Animal - Open Space最新文献

Adding fiber-rich materials to poultry feed can reduce feed cost, but it increases the content of both soluble and insoluble non-starch polysaccharides (NSPs) which decreases nutrient availability. A multiactivity enzyme, AveMix® XG 10 containing glucanase and xylanase, has been developed to ensure the breakdown of the total NSP of fiber-rich feed. A meta-analysis was performed to quantify the effects of this enzyme on the growth performance and nitrogen (N) utilization of broilers, and identify potential modulating factors. The database was made up of 18 trials for a total of 110 dietary treatments conducted between 2003 and 2021. Broilers were fed either based on wheat or corn, and these received a different coding for statistical analysis. The experimental groups were control diets without enzyme or diets with supplementation of the enzyme (ranging from 25 ppm to 100 ppm). Two sub-databases were created to study the impact of growth phase, one for starter (first phase beginning before 7 days of age; 45 dietary treatments) and another for grower/finisher (ending before or at 42 days of age; 65 dietary treatments). Performance criteria were average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR). During the starter phase, enzyme supplementation at 100 ppm linearly increased ADG (0.81 g/d; P < 0.001) and had no impact on ADFI and FCR. During the grower/finisher phase, 100 ppm supplementation increased the ADG of broilers fed with wheat by 6.89 g/d and by 0.58 g/d for the broilers fed with a corn-based diet (Enzyme, P < 0.001; Enzyme × Diet type, P < 0.001). FCR was beneficially reduced by 0.165 for the broilers fed with wheat, and by 0.0471 for the broilers fed with corn (Enzyme, P < 0.001; Interaction Enzyme × Diet type, P = 0.049). ADFI was unaffected by enzyme supplementation. Analysis of N balance during the increased N retained with enzyme in the starter (P = 0.039). During the grower/finisher phase, the enzyme increased N retained (P < 0.001) and N efficiency (P < 0.001), and decreased N excreted (P < 0.001). An interaction between enzyme supplementation and diet type for N retained (P = 0.002) and N efficiency (P = 0.010) occurred due to a higher impact on wheat-based diets. This study shows that the use of AveMix® XG 10 improves the broiler growth performance and N efficiency. These improvements are found to be greater with wheat- vs corn-based diets in the grower/finisher phase.

Heat stress is a major factor affecting animal productivity in tropical countries, with effects on physiological, hormonal, and behavioral responses. This study aimed to assess the differences in these responses between heat-tolerant and less heat-tolerant hair sheep during heat stress. Twenty-four Santa Ines sheep were selected from a group of 80 sheep, with 12 identified as heat-tolerant and 12 as less heat-tolerant based on thermotolerance assessment. The animals were exposed to heat stress in a climatic chamber at an average temperature of 36 °C (1000–1600 h) for 8 days and maintained at 28 °C (1600–1000 h). The rectal temperature, respiration rate, sweat rate, ocular surface temperature, body surface temperature, tympanic temperature, triiodothyronine level, and insulin level were measured. Skin samples were collected on the last day of the cycle for histological analysis. The results showed that the less heat-tolerant sheep had higher rectal and body surface temperatures (P < 0.05). Although no differences in skin morphology were observed between the groups, less heat-tolerant sheep continued to sweat for a longer period after the end of the thermal challenge to lose heat (P < 0.05). Less heat-tolerant animals also presented higher rectal temperatures during cooler hours and required more time to dissipate the excess heat. These findings suggest that there are individual differences in the thermoregulatory responses within the same breed under the same environmental conditions, and that breeding programs could be employed to produce more heat-tolerant, but still productive animals in tropical conditions.

This meta-analysis comprehensively evaluates the impact of production diseases on dairy cattle, examining a variety of physiological, metabolic, and behavioral traits. From an initial set of 3 349 records, a rigorous selection process resulted in 56 relevant articles, highlighting the strict criteria employed. The low inclusion rate of 1.67% underscores the dedication to studying quality and significance. Common reasons for exclusion, such as statistical methodology and the lack of a negative control group, emphasize the necessity for robust scientific investigation. The study reveals key indicators of production diseases, such as decreased milk production, weight loss, a low body condition score, digestive disorders, lameness, and respiratory distress. These findings align with existing knowledge, emphasizing the multifaceted nature of production diseases and their broad impact on dairy cattle health. Diseased animals consistently exhibit higher parameter values, supported by confidence intervals that indicate result precision. Subgroup analyses offer nuanced insights into the specific effects of diseases and interventions on different characteristics. Metritis and Mastitis significantly affect milk production, highlighting the economic implications for dairy farmers. Interventions such as improved milking techniques show promise. Similarly, interventions involving veterinary medications and controlled energy diets effectively mitigate weight loss, a low body condition score, and digestive disorders. The analysis underscores the vulnerability of dairy cattle to reproductive issues, metabolic imbalances, and increased susceptibility to infections. Interventions addressing these challenges include hormone therapy, balanced diets, and vaccination programs. Behavioral changes and feeding habits emerge as significant indicators of dairy cattle well-being. Ovarian cysts are identified as a major contributor to behavioral changes, necessitating targeted interventions. In conclusion, this meta-analysis provides valuable contributions to the field of dairy cattle health, offering specific insights into the effects of diseases and the effectiveness of interventions. These findings inform evidence-based practices for dairy stakeholders, ultimately enhancing animal welfare and promoting sustainable dairy production. However, establishing precise reference values presents challenges, warranting further investigation.

A low CP diet is an efficient strategy to decrease the environmental footprint of chicken farms, but this requires a precise knowledge of the requirements for essential amino acids (AAs). Many dose–response studies of valine have sought to estimate the standardized ileal digestible (SID) Valine (Val) requirement. Requirements vary because of many factors, such as differences in broiler ages, genetic strains, basal diet nutritional composition, and statistical model used. The purpose of this study was to estimate the Val requirement of broilers through a meta-analysis performed in two ways: first, based on amino acid requirements (AminoAcidDB); and second, based on the significant response (ResponseDB) of broilers to SID Val supply. The first database includes 8 papers describing 11 experiments and 63 treatments. The second database includes 17 papers describing 26 experiments and 144 treatments. The quadratic (QD) and curvilinear-plateau (CLP) models were tested to estimate the SID Val:Lysine (Lys) requirement using the average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F) as response criteria. The ADFI did not converge with the CLP model in either database. When using the AminoAcidDB with the QD model, the estimated SID Val:Lys requirements (95% of the maximum) were ADG of 84.6%, ADFI of 76.7%, and G:F of 88.6%. With the CLP model, ADG was 82.4% and G:F was 87.1%. In the ResponseDB using the QD model, the SID Val:Lys requirements were 82.0% for ADG, 80.9% for ADFI, and 79.0% for G:F; the CLP model predicted 84.5% for ADG and 83.6% for G:F. This study also confirmed the presence of interactions between branched-chain AA and their impact on broiler performance, with Leu appearing to be the main regulator. In light of this meta-analysis, Val recommendations appear to be underestimated and should consider the influence of other AAs on the response. The results of this meta-analysis will facilitate the implementation of the low CP strategy without affecting broiler performance.

The use of organic Zn sources has been claimed to reduce the environmental impact of poultry production and improve broiler performance and the quality of products. This study investigated the effects of three organic Zn supplementation strategies (i.e., TRE, total replacement; PRE, partial replacement; OTS, on-top supplementation) on tibia and blood biochemistry characteristics of broilers at high altitudes. Male Cobb 500 chicks were distributed in 54 floor pens (22 birds each) and assigned to nine experimental treatments. Birds were fed mash diets under three feeding phases until 42 days and following the standard Ecuadorian high-altitude production standard practices. The treatments were a basal diet supplemented with three inclusion rates of ZnSO₄ and the same diets including or not Zn from one of two organic Zn sources (i.e., ZPR, Zn proteinate; ZAC, Zn amino acid complex). Basal diets were analyzed for Zn concentration. Tibia ash and Zn concentrations and serum biochemistry variables were determined at 21 and 42 days. The strategies to supplement organic Zn were compared with the reference treatment containing 100 ppm Zn as ZnSO₄ (the standard practice; STD) using mixed models, being the block (i.e., the replication) as a random factor. The interaction of the strategy with the organic Zn source was assessed with the ANOVA and multiple comparisons. The organic Zn sources were compared considering the feed intake a random factor, and their interaction with the dietary Zn level was assessed using multiple regression. No overall effect of the Zn supplementation strategy was observed other than the reduced Zn concentration at 21 days in TRE birds. At 21 days, PRE and TRE increased the serum protein and phosphorus concentrations, respectively. At that age, TRE also increased insulin concentration, but only in the ZAC-fed birds. However, TRE produced the opposite effect on serum protein at 42 days. At the same age, ZAC-fed birds showed lower serum phosphorus concentration than ZPR-fed ones regardless of the dietary Zn supplementation level or the Zn intake. Also, ZAC under TRE produced no effect on tibia Zn concentration compared to STD, but ZPR increased it. The ZPR increased the tibia Zn concentration when fed under PRE or TRE, but not under OTS. In conclusion, the results showed no adverse effect of PRE or TRE strategies on tibia characteristics. The data indicate likely different effects of PRE and TRE on protein metabolism and a possible negative interaction of the organic Zn with a high Zn content as ZnSO₄.

Feeding broilers with organic chemical sources of Zn has recently been recommended to improve performance, immune system, carcass yield, and reduce environmental contamination. However, its use under proposed supplementation strategies (i.e., total replacement, partial replacement, on-top) needs further investigation. This study assessed the effect of total replacement, partial replacement, and on-top supplementation strategies to feed organic Zn sources and the effect of two organic chemical forms on performance and Zn excretion in broilers at high altitudes. Twenty-two male Cobb 500-day-old chicks were placed in each of 54 floor pens and raised for up to 42 days under a three-phase feeding program and following the Ecuadorian highland production system. Pens were assigned to one of nine experimental treatments consisting of a basal diet supplemented with 0, 33, and 100 ppm of Zn from ZnSO₄ and added or not 40 ppm Zn from Zn proteinate or Zn amino acid complex. A Completely Randomized Block Design was considered, being the block the replication. The Zn concentration of the basal diet was determined. Feed intake, BW, BW gain, feed conversion ratio, and European Production Efficiency Factor were assessed at 21 and 42 days of age, and the Zn excretion was estimated accordingly. Each supplementation strategy was compared with the standard practice (100 ppm Zn as ZnSO₄) using contrasts and mixed models, and the interaction with the chemical form was assessed considering the P-values of the ANOVA and the multiple comparisons between the corresponding treatments. The effects of the organic Zn forms and their interactions with the dietary Zn level were assessed considering the responses were linear functions of the organic Zn source, the feed intake, the Zn intake, the Zn supplementation level, and the block, as corresponding. None of the strategies to supplement a Zn organic source, or the organic sources themselves, showed overall detectable effects on performance. However, interactions were observed between the supplementation strategy and the organic Zn source and between the organic source and the dietary Zn levels or the Zn intake. Under the on-top supplementation strategy, the Zn organic sources showed different feed conversion ratios at 21 days. In addition, totally or partially replacing the ZnSO₄ with a Zn organic form reduced the Zn excretion. In conclusion, although no overall effect of the supplementation strategies was detected, the assessed organic Zn forms showed different effects on the feed conversion ratio at 21 days.

High-energy diets increase the risk of subacute ruminal acidosis (SARA) in ruminants. Ruminants with SARA show behavioural modifications. However, behavioural changes due to high-energy diet are often confounded with the behavioural changes due to SARA per se. Here, we aimed to disentangle diet-induced effects from SARA-induced effects on cow behaviour. We fed Holstein cows with either a low-starch diet (10.5% starch) or a high-starch diet (31.5% starch) while monitoring their SARA status. Control cows (n = 14) received the low-starch diet for 60 days. Challenge cows (n = 14) received the same low-starch diet except for 10 days when they were gradually switched from the low- to the high-starch diet and the next 14 days when they were fed the high-starch diet only. The eCow rumen bolus and the CowView activity-collar sensors were used to track the rumen pH and cows’ activities. DM intake (DMI) and milk yield of each cow were assessed on a daily basis. SARA status was defined based on a relative decrease in ruminal pH and pH variability. The high-starch diet induced SARA more often than the low-starch diet (SARA on 81% of days when receiving high-starch diet vs 8% of days when receiving low-starch diet). Cows on the high-starch diet also showed decreased milk yield and spent less time eating but ate more quickly (Challenge vs Control cows during the challenge period: milk yield 20.0 vs 18.2 L/d; % time spent eating, 22.5 vs 27.6; eating rate, 77.1 vs 69.6 g DMI/min; P (diet × period) <0.001 in all cases). Cows experiencing SARA during transition or challenge periods also tended to show lower milk yield, less time spent eating, and an increase in eating rate regardless of diet (Challenge vs Control cows: milk yield, −0.5 and −0.3 L/d, P (SARA) = 0.03; % time spent eating, −1.4 and −0.84, P(SARA) = 0.02; eating rate, +4.9 and +3.2 g DMI/min, P(SARA) = 0.06; P (diet × SARA) > 0.50). Based on these findings, an increase in eating rate, especially when combined with a decrease in milk yield, should alert farmers to the risk of ruminal acidosis.

Family succession is one of the most challenging problems of governance in agricultural systems in Brazil and worldwide. Dairy systems require particular attention in this regard, given their economic and social importance. Family succession necessitates a transfer plan for passing leadership over the dairy farm, usually from parents to their children. In this study, we sought to identify the influence of sociopsychological constructs of the theory of planned behavior on dairy farmers' intention to adopt succession planning. Questionnaires were administered to 160 dairy farmers in Paraná State, Brazil. Data were analyzed using correlation analysis and structural equation modeling. The results showed that social pressure – subjective norms was the construct that most influenced farmers' intention to adopt succession planning, followed by attitude toward the adoption of succession planning. Farmers' perceptions of their ability to carry out succession planning – perceived behavioral control did not influence their intention to adopt this strategy. There was a significant positive correlation of farm size and number of lactating cows with intention to adopt succession planning, indicating that large-scale farmers have a higher probability of practicing succession planning.

The objective of this study was to evaluate, through a life cycle assessment, the environmental impacts of the postweaning growth of pigs fed with diets with reduced levels of available phosphorus and increased phytases. In Trial I (nitrogen and phosphorus balance), 25 crossbreed barrow pigs (BP 400 × BM 500 Biriba’s®), with an average weight of 23.05 ± 3.24 kg and average starting age of 60.75 ± 4.73 days, were assigned to five dietary treatments using a randomized block design, with five replications and each animal as an experimental unit. Five experimental diets were evaluated: each increasing phytase activity units (FTU) (control [0], 250, 500, 750 and 1 000 FTU) and decreasing levels of available phosphorus (0.435, 0.375, 0.315, 0.255 and 0.195%), respectively. Due to phytase supplementation, all diets meet the requirements for available phosphorus. The pigs received two daily meals. Total collection of feces was performed, adding 2 g of ferric oxide as a fecal marker. Feces were collected daily, stored in plastic bags and frozen. All excreted urine was collected in plastic buckets containing 20 mL of HCl (1:1), and a 20% aliquot was frozen for further analysis. In Trial II (performance), 40 crossbreed barrow pigs (BP 400 × BM 500 Biriba’s®) with an initial average weight of 15.11 ± 0.67 kg, average starting age of 50.63 ± 0.81 and finishing age of 72.43 ± 2.07 days were assigned using a randomized block design to five dietary treatments, with eight replications and each animal as an experimental unit. The pigs were weighed at the beginning and at the end of the trial, as were the feed supplies and refusals. These data were used to calculate the feed conversion ratio, average daily gain and average daily feed intake. The life cycle analysis was based on the CML 2001 (baseline) method V3.02, as implemented in the Simapro software, version 8.05 (PRé Consultant, 2014). These data may further serve as a reference for the study of the impact of phytase supplementation during other breeding phases, or even in other animals whose environmental impacts are being studied.