Effect of growth rates on hormonal and pubertal status in Nellore heifers early weaned.

This study aimed to determine the effect of growth rates on the hormonal status and puberty onset. Forty-eight Nellore heifers were weaned at 3.0 ± 0.1 (means ± standard error of the mean) months old were blocked according to body weight at weaning (84 ± 2 kg) and randomly assigned to treatments. The treatments were arranged in 2 × 2 factorial according to the feeding program. The first program was high (H; 0.79 kg/day) or control (C; 0.45 kg/day) average daily gain (ADG) from 3rd to 7th month of age (growing phase I). The second program was also high (H; 0.70 kg/day) or control (C; 0.50 kg/day) ADG from the 7th month until puberty (growing phase II), resulting in four treatments: HH (n = 13), HC (n = 10), CH (n = 13), and CC (n = 12). To achieve desired gains, heifers in high ADG program were fed ad libitum dry matter intake (DMI), and the control group was offered around 50% of ad libitum DMI of high group. All heifers received a diet with similar composition. Puberty was assessed weekly by ultrasound examination, and the largest follicle diameter was evaluated every month. Blood samples were collected to quantify leptin, insulin growth factor-1 (IGF1) and luteinizing hormone (LH). At 7 months of age, heifers in high ADG were 35 kg heavier than the control. Heifers in the HH had greater DMI compared with CH in phase II. The puberty rate at 19 months old was greater in the HH treatment (84%) than in the CC (23%), but there was no difference between HC (60%) and CH (50%) treatments. Heifers from HH treatment had greater serum leptin concentration than others at 13 months old, and serum leptin was greater in HH compared with CH and CC at 18 months old. High heifers in phase I had greater serum IGF1 concentration than the control. In addition, HH heifers had a greater diameter of the largest follicle than CC. There was no interaction between phases and age in any variable relative to the LH profile. However, the heifers' age was the main factor that increased the frequency of LH pulse. In conclusion, increasing ADG was associated with greater ADG, serum leptin and IGF-1 concentration, and puberty onset; however, LH concentration was affected mainly by age of the animal. The increasing growth rate at younger age made heifers more efficient.

Implications of growth rates and compensatory growth on puberty attainment in Nellore heifers.

This study investigated the effects of growth rates and compensatory growth on puberty attainment in Nellore heifers. Nellore heifers (n = 120), weaned at 8 ± 0.75 mo of age, were blocked by sire and BW (180 ± 8.6 kg) and assigned randomly to receive 1 of 4 treatments over a 10-mo period. Treatments included ad libitum feeding (high gain, HG), feed intake to gain 0.6 kg/d (medium gain, MG), restricted feeding (0.2 kg/d) for 4 mo followed by ad libitum feeding for 6 mo (compensatory gain, CG), and alternating periods of ad libitum and restricted feeding for 2 mo each throughout the trial (alternated CG, ACG). Puberty was assessed weekly by transrectal ultrasonography. Blood samples were collected at 8, 11, and 18 mo of age and at puberty to determine circulating concentrations of leptin. At 18 mo of age, nonpubertal heifers were treated with a puberty induction protocol using an intravaginal progestin device. There was no treatment effect (P = 0.17) on the percentage of heifers pubertal by 18 mo of age (HG: 66, MG: 40, CG: 58, and ACG: 52%), BW at puberty, and age at puberty. However, HG heifers had higher ADG (P < 0.01), dry matter intake (P < 0.01), and leptin concentrations (P = 0.03) than heifers from other groups. The response to the puberty induction protocol was similar (P = 0.90) among treatments. Regarding sire effects (genetic effects), there was an effect (P = 0.03) on the percentage of heifers pubertal by 18 mo of age and a tendency (P = 0.07) of sire effect in response to the puberty induction protocol. Compensatory growth appears to be an effective managerial approach to decrease feeding costs and stimulate puberty in Nellore heifers.

Effect of thyme essential oil on rumen parameters, nutrient digestibility, and nitrogen balance in wethers fed high concentrate diets / Efeito do óleo essencial de tomilho sobre os parâmetros ruminais, a digestibilidade dos nutrientes e o balanço de nitrogênio em borregos alimentados com elevado teor de concentrado

This trial aimed to evaluate the effects of thyme essential oils (EO) on rumen parameters, nutrient digestibility and nitrogen balance in wethers fed with high-concentrate diet. Twenty rumen-cannulated wethers were blocked according to body weight (BW= 64.0±2.1kg), and received one of the following treatments: 25mg of monensin/kg of dry matter (DM; MON) or doses of thyme EO (1.25, 2.50 or 3.75g/kg of DM). The diet was composed of 90% concentrate. Thyme EO was composed mainly by thymol (46.6% of DM) and p-cymene (38.9% of DM). The nutrient intake and apparent digestibility were similar among treatments. The inclusion of 3.75g of thyme EO tended (P= 0.07) to increase butyrate compared to MON and 1.25OE and wethers fed with 1.25g of thyme EO tended (P= 0.07) to decrease ruminal pH on the 14th day compared to MON. The treatments did not affect acetate:propionate ratio, total short chain fatty acids (SCFA) and nitrogen retention. Results from this study suggest that adding thyme EO to high-concentrate diets may be used as an alternative to monensin as feed additive in feedlot lambs.(AU)

O objetivo do estudo foi avaliar os efeitos do óleo essencial (OE) de tomilho nos parâmetros ruminais, na digestibilidade e no balanço de nitrogênio em borregos alimentados com elevado teor de concentrado. Vinte borregos providos de cânulas ruminais foram blocados de acordo com o peso corporal (PC=64,0±2,1kg) e receberam um dos tratamentos: 25mg de monensina/kg de matéria seca (MS; MON) ou doses de OE de tomilho (1,25; 2,50 ou 3,75g/kg de MS). A dieta foi composta por 90% de concentrado. A composição do OE de tomilho foi principalmente timol (46,6% da MS) e p-cimeno (38,9% da MS). A ingestão e a digestibilidade dos nutrientes foram semelhantes entre os tratamentos. A inclusão de 3,75g de OE de tomilho tendeu (P=0,07) a aumentar o butirato em relação aos tratamentos MON e 1,25OE. Os borregos alimentados com 1,25g de OE tenderam (P=0,07) a apresentar menor pH ruminal no 14º dia comparado a MON. No entanto, os tratamentos não afetaram a relação acetato:propionato, concentração total de ácidos graxos de cadeia curta e retenção de nitrogênio. Os resultados sugerem que a adição de OE de tomilho em dietas com elevado teor de concentrado pode ser uma alternativa à monensina como aditivo alimentar para cordeiros em confinamento.(AU)

Thyme essential oil for sheep: effect on rumen fermentation, nutrient digestibility, nitrogen metabolism, and growth / Óleo essencial de tomilho para ovinos: efeito na fermentação ruminal, na digestibilidade dos nutrientes, no metabolismo de nitrogênio e no crescimento

Two experiments were conducted to evaluate the effect of thyme (Thymus vulgaris) essential oil (EO) doses on rumen fermentation, nutrient digestibility, and nitrogen metabolism, as well as performance and coccidia oocyst discharge. In experiment I, 20 rumen-cannulated wethers received the experimental diets containing 80% dry matter (DM) of haylage and 20% DM of concentrate. Treatments were 25mg of monensin/kg DM or doses of 1.25, 2.50, or 3.75g of thyme EO/kg DM. In experiment II, 50 ewe lambs received the same diets from experiment I, including a diet without feed additives. Wethers fed with diets containing 1.25g/kg DM of thyme EO had higher molar proportion of propionate (P= 0.03) and butyrate (P< 0.01), and lower (P= 0.04) acetate to propionate ratio than other treatments. Adding thyme EO to diets increased (P= 0.02) nitrogen retention compared to monensin. The performance of ewe lambs was not affected (P≥ 0.05) by treatments. However, lambs fed monensin had a lower (P= 0.04) number of coccidia oocyst discharge than others. Adding 1.25g/kg DM of thyme EO in high-forage diet improved ruminal fermentation. Thyme EO enhanced nitrogen metabolism, however, it did not improve performance.(AU)

Dois experimentos foram conduzidos para avaliar o efeito de doses de óleo essencial (OE) de tomilho (Thymus vulgaris) sobre a fermentação ruminal, a digestibilidade de nutrientes e o metabolismo de nitrogênio, bem como sobre o desempenho e a descarga de oocistos de coccídeos. No experimento I, 20 ovinos canulados receberam dietas experimentais contendo 80% de matéria seca (MS) de pré-secado e 20% de MS de concentrado. Os tratamentos foram 25mg de monensina/kg de MS ou doses de 1,25, 2,50 ou 3,75g de OE de tomilho/kg de MS. No experimento II, 50 borregas receberam as mesmas dietas do experimento I, incluindo uma dieta sem aditivos. Os animais alimentados com dietas contendo 1,25g de OE de tomilho apresentaram maior proporção molar de propionato (P=0,03) e de butirato (P<0,01) e menor (P=0,04) relação acetato/propionato do que outros tratamentos. A adição de OE de tomilho nas dietas aumentou (P=0,02) a retenção de nitrogênio em comparação com a monensina. O desempenho de cordeiros não foi afetado (P≥0,05) pelos tratamentos. No entanto, cordeiros alimentados com monensina apresentaram menor (P=0,04) número de oocistos de coccídeos. A adição de 1,25g/kg de MS de OE de tomilho na dieta forrageira melhorou o perfil da fermentação ruminal. O OE de tomilho aumentou a retenção de nitrogênio, no entanto não melhorou o desempenho.(AU)

Carcass characteristics and meat quality of Nellore bulls submitted to different nutritional strategies during cow-calf and stocker phase.

There have been few studies realized that evaluate the effects of adopting different nutritional systems in more than one phase of cattle production on carcass and meat characteristics. This study was realized to evaluate carcass and meat characteristics from bulls submitted to different nutritional systems during two production phases. The experiment was conducted at Figueira's farm during two production phases: I (cow-calf) - 80 calves (99.6±2.72 days of age and 109.7±2.99 kg of BW) with their mothers were randomly assigned into two supplemental diets: cow-calf mineral supplement (n=40) or cow-calf creep-feeding (n=40); II (stocker) - the same 80 calves (201.2±2.11 days of age and 190.2±3.37 kg of BW) were redistributed into two production systems: stocker pasture (n=40) or stocker feedlot (SF; n=40). After, all 80 animals were kept on a pasture system (III) for 290 days, and then finished in a feedlot system (IV) for more 33 days. Then, they were slaughtered at an average 764.2±3.06 days of age and at 499.2±3.33 kg of final BW. After slaughter, the average daily gain was calculated, and the carcass and meat characteristics were measured. The statistical model design used was completely randomized in a 2×2 factorial arrangement (two treatment groups on cow-calf phase and two treatment groups on stocker phase). The single effects between the groups in each phase and the interactions between both phases (cow-calf v. stocker) were analyzed. The results were compared by Fisher's test, using the R statistical software. A cow-calf by stocker phases interaction occurred for carcass conformation and fiber diameter. For single effects, the greatest influences observed were in the stocker phase. The feedlot group was slaughtered 17 days earlier, with greater final BW (3.8%), hot carcass weight (5.7%), average daily gain (6.9%), dressing percentage (1.8%), carcass length (1.8%), carcass width (1.5%), longissimus muscle area (4.8%) and muscle depth (2.3%) than pasture group. The SF group also had influence on fat color; showing higher L* and lower b* values. These results reveal that bulls reared in feedlot at the stocker phase have higher muscle development and that the stocker phase has the greatest potential to influence carcass characteristics and meat quality.

A combination of nutrition and genetics is able to reduce age at puberty in Nelore heifers to below 18 months.

Nelore heifers usually begin their reproductive life at ⩾24 months of age mainly due to suboptimal nutritional conditions and genetics. This study aimed to determine the effect of expected progeny difference (EPD) for age at first calving and average daily gain (ADG) on puberty in Nelore (Bos taurus indicus) heifers. A total of 58 weaned heifers (initial BW=174±6 kg; age=9±1 months) were allocated into 28 feedlot pens. Heifers were born from four sires, of which two had low EPD for age at first calving (L; n=33) and two had high EPD for age at first calving (H; n=25). Then, heifers of each EPD were randomly assigned to high ADG (HG; 0.7 kg) or low ADG (LG; 0.3 kg), resulting in four treatments: heifers from L sires were submitted to either HG (LHG; n=17) or LG (LLG; n=16), and heifers from H sires were submitted to either HG (HHG; n=12), or LG (HLG; n=13). The HG heifers were fed a 75% grain diet, whereas the LG heifers received 93% of forage in their diet. Blood samples were collected at 9, 14, 18, 24 and 28 months of age for IGF1 and leptin determination. There was a treatment effect (P<0.01) on the proportion of heifers that attained puberty by 18 (62%, 0%, 0% and 0%), 24 (100%, 6%, 54% and 0%) or 36 (100%, 100%, 100% and 38%) months of age for LHG, LLG, HHG and HLG treatments, respectively. In addition, mean age at puberty was different across treatments (P<0.01). Heifers from the LHG achieved puberty at the earliest age when compared with cohorts from other treatments (18.1, 28.9, 23.9 and 34.5 months for LHG, LLG, HHG and HLG, respectively). Serum IGF1 concentrations were higher for L heifers compared with H cohorts at 9, 14, 18, 24 and 28 months of age (P<0.01; treatment×age interaction), whereas circulating leptin concentrations were higher (P<0.01; age effect) as heifers became older, regardless of the treatments. In conclusion, only Nelore heifers with favorable genetic merit for age at first calving were able to attain puberty by 18 months of age. In heifers with unfavorable genetic merit for age at first calving, supplementary feeding to achieve high ADG was unable to shift the age at puberty below 24 months.

Desempenho e características de carcaça de três genótipos comerciais de frangos de corte alimentados com diferentes dietas / Performance and carcass traits of three commercial broiler genotypes fed different diets

Este estudo teve como objetivo avaliar o desempenho e as características de carcaça de frangos de corte de três genótipos comerciais do nascimento aos 35 dias de idade. Utilizou-se um total de 2.970 pintos de três genótipos de aves comerciais (Cobb 500, Hubbard Flex e Ross 308). Os programas nutricionais foram dieta basal, dieta com 10% mais e 10% menos de aminoácidos do que a dieta basal. As aves foram distribuídas em delineamento inteiramente ao acaso, em esquema fatorial 3x3x2 (genótipo x dieta x sexo), com cinco repetições e 33 aves por unidade experimental. Conversão alimentar, ganho de peso diário, ingestão da dieta e peso corporal aos 35 dias de idade foram registrados. Duas aves de cada unidade experimental foram amostradas e abatidas aos 35 dias de idade para avaliar as seguintes características de carcaça: peso corporal no momento do abate, peso da carcaça e rendimento, e peso e rendimento dos cortes (peito, pernas e asas). Houve uma interação significativa entre o genótipo e sexo para GPD e PC35. Os machos apresentaram melhores desempenhos e características de carcaças do que as fêmeas.(AU)

This study aimed to evaluate performance and carcass traits of three commercial broiler genotypes from hatch to 35 days of age. A total of 2,970 sexed one day old chicks of three commercial broiler genotypes (Cobb 500, Hubbard Flex and Ross 308) were used. The nutritional programs were basal diet, diet with 10% more and 10% less amino acids than the basal diets. Birds were distributed in a completely randomized experimental design in a 3x3x2 (genotype x diet x sex) factorial scheme, with five replicates and 33 birds per experimental unit. Feed conversion, daily weight gain, diet intake and body weight at 35 days of age were recorded. Two birds from each experimental unit were sampled and slaughtered at 35 days of age to evaluate the following carcass traits: slaughter body weight, carcass weight and yield, and main cuts (breast, legs and wings) weight and yield. There was a significant interaction between genotype and sex for ADG and BW35. Males fed basal diets presented higher performance and carcass traits in comparison to females.(AU)

Crude glycerin decreases nonesterified fatty acid concentration in ewes during late gestation and early lactation.

Crude glycerin is a gluconeogenic substrate in ruminants and may help to decrease the occurrence of pregnancy toxemia. The objective in this trial was to determine the effects of feeding a diet containing crude glycerin on DMI, milk yield, milk composition, and blood metabolites in periparturient ewes and lamb performance. One hundred eighteen 90 (±1.1)-d pregnant Santa Inês ewes were used. After lambing, 32 ewes (62.8 ± 1.3 kg BW) were allotted in a randomized complete block design defined by prelambing diet, BW, BCS, lambing date, type of birth (single or twin), and sex of offspring. Diets were isonitrogenous (13.0 ± 0.3% CP, DM basis), composed of concentrate and raw sugarcane bagasse (70:30 ratio, DM basis), and fed ad libitum daily. Crude glycerin (83.6% glycerol) levels were 0 or 10% (DM basis), corresponding to the experimental diets G0 and G10, respectively. From 8 until 56 d of lactation, DMI was determined. In the same period, once a week at 1000 h, the ewes were separated from the lambs and mechanically milked after intravenous administration of 10 IU of synthetic oxytocin. Three hours after the first milking, ewes were milked again and milk yield and composition were determined. Glucose, NEFA, and ß-hydroxybutyrate (BHBA) were determined at -14, -7, 0, 7, 14, 28, and 56 d relative to lambing and insulin was determined at -14, -7, 0, and 7 d. Crude glycerin did not affect DMI (2.2 kg/d for G0 vs. 2.2 kg/d for G10; = 0.93) or milk production (171 g/3 h for G0 vs. 164 g/3 h for G10; = 0.66). However, there was a decrease ( = 0.01) in milk fat percentage (8.1% for G0 vs. 7.0% for G10) for ewes fed glycerin. Ewes fed the G10 diet had decreased ( < 0.01) NEFA concentration (0.27 mmol/L for G0 vs. 0.18 mmol/L for G10). There was an interaction between diet × time for glucose ( = 0.04), insulin ( = 0.05), and BHBA ( = 0.01); feeding glycerin increased glucose (5.61 mmol/L for G0 vs. 7.42 mmol/L for G10; < 0.01) and insulin concentrations (10.5 µIU for G0 vs. 24.5 µIU for G10; < 0.01) at parturition compared with G0. The BHBA was less ( = 0.02) on the day of lambing (0.40 mmol/L for G0 vs. 0.29 mmol/L for G10) and it was greater ( < 0.01) on d 56 for ewes fed the G10 diet (0.46 mmol/L for G0 vs. 0.61 mmol/L for G10). There was no effect of diets fed to ewes on lamb growth from birth to weaning. Crude glycerin improved energy balance of periparturient ewes, suggesting a reduced risk of developing clinical metabolic-related disorders. Crude glycerin can be added at 10% of ewes' diets without affecting DMI and milk yield.

Effects of temperament on physiological, productive, and reproductive responses in beef cows.

This experiment evaluated the effects of temperament on physiological, productive, and reproductive responses in beef cows. A total of 953 lactating, multiparous, non-pregnant Nelore cows (age = 99 ± 2 mo; days post-partum = 51.4 ± 0.3 d; BCS = 5.34 ± 0.04; BW = 430 ± 2 kg) were allocated into 8 groups of approximately 120 cows each. Groups were assigned to an estrus synchronization + timed-AI protocol at the beginning of the breeding season. Concurrently with AI, blood samples were collected, hair samples were clipped from the tail switch, and cow temperament was evaluated via chute score and exit velocity. Individual exit score was calculated within each group by dividing exit velocity into quintiles and assigning cows with a score from 1 to 5 (1 = slowest; 5 = fastest cow). Temperament scores were calculated by averaging cow chute score and exit score, and used to define cow temperament ( ≤ 3 = adequate, = 726; ADQ; > 3 = excitable, = 227; EXC). Cows not pregnant to AI were assigned to a second timed-AI protocol ( = 184 ADQ and 72 EXC) or exposed ( = 269 ADQ and 90 EXC) to bulls for 60 d. Pregnancy status was verified 30 d after each AI and 45 d after the breeding season via transrectal ultrasound. Cow age, BW, BCS, and d post-partum at the beginning of the breeding season were similar ( ≥ 0.27) between ADQ and EXC cows. At first timed-AI, EXC had greater ( < 0.01) serum cortisol but similar ( ≥ 0.87) serum haptoglobin and hair cortisol concentrations compared with ADQ cows (49.1 vs. 39.1 ng/mL of serum cortisol, SEM = 1.0). Pregnancy rate to first timed-AI tended ( = 0.09) to be less in EXC vs. ADQ cows (41.0 vs. 47.3%; SEM = 3.6), whereas no treatment differences were detected ( ≥ 0.23) for subsequent pregnancy outcomes. Calving rate was less ( = 0.04) in EXC vs. ADQ cows (68.3 vs. 74.8%; SEM = 2.2), which can be attributed to the greater ( = 0.05) pregnancy loss detected in EXC cows (9.9 vs. 5.9%; SEM = 1.4). Weaning rate tended ( = 0.09) to be less, whereas calf weaning BW and age were less ( ≤ 0.05) in EXC vs. ADQ cows (63.9 vs. 69.4%, SEM = 2.4; 209 vs. 212 d, SEM = 1; 204 vs. 210 kg, SEM = 2). Hence, kg of calf weaned/cow exposed to breeding was reduced ( = 0.04) in EXC vs. ADQ cows (130 vs. 146 kg, SEM = 5). In summary, cows with excitable temperament had reduced reproductive performance and overall productivity compared to cohorts with adequate temperament when exposed to timed-AI + natural breeding.

Post-artificial insemination supplementation with calcium salts of soybean oil influences pregnancy establishment factors in beef cows.

The objective of this experiment was to compare hormonal, uterine, and conceptus factors associated with pregnancy establishment in beef cows supplemented or not with Ca salts of soybean oil (CSSO) for 21 d beginning after timed AI. One hundred lactating multiparous Nelore cows were allocated to 20 groups of 5 cows/group and timed inseminated on d 0 of the experiment. After AI, groups were randomly assigned to receive (as-fed basis) 100 g of protein-mineral mix + 100 g of ground corn per cow per day, in addition to 1) 100 g/cow daily of CSSO ( = 10) or 2) 100 g/cow daily of kaolin (CON; rumen-inert indigestible substance; = 10). Groups were maintained in 4 pastures (5 groups from the same treatment within each pasture) with ad libitum access to forage. Groups were segregated daily and individually offered treatments from d 0 to 21. Blood samples were collected and transrectal ultrasonography was performed to verify ovulation and corpus luteum (CL) volume immediately before AI (d 0) and on d 7 and 15. After ultrasonography on d 15, 60 cows (30 cows/treatment and 3 cows/group) diagnosed without the presence of a CL on d 0 but with a CL greater than 0.38 cm3 in volume on d 7 and 15 were assigned to conceptus collection via transcervical flushing with PBS followed by endometrial biopsy in the uterine horn ipsilateral to the CL. Additional blood samples were collected for whole-blood RNA extraction (d 20), and pregnancy status was verified by transrectal ultrasonography (d 30) in cows not assigned to conceptus collection. Cows receiving CSSO had greater ( ≤ 0.04) mean plasma linoleic acid concentration, plasma linoleic:linolenic acid ratio, plasma progesterone (P4) concentration, and CL volume during the experiment compared with CON cows. Moreover, CSSO supplementation increased ( ≤ 0.04) length and mRNA expression of and by the conceptus as well as blood mRNA expression of interferon-stimulated genes on d 20 in gestating cows. No treatment differences were detected ( ≥ 0.30) for endometrial mRNA expression of and . In summary, post-AI CSSO supplementation to B. indicus beef cows increased plasma concentration of linoleic acid and enhanced pregnancy establishment factors, which included CL development and plasma P4 concentration, conceptus growth, and mRNA expression of as well as blood mRNA expression of interferon-stimulated genes.

Sensitivity of breeding values for carcass traits of meat-type quail to changes in dietary (methionine + cystine):lysine ratio using reaction norm models.

Our objective was to evaluate changes in breeding values for carcass traits of two meat-type quail (Coturnix coturnix) strains (LF1 and LF2) to changes in the dietary (methionine + cystine):lysine ([Met + Cys]:Lys) ratio due to genotype by environment (G × E) interaction via reaction norm. A total of 7000 records of carcass weight and yield were used for analyses. During the initial phase (from hatching to day 21), five diets with increasing (Met + Cys):Lys ratios (0.61, 0.66, 0.71, 0.76 and 0.81), containing 26.1% crude protein and 2900 kcal ME/kg, were evaluated. Analyses were performed using random regression models that included linear functions of sex (fixed effect) and breeding value (random effect) for carcass weight and yield, without and with heterogeneous residual variance adjustment. Both fixed and random effects were modelled using Legendre polynomials of second order. Genetic variance and heritability estimates were affected by both (Met + Cys):Lys ratio and strain. We observed that a G × E interaction was present, with changes in the breeding value ranking. Therefore, genetic evaluation for carcass traits should be performed under the same (Met + Cys):Lys ratio in which quails are raised.

Lisina digestível na ração de frangos de corte tipo caipira na fase de crescimento / Dietary digestible lysine in free-range broiler chickens during the growth phase

O presente experimento foi conduzido para determinar as exigências de lisina digestível para frangos de corte (linhagem Redbro), machos e fêmeas, durante o período de crescimento. Foram utilizados 630 frangos, alojados em 30 boxes com acesso à área de pastejo. O delineamento experimental utilizado foi o inteiramente ao acaso, em esquema fatorial 5x2 (lisina e sexo), e três repetições com 21 aves cada. Os níveis de lisina digestível avaliados foram: 7,07; 8,07; 9,07; 10,07 e 11,07g/kg. Avaliou-se o consumo de lisina, o consumo de ração, o ganho de peso e a conversão alimentar. Observou-se efeito de interação (P<0,05) entre os níveis de lisina e sexo para o ganho de peso. Houve efeito (P<0,01) dos níveis de lisina sobre o consumo de lisina, o ganho de peso e a conversão alimentar. Verificou-se que todas as variáveis foram influenciadas (P<0,05) pelo sexo dos frangos. Recomendam-se 10,08 e 9,49g de lisina digestível/kg de ração, correspondendo ao consumo estimado de 21 e 20g de lisina, para machos e fêmeas, respectivamente, para melhor ganho de peso das aves. Para melhor conversão alimentar, recomendam-se 9,61g de lisina digestível/kg, para frangos de ambos os sexos, correspondendo ao consumo estimado de 20g de lisina.(AU)

This experiment was conducted to determine the requirements of digestible lysine in male and female free-range broiler chickens (Redbro lineage) during the growth phase. Six hundred and thirty broiler chickens were allocated in 30 pens with access to the pasture area. The experimental design was completely randomized in a 5x2 (lysine and gender) factorial arrangement with 3 repetitions with 21 chickens each. The levels of digestible lysine evaluated were: 7.07, 8.07, 9.07, 10.07 and 11.07g/kg. The performance traits evaluated were lysine intake, feed intake, weight gain and feed conversion ratio. An interaction effect (P<0.05) was observed between dietary lysine level and gender for body weight gain. There was an effect (P<0.01) of the levels of lysine on lysine intake, body weight gain and feed conversion ratio. It was found that all the variables were affected (P<0.05) for the gender of chickens. We recommended 10.08 and 9.49 g of digestible lysine/kg diet, corresponding to the estimated intake of 21 and 20g of lysine, for males and females, respectively, for better body weight gain of chickens. For better feed conversion ratio, the recommendation is of 9.61 g of lysine/kg of diets, for chickens of both genders, corresponding to the estimated intake of 20g of lysine.(AU)

Flint corn grain processing and citrus pulp level in finishing diets for feedlot cattle.

Four trials were conducted to evaluate the effects of flint corn processing and the replacement of corn with citrus pulp (CiP) in diets for Nellore feedlot cattle. In a 103-d finishing trial, 216 Nellore bulls (350 ± 24 kg initial BW) were used in a randomized complete block design with a 2 × 4 factorial arrangement of treatments. Factors included 2 processing methods, either ground corn (GC) or steam-flaked corn (FC), with CiP replacing each corn type at 4 levels (0, 25, 50, and 75% of DM). All diets contained 12% sugarcane bagasse and 88% concentrate (DM basis). Treatments were also evaluated in metabolism trials, in which 10 ruminally cannulated Nellore steers (389 ± 37 kg) were assigned to 2 independent but simultaneous 5 × 5 Latin squares, each using 1 method of corn processing (GC and FC). Interactions ( < 0.05) between corn processing and CiP inclusion level were observed for final BW, DMI, ADG, G:F, and HCW. With FC-based diets, added CiP linearly decreased final BW ( = 0.04), whereas with GC-based diets, added CiP quadratically increased final BW ( = 0.002). With FC-based diets, the inclusion of CiP linearly increased DMI ( = 0.03) and linearly decreased ADG ( = 0.03) and G:F ( = 0.001). Increasing CiP in GC-based diets quadratically increased DMI ( = 0.001), ADG ( = 0.005), and HCW ( = 0.003). In FC-based diets, CiP inclusion had no effect on HCW ( = 0.21). Dressing percent, LM area, and 12th-rib fat were not affected by diet ( ≥ 0.05). For steers fed GC diets, CiP inclusion in the diet quadratically decreased the molar proportion of isovalerate ( = 0.001) but linearly increased ruminal butyrate ( = 0.006). No differences ( ≥ 0.16) were observed for total VFA concentrations, acetate:propionate ratio, and ruminal NH-N as CiP replaced GC. For steers fed FC diets, the molar proportion of acetate linearly increased ( = 0.002) whereas the proportion of propionate was linearly decreased ( < 0.001), resulting in a linear increase ( = 0.001) in the acetate:propionate ratio. Replacing corn with CiP linearly reduced NEm ( = 0.001) and NEg ( < 0.001) of FC-based diets but did not affect ( = 0.15) NE values of CG-based diets. Steam flaking flint corn improved cattle performance in this trial more than has been reported for dent corn in the published literature.

Comportamento ingestivo de bovinos leiteiros alimentados com farelo de crambe / Ingestive behavior of dairy catle fed crambe bran

O objetivo deste trabalho foi estudar os efeitos da utilização de farelo de crambe em substituição ao farelo de soja sobre o comportamento ingestivo de bovinos leiteiros. Foram utilizados quatro machos castrados Holandês x Zebu, fistulados no rúmen, com peso vivo médio de 664kg, distribuídos em delineamento quadrado latino 4 x 4. Os tratamentos consistiram em quatro dietas isoproteicas e isoenergéticas, formuladas com relação volumoso:concentrado 60:40 com base na matéria seca (MS). O volumoso foi composto de silagem de milho (51% MS) e feno de Tifton (49% MS), e o concentrado formulado com níveis crescentes de substituição do farelo de soja pelo farelo de crambe em 0%, 2,8%, 6,4% e 11,0% na MS da dieta. O comportamento ingestivo foi avaliado por meio do método direto de avaliação visual, em intervalos de 10 minutos, durante períodos de 24 horas. Registraram-se a frequência de alimentação, a ruminação e o ócio, bem como a posição do animal (em pé ou em decúbito). As variáveis em pé e em decúbito não diferiram entre os tratamentos, assim como os tempos gastos em alimentação, ruminação e ócio. O consumo de matéria seca e de FDN expressos em g/dia e gFDN/dia, respectivamente, a eficiência de ruminação expressa em gMS/min, a eficiência de ruminação expressa em gFDN/dia e o tempo de mastigação total não diferiram significativamente. No entanto, a eficiência de alimentação (gMS/min) variou de forma linear decrescente com a inclusão do farelo de crambe. Os períodos do dia influenciaram todas as atividades. O maior tempo de alimentação foi observado nos períodos após o fornecimento da dieta, e a maior atividade de ruminação foi verificada no período noturno. A substituição de farelo de soja por farelo de crambe não afetou o comportamento ingestivo, exceto para o parâmetro eficiência de alimentação. Nesse sentido, considerando o comportamento ingestivo, recomenda-se a substituição do farelo de soja por farelo de crambe para alimentação de bovinos leiteiros.

The aim of this work was to study the effects of the use of crambe meal replacing soy bean meal on the ingestive behavior of dairy cattle. Four male Holstein x Zebu rumen, with average live weight of 664 kg distributed in a 4x4 latin square design. The treatments consisted of four isonitrogenous and isocaloric diets, formulated with a roughage:concentrate ratio of 60:40 based on dry matter (DM). The forage was corn silage (51% DM) and Tifton grass hay (49% DM), and the concentrate was formulated with increasing levels of substitution of soy bean meal by crambe meal at 0%, 2.8%, 6.4% and 11.0% of the diet DM. The feeding behavior was evaluated using the direct method of visual assessment in 10 minute intervals during a 24 hour period. The frequency of feeding, idling time and the animal's position (standing or supine) were recorded. The variables standing and supine did not differ between treatments as well as time spent feeding, ruminating and idling times. The consumption of dry matter and NDF expressed in g/day and gNDF/day respectively, the efficiency of rumination expressed in gDM/min, the efficiency of rumination expressed in gNDF/day and the total chewing time did not differ significantly. However, the efficiency of power (gDM/min) decreased linearly with the inclusion of crambe meal. Periods of the day influenced all the activities. The longer feeding time was observed in the periods after the diet intake and greater rumination activity was observed at night. The replacement of soy bean meal by meal crambe did not affect feeding behavior, except for the feeding efficiency parameter. In this sense, considering the feeding behavior, the replacement of soy bean meal by crambe meal to feed dairy cattle is recommended.

Seleção para a produção de ovos em períodos parciais e acumulados em linhagem de frango de corte comercial / Egg production selection in partial and accumulated periods in a commercial broiler line

Objetivou-se com este estudo estimar parâmetros genéticos para produções parciais e acumuladas de ovos em uma linha fêmea de frangos de corte comercial. Foram considerados 10 períodos mensais entre 25 e 64 semanas, três períodos parciais de 25 a 32, 33 a 48 e 49 a 64 semanas, e três períodos acumulados de 25 até 30, 40 e 50 semanas de idade. Os componentes de covariância e parâmetros genéticos foram obtidos pelo método da máxima verossimilhança restrita, sob o modelo animal considerando o efeito fixo de incubação e os efeitos aleatórios genético aditivo e residual. As estimativas de herdabilidade variaram de 0,12 a 0,41. Evidenciou-se que os períodos anteriores e posteriores ao maior nível de produção apresentam maior variabilidade genética. As correlações genéticas entre os períodos de produção de ovos estudados variaram de -0,12 a 0,98. De modo geral, o padrão de variação foi semelhante entre as estratégias avaliadas, e todas foram geneticamente associadas com a produção total. Os resultados deste estudo mostraram que a melhoria da produção total é viável por meio de seleção de registros parciais. No entanto, caso se considere a eficiência relativa de seleção, o segundo mês e os períodos a partir da quadragésima semana de produção seriam os mais indicados.

The aim of this study was to estimate genetic parameters for partial and cumulative egg production in a commercial broiler female line. Ten monthly periods between 25 and 64 weeks, three partial periods of 25 to 32, 33 to 48 and 49 to 64 cumulative weeks and three periods of 25 to 30, 40 and 50 weeks of age and total egg production were considered. The restricted maximum likelihood method under the animal model was used to estimate the covariance components and genetic parameters. The fixed effect of incubation and the additive genetic and residual random effects were considered. The estimated heritability ranged from 0.12 to 0.41. These estimates showed that the anterior and posterior periods of the higher production have greater genetic variability. The genetic correlations between periods of the egg production studied ranged from -0.12 to 0.98. In general, the pattern of variation was similar between the strategies evaluated and all were genetically associated with the total egg production. The results of this study showed that the improvement of the total egg production is feasible by selection of partial records. However, considering the relative efficiency of selection, the second month and the periods from the fortieth week of production would be the most suitable.

Seleção e classificação multivariada de modelos não lineares para frangos de corte / Selection and classification of multivariate nonlinear models for broilers

Objetivou-se com este estudo utilizar a técnica de análise de agrupamento para classificar modelos de regressão não lineares usados para descrever a curva de crescimento de frangos de corte, levando em consideração os resultados de diferentes avaliadores de qualidade de ajuste. Para tanto, utilizaram-se dados de peso corporal e idade dos seguintes grupos genéticos de frangos de corte: Cobb500, Hubbard Flex e Ross308, de ambos os sexos, constituindo, assim, seis classes. Foram ajustados 10 modelos não lineares, cuja qualidade de ajuste foi medida pelo coeficiente de determinação ajustado, pelos critérios de informação de Akaike e bayesiano, pelo quadrado médio do erro e pelo índice assintótico. A análise de agrupamento indicou os modelos logístico, Michaelis-Menten, Michaelis-Menten modificado e von Bertalanffy como os mais adequados à descrição das curvas de crescimento das seis classes estudadas.

The aim of this study was to classify non-linear models used to describe the growth curve of broilers using the cluster analysis technique, taking into account the results of different measures of quality adjustment regression. For this purpose, we used data of body weight and age the following genetic groups of broilers: Cobb500, Hubbard Flex and Ross308, of both sexes, thus constituting six classes. Ten non-linear models were fitted, the quality of fit was measured by the adjusted coefficient of determination, Akaike information criteria and Bayesian, mean square error and index asymptotic. Cluster analysis indicated the Logistico, Michaelis Menten, Michaelis Menten Modificado and von Bertalanffy models as the most appropriate description of the growth curves for the six classes studied.

Modelos de norma de reação para estudo das características de qualidade da carne de codornas de corte em função das razões (metionina + cistina): lisina da dieta / Reaction norm models for the study of meat quality of european quail in function of (methionine + cysteine): lysine diet ratio

Objetivou-se avaliar a sensibilidade dos valores genéticos para características de qualidade da carne em codornas de corte alimentadas com dietas contendo diferentes relações de (metionina + cistina): lisina, do nascimento aos 21 dias de idade, por meio de modelos de normas de reação. Utilizaram-se 9011 informações de qualidade de carne referentes a 1400 progênies de 80 reprodutores e 160 matrizes de duas linhas (LF1 e LF2). Para o ajuste dos modelos de regressão aleatória, foi usado o programa WOMBAT, considerando-se nas análises homogeneidade de variância residual. As codornas foram alimentadas do nascimento aos 21 dias de idade com dietas contendo as relações 0,61; 0,66; 0,71; 0,76 e 0,81 de (metionina + cistina): lisina, mantendo os níveis de proteína bruta de 26,12% e de energia em 2900 kcal EM/kg da dieta. Dos 22 aos 35 dias de idade, todas as codornas foram alimentadas com dieta contendo 22% de proteína bruta e 3050 kcal EM/kg da dieta. As estimativas da variância genética e da herdabilidade foram influenciadas pelo gradiente ambiental e pela linha, com mudanças nessas estimativas com o aumento do gradiente ambiental. Os valores genéticos das características de qualidade de carne referentes a cada uma das linhas se alteraram com o aumento das relações de aminoácidos das dietas em razão das mudanças no ordenamento dos valores genéticos, evidenciando a existência da interação genótipo x nível de relação dos aminoácidos da dieta para características de qualidade de carne. Predições de valores genéticos de características de qualidade de carne com base em determinada relação de (metionina + cistina): lisina da dieta não são válidas para outras relações desses aminoácidos.

This study aimed to evaluate the sensitivity of breeding values for meat quality traits of European quails fed different (methionine + cystine): lysine ratio diets from hatch to 21 days of age, using reaction norm models. A total of 9011 meat quality records from 1400 progenies of 80 sires and 160 dams from two lines (LF1 and LF2) were used in the analyses considering homogeneity of residual variance. The quails from hatch to 21 days of age were fed diets containing 0.61, 0.66, 0.71, 0.76 and 0.81 (methionine + cystine): lysine ratios, 26.12% of crude protein and 2900 ME/kcal of diet. From 22 to 35 days of age all quail were fed a diet containing 22% of crude protein and 3050 kcal ME/kg of diet. The random regression model analyses was performed using the WOMBAT program considering homogeneity of residual variance. Genetic variance and heritability estimates were affected by the environment gradient of diet and line, increasing these estimates with the increase of the (methionine + cystine): lysine ratio of the diet. The breeding values changed with the increase of the environment gradient of the diet with changes in the rank of genetic breeding values characterizing the existence of genotype by environment interaction for meat quality traits. Predictions of meat quality trait breeding values based on a given (methionine + cystine): lysine ratio are not valid for other levels of the amino acid ratio.

Crescimento de codornas de diferentes grupos genéticos por meio de modelos não lineares / Growth comparison of different genetic groups using nonlinear models

Objetivou-se com o presente trabalho ajustar modelos não lineares para descrever o padrão de crescimento de genótipos de codornas de corte e de postura do nascimento aos 35 dias de idade. Foram utilizados dados de 1280 codornas machos e fêmeas, provenientes de sete genótipos de codornas de corte (EV1, EV2, UFV1, UFV2, UFV3, LF1, LF2) e um de postura. Todas as codornas foram pesadas a cada sete dias, do nascimento aos 35 dias de idade. Foram ajustados os modelos Brody, Gompertz, Logístico, Richards e von Bertalanffy aos dados de peso corporal de todos os genótipos. As análises estatísticas foram realizadas utilizando-se o PROC NLIN do SAS (Statistical Analysis System, versão 9.0). Os critérios empregados para a escolha do melhor modelo para descrever a curva de crescimento foram o coeficiente de determinação ajustado (R2), o desvio padrão assintótico (DPA), o desvio médio absoluto dos resíduos (DMA), o índice assintótico (IA), o critério de informação bayesiano (BIC), o critério de Akaike (AIC) e o quadrado médio do erro (QME). Todos os modelos não lineares testados convergiram, com exceção do modelo Brody, que não convergiu para nenhum genótipo avaliado. O modelo Richards não convergiu para o genótipo postura. Os parâmetros da curva de crescimento estimados pelos modelos indicaram maior precocidade, em geral, do genótipo postura comparado aos demais genótipos. O modelo Richards apresentou superestimação do ponto de inflexão para todos os genótipos, exceto para o genótipo postura. Os modelos Gompertz, Logístico e von Bertalanffy são recomendados para descrever o crescimento de codornas de corte dos grupos genéticos em estudo. O modelo Brody não convergiu, por isso não é recomendado para descrever o crescimento dos grupos genéticos de codornas em estudo.

This work aimed to adjust nonlinear models to describe the growth pattern of meat type and posture quail genotypes from hatch to 35 days of age. A total of 1280 male and female quails from EV1, EV2, UFV1, UFV2, UFV3, LF1 and LF2 and Posture genotypes were weighed every seven days, from hatch to 35 days of age. Brody, Gompertz, Logistic, von Bertalanffy and Richards models were used to fit the growth of the genetic groups. Statistical analyses were performed using PROC NLIN of SAS (Statistical Analysis System, version 9.0). The criteria used to select the model showing the best goodness of fit to the growth of the genotypes were: Adjusted Coefficient of Determination (R2), Asymptotic Standard Deviation (DPA), Absolut Mean Deviation (DMA), Asymptotic Index (AI), Bayesian Information Criterion (BIC), Akaike Information Criterion (AIC) and Errors Mean Square (MSE). All nonlinear models converged for the studied genotypes, except Richard the model for the Posture genotype. In general, the estimated parameters for the growth curve using nonlinear models suggested higher precocity for the Posture genotype in comparison to meat type genotypes. The Richard model overestimates the inflection point for all genotypes, except for the Posture genotype. The Gompertz, Logistic and von Bertalanffy are recommended to describe the growth patterns of the studied quail genetic groups. The Brody model did not converge and is not recommended to describe the genetic growth of the studied groups.

Divergência genética entre genótipos de frangos tipo caipira / Genetic divergence between genotypes of alternative strain of broiler chickens

Objetivou-se com este trabalho verificar a divergência genética entre sete genótipos de frangos tipo caipira da linhagem Redbro utilizando as características de desempenho por meio de técnicas de análise multivariada. Foram utilizados 840 pintos de um dia, machos, distribuídos em delineamento inteiramente ao acaso, dos seguintes genótipos: Caboclo, Carijó, Colorpak, Gigante Negro, Pesadão Vermelho, Pescoço Pelado e Tricolor. Após a consistência dos dados, foram avaliadas as seguintes variáveis: ganho em peso médio diário, consumo de ração médio diário e conversão alimentar, para os períodos: 1 a 28, 1 a 56, 1 a 70 e 1 a 84 dias de idade; peso corporal ao nascimento, aos 28, 56, 70 e aos 84 dias de idade. O desempenho dos genótipos 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 por variáveis canônicas e pelo método de otimização de Tocher. Os genótipos Caboclo e Gigante Negro apresentaram médias canônicas diferentes dos demais genótipos. As duas primeiras variáveis canônicas explicaram 97,41% da variação entre os genótipos. A divergência genética entre os genótipos avaliados permitiu a formação de quatro grupos com os seguintes genótipos: grupo 1 - Colorpak; grupo 2 - Pesadão Vermelho e Pescoço Pelado; grupo 3 - Carijó e Tricolor; e grupo 4 - Caboclo e Gigante Negro.

The aim of this study was to evaluate the genetic divergence among seven genotypes of alternative strain of broiler chickens of the Redbro strain using the performance characteristics using multivariate analysis. We used 840 day old male chicks, distributed in a completely randomized design, with the following genotypes: Caboclo, Carijó, Colorpak, Gigante Negro, Pesadão Vermelho, Pescoço Pelado and Tricolor. After the consistency of the data, the following variables were analyzed: average daily gain, average daily feed intake and feed conversion for the periods: 1 to 28, 1 to 56, 1 to 70 and 1 to 84 days of age, body weight at birth, at 28, 56, 70 and at 84 days old. The performance of genotypes was assessed by multivariate analysis of variance and Fisher's linear discriminant function, using the tests of the largest eigenvalue of Roy and the Roy union-intersection for multiple comparisons. The study of genetic diversity was done by canonical variate analysis and the method of Tocher. The genotypes Caboclo and Gigante Negro had different canonical averages from the other genotypes. The first two canonical variables accounted for 97.41% of the variation among genotypes. The genetic divergence between the genotypes allowed the formation of four groups with the following genotypes: group 1 - Colorpak, group 2 - Pesadão Vermelho and Pescoço Pelado; group 3 - Carijó and Tricolor, and group 4 - Caboclo and Gigante Negro.

Associação entre o óleo de soja e o óleo de peixe na dieta de cabras em lactação como estratégia para melhorar o perfil de ácidos graxos do leite / Association between soybean oil and fish oil in the diet of lactating goats as a strategy to improve milk fatty acids profile

Os objetivos neste experimento foram avaliar os efeitos da associação entre o óleo de soja e o óleo de peixe na dieta de cabras em lactação sobre o consumo de matéria seca e de nutrientes, a variação do peso corporal, a produção e composição do leite, assim como o perfil de ácidos graxos. As cabras foram alocadas em baias individuais, onde receberam dieta composta por 50% de feno de "coastcross" e 50% de concentrado. Foram utilizadas nove cabras mestiças Boer x Saanen multíparas, distribuídas em três quadrados latinos 3 X 3. O experimento teve duração de 51 dias, divididos em três períodos de 17 dias, sendo os 13 primeiros dias para adaptação dos animais às dietas e os 4 dias subsequentes para colheita de amostras e de dados. Os tratamentos experimentais foram: a) dieta controle (CT), sem adição de óleo; b) dieta contendo 3% de óleo de soja (OS); e c) dieta contendo 2,5% de óleo de soja + 0,5% de óleo de peixe (OS+P). A inclusão dos óleos reduziu (P<0,05) o consumo de matéria seca, no entanto aumentou (P<0,05) a eficiência alimentar dos animais, sem afetar (P>0,05) a produção de leite. Houve efeito (P<0,05) da dieta no perfil de ácidos graxos do leite, sendo que ambos os tratamentos com adição de óleo elevaram as concentrações de ácidos graxos de cadeia média e longa, reduzindo os de cadeia curta. O tratamento com a combinação do óleo de soja com o óleo de peixe foi o que promoveu os maiores aumentos na concentração de ácido vacênico (398%), rumênico (352%) e de CLA total (341%) no leite. Os resultados permitem concluir que a suplementação lipídica elevou a eficiência alimentar dos animais e que o fornecimento de óleo de soja em combinação ao óleo de peixe aumentou a concentração no leite dos ácidos graxos benéficos à saúde humana.

The aims in this experiment were to determine the effects of the association between soybean and fish oils on dry matter intake (DMI) and nutrient intake, body weight change, milk production and composition and milk fatty acid profile of dairy goats. The animals were housed in tie stalls and fed a 50% of coastcross hay and 50% concentrate diet. Nine multiparous crossbred Boer x Saanen goats were assigned in tree 3 X 3 Latin Squares. The experimental period lasted 51 days; divided into three periods of 17 days, being the first nine days used to adapt goats to diets and the 4 other days for data collection. Experimental diets were: a) control diet (CT) without oil; b) control diet supplemented with 3% of soybean oil (SO); and c) control diet supplemented with 2.5% of soybean oil plus 0.5% of fish oil (SO+F). DMI was negatively influenced by oil addition. However, feed efficiency was higher in diets with oils, maintaining similar milk production (P>0.05 for all comparisons). The supply of oils changed milk fatty acids profile (P<0.05), increasing the concentrations of medium and long-chain fatty acids and reducing short-chain. Milk from goats fed the SO+F diet had higher concentration of vaccenic (398%), rumenic acid (352%) and total CLA (341%). The results indicate that the oil supply increased the feed efficiency of goats, and that the combination of soybean and fish oils caused a higher elevation of fatty acids considered to have health benefits.