Y.X. Yang

Effects of lysine intake during late gestation and lactation on blood metabolites, hormones, milk composition and reproductive performance in primiparous and multiparous sows

Modern genotype primiparous and multiparous sows (Yorkshire x Landrace, n=48) were used to evaluate effects of dietary lysine intake during late gestation and lactation, and their interaction on reproductive performance. Sows were randomly allotted to two gestation lysine (G, 0.6% or 0.8% lysine) treatments based on parity in a 2 x 2 factorial arrangement, and each treatment had 12 replicates comprising 1 sow. Then all the sows were assigned to two lactation lysine (L, 1.0% or 1.3% lysine) treatments within parity and gestation treatments in a 2 x 2 x 2 factorial design, and each treatment comprised six replicates with 1 sow/replicate during lactation. Feeding higher lysine level during gestation increased sow body weight and backfat thickness (P=0.001) and body condition was better (P=0.001) in multiparous than that of primiparous sows. Both of the lysine levels during lactation and parity influenced sow body condition and reproductive performance (P<0.05). Higher lysine intake during lactation increased the concentrations of total solids (P=0.024), protein (P=0.001) and solids not-fat (P=0.042) in colostrum and total solids (P=0.001), protein (P=0.001), fat (P=0.001) and solids not-fat (P=0.005) in milk. Protein concentration of milk was greater (P=0.001) in multiparous sows than that of primiparous sows. Feeding of high lysine diets resulted in an increment of plasma urea N (P=0.010; P=0.047) and a decrease of creatinine (P=0.045; P=0.002) on the day of postfarrowing and weaning, respectively. Furthermore, as lysine intake increased, the secretions of insulin, FSH, and LH were increased (P<0.05) and multiparous sows showed higher (P<0.05) concentrations of FSH and LH pulses on the day of postfarrowing and weaning, respectively. These results indicated that higher lysine intake than that recommended by NRC [NRC, 1998. Nutrient Requirements of Swine, 10th ed. National Academy Press, 458 Washington, DC] could improve sow performance during late gestation and lactation. Furthermore primiparous sows need higher lysine intake than multiparous sows. Moreover, nutritional impacts on reproduction may be mediated in part through associated effects on circulating LH concentration.

Effects of dietary energy and lysine intake during late gestation and lactation on blood metabolites, hormones, milk composition and reproductive performance in multiparous sows.

This study was conducted to investigate the effects of different energy and lysine intake on reproductive performance of multiparous sows during late gestation and lactation. Thirty-six sows were allocated to six dietary treatments in a 3×2 factorial arrangement and each treatment had six replicates. Three energy levels and two lysine levels were used during late gestation and lactation. The results demonstrated that higher lysine intake improved (p < 0.05) the body condition of sows during both periods and their reproductive performance during lactation. Both, dietary energy and lysine level had a significant effect (p < 0.05) on the composition of colostrum and milk. In general, dietary treatments had no effect on blood metabolites and hormones. These results suggest that energy levels recommended by the National Research Council (1998) for sows are enough; however, higher lysine levels than those recommended could improve reproductive performance during late gestation and lactation in multiparous sows.

Early energy and protein reduction: effects on growth, blood profiles and expression of genes related to protein and fat metabolism in broilers

1. A total of 320-d-old Ross broilers were used in a 6-week study to investigate the effects of feeding lower energy and protein diets from d 8 to 14 on growth performance, blood profiles, and gene expression of leptin and myostatin. 2. Broilers were randomly allotted to 4 treatments, each treatment applied to 4 pens with 20 birds in each. During first week, all the birds were fed on a common starter diet (13·4 MJ ME/kg, 230 g/kg CP and 11·0 g/kg lysine). The birds were then subjected to their respective treatment diets from d 8 to 14. Treatment diets comprised two ME levels, 13·4 and 12·0 MJ/kg, each with two levels of CP, 230 and 184 g/kg. This was followed by feeding common starter and finisher diets for the last 4 weeks. 3. Dietary protein reduction resulted in poor performance and feed efficiency while energy reduction resulted in poor feed efficiency between d 8 and 14. From d 14 to 42 birds previously fed diets lower in energy and protein showed similar body weight gain and feed intake to well-fed birds. Moreover from d 8 to 14, birds fed on energy and protein-reduced diets had lower nutrient metabolisability coefficients. 4. The blood urea nitrogen (BUN) and relative weights of heart and breast muscle were lower in birds fed protein-reduced diets while energy reduction resulted in lower plasma glucose, abdominal fat and intestinal weight at d 14. At d 42, birds fed on the protein-reduced diets had lower BUN, breast muscle weight and small intestine length, while feeding on the energy-reduced diets resulted in lower abdominal fat. 5. Upregulated myostatin mRNA expression in breast muscle and downregulation of leptin mRNA expression in abdominal fat were observed in birds fed on protein and energy-reduced diets, respectively. 6. In conclusion, early nutrient reduction affected growth performance and produced lesser abdominal fat in broilers. Moreover, early energy and/or protein reduction could change muscle and fat metabolism by regulating the expressions of myostatin and leptin.

Lysine restriction and realimentation affected growth, blood profiles and expression of genes related to protein and fat metabolism in weaned pigs.

To investigate the effects of lysine restriction and subsequent realimentation on growth performance, blood profiles and gene expression of leptin and myostatin, 128 weaned pigs [initial body weight (BW) 6.96 ± 1.07 kg, 26 ± 2 days of age] were randomly allotted to four treatments. The starter diets during the first 2 weeks (P1) contained 100%, 80%, 70% or 60% of recommended lysine levels (National Research Council, 1998). Then, common grower 1 and 2 diets were offered for 2 weeks (P2 and P3) each. During P1, average daily gain (ADG) was linearly reduced (p < 0.05) with the increasing levels of lysine restriction. Growth rate was greater in pigs previously fed lysine-restricted diets than well-fed pigs although it did not reach a significant level during realimentation. However, the final BW and overall ADG were the lowest (p < 0.05) and F/G was poor in pigs fed 60% lysine diet. Relative visceral organ weights and composition of skeletal muscle were similar (p > 0.05) among the treatment. Blood triglyceride and glucose levels were increased (p < 0.05) during P1, while blood urine nitrogen, total protein and albumin levels were decreased (p < 0.05) during P2 with the reduction in dietary lysine levels. The abundance of myostatin mRNA in skeletal muscle and leptin mRNA in subcutaneous adipose tissue were lower (p < 0.05) in lysine-restricted pigs than in pigs fed non-restricted diets. In conclusion, 80% and 70% lysine restriction of starter diets resulted in inferior growth and compensatory growth effect was noted during realimentation, while 60% lysine restriction had a negative influence on growth performance. Moreover, the changes in myostatin and leptin mRNA abundance caused by nutritional manipulations may be involved in the regulation of protein and fat deposition in young pigs.

Lysine restriction during grower phase on growth performance, blood metabolites, carcass traits and pork quality in grower finisher pigs

Abstract The effects of lysine restriction during grower phase and realimentation during finisher phase on growth performance, nutrient digestibility, blood metabolites, carcass traits and pork quality were studied. Sixty-four pigs (two castrated males and two females per pen) weighing 34.34±5.22 kg were assigned to four dietary treatments. During grower (35–55 kg), pigs were fed isoenergetic lysine-restricted diets. The different lysine content of diets were 0.950 (NRC recommendation), 0.760, 0.665 and 0.570%, corresponding to lysine restriction of 20, 30 and 40%. Then all pigs were fed with common finisher 1 (55–85 kg) and 2 (85–115 kg) diets. Lysine restriction during the grower phase resulted in poor performance and lower concentration of blood metabolites but improved the nutrient digestibility and efficiency of lysine utilization. Compensatory growth response in terms of improved weight gain and feed efficiency was observed in pigs previously fed lysine-restricted diets during finisher 1, but the concentration of blood urea nitrogen and total protein were lower. No differences in growth performance, digestibility of nutrients and blood metabolites were noted during finisher 2. Lysine restriction of grower diets decreased the dressing percentage (quadratic, P=0.024), and protein content of longissimus muscle (linear P=0.034, and quadratic P=0.009). Thus, it could be concluded that pigs subjected to lysine restriction during grower phase exhibited compensatory growth responses in weight gain and improved efficiency of feed and lysine utilization for weight gain and lean accretion during finisher phase.

Effects of dietary fat inclusion at two energy levels on reproductive performance, milk compositions and blood profiles in lactating sows

Abstract This study was conducted to investigate the effects of dietary fat inclusion to create two energy levels on reproductive performance, milk compositions and blood profiles in lactating sows. Twenty-four multiparous sows were randomly assigned to four treatments according to a 2×2 factorial arrangement. Two energy levels (3365 and 3265 kcal/kg) were created by supplementing different fat levels (high and low). Higher energy level resulted in less (P<0.05) body weight and backfat loss, shorter wean-to-estrus interval, and greater body weight gain of piglets. Sows fed higher fat diet had higher (P<0.05) fat concentration in colostrum. Higher concentrations of triglyceride and creatinine and lower concentrations of luteinizing hormone at weanling were noted (P<0.05) in sows fed lower energy diet than those fed higher energy diet. In conclusion, feeding of higher energy diet during lactation may improve the reproductive performance of sows during lactation.

Effects of dietary glucose inclusion on reproductive performance, milk compositions and blood profiles in lactating sows.

Twenty-four multiparous sows were used to investigate the effects of dietary glucose inclusion on reproductive performance, milk compositions, blood metabolites and hormones during lactation. The sows were randomly assigned to four treatments and each treatment had six replicates (sows). The diets were added with 0%, 1%, 3% or 5% glucose at the expense of corn and fed to sows for 24 days. The loss of backfat thickness during lactation was quadratically decreased (p = 0.008) and the wean-to-oestrus interval was shortened (linear, p = 0.013; quadratic, p = 0.009) with increasing levels of dietary glucose supplementation. The reproductive performance was not affected (p > 0.05) by different dietary glucose contents. Increased concentrations of total solid and fat in milk were noted (p < 0.05), whereas there was no difference on colostrum compositions. With increasing levels of dietary glucose inclusion, the concentrations of blood urea nitrogen (p = 0.004) and glucose (p = 0.029) were linearly increased at weaning. The concentrations of insulin were increased at post-farrowing (linear, p = 0.027; quadratic p = 0.013) and weaning (linear, p = 0.029; quadratic, p = 0.017), respectively. Furthermore, the pulses of insulin and FSH at weaning were linearly (p = 0.049) and quadratically (p = 0.015) increased with the increasing levels of dietary glucose inclusion. In conclusion, this study indicated that inclusion of 3% glucose in lactating diet could reduce backfat loss, increase milk fat and have no negative effect on reproductive performance in multiparous sows.

Effects of growth rate on carcass and meat quality traits and their association with metabolism-related gene expression in finishing pigs.

The objective of this study was to evaluate the effect of different growth rates on carcass characteristics and meat quality and their relationship with myogenesis and lipogenesis in finishing pigs. Pigs were slaughtered at the same age and were assigned to high (HGR) or low (LGR) growth rates with 120 kg or 110 kg final body weights at slaughter. The results indicated that pigs with HGR had heavier (P < 0.05) final body weight, carcass weight, dressing percentage, backfat thickness, higher (P < 0.05) concentrations of fat in the muscle and higher (P < 0.05) total RNA concentration in muscle than pigs with LGR. The messenger RNA (mRNA) expression of lipoprotein lipase, fatty acid synthase, malic enzyme, peroxisome proliferator-activated receptor γ, and sterol regulatory element binding protein-1 in fat were higher (P < 0.05) in pigs with HGR. Additionally, the mRNA expression of glycogen synthase in muscle was lower (P < 0.05) in pigs with HGR. These results indicate differences in postmortem myogenesis and lipogenesis traits of pigs with different growth rates; these differences in turn might have affected carcass characteristics and meat quality.

ORIGINAL ARTICLE: Effects of dietary glucose inclusion on reproductive performance, milk compositions and blood profiles in lactating sows

Twenty-four multiparous sows were used to investigate the effects of dietary glucose inclusion on reproductive performance, milk compositions, blood metabolites and hormones during lactation. The sows were randomly assigned to four treatments and each treatment had six replicates (sows). The diets were added with 0%, 1%, 3% or 5% glucose at the expense of corn and fed to sows for 24 days. The loss of backfat thickness during lactation was quadratically decreased (p = 0.008) and the wean-to-oestrus interval was shortened (linear, p = 0.013; quadratic, p = 0.009) with increasing levels of dietary glucose supplementation. The reproductive performance was not affected (p > 0.05) by different dietary glucose contents. Increased concentrations of total solid and fat in milk were noted (p < 0.05), whereas there was no difference on colostrum compositions. With increasing levels of dietary glucose inclusion, the concentrations of blood urea nitrogen (p = 0.004) and glucose (p = 0.029) were linearly increased at weaning. The concentrations of insulin were increased at post-farrowing (linear, p = 0.027; quadratic p = 0.013) and weaning (linear, p = 0.029; quadratic, p = 0.017), respectively. Furthermore, the pulses of insulin and FSH at weaning were linearly (p = 0.049) and quadratically (p = 0.015) increased with the increasing levels of dietary glucose inclusion. In conclusion, this study indicated that inclusion of 3% glucose in lactating diet could reduce backfat loss, increase milk fat and have no negative effect on reproductive performance in multiparous sows.

Comparison of the Efficacy of Different Organic Acids on Growth Performance and Nutrient Digestibility in Weaned Pigs

주지환*YuXin Yang*최재용*최순천*조원탁**채병조*강원대학교 동물자원과학과*, 진바이오텍**요 약본 연구는 다양한 유기산제들의 급여가 이유자돈의 성장과 영양소 소화율에 미치는 영향을 비교하기 위하여 2번의 사양실험을 수행하였다. 실험 1과 실험 2에서는 각각 이유자돈 180두(4처리, 3반복, 15두/반복)를 공시하였다. 실험 1은 기초사료에 formic acid, ammonium‐formate, lactic acid 그리고 acid mixture를 각각 0.5%씩 첨가하여 총 5주간 사양실험을 실시하였으며, 실험 2는 formic acid, ammonium-formate, lactic acid 그리고 acid mixture를 각각 0.3%씩 첨가하여 총 6주간 사양실험을 실시하였다. Acid mixture는 formic acid와 lactic acid가 50:50의 비율로 혼합된 제제를 사용하였다. 외관상 회장아미노산 소화율을 측정하기 위하여 각 처리별 3두, 총 12두를 공시하여 T-cannula를 회장 말단부에 부착시킨 후 적응기간을 거쳐 회장내용물을 채취하였다. 사양성적은 유기산 종류에 따른 개선 효과는 없는 것으로 나타났으나(실험 1), acid mixture 급여구에서 증체량이 lactic acid 급여구보다 높은 것으로 나타났다(실험 2). 외관상 회장 아미노산 소화율은 lactic acid 급여구보다 acid mixture 급여구에서 개선되는 것으로 나타났다(실험 1과 2). 실험 1과 2의 결과를 종합하였을 때 acid mixture(formic acid + lactic acid) 급여는 이유자돈의 사양성적과 외관상 회장 아미노산 소화율을 개선시키는 것으로 판단된다.(Key words :Organic acids, Efficacy, Growth, Digestibility, Weaned pigs)