Weaning Litter Size Research Articles

EVALUATION LITER SIZE OF DIFFERENT AGE MALES WITH DIFFERENT PARITY PARENTS ON SMALLHOLDER PIG FARMING IN BUAHAN VILLAGE-PAYANGAN


 
 
 This study aims to evaluate litter size of different ages males with different parent parity in smallholder pig far- ming, used 3 males of different ages (P1, P2, P3) and 18 sows of parity 1 – 4 (I1, I2, I3 and I4) with a 3 x 4 factorial RAL experimental design and unequal number of replications. The variables observed were litter size, weaning litter size, mortality and percentage of weaning litter size. Data were analyzed using a analyse of variant with the general linear model procedure. The results showed that the average litter size based on males P1, P2, P3 was 8.38; 9.13 and 10.38 (P>0.05) and based on parental parity I1, I2, I3 and I4 respectively 8.00; 8.83; 9.66 and 10.66 (P<0.05). For weaning litter size, respectively 5.75; 7.50 and 8.87 (P<0.05) and from parent parity was 6.17; 6.67; 8.17 and 8.50 (P<0.05), while the mortality respectively was 31.82%; 17.62% and 12.39% (P>0.05) and from parent parity respec- tively 23.54%; 23.21%; 15.74%; and 19.94% (P>0.05). Weaning litter size percentage of each male was 68.17; 82.50; 87.61 (P>0.05) and from parental parity 76.63; 76.78; 84.26 and 80.05 (P>0.05). Older males and fourth parity of parent produced better litter size, weaning litter size and weaning litter percentage with lower mortality. There was no interaction between the use of males of different ages and parents of different parity on the observed variables.
 
 

THE INFLUENCE OF THE MOTHER AND FATHER COMPONENT, AND THE SEASON AND YEAR ON THE REPRODUCTION OF FEMALE TERMOND WHITE AND POPIELNO WHITE RABBITS

The purpose of this study was to investigate the influence of the mother's and father's breed, as well as the season and year of littering, on the size of the litter born and reared as well as the birth weight of rabbits. The obtained litters for analysis came from the crossing of female Popielno White (n = 49) and Termonde White (n = 108) breeds with males of the breeds: Flemish Giant, California, New Zealand White, Popielno White and Termonde White. The females were allowed to mate for the first time at the age of 4.5 months. Four season of litter date were created: spring (MarchMay), summer (JuneAugust), autumn (SeptemberNovember) and winter (DecemberFebruary). The analysis of litters carried out in terms of the influence of the maternal component showed that the Termonde White does are characterized by a significantly larger litter size compared to the Popielno White rabbits. The Termonde White does were also characterised by a significantly larger weaned litter size compared to Popielno White does. Kits born to Termonde White doeses were significantly heavier than young born to Popielno White does. The breed of the sire had no significant influence on the size of the female's litter, the size of the weaned litter as well as the weight of the litter born. The significant difference between birth year were observed in the case of litter size born and weaned and born weight. The litter size born was differ between 2019 and 2020 year. When litter size weaned were analysed, the year 2020 and 2018 or 2019 were also differ significantly. The litters born and weaned in the spring and winter were larger than litters born in the litter size born was differed significantly between summer and spring or winter, summer and autumn.

Effects of Fermented Radix puerariae Residue on Nutrient Digestibility and Reproductive Performance of Sows.

This study was conducted to investigate the effect of fermented Radix puerariae residue (FRPR) on reproductive performance, apparent total tract digestibility (ATTD) of nutrients, and fecal short-chain fatty acid (SCFA) contents of sows. A total of 36 landrace × large white multiparous sows were randomly arranged into three treatments, representing supplementation with 0, 2, and 4% FRPR to a corn-soybean meal and wheat bran-based diet during the whole gestation period. The results showed that dietary FRPR had no effects on litter size and the number of total alive piglets (P > 0.05), and that the number of weaned piglets and weaning weight of litter were increased in sows with 4% FRPR treatment compared with control treatment (P < 0.05). Dietary 4% FRPR significantly decreased constipation rate, improved the ATTD of dry matter and organics, and fecal contents of acetate, propionate, and total SCFAs (P < 0.05). In the offspring piglets, serum concentrations of total protein, alkaline phosphatase, IgG, IL-10, and TGF-β were increased, but blood urea nitrogen content was decreased with 4% FRPR treatment (P < 0.05). There were no significant differences in all determined indexes except for fecal acetic acid and total SCFAs between control and 2% FRPR treatment (P > 0.05). These findings indicated that FRPR used in the diets of sows showed positive effects on fecal characteristics, utilization of nutrients, and reproductive performance. Maternal supplementation with 4% FRPR is recommended for improving immune responses, weaning litter size, and litter weight of offspring piglets, which provide useful information for the application of residues of R. puerariae.

The combination effect of superovulation induction and dietary protein level in sow towards birth weight, mortality, and litter size of weaning piglets

This study was aimed to evaluate the birth weight, mortality, and litter size of weaning piglets in sow given superovulation hormones and level of protein diet before mate. Eighteen gilts, weighing 100–107 kg were used in this research. Both PMSG and hCG hormones were used as the superovulation agent and prostaglandin PGF2α as estrous synchronization. The statistical design used in this experiment was completely randomized with a 2×3 factorial pattern, where the combination of each factor was repeated three times. The superovulation hormone as the first factor, consisted of two levels of treatment, i.e., without hormone injection (NSO) and with hormone injection (SO), and dietary protein as the second factor, consisting of three levels of treatment, i.e., 14%, 16%, and 18%. The variables measured include: birth weight, mortality, and weaned litter size of piglets. The results showed that the administration of superovulation induction combined with dietary protein level affected significantly on birth weight, mortality, and litter size of weaning piglets better than non-superovulation induction treatments. The research concluded that the administration of both superovulation induction and dietary protein level in sows before their mating were able to increase birth weight, suppress mortality, and increase of weaning litter size of the piglets.

Sow-related factors affecting the postweaning feed intake in Landrace × Large White females.

During the weaning-to-estrus interval (WEI), a high feeding level is usually offered to recover losses due to lactational catabolism. However, several factors can affect the appetite, possibly impairing the efficacy of this strategy. This study aimed to investigate the effect of sow-related factors on average daily feed intake (ADFI) during WEI in 142 primiparous and 458 multiparous sows. After weaning, the sows received 4.3 kg/day of feed and the wastage was recorded. The ADFI after weaning was lower in primiparous than multiparous sows, and on estrous day than in 2 and 3 days preceding estrus (P ≤ 0.05). In primiparous sows, lower ADFI was observed if they had higher backfat thickness at 112 days of gestation (BFT ≥ 11.5 mm) or higher reserves at weaning (BFT ≥ 10.5 mm, caliper units ≥ 12 or ≥ 157 kg; P ≤ 0.05). Higher body reserves at the end of gestation (caliper units ≥ 12, BFT ≥ 11.0 mm, or BCS ≥ 3.0) or weaning (caliper units ≥ 13, BFT ≥ 12.5 mm) negatively affected the ADFI in multiparous sows (P < 0.04). Weaned litter size ≤ 11 piglets (P = 0.06) and shorter lactation length (P< 0.01) decreased the ADFI in primiparous sows. Greater loss in caliper units during lactation tended to reduce ADFI in primiparous and multiparous sows (P ≤ 0.07). Multiparous sows with greater losses in BFT and BCS had lower ADFI (P ≤ 0.03). The ADFI during WEI is reduced when sows are in estrus or if they have greater body reserves.

Performance characteristics of sows fed enriched diet from weaning to service in a commercial flock

Fielded data from 40 sows together with obtained data from 1999 to 2005 we analysed to determine the performance of sows fed enriched diet from weaning to a service in a commercialflock. The data were on litter size at birth (LTZVT), litter size at weaning (LTZWN), weaning age (WNAGE) forrowing interval (FRINT), purity (PRTY) and reproductive life (PRODLF). Mean value of 9.44(no), 6.04(no), 31.874, 453.58d and 3.65yrs were obtained for LTZBT, LTZWN, WNAGE, FRINT and PRODLF respectively. The influence of parity on sow's performance was analyzed while mortality and sows efficiency of production were determined. Anagonistic relationship existed between production and reproduction traite. Mortality amongst piglets increased with weaning age. Over 80% of sows hold PRINT of less than 157 days, farrowed litters greater than 7 and 55% weaned litter size of over 8. Parity had no influence on sow's performancw. Sow efficiency of production indices showed that sows had 2 farrowing/year, a farrowing rate of 84% and small litter index of less than 17%. The findings of this study have indicated that better performance of sows can be achieved by giving enriched diet (flushing) from weaning to a service rather than the practice of flushing only few days to service

HUBUNGAN BOBOT LAHIR ANAK BABI DENGAN PERTAMBAHAN BOBOT BADAN, BOBOT SAPIH, MORTALITAS, DAN LITTER SIZE SAPIHAN PADA PETERNAKAN PT. KARYA PROSPEK SATWA

RELATIONSHIP OF WEIGHT BIRTH PIGLET WITH ADDITION OF AGENCY WEIGHT, WEANING WEIGHT, MORTALITY, AND LITTER SIZE WEANING IN LIVESTOCK PT. KARYA PROSPEK SATWA. This study aims to determine how much the relationship of birth weight with weight gain, weaning weight, mortality, and litter size of weaning in animal husbandry companies owned by Animal Prospects. The material used is 7 pregnant sows from Yorkshire and Landrace, with an average body weight of 140 kg which will be taken by 54 children randomly. Furthermore, this research data obtained from weighing piglets during parturition, weighing weekly during weaning and weighing when weaned and taking data on live and dead piglets during the study. The data is then processed by procentage descriptive method and evaluated by simple correlation (r) and determination (R) tests. The variables measured in the study were body weight gain, weaning weight, mortality, and weaning litter size. Birth weight has a very close relationship with weight gain and weaning weight, but litter size weaning has a very weak relation. While mortality is not related. Key words: Piglets, Birth weight, Weight gain, Weaning weight, Mortality, Litter size weaning.

Optimal lysine in diets for high-yielding lactating sows1.

The objective of the current study was to determine the optimal concentration of dietary standardized ileal digestible (SID) Lys required to maximize litter gain and minimize sow BW loss in modern high-yielding lactating sows when SID CP was kept constant across dietary treatments. A total of 396 parity 1 to 5 sows (L × Y, DanBred, Herlev, Denmark) were included in the study from day 3 after farrowing until weaning at day 26. Sows were allocated to 6 dietary treatments increasing in SID Lys concentration (6.19, 6.90, 7.63, 8.33, 9.04, and 9.76 g/kg). Diets were isoenergetic (14.04 MJ ME/kg as-fed). Litters were standardized to 14 piglets at day 3 ± 2 d postpartum. At day 3 ± 2 d and at day 26 ± 3 d in lactation, litter weight, and sow BW and back fat were registered. On a subsample of 72 parity 2 to 4 sows, litters were additionally weighed at days 10 and 17 ± 3 d, and milk and blood were sampled at day 3 ± 2 d, and 10, 17 and at 24 ± 3 d in lactation. For the 72 sows, body pools of fat and protein were also determined at days 3 ± 2 and 26 ± 3 d using the D2O dilution technique. All data were analyzed as a randomized complete block design using PROC MIXED in SAS. Furthermore, data were subjected to linear and quadratic polynomial contrasts. Variables with quadratic or linear effects or days in milk × treatment interactions were selected for analysis in PROC NLMIXED using linear broken-line models to evaluate optimal SID Lys concentrations. Only models that converged and the best fitting models were included. Average daily litter gain increased until a breakpoint at 8.11 g/kg of SID Lys (as-fed). At and above the breakpoint, multiparous and primiparous sows had litter gains of 3.36 and 2.93 kg/d, respectively. Weaning litter size (13.0 ± 0.1) was similar between the 6 dietary treatments (P = 0.28). Lactation sow BW loss was minimized to 0.17 kg/d at 9.05 g/kg of SID Lys and sow body protein loss was minimized to 0.23 kg at 9.22 g/kg of SID Lys. Linear broken-line analyses showed that for 3, 10, 17, and 24 DIM, plasma urea was minimized at 7.02, 8.10, 8.73, and 8.32 g/kg of SID Lys, respectively, and milk fat was maximized at 7.80 g/kg of SID Lys. In conclusion, in our conditions, high-yielding lactating sows required 8.11 g/kg of SID Lys to maximize litter gain and 9.05 g/kg of SID Lys to minimize sow BW loss. Based on plasma urea, the optimal dietary concentration of SID Lys was lowest in week 1, intermediate in week 2 and 4, and greatest in week 3 of lactation.

PENGARUH SISTEM PENGAWINAN (INSEMINASI BUATAN DAN ALAMI) DAN PARITAS INDUK BABI TERHADAP LITTER SIZE DI USAHA PETERNAKAN BABI PT. ADHI FARM, SOLO

The aims of this study was to determine the optimal litter size which produce from the mating system and the sow parity by noticing the litter size born alive, the age of weaning, litter size at weaning, mortality during the suckling period and litter size at weaning percentage. Fourty one farrowing and weaned sows are used in this research. The first factor is the mating system, included artificial insemination and natural service. The second factor is the parity of the sow (1 up to 5). The data collected were litter size born alive, the age of the weaning, the weaned litter size, mortality of the suckling period and litter size at weaning percentage.The result showed that the mating system had significant effect (P0.05) on the age of the weaning, the litter size at weaning, mortality during the sucling period and litter size at weaning percentage. The parity had significantly effect (P0.05) on the litter size born alive, mortality during the sucling period and litter size at weaning percentage. The interaction between the mating system and the parity was significantly effected (P

Providing ‘get-away bunks’ and other enrichments to primiparous adult female mink improves their reproductive productivity

This study investigated whether simple, cheap enrichments – ‘get-away bunks’ (a wire mesh semi-cylinder attached to the cage ceiling) and small manipulable objects (balls and suspended chewing items) – could improve welfare and productivity in nursing mink dams (Neovison vison) in commercial farm conditions in southern Ontario (Canada). Experiment 1 replicated a study conducted the previous whelping season on the same farm. It evaluated whether providing bunks to multiparous dams (n=164) could decrease their morbidity and mortality or boost kit weaning weight, and assessed dams’ overnight use of these structures to compare day and night utilization. Overnight bunk-use proved to be no different from daytime use, and night- and day-use co-varied; bunk use recorded in daylight is thus a good proxy for overall use. Bunk use did not, however, influence kit weights at weaning, nor reduce dam deaths from nursing sickness (replicating the previous year's findings), nor significantly improve subjectively scored teat health (unlike the previous year's findings). Experiment 2 reassessed bunk effects using larger sample sizes, and investigated their interaction with enrichment objects. Focusing on primiparous dams (n=318), it evaluated whether providing balls and items to chew, along with bunks in a cross-factored design, could decrease stereotypic behaviour, glucocorticoid output (assessed via faecal cortisol metabolites: FCM), kit losses, and, again dam mortality. Objects were provided c. 10 months earlier (since the previous July) for approximately 60% of the object-enriched dams, and c. 5 months earlier (since January) for the remaining 40%. Analyses showed that effects of bunks and enrichment-objects did not significantly interact for any variable. Bunks significantly reduced kit mortality: kit losses/litter were reduced by c. 0.3 infants, resulting in negligible levels of mortality, and bunks tended to reduce dam stereotypy levels by about half (from approximately 12.5% to 6% of time spent active). However, bunks had no significant effects on FCM or dam mortality rates. Bunk-use also significantly co-varied with litter size, being greatest in dams with bigger litters. Enrichment objects tended to increase weaning litter size, an effect caused by dams provided with these objects for 5 months weaning 0.9 more kits per litter than females without these items. However, this type of enrichment again had no significant effects on FCM or dam mortality. Instead, which farm animals lived on appeared to be the major determinant of FCM and dam mortality: both significantly varied between farms, with one farm showing notably higher levels of both. Also, even controlling for farm, females who died tended to have had elevated glucocorticoids when sampled 2–3 weeks prior to death. In conclusion, bunks and manipulable enrichment objects seem ineffective against nursing sickness, but had independent, additive effects on the productivity of young adult females, possibly acting by improving primiparous dams’ welfare.

Life history traits in a cyclic ecosystem: a field experiment on the arctic fox

The reproduction of many species depends strongly on variation in food availability. The main prey of the arctic fox in Fennoscandia are cyclic small rodents, and its number of litters and litter size vary depending on the phase of the rodent cycle. In this experiment, we studied if the arctic fox adjusts its reproduction as a direct response to food abundance, in accordance with the food limitation hypothesis, or if there are additional phase-dependent trade-offs that influence its reproduction. We analysed the weaning success, i.e. proportion of arctic fox pairs established during mating that wean a litter in summer, of 422 pairs of which 361 were supplementary winter fed, as well as the weaned litter size of 203 litters of which 115 were supplementary winter fed. Females without supplementary winter food over-produced cubs in relation to food abundance in the small rodent increase phase, i.e. the litter size was equal to that in the peak phase when food was more abundant. The litter size for unfed females was 6.38 in the increase phase, 7.11 in the peak phase and 3.84 in the decrease phase. The litter size for supplementary winter-fed litters was 7.95 in the increase phase, 10.61 in the peak phase and 7.86 in the decrease phase. Thus, feeding had a positive effect on litter size, but it did not diminish the strong impact of the small rodent phase, supporting phase-dependent trade-offs in addition to food determining arctic fox reproduction.

Using pregnancy rates and perinatal mortality to evaluate the success of recovery strategies for endangered island foxes

AbstractFollowing a dramatic population decline in 1999, captive‐breeding and translocation programs were initiated to recover the Santa Catalina Island fox Urocyon littoralis. Neonatal losses during the first year of captive breeding raised concerns, but little information was available on which to base reproductive expectations in captivity, and pregnancy rates and pup mortality had not been assessed in free‐ranging foxes. In 2002 and 2003 we evaluated the relative contributions of captive breeding and translocation to population recovery by comparing pregnancy rates and perinatal mortality in free‐ranging and captive Santa Catalina Island foxes, and by comparing pregnancy rates and perinatal mortality were also compared between resident free‐ranging foxes and foxes that had been captive bred and released, or translocated as juveniles. Pregnancy rates and fetal number were determined using ultrasound. Free‐ranging pregnant foxes were followed via radiotelemetry, and a combination of camera‐traps, observation and targeted trapping was used to determine how many pups survived to weaning. Video cameras and observations were used to determine the weaning success for captive foxes. The adult pregnancy rate for free‐ranging foxes (95.0%) was higher than for adult captive foxes (47.6%; P=0.003). Perinatal mortality for pups born to free‐ranging mothers (43.2%) was higher than for pups born to captive mothers (15.0%, P=0.055). Adult pregnancy rates and perinatal mortality were 100 and 25.0% for translocated and captive‐bred foxes combined, and 92.3 and 53.6% for resident wild foxes. The average weaned litter size (±standard deviation) for free‐ranging foxes (1.8±0.6) was similar to that for captive foxes (2.1±0.4). Successful pup production by translocated and captive‐bred foxes supports the utility of these strategies to recover island foxes. Our approach, integrating veterinary and field biology techniques to assess the contributions of different management strategies to population recovery, can be utilized for other endangered species.

Reproductive performance in primiparous sows after postweaning treatment with a progestagen

The purpose of this study was to determine whether administration of altrenogest (Regumate; Roussel-Uclaf, París, France) to primiparous sows would improve estrus synchronization rate and reproductive efficiency of the herd, measured in terms of the weaning-to-estrus interval (WEI), the weaning-to-first-fertile-estrus-interval (WFEI), rate of sows repeating estrus, and conception rate at first estrus. First-parity sows (Landrace x Large White) from a commercial herd received altrenogest, 20 mg per sow per day, for 5 consecutive days starting the day after weaning. A group of untreated sows acted as controls. The percentage of sows showing estrus 4 to 7 days postweaning (controls; 65.6%) or 4 to 7 days after treatment ended (8 to 11 days postweaning) was higher (P &lt; .05) in the altrenogest-treated group (86.2%). Sows were mated naturally twice at the first estrus after weaning and pregnancy was diagnosed by ultrasonography 23 to 24 days later. There were no differences between treated and control sows in means of WEI, WFEI, rate of sows repeating estrus, or conception rate to first service. Litter size at farrowing, number of live born piglets, number of stillborn piglets, preweaning mortality, and weaned litter size were also similar between groups.

Reproductive output, maternal age, and survivorship in captive common marmoset females (Callithrix jacchus).

Common marmosets (Callithrix jacchus) demonstrate significant variation in reproductive output on both a yearly and lifetime basis in comparison to other anthropoid primates. We explore the factors that may be most important in determining reproductive variation in captive common marmosets. Studies have found that maternal age, maternal condition, and dam survivorship are related to reproductive output; however, these reports are not in agreement and are far from conclusive. With the use of a large, multicolony, demographic database pooling data across five marmoset colonies, we examined litter information for 1,649 litters, and reproductive summaries for 400 dams to assess 1) how reproductive output variation (total production, total weaned production) is determined by litter size, interbirth interval (IBI), age at first birth, and dam survival age; 2) the relationship between maternal age and reproductive output variables; and 3) relationship between the reproductive output variables and survival. We used stepwise regression procedures to describe the amount of variation in lifetime reproductive output among dams, and found that mean litter size accounted for 18% of the variance in total production, survival age accounted for 10.6%, age at first birth accounted for 8.8%, and mean IBI accounted for 5%. For total (nonzero) weaned production, survival age accounted for 7.6% of variance, age at first birth accounted for 7.2%, mean IBI accounted for 2%, and mean litter size accounted for 1.6%. We identified significant effects (P<0.05) of maternal age on litter size and IBI length, but no effect of dam age on weaned litter size. Cox proportional hazards regression analyses revealed significant effects (P<0.01) of number of litters, age at first birth, and site on dam survivorship. Dams that produced more litters showed higher survivorship. Age at first birth showed a positive relationship with dam survivorship, i.e., dams that delayed first reproduction had higher survival. Our findings about reproductive variation in marmosets may have practical applications for the management of marmoset breeding colonies.

Desempenho produtivo de leitoas alimentadas com dietas de gestação de baixo ou alto nível de casca de soja

Leitoas foram alimentadas com dietas de gestação com inclusão de 7% (T1) e 35% (T2) de casca de soja, as quais continham níveis de 4,5 e 13,1% de fibra bruta, respectivamente. Após a inseminação, todas as fêmeas receberam 1,8kg da ração T1 (5470Kcal EM dia-1) até os 35 dias de gestação, quando foram separadas em dois grupos que receberam 2,4kg (7294Kcal EM dia-1) da ração T1 (n=108) ou 2,7kg (7249Kcal EM dia-1) da ração T2 (n=99). Aos 90 dias de gestação, as fêmeas T1 e T2 receberam respectivamente 3,0kg (9117Kcal EM dia-1) e 3,4kg (9129Kcal EM dia-1) de ração. As fêmeas T1 foram mais pesadas que as T2 aos 110 dias de gestação e ao parto (P&lt;0,05). No entanto, o consumo diário médio de ração durante a lactação foi 5,3% maior para as fêmeas T2 (P=0,01) do que para as fêmeas T1. Não houve efeito dos tratamentos sobre a produção e composição do leite, a variação de peso das fêmeas durante a lactação e o intervalo desmame-estro (P&gt;0,05). O número de nascidos totais, nascidos vivos, natimortos e mumificados foi semelhante (P&gt;0,05) entre os tratamentos. O peso médio ao nascer foi maior (P=0,03) para os leitões das fêmeas T1, mas não houve diferença entre os tratamentos no peso médio da leitegada (P&gt;0,05). O peso e número de leitões ao desmame não foram afetados pelos tratamentos (P&gt;0,05). Os dois níveis de inclusão de casca de soja na dieta de gestação de leitoas resultaram em desempenho produtivo semelhante.

Effects of Sire Breed on the Subsequent Reproductive Performances of Landrace Sows

Reproductive traits of sows are determined chiefly by the genetic background of the dam herself. Whether the breed of the serviced boars also contributes is not yet clear. A total of 8,946 litters of Landrace (L) sows from 68 farms were examined. Of these, 876, 1,260, and 6,810 litters were produced from natural mating with L, Yorkshire (Y), and Duroc (D) breeds, respectively. The birth litter size (BLS), weaning litter size (WLS), live born piglets (LBP), and survival rate % (SR), of every litter were recorded. A general linear-model procedure was followed to estimate the effects of boars' breed (B), parity (P) and B×P interaction on the reproductive traits of the sows. Results show that BLS, WLS, and LBP were all significantly (p<0.001) affected by B and P. SR% was significantly influenced by B but not by P. L sows crossbred with Y or purebred with L produced litters with higher BLS, WLS, and LBP values than those bred with D. Pure L breeding yielded litters with lower SR% than did crossbreeding with D, while the difference between SR% due to LY and that due to LD crossbreeding was not significant. The interaction of B with P was significant with respect to BLS, WLS, and LBP (p<0.001), but not SR%. No significant B effect on reproductive traits was measured in sows at their first parity; but at latter parities, LL or LY produced litters with similarly high BLS, WLS and LBP, which values were all significantly greater than those of LD litters. The breed of boar evidently affected the subsequent reproductive performance of L sows and this effect may be further manipulated by the parity effect. Breed differences in semen quality and the success of fetus development with different interactions of the genetic background with the uterus function of the sow that may contribute to these effects are discussed. (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 4 : 489-493)

Estudo da divergência genética entre raças suínas utilizando técnicas de análise multivariada

Avaliação do desempenho e divergência genética entre três raças suínas, Duroc, Landrace e Large White, foram realizadas utilizando-se técnicas de análise multivariada. Foram incluídas no estudo seis características reprodutivas: tamanho da leitegada ao nascimento (TLN), tamanho da leitegada ao desmame (TLD), peso da leitegada ao nascimento (PLN), peso da leitegada ao desmame corrigido para os 21 dias de idade (PL21), ganho de peso médio do nascimento ao desmame (GPM) e taxa de mortalidade do nascimento ao desmame (TM). O desempenho das raças foi avaliado por meio da análise de variância multivariada e da função discriminante linear de Fisher usando os testes do maior autovalor de Roy e da união-interseção de Roy para as comparações múltiplas. O estudo da divergência genética foi feito por meio da análise de variáveis canônicas. As raças Landrace e Large White apresentaram, de modo geral, melhor desempenho que a raça Duroc nas características estudadas. As três raças apresentaram desempenho semelhante na característica tamanho da leitegada ao nascimento. As raças Landrace e Large White foram geneticamente semelhantes porém apresentaram alta divergência genética em relação à raça Duroc.

Effect of dietary protein and supplemental soyabean oil fed during lactation on sow and litter performance through two parities

The effects of protein and/or energy intakes on sow and litter performance during a 21 day lactation were examined through two parities. A 2 × 2 factorial design with four replications per parity was used. Dietary treatments consisted of two dietary protein levels (14 or 16%) and two levels of soyabean oil (0 or 3%). One hundred and fifty-eight primiparous sows were utilized in Parity 1. Eighty-seven sows completed both parities. All females received 1.8 kg day −1 of a 14% crude protein (CP) diet during gestation. Sows were allotted to lactation treatment in Parity 1 and remained on the same treatment in Parity 2. No protein soya-bean oil interaction occurred for any of the criteria measured in either Parity 1 ( P > 0.24) or Parity 2 ( P > 0.07). Also, no diet by season interaction occurred ( P > 0.18) for any criteria measured in either parity. In Parity 1, dietary protein or soya-bean oil had no effect ( P > 0.12) on sow weight loss, sow backfat loss, pig survivability, weaning litter size, weaning litter weight, average pig weaning weight, or percentage of sows returning to estrus by Day 7 post-weaning. Also, neither dietary protein nor soya-bean oil had any effect on serum concentrations of urea, creatinine, or free fatty acids. Feed intake was depressed ( P < 0.05) for sows receiving 3% soyabean oil. However, caloric intake was not affected ( P > 0.59) by dietary addition of soya-bean oil. Dietary protein intake had no effect ( P > 0.47) on daily feed intake or on the percentage of sows returning to estrus by Day 14 post-weaning. However, fewer sows on the 16% protein diet had returned to estrus by Day 28 post-weaning ( P < 0.08). Fewer sows fed a diet containing 3% soya-bean oil returned to estrus by Day 14 or Day 28 following weaning ( P < 0.03). In Parity 2, neither dietary protein level nor addition of 3% soya-bean oil had any effect ( P > 0.10) on sow or litter performance, with the exception that sows receiving 3% soya-bean oil had a longer interval from wearing to estrus ( P < 0.05). In conclusion, a 14% protein diet without added fat was adequate during the first and second lactation for the sows used in this experiment.