J. A. Calderón Díaz

Longitudinal study of the effect of rubber slat mats on locomotory ability, body, limb and claw lesions, and dirtiness of group housed sows

This study evaluated the influence of floor type on sow welfare with particular focus on lameness, claw lesions (CL), and injuries. The study used 164 gilts housed in groups of 8 from AI to 110 d of pregnancy in pens with concrete (n = 84) slatted floor left uncovered or covered by 10-mm rubber slat mats (n = 80) through 2 parities. Lameness (0 = normal to 5 = severe), limb (0 = normal to 6 = severe) and body (0 = normal to 5 = severe) lesions, and manure on the body (MOB; score 0 to 2) were recorded at AI, 24 to 72 h postmixing, between 50 and 70 d of pregnancy, and 2 wk before farrowing. Claw lesions (score 0 = normal to 3 = severe) were recorded at AI and between 50 and 70 d of pregnancy. The dirtiness and wetness of the floors was scored weekly (score 0 = clean to 4 = >75% of the pen soiled/wet). Data from the first and second parities were analyzed separately. Sows were categorized as nonlame (score ≤ 1) or lame (score ≥ 2). Median (M(e)) scores were calculated for CL and body and limb lesions and were classified as less than or equal to the median or greater than the median lesion scores. Sows on rubber slat mats had a reduced risk of lameness during both parities (P < 0.01) compared with sows on concrete. They also had an increased risk of scores greater than the median for toe overgrowth (M(e) = 2 and M(e) = 3 in the first and second parity, respectively) and heel sole crack (HSC; M(e) = 3) during both parities (P < 0.01) and for cracks in the wall (CW; M(e) = 4) and white line damage (WL; M(e) = 4; P < 0.01) in the first and second parity, respectively. There was a reduced risk of lameness in sows with scores greater than the median for HSC (P = 0.05) in the first parity and WL (M(e) = 3; P < 0.01) and CW (M(e) = 3; P < 0.05) in the second parity. Wounds (M(e) = 3) and severe lesions (M(e) = 0) on the limbs with scores greater than the median were associated with an increased risk of lameness (P < 0.01) in the first and second parity, respectively. Sows on rubber slat mats had a reduced risk of scores greater than the median for swellings (M(e) = 4) and wounds (P < 0.01) during both parities. Pens with rubber slat mats were dirtier than uncovered pens (P < 0.01); however, there was no association between MOB and flooring type. There was also no association between body lesion score and flooring type. In this study, CL were not associated with an increased risk of lameness. Therefore, even though rubber slat mats were associated with an increased risk of CL, they improved the welfare of group housed sows by reducing the risk of lameness and limb lesions.

Effects of gestation housing system and floor type during lactation on locomotory ability; body, limb, and claw lesions; and lying-down behavior of lactating sows

This study evaluated the influence of housing system during gestation and floor type during lactation on the welfare and lying-down behavior of lactating sows. Multiparous sows (n = 85) were housed either in individual gestation stalls (n = 42) or loose (n = 43) in a single dynamic group with 2 electronic sow feeders moved to farrowing crates on either slatted steel (n = 48) or cast iron (n = 37) flooring. Lameness (0 = normal to 5 = severely lame) was scored on transfer to the farrowing crate (-5 d). Limb and body lesions were recorded on -5 d, 24 h after entering the farrowing crate (-4 d), 10-d postpartum, and before weaning. Claw lesions were recorded on -5 d and before weaning, whereas all behavioral observations were made on -5, -4, and 10 d. Median (Me) scores were calculated for claw, body, and limb lesions and classified as either less than or equal to the Me or greater than the Me lesion scores. Sows were classified as nonlame (≤ 1) or lame (≥ 2). Loose-housed sows had an increased (P < 0.01) risk of lameness; a reduced (P < 0.05) risk for claw lesions, particularly white line damage, horizontal wall cracks, and dewclaw injuries; and a reduced (P < 0.05) risk for calluses and bursitis on the limbs compared to stall-housed sows. Sows housed on cast iron floors during lactation had a reduced (P < 0.01) risk for heel overgrowth and erosion and heel-sole cracks compared with sows on slatted steel floors. There was no (P > 0.05) association between flooring type during lactation and body lesion score. On -4 d, loose-housed sows had a shorter latency to lie down (P < 0.01), spent more time inactive (P < 0.05), and shifted weight between the limbs more often (P = 0.05) while standing compared with stall-housed sows. Lame sows had a shorter (P < 0.01) latency to lie down compared to nonlame sows on -5 and -4 d. In conclusion, there was an increased risk of lameness in sows housed loose compared to those housed in gestation stalls on transfer to the farrowing crate. Claw health deteriorated in the farrowing crate regardless of gestation housing or floor type but the deterioration in claw health was increased on slatted steel compared to on cast iron.

Association of calf growth traits with production characteristics in dairy cattle

The objective of this study was to understand the associations of calf growth traits with subsequent milk yield and body weight (BW). Data were collected for 281 Holstein heifer calves from 6 different calf trials of varying lengths (4 to 8 wk) conducted at Pennsylvania State University between 2003 and 2010. Calves were classified as high, medium, or low for hip height, starter feed intake, BW, and growth rate. Milk yield and cow BW were recorded during subsequent lactations. In total, there were 169,734 daily milk records and 136,153 cow BW records available. Data were evaluated using mixed model equations. Separate models were used for each calf growth trait initially, followed by models that considered multiple growth measures. Each model included age at calving, treatment within trial, parity, days in milk, lactation, and one of the calf growth traits as well as the interaction between lactation and days in milk as fixed effects. Cow and calendar week by year were fitted as random effects. Heifers from the low hip height classification as calves produced less milk across lactations after accounting for BW differences. Cows from the medium BW classification as calves produced more milk in early lactation than cows from the high BW classification as calves after accounting for differences in height. Calves that grew more quickly, ate more, and weighed more were heavier as first-lactation heifers and as mature cows. Our results suggest that the type of preweaning growth is an important consideration for future milk yield. Calves that were the shortest had the lowest milk production potential and were the least likely to remain in the herd until first lactation.

Age at puberty, ovulation rate, and uterine length of developing gilts fed two lysine and three metabolizable energy concentrations from 100 to 260 d of age.

The objective of this study was to determine the effect of ad libitum feeding diets differing in standard ileal digestible (SID) lysine and ME concentrations that bracket those fed to developing gilts in U.S. commercial settings. Average SID lysine and ME concentrations in diets currently fed to developing gilts were obtained from a poll of the U.S. commercial swine industry. Crossbred Large White × Landrace gilts (n = 1,221), housed in groups, were randomly allotted to 6 corn-soybean diets in a 2 × 3 factorial arrangement formulated to provided 2 SID lysine and 3 ME concentrations. Gilts received grower diets formulated to provide 1.02% (control = survey average) or 0.86% (control minus 15%) SID lysine and 2.94, 3.25, or 3.57 (survey average ME ± 10%) Mcal of ME/kg from 100 d of age until approximately 90 kg BW. Then, gilts were fed finisher diet containing 0.85% (control = survey average) or 0.73% (control minus 15%) SID lysine and 2.94, 3.26, or 3.59 (control ± 10%) Mcal of ME/kg until 260 d of age. Gilts were weighed, and backfat thickness and loin muscle area were recorded at the beginning of the trial and then every 28 d. Starting at 160 d of age, gilts were exposed daily to vasectomized boars and observed for behavioral estrus. At approximately 260 d of age, gilts were slaughtered and their reproductive tract was collected. Each reproductive tract was examined to determine whether the gilt was cyclic, the stage of estrus cycle, ovulation rate, and uterine length. Data were evaluated for normality and analyzed using mixed model methods. Average age at puberty was 193 d of age with a range from 160 to 265 d. When all gilts on trial at 160 d of age were included in the analysis, 91.0% reached puberty as determine by observation of standing estrus. Differences between dietary treatments on age at puberty or measurements of the reproductive tract were not detected. Growth rates to 160 d were not limiting for attainment of puberty in response to daily boar stimulation from 160 d.

Optimal dietary energy and amino acids for gilt development: Growth, body composition, feed intake, and carcass composition traits

The objective of this study was to determine if body composition of developing gilts could be altered at the onset of estrus by ad libitum feeding diets differing in standard ileal digestible (SID) lysine and ME using levels that are within those used in practice by pig producers in the United States. Crossbred Large White × Landrace gilts ( = 1,221), housed in groups, were randomly allotted to 6 corn-soybean diets in a 2 × 3 factorial arrangement formulated to provide 2 SID lysine and 3 ME levels. Gilts received grower diets formulated to provide 0.86 (low) or 1.02% (high) SID lysine and 2.94 (low), 3.25 (medium), or 3.57 (high) Mcal of ME/kg from 100 d of age until approximately 90 kg BW. Then, gilts were fed finisher diets containing 0.73 (low) or 0.85% (high) SID lysine and 2.94 (low), 3.26 (medium) or 3.59 (high) Mcal of ME/kg until 260 d of age. The medium SID lysine and medium-ME diets were based on an informal survey from the U.S. commercial swine industry to obtain average levels that are currently being formulated for developing gilts. Gilts were weighed and backfat thickness and loin area were recorded at the beginning of the trial and then every 28 d. Feed intake (FI) was recorded as feed disappearance within the pen at 2-wk intervals. Lysine (g) and ME (Mcal) consumed were calculated based on diet formulations. At approximately 260 d of age, gilts were slaughtered and warm carcass weight and fat thickness were recorded. There were no differences between lysine or ME levels for growth and body composition, except for backfat, which was slightly greater for gilts fed a high-ME diet. Gilts fed high-ME diets had a lower FI but a greater ME intake compared with gilts fed low ME ( < 0.05). Additionally, gilts fed the high-ME diet had lower FI and lysine intake per kilogram of BW gain when compared with gilts fed low- or medium-ME diets ( < 0.05). However, there was no difference in the megacalories consumed per kilogram of BW gain among treatments ( > 0.05). Carcasses from gilts fed the high-ME diet were 3.3 and 2.5 kg heavier than those from gilts fed the low- or medium-ME diets ( < 0.05). Despite significant differences in the lysine:ME ratio in the diets, no changes in growth or body composition occurred, likely due to compensatory changes in FI in response to dietary ME content. Caloric efficiency (Mcal to deposit 1 kg of BW) was similar among treatments.

Effect of feeding three lysine to energy diets on growth, body composition and age at puberty in replacement gilts

This study evaluated the effect of diets differing in standard ileal digestible (SID) lysine on lysine intake, growth rate, body composition and age at puberty on maternal line gilts. Crossbred Large White×Landrace gilts (n=641) were fed corn-soybean diets differing in SID lysine concentration (%, g SID lysine:Mcal ME); diets were not isocaloric. Gilts received three grower, finisher diet combinations: low (0.68% lysine grower, 0.52% lysine finisher), medium (0.79% lysine grower, 0.60% lysine finisher) or high (0.90% lysine grower, 0.68% lysine finisher). Grower diets were fed from 100 until 142days of age, and finisher diets were fed until they reached 220days of age. Body weight (BW), backfat thickness (BF), and loin depth (LD) were recorded every 28days. From 160-220days of age, gilts were exposed daily to vasectomized boars and observed for behavioral estrus. Gilts fed the low lysine diet had lower average daily gain and BW (P<0.05), but not fat depth:LD ratio. The percentage of gilts that displayed natural estrus by 220days of age was low but not different among dietary treatments (low 27.7%, medium 31.0% and high 37.7%, respectively; P=0.1201). Gilts fed the high and medium diets reached puberty 10 and 6days earlier, however, than gilts fed the low lysine diet (P<0.05). The rate of puberty attainment may have been less because all gilts contracted porcine epidemic diarrhea (PEDv) just as boar exposure was to begin for the first group of gilts. Results from the present study indicate that growth rate and age at puberty can be altered by ad libitum fed diets that differ in SID lysine concentration.