Thermoregulatory responses and ingestive behavior of sheep subjected to water restriction and high- and low-energy diets in a semi-arid environment.

The aim of the study was to evaluate the effect of water restriction and low- and high-energy diets on sheep's thermoregulatory responses and ingestive behavior. Forty sheep, non-castrated, with an average body weight of 18.85 kg (SD = 2.80 kg) and an average age of 5 months were assigned to a 2 × 2 factorial arrangement, comprising 2 diets (high- and low-energy) and 2 water offers (ad libitum and 50% water restriction), with 10 replicates. Thermoregulatory responses were evaluated in two periods (morning and afternoon). There was an interaction effect of Diet x Water supply x Periods on respiratory rate (P < 0.05). High-energy diets resulted in increased heart rate, idleness, dry matter feeding and rumination efficiency, and water intake. Low-energy diets increased feeding time, rumination time, the number of ruminal cuds, chews per day, total chewing time, neutral detergent fiber intake and rumination efficiency, number of ruminations per day, average duration of rumination, and defecation frequency. Water supply affected heart rate and idleness (P < 0.05). Sheep had higher values of heart rate and rectal and surface temperatures during the afternoon (P < 0.05). Water restriction combined with a low-energy diet and high environmental temperature leads to a reduction in the respiratory rate of Santa Inês crossbred sheep. Regardless of the dietary energy value, water restriction by 50% of the daily requirement of sheep reduces dry matter intake and increases idleness.

Non-invasive methods to quantify the carcass parameters of sheep: Interaction between thermal environment and residual feed intake.

The thermal environment is important in unit production because the perception of thermal stress can reduce fertility, and productive performance, therefore its management is necessary. The use of non-invasive methods, such as infrared thermography and real-time ultrasonography, are widely used to evaluate indicators in animal production, without the need to slaughter the animals. Thus, we aimed to assess the effect of the thermal environment on the physiological parameters and carcass characteristics of Dorper sheep with positive and negative residual feed intake (RFI) using infrared thermography and real-time ultrasonography techniques. Twenty uncastrated male Dorper sheep (17.8 ± 2.4 kg) were confined for 40 days for RFI classification. Sheep were separated into positive RFI (n = 10) and negative RFI (n = 10). The experimental design was in randomized blocks, in a 2 × 2 factorial arrangement, with 2 thermal environments (full sun or shade) and two feed efficiency groups (positive RFI or negative RFI), with 5 replications. The sheep remained in confinement for 60 days. The animals were slaughtered at the end of the experiment and the carcasses dissected for tissue separation. Rectal temperature (RT) and respiratory rate (RR) were measured at two times (14:00 h and 18:00 h) for periods of 5 days. The RR was determined by indirect auscultation of heart sounds at the level of the laryngotracheal region. The RT was measured introduced a digital clinical thermometer into the animal's rectum. Surface temperature (ST) was obtained using a thermographic infrared camera, collecting the temperatures of the eyeball and skin surface in the regions of the head, ribs, rump, flank and shin. Sheep confined in full sun showed higher RR (P = 0.0001), ST ribs (P = 0.0020), ST rumb (P = 0.0055), ST flank (P = 0.0001) and heat tolerance coefficient (HTC) (P = 0.0010). For sheep confined in full sun, a strong correlation was observed between the RR and the mean ST (MST; r = 0.6826; P = 0.0236) and between the final loin eye area (LEAf) with the real LEA (LEAr) (r = 0.9263; P = 0.0001) and slaughter body weight (SBW) (r = 0.7532; P = 0.0325). For negative RFI sheep, a positive correlation was observed between the RR and the ST rump (r = 0.7343; P = 0.0025) and ST ribs (r = 0.6560; P = 0.0178) and the MST (r = 0.7435; P = 0.0001), between the MST and the LEAr (r = 0.6837; P = 0.0025) and the final LEA (r = 0.6771; P = 0.0144), and between the final LEA and LEAr (r = 0.9942; P = 0.0001), BW (r = 0.8415; P = 0.0277) and MST (r = 0.6771; P = 0.0045). Positive RFI sheep confined to shade showed a high correlation between final LEA and LEAr (r = 0.9372; P = 0.0001). The use of shading in confined Dorper sheep, regardless of the RFI classification, reduces the effects of heat stress on physiological parameters.

Retracted: Economic viability in free-range chicken production.

Despite the lack of large-scale farming of free-range chickens in Brazil, their production generates income in the countryside and prevents exodus of rural families in agricultural regions. The objective of this study is to evaluate the economic viability of free-range broiler production in different facilities. The experiment was conducted in two different sheds (masonry shed-SM and wooden shed-SW) located in the Plural Space of the Universidade Federal do Vale São Francisco, municipality of Juazeiro, BA. Here, 200 heavy red French free-range chickens were distributed in the two sheds and were raised from the 1st to the 88th day (slaughter). Assuming that the minimum age for slaughter is 85 days, the results indicated that at least 205 birds in SM and 217 birds in SW were necessary for the producer to earn the minimum per capita monthly wage in Brazil (2020); at least 411 birds in CG and 600 birds in GM were found to be necessary to achieve maximum productivity at the end of the production cycle. The maximum profitability in the slaughter of the chickens was achieved at an age of 60 days.

Retraction to: Economic viability in free-range chicken production.

[This retracts the article DOI: 10.1093/tas/txab109.].

Water intake and ingestive behavior of sheep fed diets based on silages of cactus pear and tropical forages.

The objective was to evaluate the water intake and ingestive behavior of sheep fed diets containing silages of cactus pear combined with tropical forages. Forty sheep without defined breed, intact, with initial average weight of 22.65 ± 1.01 kg were distributed in a completely randomized design with 5 treatments and 8 replications. The experimental diets consisted of cactus pear silage (CPS), cactus pear + buffel grass silage (CPBS), cactus pear + gliricidia silage (CPGS), cactus pear + pornunça silage (CPPS), and corn silage (CS). CPGS provided higher water intake via food, total water intake, metabolic water, and excretion via feces and urine (P < 0.05). Animals that received diets containing CS showed higher water intake via drinking fountain, less efficient feeding and rumination of dry matter, less efficient rumination of neutral detergent fiber, grams of dry matter per cud, grams of neutral detergent fiber per cud, and the shortest average time spent in chewing per cud (P < 0.05). CPGS, CPPS, and CS provided longer times for rumination and numbers of cuds per day (P < 0.05). CPS showed animals spending more time in idleness, lower quantity of cuds per minute, higher concentration of crystals in urine, with a higher frequency of ammonia-magnesium phosphate and calcium oxalate. Silages based on cactus pear are an alternative to the supply of water via food for sheep in semi-arid.

Black globe temperature from meteorological data and a bioclimatic analysis of the Brazilian Northeast for Saanen goats.

The black globe temperature (BGT) is not a common measurement for weather station networks, despite having great relevance to bioclimatic studies. The aim of this study was to propose equations for estimating the BGT, using meteorological data for different time scales and a bioclimatic evaluation of the Brazilian Northeast for breeding Saanen dairy goats. The data used in elaborating the equations were collected between 1 November 2014 and 31 October 2017. Data for BGT, incident global solar radiation (SR), air temperature (AT), relative humidity (RH) and wind speed were handled on a daytime, night-time, daily and monthly scale. One half of the database was used to adjust the equations and the other half in the evaluation. The bioclimatic diagnosis of the Brazilian Northeast was carried out based on mean monthly values of the black globe temperature and humidity index (BGHI) estimated for the four seasons of the year. For the daytime scale, an equation based on AT (BGT = 1.3897.AT-5.4421, r2 = 0.80) and a multiplicative model combining the effects of AT and SR (BGT = [1.3897.AT-5.4421] (0.0384.ln(SR)+0.7935], r2 = 0.91) were obtained. AT adjusted well for BGT on the night-time scale (BGT = 0.995.AT-0.6964, r2 = 0.99), daily scale (BGT = 1.1641.AT-1.5941, r2 = 0.97) and monthly scale (BGT = 1.1550.AT-1.3498, r2 = 0.98). The BGT can therefore be calculated from AT and/or SR for the daytime scale, and from AT only for the night-time, daily and monthly scales. In general, the west and centre-south of the state of Bahia offer the animals the most thermal comfort during each season of the year. In the state of Maranhão, heat stress occurs throughout the year, with the BGTI predominately in the range of 85-95. As such, strategies to combat heat stress should be encouraged to minimise the negative effects of climate on milk production in Saanen goats, and favour the milk-production chain in the northeast of Brazil.