H. K. Wei

Effects of feeding regimen on weight gain, semen characteristics, libido, and lameness in 170- to 250-kilogram Duroc boars1

A 2-period field trial was conducted to determine the effects of feeding regimen on weight gain, semen characteristics, libido, and lameness in 170- to 200-kg (period 1) and 200- to 250-kg (period 2) boars. Sixty-one Duroc boars were allotted to 1 of 3 dietary treatments and 15 g/d fish oil was also provided for each experimental boar, to maintain the n-6:n-3 intake ratio at approximately 6.1:1. The energy intakes of the 3 treatment groups were controlled by basing the feed intake on a corn-soybean meal-based diet (3.11 Mcal/kg of ME) to create: 1) low energy intake group (L, = 20, 7.3 Mcal/d of ME), 2) medium energy intake group (M, = 20, 7.7 Mcal/d of ME), and 3) high energy intake group (H, = 21, 8.3 Mcal/d of ME) in period 1. Feed intake was then increased to 7.6, 8.2, and 8.6 Mcal/d of ME for the 3 groups, respectively, in period 2. During the 28-wk experimental period, boar weight gain, testis volume, semen characteristics, libido, toe measurements, claw lesions, and lameness were examined, and the number of boars culled in each group was recorded to calculate the culling rate. Although there were no differences in testis volume, sperm concentration, and motility, the percentage of abnormal sperm, the percentage of claw lesions, and claw lesion scores differed among treatments ( > 0.05), and ADG was significantly increased with the increase of energy intake between the 2 periods ( < 0.05). The M and H boars had significantly greater total sperm number and functional sperm number than the L boars ( < 0.05), while no significant difference was observed between the M and H groups ( > 0.05). Nonetheless, the H boars took more time to mount the collection dummy and produce an ejaculate and, in particular, showed a greater percentage of lameness than the L and M boars ( < 0.05). Therefore, the medium energy intake regimen (energy intakes of 7.7 and 8.2 Mcal/d of ME with ADG of 454.5 and 375.3 g/d in 2 periods, respectively) improved the total sperm number and functional sperm number, and meanwhile decreased the occurrence of lameness in 170- to 250-kg Duroc boars.

Effects of Low-Protein Diets Supplemented with Branched-Chain Amino Acid on Lipid Metabolism in White Adipose Tissue of Piglets

This study evaluated the effect of branched-chain amino acid (BCAA) supplementation in low-protein diets on lipid metabolism in dorsal subcutaneous adipose (DSA), abdominal subcutaneous adipose (ASA), and perirenal adipose (PRA) tissues. A total of 24 piglets were allotted to four treatments, and each group was fed the adequate protein (AP) diet, low-protein (LP) diet, LP diet supplemented with BCAA (LP + B), or LP diet supplemented with twice BCAA (LP + 2B). Serum concentrations of leptin in the BCAA-supplemented treatments were higher (P < 0.01) than in the AP treatment, but lower (P < 0.01) than in the LP treatment. In DSA, the mRNA and protein levels for lipogenic-related genes were highest in the LP treatment and lowest in the LP + 2B treatment. However, in ASA and PRA, the expression levels for those genes were significantly elevated in the LP + 2B treatment. In conclusion, BCAA supplementation could alter the body fat condition, and this effect was likely modulated by the expression of lipid metabolic regulators in DSA, ASA, and PRA in a depot-specific manner.

Supplementation of branched-chain amino acids in protein-restricted diets modulates the expression levels of amino acid transporters and energy metabolism associated regulators in the adipose tissue of growing pigs

This experiment was conducted to investigate the effects of branched-chain amino acids (BCAA) supplemented in protein-restricted diets on the growth performance and the expression profile of amino acid transporters and energy metabolism related regulators in the white adipose tissue (WAT) of different regional depots including dorsal subcutaneous adipose (DSA) and abdominal subcutaneous adipose (ASA). A total of 24 crossbred barrows (7.40 ± 0.70 kg) were randomly divided into 4 groups and were fed the following isocaloric diets for 33 days: 1) a recommended adequate protein diet (AP, 20% CP, as a positive control); 2) a low protein diet (LP, 17% CP); 3) the LP diet supplemented with BCAA (LP + B, 17% CP) to reach the same level of the AP diet group; 4) the LP diet supplemented with 2 times the amount of BCAA (LP + 2B, 17% CP). The daily gain and daily feed intake of the LP diet group were the lowest among all the treatments (P < 0.01). The feed conversion was improved markedly in the group of LP + B compared with the LP diet group (P < 0.05). No significant difference was noted for the serum biochemical parameter concentrations of glucose, triglyceride, nonesterified fatty acid and insulin among the groups (P > 0.05). Moreover, BCAA supplementation down-regulated the expression levels of amino acid transporters including L-type amino acid transporter 1 and sodium-coupled neutral amino acid transporter 2 in DSA, but up-regulated the expression level of L-type amino acid transporter 4 in ASA (P < 0.05). Meanwhile, the energy sensor AMP-activated protein kinase α was activated in the DSA of pigs fed LP diet and in the ASA of the pigs fed AP or LP + 2B diets (P < 0.05). The mRNA expression profile of the selected mitochondrial component and mitochondrial biogenesis associated regulators in DSA and ASA also responded differently to dietary BCAA supplementation. These results suggested that the growth performance of growing pigs fed protein restricted diets supplemented with BCAA could catch up to that of the pigs fed AP diets. The results also partly demonstrated that the regulation mechanisms of BCAA are different in the adipose tissues of different depots.

Linear growth model analysis of factors affecting boar semen characteristics in Southern China1

This study investigated the factors affecting the semen traits of boars in Southern China. A total of 172,408 ejaculates of boars from 9 AI centers were collected from January 2013 to May 2016. A linear growth model was used to analyze the effects of leve1 1 (boar breed, age, season, and boar age at herd entry) and level 2 (housing type) factors on semen quality. The intraclass correlation coefficients of semen volume, total sperm number, functional sperm number, sperm concentration, motility, and abnormal sperm were 0.62, 0.62, 0.61, 0.60, 0.54, and 0.70, respectively. Boars reared in ordinary houses had lower total and functional sperm numbers than those reared in air filtration houses ( < 0.05). The functional sperm number of Duroc boars was lower than that of Landrace and Yorkshire boars ( < 0.05). The total and functional sperm numbers were lowest from May to September and peaked at the age of 34.1 and 37.7 mo, respectively. Furthermore, boars aged 8 and 9 mo at herd entry had greater functional sperm numbers than those aged 5, 6, 7, and 12 mo at herd entry ( < 0.05), whereas no significant difference was observed between boars aged 8 mo and boars aged 9 mo at herd entry ( > 0.05). In conclusion, the linear growth model is suitable for longitudinal data analysis. To improve boar breeding, sunstroke prevention in the early spring should be given greater attention. Importantly, 8 mo appears to be the most suitable age for boar introduction, especially for Duroc boars.

Effects of soluble fiber inclusion in gestation diets with varying fermentation characteristics on lactational feed intake of sows over two successive parities

The effects of soluble fiber inclusion in gestation diets with varying fermentation characteristics (fermentation kinetics and short-chain fatty acids (SCFA)-profile) on lactational feed intake of sows and their piglet growth over two parities were investigated using an in vitro-in vivo methodology. After breeding, 90 multiparous Landrace sows were randomized to one of three experimental diets: the control (CON) diet, konjac flour (KF) diet or sugar beet pulp (SBP) diet. All diets had similar levels of net energy, CP, insoluble fiber and NDF, but KF and SBP diets had higher soluble fiber levels than the CON diet. During gestation, the sows were restrictively fed with three different diets, but during lactation, all the sows were similarly fed ad libitum. The three gestation diets were enzymatically hydrolyzed using pepsin and pancreatin, and enzymolyzed residues were used in in vitro fermentation. Gas and SCFA production were monitored during fermentation. After fermentation, enzymolyzed residues of KF or SBP diets resulted in higher final asymptotic gas volume than those of the CON diet. The enzymolyzed residues of KF diet were mainly part of rapidly fermented fractions, whereas those of SBP diet were mainly part of slowly fermented fractions. In addition, the acetic acid, butyric acid and total SCFA concentrations of enzymolyzed residues of KF diet were higher (P<0.01) than the control and SBP diets. In the in vivo studies, on day 90 of gestation, the KF diet sows had higher plasma SCFA concentration (P<0.05) at 4 h after feeding than the CON diet sows. Furthermore, the KF diet sows had lower plasma free fatty acid (FFA) concentration (P<0.01) at 4 h after feeding, and a lower value of homeostasis model assessment (HOMA)-insulin resistance (P<0.05), but a higher value of HOMA-insulin sensitivity (P<0.01). The KF diet sows also consumed more feed during lactation (P<0.01) and weaned significantly heavier pigs (P<0.01) than the CON diet sows. The overall results showed that the high fermentation capacity KF diet contributed to an increased lactational feed intake and improved performance of piglets in the second reproductive cycle.

Supplementing oregano essential oil to boar diet with strengthened fish oil: Effects on semen antioxidant status and semen quality parameters.

Previous research has shown benefits of dietary fish oil supplementation on semen quality of boars. However, little is known about how antioxidant protects lipid peroxidation on spermatozoa from n‐3 polyunsaturated fatty acid (PUFA) addition. This study evaluated the effect of oregano essential oil (OEO) supplementation on semen antioxidant status and semen quality in boars fed a diet enriched with fish oil. Thirty‐four mature boars of proven fertility, received daily 2.5 kg basal diet top‐dressed with 45 g soybean oil and 15 g fish oil to meet the n‐3 PUFA requirement of spermatozoa, randomly allocated to one of four groups supplemented with 100 mg α‐tocopheryl acetate kg−1 (control), or 250 or 500 or 750 mg OEO kg−1 for 16 weeks. Semen was collected at weeks 0, 8, 12 and 16 for measurements of sperm production, motion characteristics, sperm α‐tocopherol content, antioxidant enzyme activities, reactive oxygen species (ROS), DNA damage (8‐hydroxydeoxyguanosine, 8‐OHdG), lipoperoxidation (malondialdehyde, MDA) and seminal total antioxidant capacity (TAC). Sperm production and motion characteristics were similar (p > .05) among groups throughout the experimental week 16, but increased (p < .01) with experimental week. Although higher α‐tocopherol content and superoxide dismutase (SOD) activities were in OEO group spermatozoa, feeding diet with 500 mg/kg OEO resulted in elevation in seminal TAC, decrease in sperm ROS, MDA and 8‐OHdG than control group (p < .05). Overall, these results support the view that oregano essential oil has a positive effect on antioxidant capacity in boar when used fish oil.

Estimation of the optimum digestible lysine level for Cherry Valley ducks

&NA; The aim of the current study was to determine the digestible lysine (DLys) requirement of Cherry Valley ducks from 1 to 14 d and from 15 to 35 d of age. One‐day‐old male Cherry Valley ducks (n = 320) were divided randomly and evenly into five treatments with 8 replicates of 8 birds. Ducks were fed adequate levels of digestible amino acid but with graded levels of DLys: 0.80, 0.88, 0.96, 1.04, and 1.12% from 1 to 14 d; 0.60, 0.68, 0.76, 0.84, and 0.92% from 15 to 35 d. At 35 d of age, 8 ducks per treatment were slaughtered for evaluating the yields of abdominal fat, subcutaneous fat, breast meat, and leg meat. Additionally, a 7‐d metabolizable experiment was conducted with ducks of the same hatch beginning on d 35 (8 ducks per treatment). The results showed that the DLys level in diet had a quadratic relationship both with the average daily gain (ADG) and feed:gain ratio (F/G). According to the quadratic model, an optimum digestible lysine level was 0.948% from 0 to 14 d and 0.758% from 15 to 35 d based on ADG. The digestible lysine level for obtaining minimum F/G were 0.986% (0 ˜ 14 d) and 0.792% (15 ˜ 35 d), respectively. Breast meat yield (P = 0.110) and subcutaneous fat percentage (P = 0.021) showed a quadratic or linear response to the increasing dietary DLys level. To achieve maximum breast meat yield, the digestible lysine level of 0.961% and 0.761% were needed for the starter period (1 ˜ 14 d) and the growth period (14 ˜ 35 d), respectively. N excretion showed a quadratic response to the increasing dietary DLys level (P = 0.103). The results of the current study suggested that the optimum digestible lysine level was very different with the response criterion. The dietary digestible lysine levels were 0.948, 0.961% in the starter period (1 ˜ 14 d) and 0.758, 0.761% in the growth period (15 ˜ 35 d) for ADG, F/G, respectively.