing with the control group. Taken together, the results showed that decreasing dietary lysine content and nutrient level increased intramuscular fat content and water loss rate of longissimus dorsi muscle; On the other hand, both lowering dietary lysine and nutrient level markedly compensated to increase back fat deposition in the later finishing period (body weight from 60 to 90 kg) in contrast to the control group.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.2
• /
• pp.232-236
• /
• 2008

This experiment was performed to investigate the effects of two energy levels and four lysine:digestible energy (DE) ratios on the apparent digestibility of nutrients in finishing pigs. The experiment was conducted using a $2{\times}4$ randomized complete block (RCB) design with three replicates. Twenty-four cross-bred finishing barrows ((Landrace${\times}$Yorkshire)${\times}$Duroc) with an average body weight of $64.2{\pm}0.69kg$ were assigned to one of eight treatments. Each barrow was placed in an individual metabolism crate and dietary treatment and water was provided ad libitum. Diets were designed to contain lysine:ME ratios of 1.5, 1.8, 2.1 and 2.4 g/Mcal at 3.35 and 3.6 Mcal/kg of diet in a $4{\times}2$ factorial arrangement. Dry matter (DM), ash, Ca and P digestibility were not affected by energy density or lysine:DE ratios. Crude fat digestibility increased as the energy density increased from 3.35 to 3.6 Mcal of DE/kg. Increasing the lysine:DE ratio also increased crude protein digestibility. There were no interactions between energy density and lysine:DE ratio in terms of nutrient digestibility. Nitrogen excretion via feces was not affected by energy density and lysine:DE ratio, while nitrogen excretion via urine was significantly affected by energy density and lysine:DE ratio. The apparent digestibility of all amino acids except for isoluecine, arginine and aspartic acid as well as average values of essential amino (EAA), non-essential amino acids (NEAA) and total amino acid digestibility (p>0.05) were not affected by energy density. The apparent digestibility of all amino acids except for leucine, proline, alanine and tyrosine, NEAA and total amino acid digestibility were significantly affected by lysine: DE ratio (p<0.05). Interactive effects of energy and lysine:DE ratio also significantly affected amino acid digestibility except for isoleucine, alanine, cystine, leucine, phenylalanine, glutamine and proline (p<0.05). In conclusion, these results suggest that maintaining the appropriate lysine:DE ratio becomes more important as the energy density of the diet increases. Consequently, increasing the lysine:DE ratio can result in increased crude protein digestibility and urinary nitrogen excretion, although apparent protein digestibility and nitrogen excretion were not affected by energy density Furthermore, increasing the lysine:DE ratio also increased the apparent digestibility of essential amino acids, except for leucine, regardless of energy density. The optimum lysine:DE ratio for maximum essential amino acid digestibility of the $64.2{\pm}0.69kg$ pig is approximately 2.4 g of lysine/Mcal of DE.

• Asian-Australasian Journal of Animal Sciences
• /
• v.11 no.6
• /
• pp.718-724
• /
• 1998

Twelve gilts were used to investigate the effect of lysine to protein ratio (5.2 g lysine/100 g CP vs. 6.7 g lysine/100 g CP) in practical diets on nitrogen retention and the efficiency of utilization in growing pigs. Treatments involved 2 levels of dietary lysine (5.2 or 6.7 g/100 g CP) and 3 levels of dietary crude protein (11, 14 and 17% in diet). Nitrogen retention was greatest when pigs were fed the control diet containing 17% protein. Nitrogen retention progressively increased as dietary protein increased (p < 0.01), but it was not affected by lysine concentration (g/100 g CP). Apparent biological value (ABV, nitrogen retained/apparently digestible nitrogen) was estimated to be ~50% at the maximum nitrogen retention. ABV was not affected by lysine concentration, but declined (p < 0.05) as the dietary protein level increased. The efficiency of intake N used for maximum nitrogen retention was approximately 44%. One gram of lysine supported approximately 9 to 10 g apparent protein accretion (nitrogen retention ${\times}$ 6.25/lysine intake) in pigs fed control diets. The efficiency of lysine utilization for protein accretion was lower in pigs fed high-lysine diets (6.7 g lysine/l00 g CP) so that 1 g of lysine accounted for 7 to 8 g of protein accretion in these pigs (p < 0.01). The lysine required to support maximum nitrogen retention in pigs fed high-lysine diets was higher than that in pigs fed control diets, which suggests that lysine was over-fortified relative to crude protein, since practical diets can not be formulated without excess of some amino acids. In summary the concentration of 5.2 g total lysine/100 g CP in diet is more appropriate for corn-soybean diets than the commonly suggested the content of 6.7 g total lysine/100 g CP.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.6
• /
• pp.939-943
• /
• 2007

Two experiments were conducted to determine the lysine requirement of straight-run broiler chickens ($Hubbard{\times}Hubbard$) during the period 4-21 (Exp. 1) and 21-40 (Exp. 2) days of age. Experiments were conducted during the summer months (June-August) in open-sided houses, thus exposing chicks to chronic heat stress. Daily min-max temperature averaged $28-40^{\circ}C$ (Exp. 1) and $28-36^{\circ}C$ (Exp. 2). Lysine deficient basal diets were formulated to contain low-nutrient-density, i.e., 2,700 kcal per kg ME, 18.6% CP (Exp. 1), and 2,750 kcal per kg ME, 17.1% CP (Exp. 2), to mimic typical commercial broiler diets used in Pakistan. Diets were supplemented with L-lysine HCl to provide total lysine level ranging from 0.85 to 1.10% (six increments) and 0.72 to 1.02% (six increments), respectively in Exp. 1 and 2. Live performance data were subjected to quadratic analysis and requirement was defined as the level achieving 95% of maximum or minimum values. Lysine requirements were found to be 0.98 and 0.97% total lysine, respectively, for gain and feed efficiency during 4-21 days, and 0.87% total lysine for both gain and feed efficiency during 21-40 days of age. Calculated on a digestible lysine basis, the estimates were 0.85 and 0.84%, respectively, for gain and feed efficiency during 4-21 days of age; and 0.75% for gain and feed efficiency during 21-40 days of age.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.6
• /
• pp.861-882
• /
• 2000

The seed, or grain, of modern cultivars of Lupinus angustifolius, commonly known as Australian sweet lupins (ASL), is an established feed resource for the intensive animal industries of Australia, Japan, Korea and several other countries in Asia and Europe. Since the introduction of ASL to the world marketplace about 25 years ago, researchers in many countries have found them to be a valuable component of the diet of beef and dairy cattle, sheep, pigs, poultry, finfish and crustaceans. The seed of ASL contains ~32% crude protein (CP) (~35% DM basis) and 5% oil. The main storage carbohydrates in the seed are the ${\beta}$-galactans that comprise most of the cell-wall material of the kernel and the cellulose and hemicellulose of the thick seed coats. ASL seeds contain about 40% non-starch polysaccharides (NSP) and a negligible amount of starch. This makes them an excellent ingredient for ruminant diets, as the risk of acidosis is very low. The seed of modern cultivars of domesticated Lupinus species contain negligible amounts of lectins and trypsin inhibitors so they do not require preheating before being used as an ingredient in feeds for monogastric species. They have a high digestibility coefficient for protein, >90% for most species, but a low energy digestibility, ~60%, which is mostly due to the high content of NSP. The low content of methionine (0.22%) and of lysine (1.46%) is typical of the legumes. The lysine availability for pigs is >70%. Lupin kernels contain ~39% CP (~42% DM basis), 6% oil and 30% NSP. They have a higher digestible energy for pigs and finfish and a higher metabolisable energy for poultry than whole seed. Commercial operations rarely achieve complete separation of kernel from hull and it is more likely that the kernel fraction, called splits or meats, will contain ~36% CP. The replacement of soybean meal or peas with ASL in cereal-based diets for most intensively reared animals, birds and fish is possible provided lysine, methionine and digestible energy levels are kept constant. This makes ASL economically competitive in many, but not all, circumstances.

• Animal Bioscience
• /
• v.34 no.5
• /
• pp.886-894
• /
• 2021

Objective: An experiment was conducted to study the effect of graded concentration of digestible lysine (dLys) on performance of layers fed diets containing sub-optimal level of protein. Methods: Five diets were formulated to contain graded concentrations of dLys (0.700%, 0.665%, 0.630%, 0.593%, and 0.563%), but similar levels of crude protein (15% CP), energy (10.25 MJ ME/kg) and other nutrients. A total of 3,520 hens (26 wk of age) with mean body weight of 1,215+12.65 g were randomly divided into 40 replicate groups of 88 birds in each and housed in an open sided colony cage house. Each diet was offered ad libitum to eight replicates from 27 to 74 wk of age. The performance was compiled at every 28 d and the data for each parameter were grouped into three phases, that is early laying phase (27 to 38 wk), mid laying phase (39 to 58 wk), and late laying phase (59 to 74 wk of age) for statistical analysis. Results: Egg production, egg mass and feed efficiency (feed required to produce an egg) were significantly improved by the dLys level during the early and mid laying phases but not during the late phase. Whereas feed intake was significantly reduced by dLys concentration during mid and late laying phases but not during early laying phase. The egg weight was not affected by dLys concentration in any of the three phases. Conclusion: Based on best fitted statistical models, dietary requirements of dLys worked out to be 0.685%, 0.640%, and 0.586% during early phase, mid phase, and late egg laying phase, respectively. The calculated requirement of dLys for the respective production phases are 727 mg/b/d during the early and mid laying phases and 684 mg/b/d during the late laying phase in diets containing 15% CP.

• Animal Bioscience
• /
• v.36 no.12
• /
• pp.1880-1888
• /
• 2023

Objective: The present experiment aimed to determine standardized ileal digestible (SID) lysine (Lys) requirements for pregnant sows individually housed under commercial farm conditions. Methods: Two hundred multiparous sows (parity = 5.1±2.0) on day 42 of gestation were randomly allocated to five dietary treatments with a balanced parity. Experimental diets were formulated to contain 0.22%, 0.32%, 0.42%, 0.52%, and 0.62% of SID Lys for the mid-gestation period (days 42 to 76) and 0.36%, 0.46%, 0.56%, 0.66%, and 0.76% of SID Lys for the late gestation period (days 77 to 103). All indispensable amino acids except Lys were provided at 110% of their requirement estimates. Daily feed allowance per sow was determined based on the back-fat thickness and body condition score at the second pregnancy check and on day 90 of gestation. Three different statistical models were used to estimate the SID Lys requirement. Results: Total born piglets alive per litter increased linearly and quadratically (p<0.001) as dietary SID Lys increased. For total born piglets alive per litter, the SID Lys requirement estimates ranged from 9.69 to 12.4 g/d for the mid-gestation period (1.19 to 1.52 g/Mcal metabolizable energy; 0.39% to 0.49%) and 14.6 to 17.4 g/d for the late gestation period (1.62 to 1.93 g/Mcal metabolizable energy; 0.52% to 0.62%). Conclusion: The mean values of the SID Lys requirement for the mid-gestation period and the late gestation period are 11.1 and 16.1 g/d (1.36 and 1.79 g/Mcal metabolizable energy; 0.44% and 0.58%), respectively, for maximal total born piglets alive per litter.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.1
• /
• pp.106-115
• /
• 2018

Objective: The goal of this study was to investigate the effects of dietary standard ileal digestible (SID) valine:lysine ratios on performance, intestinal morphology, amino acids of liver and muscle, plasma indices and mRNA expression of branched-chain amino acid (BCAA) metabolism enzymes. Methods: A total of 144 crossbred pigs (Duroc${\times}$Landrace${\times}$Large White) weaned at $28{\pm}4days$ of age ($8.79{\pm}0.02kg$ body weight) were randomly allotted to 1 of 4 diets formulated to provide SID valine:lysine ratios of 50%, 60%, 70%, or 80%. Each diet was fed to 6 pens of pigs with 6 pigs per pen (3 gilts and 3 barrows) for 28 days. Results: Average daily gain increased quadratically (p<0.05), the villous height of the duodenum, jejunum and ileum increased linearly (p<0.05) as the SID valine:lysine ratio increased. The concentrations of plasma ${\alpha}-keto$ isovaleric and valine increased linearly (p<0.05), plasma aspartate, asparagine and cysteine decreased (p<0.05) as the SID valine:lysine ratio increased. An increase in SID lysine:valine levels increased mRNA expression levels of mitochondrial BCAA transaminase and branched-chain ${\alpha}-keto$ acid dehydrogenase in the longissimus dorsi muscle (p<0.05). Conclusion: Using a quadratic model, a SID valine:lysine ratio of 68% was shown to maximize the growth of weaned pigs which is slightly higher than the level recommended by the National Research Council.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.8
• /
• pp.1147-1153
• /
• 2000

A total of 9,540 pigs were evaluated for their growth performance to provide information on the development of different feeding strategies to support maximum rate of protein deposition (PD). Large variations in growth performance and protein deposition rate were found in the population used in this study (ADG from 701 to 974 g/day; ADFI from 1,726 to 2,498 g/day; Feed/gain from 2.10 to 2.90; Backfat thickness from 12.4 to 20.5 mm and PD rate from 103 to 153 g/day). It was found that ADG was positively correlated to PD ($R^2=0.9362$, p<0.0001) while FCR was negatively correlated to PD ($R^2=0.4031$, p<0.0001). Backfat thickness was negatively correlated to PD ($R^2=0.7024$, p<0.0001) and to ADG ($R^2=0.5096$, p<0.0001). The estimated lysine requirement based on PD rate also showed large variation (12.37 to 18.38 g/day true ileal digestible lysine on average between 25 and 100 kg), thus strongly indicated the need of separate feeding strategies for each group of pigs. When pigs were divided into three categories according to estimated whole body PD rate, the group of pigs with the highest PD rate grew faster by 6.3 and 13.9% than pigs with intermediate and low PD rate, respectively. Feed utilization was also more efficient in pigs with a high PD rate. It appeared that pigs with high PD rate maintained higher PD rate especially in the later stage of their life. Pigs with high PD rate require an extra amount of 1.2 and 2.4 g/true digestible lysine per day and 0.4 and 0.8% more lysine in the diet than pigs with intermediate and low PD rate during the growing-finishing period respectively. Results of this study suggest that there is a need for separate feeding strategies for individual group of pigs with different PD rate. It should be noted that average value for each group presented in this report is not the adequate amount for an animals potential for maximum PD rate. With recent development in growth modeling and access to computer technologies to facilitate computation, pork producers can easily estimate pigs protein deposition rate and thus can make their own feeding strategies.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.8
• /
• pp.1172-1180
• /
• 2013

Two experiments were conducted to determine the standardized ileal digestible (SID) lysine (Lys) requirement and the ideal SID threonine (Thr) to Lys ratio for finishing barrows. In Exp. 1, 120 barrows with an average body weight of $72.8{\pm}3.6$ kg were allotted to one of six dietary treatments in a randomized complete block design conducted for 35 d. Each diet was fed to five pens of pigs containing four barrows. A normal crude protein (CP) diet providing 15.3% CP and 0.71% SID Lys and five low CP diets providing 12% CP with SID Lys concentrations of 0.51, 0.61, 0.71, 0.81 and 0.91% were formulated. Increasing the SID Lys content of the diet resulted in an increase in weight gain (linear effect p = 0.04 and quadratic effect p = 0.08) and an improvement in feed conversion ratio (FCR) (linear effect p = 0.02 and quadratic effect p = 0.02). For weight gain and FCR, the estimated SID Lys requirement of finishing barrows were 0.71 and 0.71% (linear broken-line analysis), 0.79 and 0.78% (quadratic analysis), respectively. Exp. 2 was a 26 d dose-response study using SID Thr to Lys ratios of 0.56, 0.61, 0.67, 0.72 and 0.77. A total of 138 barrows weighing $72.5{\pm}4.4$ kg were randomly allotted to receive one of the five diets. All diets were formulated to contain 0.61% SID Lys (10.5% CP), which is slightly lower than the pig's requirement. Weight gain was quadratically (p = 0.03) affected by SID Thr to Lys ratio while FCR was linearly improved (p = 0.02). The SID Thr to Lys ratios for maximal weight gain and minimal FCR and serum urea nitrogen (SUN) were 0.67, 0.71 and 0.64 using a linear broken-line model and 0.68, 0.78 and 0.70 using a quadratic model, respectively. Based on the estimates obtained from the broken-line and quadratic analysis, we concluded that the dietary SID Lys requirement for both maximum weight gain and minimum FCR was 0.75%, and an optimum SID Thr to Lys ratio was 0.68 to maximize weight gain, 0.75 to optimize FCR and 0.67 to minimize SUN for finishing barrows.