Ovarian follicular structure of White Leghorns fed ad libitum and dwarf and normal broiler breeders fed ad libitum or restricted until point of lay

1. Yellow follicle numbers when the first egg was laid were 6.3, 9.0 and 12.4 for ad libitum reared Leghorns, sex-linked Dwarf (AL Dwarf) and Normal broiler breeders respectively. Multiple ovulation resulted in low egg production and a high proportion of defective egg shells in AL Dwarf and Normal broiler breeders during early lay. 2. Restricting the growth of broiler breeders during rearing by restricting food intake (R Dwarfs) reduced the number of yellow follicles to 6.8 and increased the rate of lay. 3. Atretic yellow follicles were common among broiler breeders but not in Leghorns or R Dwarfs when the first egg was laid. 4. Poor egg production in older broiler breeders was caused by birds with few or no developing yellow follicles, atresia in yellow follicles and the continued occurrence of multiple ovulations. 5. There was no relationship between the number of yellow follicles and the number of white follicles less than 5 mm diameter but atresia in white follicles 2 to less than 5 mm was negatively related to the number of yellow follicles. 7. No relationship was observed between abdominal fat weight and yellow follicle number, though birds which ate more had more yellow follicles. 8.The sex-linked dwarfing gene dw was associated with increased atresia among the white follicles and low numbers of yellow follicles compared with the Normal DW broiler breeder genotype.     

Haematology and blood composition at two ambient temperatures in genetically fat and lean adult broiler breeder females fed ad libitum or restricted throughout life

1. Genetically fat and lean adult broiler breeder females were fed ad libitum or restricted throughout life. At one year of age, comparisons of blood viscosity and haematology and changes in blood chemistry after exposure to thermal stress were conducted.

2. Whole blood viscosity was more than twice as high, and plasma triglyc‐eride and haemoglobin concentrations were over 30% higher in fat line than in lean line females fed ad libitum or in restricted birds of both genotypes.

3. Mean cell haemoglobin concentration was higher and mean cell volume lower in fat compared with lean line females.

4. Food restriction was associated with lower plasma triglyceride concentrations, lower numbers of heterophils and monocytes and a lower heterophil‐lymphocyte ratio.

5. Fat line birds had a higher blood pCO₂ and lower pH than lean line birds.

6. Thermal stress was associated in ad libitum‐fed birds with a rise in blood pH and a decrease in pCO₂, and in restricted birds with a decline in blood pH and an increase in pCO₂.

7. Blood creatine kinase activity increased in all groups under thermal stress.     

Effect of restricted and ad libitum feeding on semen production and fertility in broiler breeder males

1. The effect of food restriction on the quality of semen production and fertility in broiler breeder males was studied.

2. Seventy‐two Ross broiler breeder males, from 20 to 54 weeks of age, were divided into 4 groups and fed as follows: group 1 = 110 g/bird/d; group 2 = 120 g/ bird/d; group 3 = 130 g/bird/d; group 4 = ad libitum.

3. Body weight, sperm quality (volume, concentration, % motility and % live cells) and fertility were measured. The birds were slaughtered at 55 weeks of age; the abdominal fat pad and testicles were weighed.

4. Groups 2 and 3 produced the highest volume of semen. The quality of semen was very similar in all the restricted groups.

5. Males fed ad libitum produced semen with the best motility and percentage of live cells. Groups 3 and 4 showed the best fertility percentage (79%) against group 1 and 2 (59 and 72% respectively).     

Changes in ovarian function of female turkeys photostimulated at 18, 24 or 30 weeks of age and fed ad libitum or restricted until point of lay.

1. Females from a medium body weight strain of turkeys were fed ad libitum or restricted to 0.6 of ad libitum-fed body weight at sexual maturity and were photostimulated at 18, 24 or 30 weeks of age. Ovarian follicular structure was assessed in 8 birds from both rearing treatments at photostimulation, after photostimulation for 6 or 12 weeks and at 55 weeks of age. 2. The patterns of small white follicles and of larger yellow follicles were similar in restricted and in ad libitum-fed turkeys for birds in lay at the same age, regardless of the time elapsed since photostimulation. 3. Among birds in lay the number of normal yellow follicles and the proportion of multiple yellow follicles declined with age. A relatively low proportion of restricted birds photostimulated at 18 and 24 weeks were in lay after 12 weeks of photostimulation. 4. For birds in lay the number of white follicles 1.4 to less than 1.8 mm in diameter increased and the number greater than 1.8 mm declined with age. There was a corresponding increase in the rates of atresia in follicles 1.8 to less than 5.0 mm in diameter.     

Effects of photostimulation at 18, 24 and 30 weeks of age on the productivity of female turkeys fed ad libitum or restricted until point of lay.

1. Turkey females were fed ad libitum or restricted from 6 weeks of age to achieve mean body weights of 0.6 of ad libitum fed birds on photostimulation at 18, 24 or 30 weeks of age. Body weight, food intake, egg production and hatchability were recorded to 54 weeks of age. 2. Restricted turkeys were fed ad libitum after first egg or 36 weeks of age. Food intake after 30 weeks of age averaged 170 g/bird/d and was similar for all treatments. At 54 weeks of age, restricted turkeys photostimulated at 24 and 30 weeks were not as heavy as turkeys photostimulated at 18 weeks and ad libitum fed turkeys. 3. A large proportion of restricted turkeys photostimulated at 18 weeks of age did not commence lay until 30 to 40 weeks and a significant number of restricted birds photostimulated at 24 weeks had short laying cycles. Restricted birds photostimulated at 30 weeks came into lay and showed similar persistency of lay to ad libitum fed turkeys. 4. Ad libitum fed turkeys laid 115.0, 122.0 and 101.0 and restricted turkeys 92.4, 99.5 and 103.4 eggs when photostimulated at 18, 24 and 30 weeks, respectively. The number of non-settable eggs was lower in restricted compared with ad libitum fed turkeys and declined with age at photostimulation. 5. Egg size at the end of the experiment was similar for ad libitum fed turkeys and restricted birds photostimulated at 18 weeks but was 2.3 g lower for restricted birds photostimulated at 24 and 30 weeks of age. 6. Hatchability was higher, and the proportion of second quality poults was lower with eggs from restricted turkeys. The mean numbers of poults hatched were 59.9, 75.1 and 66.0 for ad libitum fed and 71.7, 65.7 and 79.4 for restricted turkeys photostimulated at 18, 24 and 30 weeks of age.     

Ovarian follicular dynamics in selected and control (relaxed selection) male- and female-lines of broiler breeders fed ad libitum or on restricted allocations of food

1. The reproductive structures of 4 broiler breeder lines fed ad libitum or restricted were compared at 1st egg. The lines were contemporary male- and female-lines and their respective progenitor lines maintained without selection for 20 years. 2. The selected lines were larger and had more hierarchical yellow follicles than the relaxed lines. The numbers of positions in the hierarchy were greater in the selected lines. The number of atretic follicles and the proportion of multiple follicles were relatively high in the selected male-line. 3. There were more white follicles in the range 1.8 to 5.0 mm diameter in the selected male-line than in the relaxed line, whereas selection did not change white follicle numbers in the female-line. 4. Food restriction decreased the numbers of normal and atretic yellow follicles and the proportion of multiples but had no effect on the number of positions in the hierarchy. Restricted feeding decreased the number of white follicles 1.4 to 2.4 mm and increased follicles 2.4 to 5.0 mm diameter. 5. There was little change in age at 1st egg among lines fed ad libitum. Restricted feeding increased age at 1st egg and the difference was greater in female- than in male-lines and in relaxed compared with selected birds. 6. Abdominal fatness was similar among the lines fed ad libitum and was decreased by restricted feeding. 7. Oviduct weights were greater in selected than in relaxed lines and were decreased by restricted feeding only in the selected male-line. 8. The weight of the largest follicle was higher in the selected lines and in restricted compared with ad libitum-fed birds. Plasma triglyceride concentrations were lower in restricted birds from the selected and relaxed female-lines compared with the other groups. Differences in plasma oestrogen concentrations could not be detected.     

Adaptation of wheat and protein-mineral concentrate intakes by individual hens fed ad libitum in sequential or in loose-mix systems

1. Feed intake and performance of birds given sequential or loose-mix feeding was investigated from 19 to 42 weeks of age. A complete diet was fed as control (C). A balancer diet (50) was fed either sequentially (S50) or in a loose-mix (L50) with wheat. This diet was formulated to provide a similar nutritive value as C assuming a 50 : 50 diet and wheat intake. Another balancer diet (25) was fed sequentially (S25) or in a loose-mix (L25) with wheat. The diet was to provide a similar nutritive value as C assuming 75 : 25 diet and wheat intakes. In sequential feeding, only wheat was fed in the morning (4 h after lights-on) and the balancer diet in the late afternoon (4 h before lights-off). In the loose-mix treatment, a mixture of the two diets was fed throughout the 16-h daily light. Each treatment was given ad libitum to 25 birds in individual cages. 2. Birds fed on L25 had lower total feed intakes than those receiving C, S50 or S25. Protein intake was reduced with L25 compared to C, S50, S25 and L50. Metabolisable energy (ME) intake was, however, similar among all treatments. Egg production and weight were reduced with L25 compared to S50 and S25. Body weight (BW) was lowered with L25. However, there was high individual variation in all variables. 3. Feeding system (sequential vs loose-mix) had no effect on ME intake. However, the loose-mix treatment reduced feed and protein intake due to lower balancer diet intake. It also resulted in low egg production, egg and BWs compared to sequential feeding. The weights of pancreas and gizzard were heavier with sequential and loose-mix compared to the control. 4. The loose-mix treatment reduced egg-laying performance. Sequential feeding resulted in similar egg-laying performance to conventional feeding and thus could be used to advantage in situations where it is applicable.     

Comparative development of the ovary and production,fertility and hatchability of eggs from traditional turkeys and a contemporary male-line fed ad libitum or restricted

1. Ovarian function was assessed at first egg and at 44 and 54 weeks of age in traditional turkeys and in a male-line fed ad libitum or restricted to 0.5 of ad libitum during rearing. Egg production was recorded daily and fertility and hatchability were determined at 2 ages. 2. Age at sexual maturity did not differ between the 3 treatments. 3. The number of follicles at first egg in the male line averaged 16.3 compared with 8.9 in traditional turkeys. Food restriction in the male line decreased the number of yellow follicles to 14.6 at first egg and restricted birds were largely in a non-reproductive state from 44 to 54 weeks of age. 4. The total number of recorded ovipositions to 54 weeks of age in male line fed ad libitum or restricted and traditional turkeys respectively were 40.1, 25.2 and 70.7; comparable productions of normal shelled eggs were 28, 20 and 66.3. 5. There were no differences between treatments in fertility after a single insemination at 2 different ages. Hatch of fertiles after the first inseminations were 71.4, 45.5 and 90.3 respectively for male line fed ad libitum or restricted and traditional turkeys.     

Limiting amino acids in low protein maize-soyabean meal diets fed to broiler chicks from 3 to 7 weeks of age

1. An experiment with separately housed male and female broiler chicks was carried out during the period of 3 to 7 weeks of age to determine the limiting amino acids (AA) in a low protein maize-soyabean meal diet. Chicks were fed on diets containing 170, 180, 190 and 200 g crude protein (CP)/kg with or without combined additions of L-threonine (Thr), L-tryptophan (Trp) and L-arginine (Arg) to those in the 180, 190 or 200 g CP/kg diets and a 170 g CP/kg diet with or without combined additions of Thr, Trp, Arg, L-isoleucine (Ile), L-leucine (Leu) and L-valine (Val) to those in the 190 g CP/kg diet. The diets were iso-energetic and contained the same concentrations of lysine (Lys) and sulphur-containing amino acids. 2. Decreasing the dietary CP had a significantly negative effect on performance. 3. No significant effects on performance were found when diets with 180 and 190 g CP/kg were supplemented with Thr, Trp and Arg to those in the 200 g CP/kg diet. 4. There were no significant differences in performance between the groups fed on the diets with 170, 180 and 190 g CP/kg when the 170 and 180 g CP/kg diets were supplemented with Thr, Trp and Arg to those in the 190 g CP/kg diet.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of age and body weight at photostimulation on the sexual maturation of broiler breeder pullets transferred from 8L:16D to 16L:8D

1. In two trials, broiler breeders were grown to a mean body weight of 2.0 to 2.2 kg at 20 weeks on 8L:16D and transferred to 16L:8D at various ages between 69 and 175 d of age at mean body weights varying between 1.0 and 2.7 kg. Other groups were grown to have a mean 20-week body weight 0.87, 1.15, 1.25 or 1.37 of the normal birds and photostimulated simultaneously with the normal weight birds. Controls were held on 8L:16D in each weight group. In a third trial, broiler breeders were transferred from 8L:16D to 16L:8D at 45 (ad libitum fed), 75 or 90 d (mild feed control), when the mean body weight of each group had reached 2.1 kg. Controls weighing 2.0 kg at 20 weeks were held on 8L:16D or 16L:8D. 2. In trial 1, photostimulating normal weight birds at 69, 76, 83 or 97 d delayed maturity and widened the spread of individual maturities, whilst transferring to 16L:8D at 111 or 125 d advanced maturity. Increasing the mean 20-week body weight to 2.8 kg advanced maturity in birds transferred to 16L:8D at 97, 111 or 125 d. Birds photostimulated at 69, 76 and 83 d matured at a similar age to controls held on 8L:16D. 3. In trial 2, transferring normal weight birds to 16L:8D at 91, 112, 133, 147, 161 or 175 d advanced maturity. Reducing the 20-week mean body weight to 1.91 kg delayed maturity in birds photostimulated at 91 or 112 d, but advanced it in birds photostimulated at 112, 133, 147, 161 or 175 d. Sexual maturity was similar for birds with a 20-week mean body weight of 2.54 or 2.74 kg, with advances for all groups photostimulated between 91 and 175 d. 4. In trial 3, birds maintained on 16L:8D matured later than birds held on 8L:16D, but maturity was advanced when birds were transferred to 16L:8D at 45, 75 or 90 d at a common body weight of 2.1 kg.     

Effect of methionine hydroxy analog-free acid on growth performance and chemical composition of liver of broiler chicks fed a corn–soybean based diet from 0 to 6 weeks of age

The experiment was carried out to determine the effects of liquid DL‐methionine hydroxy analog‐free acid (LMA) and dry DL‐methionine (DLM) on growth performance, carcass quality and chemical composition of the livers of broiler chicks during 0–6 weeks of age. Four hundred and fifty male commercial broiler chicks (Ross strain) were used. The chicks were divided into three groups, and each group consisted of six replicates of 25 chicks each. The chicks were kept in floor pens, and water and feed were supplied ad libitum throughout the experiment. Three experimental diets were provided as follows: (i) corn–soybean‐based diet deficient in methionine; (ii) methionine‐deficient corn–soybean‐based diet supplemented with DLM to meet the methionine requirements of broiler chicks; and (iii) methionine‐deficient corn–soybean‐based diet supplemented with LMA (1.25‐fold (w/w) the amount of DLM supplied to the second group, given an assumption that 100 units of liquid LMA can be replaced by 80 units DLM to give similar performance results). During the starter period, the weight gains of chicks fed LMA or DLM were significantly greater than those in chicks receiving the methionine‐deficient diet (P < 0.05), and the addition of LMA significantly improved weight gain compared with the addition of DLM. Adding DLM or LMA significantly improved the feed conversion ratio (FCR) and percentage of uniformity (P < 0.05). No significant differences between the effects of DLM and LMA on these parameters were found. During the grower period (3–6 weeks of age), weight gain, FCR, uniformity and feed intake of chicks that received diet supplemented with DLM or LMA were superior to those of the methionine‐deficient group (P < 0.05). Chicks fed LMA had the same bodyweight gain and uniformity as those fed DLM. However, adding LMA resulted in a significant increase of FCR resulting from excess feed consumption. Outer breast meat yields were significantly improved and abdominal fat was significantly decreased when methionine sources were added (P < 0.05), and adding LMA tended to promote edible meat growth better than did adding DLM. Although no significant effects of methionine sources on the chemical composition of the liver were seen, adding methionine sources tended to increase liver fat content. In conclusion, it seems that the bioefficacy of LMA relative to DLM is not less than 80%. Therefore, chicks fed with diet supplemented with 1.25‐fold (w/w) as much LMA as DLM might exceed requirements for growth performance, while meeting requirements for meat production. Moreover, the relative bioefficacies of LMA and DLM between the starter and grower periods may perhaps be different.     

Post-pellet liquid application fat disproportionately coats fines and affects mixed-sex broiler live performance from 16 to 42 d of age

The effect of 2 fat application sites (FAS) and 2 levels of fines on feed manufacturing parameters and broiler live performance from 16 to 42 d was studied. The FAS included mixer-added fat (MAF) and post-pellet liquid application (PPLA) of fat. While the MAF diets had all fat added to the diet prior to pelleting, the PPLA diets were pelleted with 0.5% MAF, and the remaining 3.5% fat was added subsequent to pellet cooling. The levels of fines included 0 and 30%. A total of 32 pens was placed with 8 males and 8 females (mixed-sex) in each pen. Broiler chicks were fed a common crumbled starter for approximately 16 d and then transitioned to one of the 4 dietary treatments. The PPLA pellets were more durable than were MAF pellets (P < 0.01), but required more energy to pellet (P < 0.01). When adding liquid fat post pellet to the diets with 30% fines, the fines absorbed more liquid fat and exhibited a greater gross energy when compared to pellets (P < 0.01). Male broilers consuming the PPLA diets were 50, 97, and 120 g heavier than male broilers consuming the MAF diets at 28, 35, and 42 d, respectively (P < 0.01). Female broilers consuming the PPLA diets with 30% fines were 71 and 90 g heavier than female broilers consuming the MAF diets with 30% fines at 28 and 35 d, respectively (P < 0.05). It was concluded that the females may have benefited from consuming high-energy-density fines present in the PPLA diets with 30% fines when compared to females consuming MAF diets with 30% fines because the additional fat that coated the fines offset the negative energy associated with prehension of the fines.     

Cage type and mineral nutrition had independent impact on skeletal development in Lohmann LSL-Lite pullets from hatch to 16 weeks of age

The effects of rearing cage type and dietary Ca, available P and vitamin D₃ (VitD₃) on body and skeletal development were studied. A total of 3,420 Lohmann LSL-Lite day-old chicks were reared in conventional (CON) or furnished cages (FUR) to 16 wk of age. Initially, 40 and 150 chicks/cage were placed in CON and FUR and transitioned to 20 and 75 chicks/cage at 8 wk of age, respectively. Three diets: Diet 1, Diet 1.5 and Diet 2 were formulated to meet nutrient specifications with Diet 1.5 and Diet 2 containing 1.5 and 2 times more Ca, P and VitD₃ than Diet 1, respectively. Diets were allocated within cage type to give 6 replicates and fed in 3 feeding programs: starter, grower and developer. At 4, 12 and 16 wk of age, BW was recorded, and femur, tibia and blood samples for bone quality and related parameters. There were no interactions (P > 0.05) of cage type, diet and pullet age on BW, plasma Ca and inorganic P, femur and tibia morphometry, mineral density (MD), breaking strength (BS) and ash concentration (AC). Concentration of Ca, P and VitD₃ linearly decreased BW (P < 0.001), relative femur (P = 0.010) and tibia weight (P = 0.013). A quadratic increase on femur MD (P = 0.03) and BS (P = 0.026) was observed with dietary concentration of Ca, P and VitD₃. Femur (P = 0.031) was longer for CON than FUR pullets, however, femur for FUR pullets had higher (P = 0.003) AC. Cage had no effect (P ≥ 0.415) femoral MD and BS. Pullets reared in FUR cages exhibited higher tibial MD (P = 0.015), BS (P = 0.071), AC (P < 0.01) and whole-body mineral content (P < 0.01). In conclusion, cage type and diets showed independent effect on femur and tibia quality with FUR pullets exhibiting enhanced indices of mineralization. Feeding pullets twice the recommended Ca, P and VitD₃ decreased BW, relative weight of leg bone but enhanced femoral strength with no effects on tibia attributes.     

Mating behavior, boar-to-boar behavior during rearing and soundness of boars penned individually or in groups from 6 to 27 weeks of age

Individual and group-reared boars were compared in two experiments, for treatment effects on mating behavior, growth rate, feed consumption and feed/gain. Soundness also was evaluated in one experiment. Boar-to-boar behaviors were studied in group-penned boars. In Exp. 1, boars were either reared in a group of five or individually from 12 to 27 wk of age, or group-penned from 12 to 19 wk and individually from 1-9 wk. In Exp. 2, boars were either penned individually from 6 to 27 wk, group-penned (eight/pen) from 6 to 27 wk, grouped from 6 to 12 wk and then penned individually, or individually penned from 6 to 12 wk and then group-penned. Beginning at 29 wk of age, boars were tested every 2 wk for mating behavior in the presence of an estrous gilt. Four mating tests were conducted in Exp. 1 and five tests in Exp. 2. Individually penned boars grew faster from 6 to 12 wk old in Exp. 2, but no other treatment effects on growth rate were observed. Treatment had very little effect on mating test behaviors, but individual penning markedly reduced leg soundness. Sheath sniffing first appeared at 16 to 18 wk of age in group-penned boars and was followed closely by anal sniffing. Side nosing increased between 20 and 23 wk. Mounting activity from 12 to 27 wk old was correlated with mating test score in Exp. 1 (.76; P less than .01) and Exp. 2 (.55; P less than .05).     

Reassessment of riboflavin requirement for single comb White Leghorn pullets from 0 to 6 weeks of age fed on maize-soyabean meal diets and its subsequent effect on sexual maturity and egg production

1. Two experiments were conducted using a total of 228 Hyline W-26 1-d-old pullets in each experiment. The purpose of the study was to reassess the riboflavin requirement from 0 to 6 weeks of age (WOA) and its subsequent effect on sexual maturity and egg production using a maize-soybean meal diet. 2. Approximately 10% incidence of curly toe paralysis was observed among birds fed on the diet with no added riboflavin (1.5 mg total riboflavin/kg diet). 3. Applying the non-linear regression model to the body weight gain data at 3 and 6 WOA in both the experiments, it was found that the minimum total riboflavin required to achieve maximum body weight gain for the two age periods was 2.3 and 2.0 mg/kg of the total diet. This is equivalent to 5.0 and 5.7 micrograms riboflavin/g of body weight gain from 0 to 3 and 3 to 6 WOA respectively. 4. Birds fed on the diet containing no added (1.5 mg total/kg) riboflavin laid fewer eggs and had lower body weights at 24 weeks. 5. We conclude that, from 0 to 6 WOA, at least 2.3 mg total riboflavin/kg should be present in the diet to prevent curly toe paralysis, obtain the maximum body weight gain and sustain the subsequent performance at sexual maturity.     

Evaluation of cognitive learning, memory, psychomotor, immunologic, and retinal functions in healthy puppies fed foods fortified with docosahexaenoic acid-rich fish oil from 8 to 52 weeks of age

Objective-To assess effects of foods fortified with docosahexaenoic acid (DHA)-rich fish oil on cognitive, memory, psychomotor, immunologic, and retinal function and other measures of development in healthy puppies. Design-Evaluation study. Animals-48 Beagle puppies. Procedures-Puppies were assigned to 3 groups after weaning (n = 16/group) and received 1 of 3 foods (low-DHA, moderate-DHA, or high-DHA food) as their sole source of nutrition until 1 year of age. Visual discrimination learning and memory tasks, psychomotor performance tasks, and physiologic tests including blood and serum analysis, electroretinography, and dual-energy x-ray absorptiometry were performed at various time points. Anti-rabies virus antibody titers were evaluated 1, 2, 4, and 8 weeks after vaccination at 16 weeks of age. Results-Foods had similar proximate analysis results but varied in concentration of DHA from fish oil; the high-DHA food also contained higher concentrations of vitamin E, taurine, choline, and l-carnitine than did other foods. The high-DHA group had significantly better results for reversal task learning, visual contrast discrimination, and early psychomotor performance in side-to-side navigation through an obstacle-containing maze than did the moderate-DHA and low-DHA groups. The high-DHA group had significantly higher anti-rabies antibody titers 1 and 2 weeks after vaccination than did other groups. Peak b-wave amplitudes during scotopic electroretinography were positively correlated with serum DHA concentrations at all evaluated time points. Conclusions and Clinical Relevance-Dietary fortification with fish oils rich in DHA and possibly other nutrients implicated in neurocognitive development following weaning improved cognitive, memory, psychomotor, immunologic, and retinal functions in growing dogs.